IPAC2014 - List of Keywords (operation)

Paper	Title	Other Keywords	Page
MOYAA01	Innovative Ideas for Single-pass FELs	electron, FEL, undulator, photon	12
	T. Hara RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	SASE FELs are a powerful light source in short wavelengths from VUV to X-ray regions to investigate matters and phenomena. SASE was first experimentally obtained in 2000 at DESY TTF with an output wavelength of 10⁹ nm. Subsequently, FLASH, LCLS and SACLA have achieved lasing in VUV, soft X-rays and hard X-rays. Although SASE has already been widely used for many application experiments in broad scientific fields, its spiky spectrum and time structures due to the lack of longitudinal coherence sometimes become problematic. To improve its longitudinal coherence, various ideas have been proposed and some of them are already demonstrated experimentally, such as a self-seeded scheme, high-gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG). There is also another direction of developments to enhance the capability and potentiality of SASE, for example short pulse generation and two-color lasing. This talk will review recent innovative ideas of short wavelength FELs together with their experimental results.
	Slides MOYAA01 [10.701 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOYAA01
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MOZA02	Advanced RF Design and Tuning Methods of RFQ for High Intensity Proton Linacs	rfq, linac, coupling, dipole	34
	A. France CEA/IRFU, Gif-sur-Yvette, France
	The injector of high intensity linacs includes a Radio Frequency Quadrupole (RFQ) which must sustain high surface fields and thermal effects while accelerating intense low energy beams. For this purpose, the modelisation, realisation and tuning of accurate field laws is mandatory to preserve beam emittances and minimize beam losses. This presentation reviews the progress of advanced methods for the RF design, RF measurements during fabrication and final tuning of RFQ for high intensity linacs. It reports the ongoing developments on the injectors of high intensity demonstrators and of the linacs under construction such as SPIRAL2, LINAC4 or IFMIF-EVEDA.
	Slides MOZA02 [2.026 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOZA02
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MOOCA01	High Power Test Results of the SPARC C-Band Accelerating Structures	controls, accelerating-gradient, klystron, vacuum	39
	D. Alesini, M. Bellaveglia, M.E. Biagini, R. Boni, P. Chimenti, R. Clementi, G. Di Pirro, R. D. Di Raddo, M. Ferrario, A. Gallo, V.L. Lollo INFN/LNF, Frascati (Roma), Italy M. Brönnimann, R. Kalt, T. Schilcher PSI, Villigen PSI, Switzerland L. Ficcadenti INFN-Roma, Roma, Italy L. Palumbo URLS, Rome, Italy
	The energy upgrade of the SPARC photo-injector at LNF-INFN (Italy) from 150 to more than 240 MeV will be done by replacing a low gradient S-Band accelerating structure with two C-band structures. The structures are Traveling Wave (TW) and Constant Impedance (CI), have symmetric axial input couplers and have been optimized to work with a SLED RF input pulse. In the paper we present the results of the low and high power RF tests on the two final fabricated structures that shown the feasibility of the operation at accelerating gradients larger than 35 MV/m.
	Slides MOOCA01 [6.242 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOOCA01
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MOOCA02	RF Design and Operation of a Modular Cavity for Muon Ionization Cooling R&D	cavity, instrumentation, solenoid, vacuum	42
	Y. Torun IIT, Chicago, Illinois, USA D.L. Bowring, M.A. Palmer, K. Yonehara Fermilab, Batavia, Illinois, USA
	Funding: Supported by the US Department of Energy Office of Science through the Muon Accelerator Program. Ionization cooling channel designs call for the operation of high-gradient, normal-conducting RF cavities in multi-Tesla solenoidal magnetic fields. However, strong magnetic fields have been shown in some cases to limit the maximum achievable gradient in RF cavities. This gradient limit is characterized by RF breakdown and damage to the cavity surface. To study this issue, we have developed an experimental program at Fermilab's MuCool Test Area (MTA) based on a modular pillbox cavity operating at 805 MHz. The modular cavity design allows for the evaluation of different cavity geometries and materials – such as beryllium – which may ameliorate or circumvent RF breakdown triggers. We present a summary of recent results and plans for the future of the MTA normal conducting RF cavity program.
	Slides MOOCA02 [32.552 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOOCA02
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MOOCB02	A Common Operation Metrics for Third Generation Light Sources	experiment, feedback, survey, insertion	56
	A. Lüdeke PSI, Villigen PSI, Switzerland M. Bieler DESY, Hamburg, Germany J.-F. Lamarre SOLEIL, Gif-sur-Yvette, France M. Pont CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	High reliability is a very important goal for third generation light sources. Very often the beam availability is used as the operation metrics to measure the reliability of the accelerator. A survey at several light sources revealed that the calculation of this statistics varies significantly between facilities. This prevents a useful comparison of their reliabilities. The authors propose a specific metrics for the reliability of third generation light sources; a metrics that will allow a detailed and meaningful comparison of these particle accelerators.
	Slides MOOCB02 [0.701 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOOCB02
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MOPRO002	The Momentum Distribution of the Decelerated Drive Beam in CLIC and in the Two-beam Test Stand at CTF3	emittance, simulation, distributed, controls	62
	Ch. Borgmann, M. Jacewicz, J. Ögren, M. Olvegård, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden
	We present analytical calculations of the momentum spectrum of the drive beam in CLIC and the CLIC Test Facility CTF3 after part of its kinetic energy is converted to microwaves for the acceleration of the main beam. The resulting expressions are used to determine parameters of the power conversion process in the Power Extraction Structure (PETS) installed in the Two-beam Test Stand in CTF3.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO002
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MOPRO019	Energy Deposition and Quench Level Calculations for Millisecond and Steady-state Quench Tests of LHC Arc Quadrupoles at 4 TeV	simulation, proton, beam-losses, quadrupole	105
	N.V. Shetty, B. Auchmann, V. Chetvertkova, A. Lechner, A. Priebe, M. Sapinski, A.P. Verweij, D. Wollmann CERN, Geneva, Switzerland
	In 2013, beam-induced quench tests with 4 TeV protons were performed to probe the quench level of LHC arc quadrupole magnets at timescales corresponding to millisecond beam losses and steady-state losses. As the energy deposition in magnet coils cannot be measured directly, this study presents corresponding FLUKA simulations as well as estimates of quench levels derived with the QP3 code. Furthermore, beam loss monitor (BLM) signals were simulated and benchmarked against the measurements. Simulated and measured BLM signals are generally found to agree within 30 percent.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO019
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MOPRO021	Power Deposition in LHC Magnets With and Without Dispersion Suppressor Collimators Downstream of the Betatron Cleaning Insertion	proton, simulation, dipole, collimation	112
	A. Lechner, B. Auchmann, R. Bruce, F. Cerutti, P.P. Granieri, A. Marsili, S. Redaelli, N.V. Shetty, E. Skordis, G.E. Steele, A.P. Verweij CERN, Geneva, Switzerland
	The power deposited in dispersion suppressor (DS) magnets downstream of the LHC betatron cleaning insertion is governed by off-momentum protons which predominantly originate from single-diffractive interactions in primary collimators. With higher beam energy and intensities anticipated in future operation, these clustered proton losses could possibly induce magnet quenches during periods of short beam lifetime. In this paper, we present FLUKA simulations for nominal 7 TeV operation, comparing the existing layout with alternative layouts where selected DS dipoles are substituted by pairs of shorter higher-field magnets and a collimator. Power densities predicted for different collimator settings are compared against present estimates of quench limits. Further, the expected reduction factor due to DS collimators is evaluated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO021
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MOPRO028	Measurements on Prototype Inductive Adders with Ultra-flat-top Output Pulses for CLIC DR Kickers	kicker, flattop, damping, high-voltage	128
	J. Holma, M.J. Barnes CERN, Geneva, Switzerland C. Belver-Aguilar IFIC, Valencia, Spain
	The CLIC study is investigating the technical feasibility of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the DR extraction kickers call for a 160 ns duration flat-top pulses of ±12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications because this topology allows the use of both passive and analogue modulation methods to adjust the output waveform. Recently, two five-layer, 3.5 kV, prototype inductive adders have been built at CERN. The first of these has been used to test the passive and active analogue modulation methods to compensate voltage droop and ripple of the output pulses. Pulse waveforms have been recorded with ±0.05 % relative (±1.0 V) stability for 160 ns flat-top duration at 1.823 kV.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO028
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MOPRO030	Changes to the LHC Beam Dumping System for LHC Run 2	dumping, kicker, controls, vacuum	134
	J.A. Uythoven, M.G. Atanasov, J. Borburgh, E. Carlier, S. Gabourin, B. Goddard, N. Magnin, V. Senaj, N. Voumard, W.J.M. Weterings CERN, Geneva, Switzerland
	The LHC beam dumping system performed according to expectations during Run 1 of the LHC (2009 – 2013). A brief overview of the experience is given, including a summary of the observed performance in comparison to expectations. An important number of changes are applied to the beam dumping system during the present Long Shutdown on order to further improve its system safety and performance. They include the addition of a direct link between the Beam Interlock System and the re-triggering system of the dump kickers, the modification of the uninterrupted electrical power distribution architecture, the upgrade of the HV generators, the consolidation of the trigger synchronization system, the modifications to the triggering system of the power switches and the changes to the dump absorbers TCDQ.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO030
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MOPRO031	Abort Gap Cleaning for LHC Run 2	luminosity, emittance, extraction, quadrupole	138
	J.A. Uythoven, A. Boccardi, E. Bravin, B. Goddard, G.H. Hemelsoet, W. Höfle, D. Jacquet, V. Kain, S. Mazzoni, M. Meddahi, D. Valuch CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO031
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MOPRO044	Construction and Bench Testing of a Prototype Rotatable Collimator for the LHC	vacuum, impedance, collimation, controls	178
	T.W. Markiewicz, E.L. Bong, L. Keller SLAC, Menlo Park, California, USA O. Aberle, A. Bertarelli, P. Gradassi, A. Marsili, S. Redaelli, A. Rossi, B. Salvachua, G. Valentino CERN, Geneva, Switzerland
	Funding: This work partially supported by the U.S. Department of Energy through the US LHC Accelerator Research Program (LARP) and contract DE-AC02-76SF00515. A second generation prototype rotatable collimator has been fabricated at SLAC and delivered to CERN for further vacuum, metrology, function and impedance tests. The design features two cylindrical Glidcop jaws designed to each absorb 12kW of beam in steady state and up to 60kW in transitory beam loss with no damage and minimal thermal distortion. The design is motivated by the use of a radiation resistant high Z low impedance readily available material. A vacuum rotation mechanism using the standard LHC collimation jaw positioning motor system allows each jaw to be rotated to present a new 2cm high surface to the beam if the jaw surface were to be damaged by multiple full intensity beam bunch impacts in a asynchronous beam abort. Design modifications to improve on the first generation prototype, pre-delivery functional tests performed at SLAC and post-delivery test results at CERN are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO044
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MOPRO050	Status of the ASTRID2 Synchrotron Light Source	controls, wiggler, insertion, insertion-device	197
	J.S. Nielsen, N. Hertel, S.P. Møller ISA, Aarhus, Denmark
	With regular user beam delivered to experiments, the commissioning of the ASTRID2 synchrotron light source is now mostly completed. The ring is running stable in top-up mode for beam currents up to 90 mA, with a lifetime of ~0.8 h at 90 mA. The orbit is controlled by a 10 Hz feedback loop, which includes feed forward loops when the insertion devices change gap. A similar 10 Hz loop compensates tune and beta function changes from the insertion devices. Some issues are still remaining. These include installation of a Landau cavity for lifetime improvements, a reduction in the heating of the in-vacuum ferrites of the injection bumpers, and a shielding of the stray magnetic field from the booster dipoles.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO050
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MOPRO051	SOLEIL Operation and On-going Projects	injection, storage-ring, vacuum, photon	200
	L.S. Nadolski, C. Benabderrahmane, P. Betinelli-Deck, F. Bouvet, P. Brunelle, A. Buteau, L. Cassinari, M.-E. Couprie, X. Delétoille, C. Herbeaux, N. Hubert, M. Labat, J.-F. Lamarre, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, J.L. Marlats, A. Nadji, R. Nagaoka, P. Prigent, J.P. Ricaud, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	The 2.75 GeV synchrotron light source SOLEIL delivers photons to 27 beamlines; 2 new ones are under construction together with the FEMTOSLICING project of which commissioning started in January 2014. Five filling patterns are available for the users in Top-up injection mode. The storage ring is running with an upgraded optics less sensitive to insertion device (ID) configurations and giving both better beam lifetime and injection efficiency. The beam position stability remains excellent with a focus on electron vertical beam-size stability for the new very long beamlines. A gating system during Top-up injection improves significantly the quality of the spectrum on an infrared beamline. Several heavy actions of maintenance and upgrades on crucial subsystem equipment are underway. Others accelerator projects are going on such as the design and construction of new IDs, new Multipole Injection Kicker, radiation damage studies as well as R&D on solid-state amplifiers.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO051
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MOPRO059	Fluka Calculations of Gamma Spectra at BESSY	injection, radiation, synchrotron, vacuum	219
	K. Ott, Y. Bergmann HZB, Berlin, Germany
	Funding: Funded by the Bundesministerium für Bildung und Forschung and by the Land Berlin Since 22nd October 2012 BESSY is operated in top-up mode. Losses of electrons during injection cause an electromagnetic cascade, that consists of high energetic photons of the bremsstrahlung, and secondary electrons and positrons from the pair creations. The bremsstrahlung spectrum has a maximum at 1.022 MeV owing to pair creations. The spectrum has a high energetic tail, that reaches up to the electron energy of 1.7 GeV at BESSY. The low energy part of the electromagnetic cascade is produced by compton scattering or the photo - effect. Due to the opened beamshutters during top-up injections, the low energetic part of the bremsstrahlung spectrum can reach the experimental hall. We used the particle interaction and transport code FLUKA for the calculations of both the fluence and the dose distribution. We calculated the gamma spectra of the radiation through the shielding walls and through the front-ends. We discuss the question whether additional safety measures are necessary for top-up operation due to the low energy part of the spectrum. From our calculations we determined the correction factors for our ionisation chambers of the ambient dose measurement system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO059
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MOPRO063	Studies of Bursting CSR in Multi-bunch Operation at the ANKA Storage Ring	radiation, storage-ring, synchrotron, detector	225
	V. Judin, M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schuh, N.J. Smale, J.L. Steinmann, M. Weber KIT, Karlsruhe, Germany
	The ANKA storage ring can generate brilliant coherent synchrotron radiation (CSR) in the THz range due to a dedi- cated low-αc -optics with reduced bunch lengths. At higher electron currents the radiation is not stable, but occurs in powerful bursts caused by micro-bunching instabilities. This intense THz radiation is very attractive for users. However, the reproducibility of the experimental conditions is very low due to those power fluctuations. Systematic studies of bursting CSR in multi-bunch operation were performed with fast THz detectors at ANKA using a dedicated, ultra-fast DAQ-FPGA board. The technique and preliminary results of these studies are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO063
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MOPRO068	Fluctuation of Bunch Length in Bursting CSR: Measurement and Simulation	simulation, synchrotron, storage-ring, optics	237
	P. Schönfeldt, A. Borysenko, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, S. Naknaimueang, M. Schuh, M. Schwarz, J.L. Steinmann KIT, Karlsruhe, Germany
	The ANKA electron storage ring of the Karlsruher Institute of Technology (KIT, Germany) is regularly operated in low-alpha mode to produce short bunches for the generation of coherent synchrotron radiation (CSR). This paper evaluates systematic bunch length measurements taken in low-alpha operation of the ANKA storage ring. Above the bursting threshold not only the emission of CSR occurs in bursts, but also a continuous fluctuation of the bunch's length is observed. The measurements were carried out using concurrent multi turn (using a streak camera) as well as single shot (using electro-optical spectral decoding) methods. Furthermore, we compare information obtained on the fluctuation to simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO068
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MOPRO070	Study on Ground Vibration Characteristics of Iranian Light Source Facility	site, ground-motion, synchrotron, data-analysis	243
	A. Iraji, B. Kamkari, J. Rahighi, M. Rahimi, N. Ranjbar, F. Saeidi ILSF, Tehran, Iran
	In this study the results of ground vibration measurement for the site of Iranian Light Source Facility (ILSF) has been investigated. Light source buildings are very sensitive to the ground weak motions. Sources for the ground vibrations could be Cultural noise from human activities like traffic and industrial works. In order to satisfy requirements for level of the ground vibrations, a perfect ground vibration survey has been conducted and compared with other same projects. Two broad-band seismometers were utilized for surveying the ground vibration at ILSF site. The raw data were pre-processed as well as analyzed in term of seismology and engineering aspects. Spectrum amplitudes along with powers of the vibration amplitudes were calculated at the time domain. The power spectral density of vibration displacements were extracted from the measurements and were compared with results of other synchrotron projects. The results show that the dedicated site for ILSF is in the appropriate condition in the point view of ground vibration issues.
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MOPRO076	Elettra Status and Upgrades	controls, coupling, dipole, emittance	261
	E. Karantzoulis, A. Carniel, S. Krecic Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the latest studies and upgrades.
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MOPRO080	Fast Beam Orbit Monitoring System during Beam Abort at SPring-8 Storage Ring	closed-orbit, storage-ring, betatron, electronics	274
	T. Fujita, T. Masuda, S. Sasaki JASRI/SPring-8, Hyogo-ken, Japan H. Sumitomo SES, Hyogo-pref., Japan
	SPring-8 is a 3rd generation light source which has been operated stably. During user operation, an interlock system which turns off the RF acceleration signal if the beam orbit at insertion devices exceed a window is in operation. Beam abort events due to the interlock system have occurred as a rare event at SPring-8. Though in most cases we find trouble in accelerator devices as the source of the beam orbit shift, sometimes we cannot find any evidence after the beam abort. In order to identify the sources of such aborts, we have developed a system which observe beam orbit along the storage ring during beam abort. The system was realized by modification of the digital part of the existing COD measurement system. Every 1 ms, the system measures beam position at all BPMs with the position resolution of 1 micron or less. This system enabled us to identify the source when a beam abort due to an orbit shift with a time constant of longer than a few milliseconds. Furthermore, this system is applicable to survey sources of beam orbit fluctuations during stable operation. In this proceeding, we describe the system, beam orbit data during beam abort and source analysis.
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MOPRO082	Suppression of Stored Beam Oscillation at Injection by Fast Kicker in the SPring-8 Storage Ring	kicker, timing, injection, storage-ring	280
	C. Mitsuda, K. Fukami, K. Kobayashi, M. Masaki, H. Ohkuma, S. Sasaki, K. Soutome JASRI/SPring-8, Hyogo-ken, Japan T. Nakanishi SES, Hyogo-pref., Japan
	When the injection bump orbit is not closed perfectly at the beam injection, the horizontal stored beam oscillation is excited. In the SPring-8 storage ring, many efforts had been paid to reduce the beam oscillation by adjusting the temporal shape and timing of four bump magnets and by applying a counter kick to the residual oscillation, whose amplitude is as large as 0.4mm and the width is as narrow as 500ns. Now, the averaged oscillation amplitude has successfully been suppressed to the level of less than 0.1mm. To confirm the suppression effect, we observed the turn-by-turn photon beam profile at the diagnostics beamline with the insertion device. We confirmed that the light axis oscillation was significantly suppressed by a factor of 5 comparing by applying a counter kick. We also found that the oscillation shape and the oscillation amplitude, which were caused by the timing shift of firing bump magnets, are drastically changed by only timing shift of one magnet. We are considering the feedback scheme to keep the suppression effect at the initial level during the user-time.
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MOPRO084	Recent Development and Operational Status of PF-Ring and PF-AR	undulator, vacuum, injection, photon	286
	T. Honda, M. Adachi, S. Asaoka, K. Haga, K. Harada, Y. Honda, M. Izawa, T. Kageyama, Y. Kamiya, Y. Kobayashi, K. Marutsuka, T. Miyajima, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, M. Ono, T. Ozaki, H. Sagehashi, H. Sakai, S. Sakanaka, H. Sasaki, Y. Sato, M. Shimada, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Ma. Yoshida, S.I. Yoshimoto KEK, Ibaraki, Japan
	Update of the first-generation undulators installed in 1980s is pushed forward at PF-Ring, a 2.5-GeV SR source of KEK, taking advantage of the expanded straight sections reconstructed in 2005. New undulators have been designed as elliptically polarizing undulators each has 6 magnetic arrays to obtain various polarization states, not only circular polarization but also linear (horizontal and vertical) polarization. Three undulators will be installed in FY2013 and FY2014 for BL02, BL13 and BL28. For BL02, the longest straight section of about 9 m, the new undulator will be installed in tandem with the existing planar undulator, in order to cover the wide photon energy range from 15 eV to 2 keV. At PF-AR, a 6.5-GeV SR source, a new direct beam transport (BT) line from the injector LINAC is under construction. Super KEKB which shares the injector LINAC with PF-Ring and PF-AR will be commissioned at the end of FY2014. The full-energy continuous injection of PF-AR will be available as a simultaneous injection with the 7-GeV HER, the 4-GeV LER and PF-Ring not so later than the commissioning of Super KEKB.
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MOPRO087	High Voltage Generators Upgrade of Siberia-2 Injection System	kicker, injection, high-voltage, power-supply	292
	S.I. Tomin, A. Belkov, V. Korchuganov, I. Kuzmin, K. Kuznetsov NRC, Moscow, Russia
	The injection system is one of the important systems which determine efficiency and reliability of the accelerator facility. The spark gap switches (SGS), which were used before at Siberia-2 in high voltage nanosecond pulse generators, are the critical components requiring permanent maintenance. SGS has a series of limitations such as a relatively large pulse jitter and a work at a high pressure nitrogen atmosphere. The new injection system uses new half-sine microsecond pulse generators which based on Pseudo-Spark Switches. Some technical aspects of the new injection system are considered and results of generators operation are shown in the article.
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MOPRO089	Towards a Low Alpha Lattice for the ALBA Storage Ring	lattice, quadrupole, sextupole, storage-ring	298
	M. Carlà, G. Benedetti, Z. Martí, F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	Funding: CELLS-ALBA A proposal of a low alpha lattice for the ALBA third generation light source is presented. Opposed to most of other machines, belonging to the same category, ALBA employs an optimized lattice making use of combined function dipoles. This has permitted a very compact design stripped out of all not strictly necessary quadrupoles resulting in a lack of flexibility. For such a reason the common approaches used in many other synchrotrons can not be directly applied to ALBA and a different strategy has to worked out.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO089
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MOPRO090	Top-up Operation at ALBA Synchrotron Light Source	injection, radiation, storage-ring, simulation	301
	M. Pont, G. Benedetti, J. Moldes, R. Muñoz Horta, A. Olmos, F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA light source has been operating in decay mode since May 2012. Now it is ready for top-up operation, which should become the standard operation mode for users from mid 2014. In this paper we are going to summarise the different steps that have taken place before the start of top-up operation: radiation safety simulations and measurements, upgrade of hardware and software interlocks, control software and injection optimisation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO090
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MOPRO116	Mechanical Engineering and Design of Novel Collimators for HL-LHC	impedance, proton, experiment, collimation	369
	F. Carra, A. Bertarelli, A. Dallocchio, L. Gentini, P. Gradassi, A. Manousos, N. Mariani, G. Maîtrejean, N. Mounet, E. Quaranta, S. Redaelli, V. Vlachoudis CERN, Geneva, Switzerland
	In view of LHC intensity upgrades, collimator materials may become a limit to the machine performance: the high RF impedance of Carbon-Carbon composites can lead to beam instabilities, while the Tungsten alloy adopted in tertiary collimators exhibits low robustness in case of beam-induced accidents. An R&D program has been pursued to develop new materials overcoming such limitations. Molybdenum-Graphite, in addition to its outstanding thermal conductivity, can be coated with pure molybdenum, reducing collimator impedance by a factor of 10. A new secondary collimator is being designed around this novel composite. New high-melting materials are also proposed to improve the robustness of tertiary collimators. All the new collimators will be equipped with BPMs, significantly enhancing the alignment speed and the beta-star reach. This implies additional constraints of space, as well as detailed static and fatigue calculations on cables and connectors. This paper describes the mechanical design and the engineering calculations of such future collimators, focusing on the study via state-of-the-art numerical methods of interactions between the particle beams and the new materials adopted.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO116
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MOPME011	Matrix Integration of ODEs for Spin-orbit Dynamics Simulation	simulation, lattice, quadrupole, resonance	400
	A.N. Ivanov, Y. Senichev FZJ, Jülich, Germany
	MODE (Matrix integration of Ordinary Differential Equations) is a software package that provides nonlinear matrix maps building for spin-orbit beam dynamics simulation. In this article we briefly describe the developed integrated development environment features and present computational comparison with other simulation tools. MODE mathematical model is based on Newton-Lorentz and T-BMT equations that are expanded to Taylor series up to the necessary order of nonlinearity. The numerical algorithm is based on matrix presentation of Lie propagator. Spin-orbit simulation results of MODE are compared with results of COSY Infinity and OptiM. MODE provides a flexible graphic user interface, code auto complete technology and visual designer for accelerators. There is also a possibility to generate codes in different programming languages and parallelization techniques.
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MOPME022	Investigation of the Breakdown and RF Sheath Potential for EAST ICRF Antenna	plasma, ion, experiment, simulation	424
	H. Yang, S. Dong, L. Shang, K. Tang, C.-F. Wu USTC/NSRL, Hefei, Anhui, People's Republic of China
	A new ion cyclotron range of frequency (ICRF) antenna was designed with four current straps in Experimental Advanced Superconducting Tokamak (EAST). It is to provide heating, current drive and some physics experiments in EAST. The breakdown and RF sheath potential for the antenna are investigated by a three dimension electromagnetic code in the paper. The plasma is simulated by a slab with high relative permittivity approximating the plasma loading of the antenna. Calculations show that the maximum of electric field is around the end of the coaxial feeds and the strip line and the electric field is strongly dependent on antenna phasing. Especially the maximum of electric field is decreased to 27.5 KV/cm with the (0,π,π,0) phasing between toroidal straps while the value is 32.8 KV/cm with (0,0,π,π) phasing. A challenge in ICRF is the impurity contamination which is related to sheath potential. The topology of the radio frequency (RF) sheath is optimized to reduce the potential for EAST ICRF antenna. The RF potential is mitigated obviously with the broader side limiter by a factor of 2.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME022
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MOPME025	New Possibilities of MultP-M Code	simulation, multipactoring, electron, RF-structure	433
	M. Gusarova, S. Khudyakov, I.I. Petrushina, Ya.V. Shashkov MEPhI, Moscow, Russia
	Implementation and Testing of the new module package for geometry import of the MultP-M 3D code for multipacting prediction was performed. The results of simulations for the coaxial line specimen using this new module are presented. These results are compared with analytical calculations and experimental data.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME025
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MOPME035	Current Status of the GPU-Accelerated ELEGANT	GPU, simulation, acceleration, linac	454
	I.V. Pogorelov, K.M. Amyx, J.R. King Tech-X, Boulder, Colorado, USA M. Borland, R. Soliday ANL, Argonne, Ilinois, USA
	Funding: Work supported by the DOE Office of Science, Office of Basic Energy Sciences grant No. DE-SC0004585, and in part by Tech-X Corporation. Efficient implementation of general-purpose particle tracking on GPUs can result in significant performance benefits to large-scale tracking simulations. This presentation is an update on the current status of our work on accelerating Argonne National Lab’s particle accelerator simulation code ELEGANT using CUDA-enabled GPU. We summarize the performance of beamline elements ported to GPU, and discuss optimization techniques for some important collective effects kernels, in particular our methods of avoiding costly thread contention. We also present preliminary results of a scaling study of the GPU-accelerated version of the code.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME035
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MOPME046	Supervision Software for the Integration of the Beam Interlock System with the CERN Accelerator Complex	software, monitoring, hardware, linac	476
	M. Audrain, D. Anderson, M. Dragu, K. Fuchsberger, J.C. Garnier, A.A. Gorzawski, M. Koza, K.H. Krol, A. Moscatelli, B. Puccio, K. Stamos, M. Zerlauth CERN, Geneva, Switzerland
	The Accelerator complex at the European Organisation for Nuclear Research (CERN) is composed of many systems which are required to function in a valid state to ensure safe beam operation. One key component of machine protection, the Beam Interlock System (BIS), was designed to interface critical systems around the accelerator chain, provide fast and reliable transmission of beam dump requests and trigger beam extraction in case of malfunctioning of equipment systems or beam losses. Numerous upgrades of accelerator and controls components during the Long Shutdown 1 (LS1) are followed by subsequent software updates that need to be thoroughly validated before the restart of beam operation in 2015. In parallel, the ongoing deployments of the BIS hardware in the PS booster (PSB) and the future LINAC4 give rise to new requirements for the related controls and monitoring software due to their fast cycle times. This paper describes the current status and ongoing work as well as the long-term vision for the integration of the Beam Interlock System software into the operational environment.
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MOPME048	CLIC Decelerator - Machine Protection	emittance, quadrupole, alignment, collider	482
	L.M. Hein, J. Esberg, M. Jonker CERN, Geneva, Switzerland
	The Compact Linear Collider CLIC is based on a four beam scheme, two colliding beams (main beams) and two drive beams, which are used to accelerate the main beams. The intended drive beam parameters exceed the "safe beam" threshold by a factor of 100. Hence, in case of a beam impact serious structural damages of the accelerator equipment are expected. In order to avoid structural damages caused by the drive beam detailed studies of its beam dynamics are on-going. In this paper the major characteristics of the drive-beam beam-dynamics and preliminary machine protection results are summarised.
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MOPME054	Upgrade of the Elettra Magnet Power Supply Controllers	controls, interface, power-supply, electronics	495
	S. Cleva, M. Cautero, T.M. Cieśla, M. Lonza, L. Pivetta, C. Scafuri, R. Visintini Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Ageing of devices and components phasing-out, as well as the increasing maintenance costs, affect particle accelerators similarly to any industrial plant. A careful maintenance plan can cope with these problems in the medium-term, but then a complete update of the oldest parts is required. The most recent technologies available on the market together with a modular and open design approach are the basis of an upgrade program aimed at replacing the existing controllers of the Elettra storage ring magnet power supplies. The design considerations, the constraints and the first results are reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME054
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MOPME059	Design of a Multi-harmonic Buncher for LINCE	ion, rfq, bunching, linac	508
	J. Labrador, C. Bonțoiu, J.A. Dueñas, I. Martel University of Huelva, Huelva, Spain M.A. Carrera, A. Garbayo AVS, Elgoibar, Spain A.C.C. Villari FRIB, East Lansing, Michigan, USA
	Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA. Continuous beams delivered by the LINCE ECR ion source will be bunched by a multi-harmonic buncher consisting of two copper-made electrodes. Its numerical design is reported here along with electric and magnetic field maps. Multi-frequency operation is proven by tracking a continuous beam and optimizing the its longitudinal phase space bunching for various ion species under the influence of space charge effects. A thermo-mechanical study carried out in order to estimate the needed water flow through the electrodes is presented as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME059
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MOPME061	Design of a Three Legs and Phase Shift AC to DC Converter for Taiwan Photon Light Source	controls, feedback, power-supply, electronics	511
	Y.S. Wong, K.-B. Liu NSRRC, Hsinchu, Taiwan J.F. Chen, W.C. Hsu, W.C. Hung, P.H. Tseng NCKU, Tainan city, Taiwan
	A novel low voltage high current AC/DC converter will be achieved which input is utility power supplies a low voltage DC output to load. The new three legs phase shift AC / DC power supply, can divided to five parts : diode full bridge rectifier, three legs phase shift control circuits, transformers, double inductor circuit and feedback circuit. Circuit operates as a single-phase 110 Vrms AC mains power input three legs phase shift control mode from the diode bridge rectifier circuit, the output voltage through the transformer and the phase shift control method converts to low voltage DC 12V output and supplies to loading, feedback circuit are using a feedback resistor across the filter capacitor voltage to product a feedback signal. Digital signal processing (DSP) control board by a feedback voltage determines the three legs phase shift displacement in order to control the output voltage keep a constant value 12V. For this circuit have a zero voltage switching characteristics of the three legs phase shift mode power supply, the input voltage for single phase 110Vac and output load power is 12V/20A.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME061
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MOPME066	Development of 400 kA Pulsed Power Supply for Magnetic Horn at FAIR Antiproton Target	antiproton, radiation, power-supply, coupling	517
	S.S. Mohite, R. Hettinger, K. Knie, I.J. Petzenhauser GSI, Darmstadt, Germany
	This report presents an overview of the magnetic horn and its pulsed power system at the upcoming FAIR (Facility for Antiproton and Ion Research) complex at GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. In the planned antiproton (pbar) separator scheme a magnetic horn will be used as a device for collection and focusing of highly divergent antiprotons emerging from the target with energies around 3 GeV and within a cone of about 80 mrad .To achieve the desired focusing effect, the horn needs to be powered with a current pulse of 400 kA peak amplitude at the same repetition rate as the primary proton beam, i.e. 0.1 Hz. In future, operation up to 0.2 Hz is planned without major design alterations. Due to civil construction and radiation protection limitations, possible technical realization of this system has some key design issues. The aim is to develop a reliable and efficient magnetic horn system for effective focusing of antiprotons by producing a very strong pulsed magnetic field.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME066
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MOPME069	Upgrade of the Injection Kicker System for J-PARC Main Ring	injection, kicker, timing, feedback	526
	T. Sugimoto, K. Fan, K. Ishii, H. Matsumoto KEK, Ibaraki, Japan
	Four lumped inductance injection kicker magnets for the J-PARC main ring (MR) produce a kick of 0.1096 T·m with a 1% to 99% rise-time of about 400 nsec. A residual field of about 6% of the flat-top exists at the tail of the pulse due to an impedance mismatching. The residual field is required to be suppressed less than 1% to reduce injection losses. For a higher intensity beam operation, the kicker rise-time of less than 300nsec is required to inject longer beam bunches which reduces a space charge effect. During the long shutdown in FY2013, 140Ω resistor and 7nF capacitor were connected to the thyratron to improve the post-pulse shape. In addition, an optimization of a capacitance in the matching circuit was carried out to optimize the waveform. As the result, the rise-time of 195nsec and the residual tail field of 2% were achieved. However, another reflection peak of about 9% is appeared. We plan to compensate the effect of the new peak by using a new small kicker magnet. This paper discusses the detail of the circuit and the beam test results.
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MOPME074	High Voltage Performance of the Beam Screen of the LHC Injection Kicker Magnets	injection, kicker, vacuum, impedance	541
	M.J. Barnes, P. Adraktas, G. Bregliozzi, S. Calatroni, P. Costa Pinto, H.A. Day, L. Ducimetière, V. Gomes Namora, T. Kramer, V. Mertens, M. Taborelli CERN, Geneva, Switzerland
	The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wakefields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. The design of the beam screen has been upgraded to overcome limitations and permit LHC operation with increasingly higher bunch intensity and short bunch lengths: the new design also significantly reduces the electric field associated with the screen conductors, decreasing the probability of electrical breakdown. The high voltage conditioning process for the upgraded kicker magnets is presented and discussed. In addition a test setup has been utilized to study flashover, on the inner wall of the ceramic tube, as a function of both applied voltage and vacuum pressure: results from the test setup are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME074
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MOPME075	Cooling of the LHC Injection Kicker Magnet Ferrite Yoke: Measurements and Future Proposals	vacuum, kicker, injection, simulation	544
	M.J. Barnes, S. Bouleghlimat, L. Ducimetière, M. Garlaschè, V. Gomes Namora, T. Kramer, R. Noulibos, Y. Sillanoli, Z.K. Sobiech, W.J.M. Weterings CERN, Geneva, Switzerland
	LHC operation with high intensity beam, stable for many hours, resulted in significant heating of the ferrite yoke of the LHC Injection Kicker Magnets. For one kicker magnet the ferrite yoke approached its Curie temperature. As a result of a long thermal time-constant the yoke can require several hours to cool sufficiently to allow re-injection of beam, thus limiting the running efficiency of the LHC. The beam screen, which screens the ferrite yoke from wakefields, has been upgraded to limit ferrite heating. In addition it is important to improve the cooling of the ferrite yoke: one method is to increase the internal emissivity of the cylindrical vacuum tank, in which the kicker magnet is installed. This paper describes a method developed for measuring the emissivity of the inside of the tanks, which has been benchmarked against measurements of the ferrite yoke temperature during heat treatment in an oven and transient thermal simulations. Conclusions are drawn regarding an ion bombardment technique evaluated for improving emissivity without degrading vacuum properties. In addition initial concepts for improved cooling are presented.
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MOPME082	ILC-Class Marx Modulator at KEK	controls, high-voltage, damping, flattop	562
	M.P.J. Gaudreau, N. Silverman, B.E. Simpson Diversified Technologies, Inc., Bedford, Massachusetts, USA J.A. Casey Rockfield Research Inc., Las Vegas, Nevada, USA
	Funding: US Department of Energy, Award DE-FG02-05ER84352 KEK, High Energy Accelerator Research Organization In October 2013, Diversified Technologies, Inc. (DTI) successfully installed and began operation of a 120 kV, 120 A, 1.7 ms Marx modulator for the High Energy Accelerator Research Organization (KEK) in Japan. Originally conceived, and built under a DOE SBIR grant to support SLAC (completed in 2010), the Marx bank modulator demonstrates a new technology for compact and economic ILC-class performance; the design meets the performance requirements for ILC, does so in a more compact form factor than other known technologies, and, we believe, will be more economic than other technologies. The basic concept of a Marx modulator is that it charges an array of capacitors in parallel (low voltage), then erects them in series to form a high-voltage discharge. Using DTI’s solid-state switches (instead of traditional spark gaps or SCRs) to construct a Marx modulator enables it to open and close; thus the capacitors serve as storage capacitors rather than fully exhausting during each pulse. The opening capability of the DTI switches also provides for arc protection of the load, exactly as they would in a hard-switch. Such a system requires no crowbar protection to protect the load against arcs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME082
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MOPRI004	SuperKEKB Positron Source Construction Status	positron, electron, target, solenoid	579
	T. Kamitani, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, Y. Funakoshi, K. Furukawa, T. Higo, H. Honma, N. Iida, M. Ikeda, E. Kadokura, H. Kaji, K. Kakihara, H. Katagiri, M. Kikuchi, H. Koiso, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, Y. Ohnishi, S. Ohsawa, M. Sato, T. Shidara, A. Shirakawa, M. Suetake, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, M. Tawada, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	The KEKB positron source is under the upgrade for SuperKEKB. The previous positron production target and capture section have been removed and the new system is constructed at a location forty meters upstream to have sufficient energy margin for beam injection to the newly introduced damping ring. A flux concentrator is introduced in the new capture section to make an adiabatic matching system. Large aperture (30mm in diameter) S-band accelerating structures are introduced in the capture section and in the subsequent accelerator module to enlarge the transverse phase space acceptance. The beam focusing system of quadrupoles is also upgraded for a comparable beam acceptance to that of the capture section. This paper reports on the status of the SuperKEKB positron source construction and the preliminary positron beam commissioning.
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MOPRI017	Status of AREAL RF Photogun Test Facility	gun, electron, laser, emittance	620
	B. Grigoryan, G.A. Amatuni, V.S. Avagyan, H. Avdishyan, H. Davtyan, A.A. Gevorgyan, L.H. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, A. Lorsabyan, M. Manukyan, I.N. Margaryan, N. Martirosyan, T.H. Mkrtchyan, S. Naghdalyan, V.H. Petrosyan, H. Poladyan, V. Sahakyan, A. Sargsyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, V. V. Vardanyan, G.S. Zanyan CANDLE SRI, Yerevan, Armenia T.K. Sargsyan LT-PYRKAL cjsc, Yerevan, Armenia
	Advanced Research Electron Accelerator Laboratory (AREAL) is a 20 MeV laser driven RF linear accelerator which is being constructed in the CANDLE institute. The construction of phase-1 is finished and at present the machine commissioning is in progress. In phase-1 a photocathode RF gun provides a 5 MeV small emittance electron beam with the 100 pC bunch charge and variable electron bunch length from 0.5 to 8 ps. Two main operation modes are foreseen for this phase – single and multibunch regimes to satisfy experimental demands. We report the status of linac, first experience and nearest machine run schedule. The brief review of the facility, main parameters, performance and first results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI017
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MOPRI021	Laser Systems Generating Short Polarized Electron Bunches at the S-DALINAC	laser, electron, experiment, cathode	633
	M. Espig, J. Enders, Y. Fritzsche, A. Kaiser, M. Wagner TU Darmstadt, Darmstadt, Germany
	Funding: Supported by DFG within CRC634 and by the state of Hesse through the LOEWE center HIC for FAIR. The source of polarized electrons at the superconducting Darmstadt electron linear accelerator S-DALINAC uses photo-emission from strained-layer superlattice-GaAs and bulk-GaAs photocathodes. This system is driven by either 3 GHz gain-switched diode lasers or a short-pulse Ti:Sapphire laser system. Highly polarized electrons are generated with laser light at 780 nm, while blue laser light is used for unpolarized high-current experiments. We present the existing pulsed laser systems and the planned developments for the diode laser system, including, e.g., impedance matching of the diode lasers, gain switching with short electrical pulses and pulsing with a Mach-Zehnder modulator. The pulsed operation is aimed at generating short electron bunches (< 50 ps) at the S-DALINAC with variable repetition rates from some MHz to 3 GHz.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI021
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MOPRI027	Dark Current Studies at Relativistic Electron Gun for Atomic Exploration – REGAE	electron, gun, cavity, vacuum	649
	H. Delsim-Hashemi, K. Flöttmann DESY, Hamburg, Germany
	Electron diffraction is a tool for exploring structural dynamics of matter. The scattering cross section is orders of magnitude higher for electrons than for X-rays so that only a small number of electrons is required to achieve comparable results. However, the required electron beam quality is extraordinary. To study e. g. proteins a coherence length of 30 nm is required which translates into a transverse emittance of 5 nm at a spot size of 0.4mm. In addition short bunch lengths down to 10 fs and a temporal stability of the same order are required in order to study chemical reactions or phase transitions in pump probe type experiments. These are challenging parameters for an electron source, which demand improvements at many frontiers. Dark current degrades contrast of diffraction patterns in all experiments. Understanding dark-current generation and propagation can lead to better methods to decrease it. In this paper dark current studies that are performed at REGAE will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI027
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MOPRI042	Recent Developments at the High-charge PHIN Photoinjector and the CERN Photoemission Laboratory	laser, cathode, vacuum, feedback	695
	C. Heßler, E. Chevallay, S. Döbert, V. Fedosseev, I. Martini, M. Martyanov, A. Perillo Marcone, Sz. Sroka CERN, Geneva, Switzerland
	The high-charge PHIN photoinjector has originally been developed to study the feasibility of a photoinjector option for the drive beam of the CLIC Test Facility 3 (CTF3) at CERN and is now being used to investigate the feasibility of a drive beam photoinjector for CLIC. In this paper recent R&D efforts to improve the parameters of the existing system towards CLIC requirements will be discussed. This includes studies of a feedback loop for intensity stabilization, the upgrade of the PHIN vacuum system and the planned upgrade of the driving laser system. For photocathode production and R&D a dedicated photoemission laboratory is available at CERN. To increase the production rate of photocathodes and the availability of the photoemission lab for other studies, an upgrade of the photocathode preparation system with a load-lock system is under study and will also be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI042
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MOPRI056	Design and Fabrication of a VHF - CW High Repetition Rate Electron Gun	cavity, cathode, gun, vacuum	733
	R.P. Wells, B. Ghiorso, F. Sannibale, J.W. Staples LBNL, Berkeley, California, USA T.M. Huang IHEP, Beijing, People's Republic of China
	Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 A high repetition rate, MHz, electron source is a key element in future FEL based light sources. The Advance Photo-injector Experiment (APEX) at Lawrence Berkeley National Laboratory (LBNL) consists of a high repetition rate 186 MHz (VHF-band) CW electron gun, 1 MHz UV laser source and the diagnostic components necessary to quantify the gun’s performance. The gun design is based on well established, conventional RF cavity design, with a couple notable exceptions. The basis for the selection of this technology, novel design features, fabrication techniques and measured cavity performance are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI056
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MOPRI070	2MeV Electron Cooler for COSY and HESR – First Results	electron, proton, experiment, heavy-ion	765
	V. Kamerdzhiev, U. Bechstedt, F.M. Esser, O. Felden, R. Gebel, A.J. Halama, F. Klehr, G. Langenberg, A. Lehrach, B. Lorentz, R. Maier, D. Prasuhn, K. Reimers, M. Retzlaff, R. Stassen, H. Stockhorst, R. Tölle FZJ, Jülich, Germany N. Alinovskiy, T.V. Bedareva, E.A. Bekhtenev, O.V. Belikov, V.N. Bocharov, V.V. Borodich, M.I. Bryzgunov, A.V. Bubley, V.A. Chekavinskiy, V.G. Cheskidov, B.A. Dovzhenko, A.I. Erokhin, M.G. Fedotov, A.D. Goncharov, K. Gorchakov, V.K. Gosteev, I.A. Gusev, G.V. Karpov, Y.I. Koisin, M.N. Kondaurov, V.R. Kozak, A.M. Kruchkov, A.D. Lisitsyn, I.A. Lopatkin, V.R. Mamkin, A.S. Medvedko, V.M. Panasyuk, V.V. Parkhomchuk, I.V. Poletaev, V.A. Polukhin, A.Yu. Protopopov, D.N. Pureskin, A.A. Putmakov, V.B. Reva, P.A. Selivanov, E.P. Semenov, D.V. Senkov, D.N. Skorobogatov, N.P. Zapiatkin BINP SB RAS, Novosibirsk, Russia J. Dietrich HIM, Mainz, Germany T. Katayama Nihon University, Narashino, Chiba, Japan L.J. Mao IMP, Lanzhou, People's Republic of China
	The 2 MeV electron cooler was installed in the COSY ring in the spring 2013. The new system enables electron cooling in the whole energy range of COSY. The electron beam is guided by longitudinal magnetic field all the way from the electron gun to the collector. This well-proven optics scheme was chosen because of the wide electron energy range of 0.025-2 MeV. The electrostatic accelerator consists of 33 individual sections of identical design. Electrical power to each section is provided by a cascade transformer. Electron beam commissioning and first studies using proton and deuteron beams were carried out. Electron cooling of proton beam up to 1662 MeV kinetic energy was demonstrated. Maximum electron beam energy achieved so far amounted to 1.25 MeV. Voltage up to 1.4 MV was demonstrated. The cooler was operated with electron current up to 0.5 A. The paper provides insights into the recent progress in high energy electron cooling at COSY and perspectives for the HESR ring at FAIR.
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MOPRI089	Upgrade of J-PARC Fast Extraction System	septum, extraction, quadrupole, kicker	821
	K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan T. Shibata JAEA, Ibaraki-ken, Japan
	The J-PARC main ring (MR) fast extraction (FX) system has two functions: to deliver a high power beam to the neutrino experimental facility and to dump the beam at any time in case of hardware failures. The present FX system consists of five bipolar kickers and eight bipolar septa. In order to raise the beam power to the design limit, both the beam intensity and the repetition rate will increase gradually. The FX system needs to be upgraded to satisfy the new requirements. The upgrade includes FX orbit optimization and new design of devices. Firstly, two high performance eddy current septa have been designed and fabricated. Then downstream high field septa are redesigned and using ceramic beam pipe to eliminate eddy current effects, which meets the requirement of high repetition rate operation. A new large physical aperture quadrupole is needed to accommodate high intensity beam. In order to evaluate the beam loss in the new system, realistic 3D beam tracking is studied.
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MOPRI093	Technical Design of Normal Conducting Re-buncher in the MEBT for Rare Isotope Science Project	cavity, rfq, acceleration, ion	830
	H.J. Kim, W.K. Han, I.S. Hong, D. Jeon IBS, Daejeon, Republic of Korea
	Funding: This work was supported by the RISP of Institute for Basic Science funded by Ministry of Science, ICT and Future Planning and National Research Foundation of Korea.(2011-0032011) The front-end system of RISP heavy-ion accelerator(RAON) consists of an electron cyclotron resonance ion source, a low energy beam transport line, a radio frequency quadrupole accelerator and a medium energy beam transport(MEBT) line. The MEBT system, which consists of quadrupole magnets, three normal-conducting re-bunchers and diagnostic devices, is installed between the RFQ accelerator and the superconducting linac(SCL). The three normal-conducting re-bunchers are used to minimize the growths of the longitudinal emittance and to manipulate the particle distribution on longitudinal phase space for beam transportation in SCL. Several combination of the number of cavities was examined, and the quarter wave resonator(QWR) type re-buncher was chosen for MEBT line in RAON. The QWR cavity has a frequency of 81.25 MHz, a maximum electric field of 2.53 MV/m on the cavity surface with an electric field of 1 MV/m on the beam axis, a geometrical beta factor of 0.032 and an effective length of 24 cm. In this presentation, I will present the results of baseline design for electro-magnetic field analysis and mechanical design for stress analysis, thermal stress analysis and cooling channel.
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MOPRI107	The Mitigation System of the Large Angle Foil Scattering Beam Loss caused by the Multi-turn Charge-exchange Injection	injection, simulation, scattering, insertion	873
	S. Kato Tohoku University, Graduate School of Science, Sendai, Japan H. Harada, H. Hotchi, M. Kinsho, K. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	Funding: Research Fellow of Japan Society for the Promotion of Science In the J-PARC RCS, the significant losses were observed at the branch of H⁰ dump line and the Beam Position Monitor which was put at the downstream of the H⁰ dump branch duct. These losses were caused by the large angle scattering of the injection and the circulating beam at the charge exchange foil. To realize high power operation, we have to mitigate these losses. So, we developed a new collimation system in the H⁰ branch duct and installed in October 2011. In order to optimize this system efficiently, we focused on the relative angle of collimator block from scattering particles. We developed the beam based angler regulation method by the simulation and achieved the sufficient mitigation of the loss at 181 MeV injection energy. Since the injection energy will be upgraded to 400 MeV in this year, we will start to estimate again the collimator performance by the upgraded simulation set. We present this system as one of the mitigation methods of the large angle foil scattering beam loss caused by the multi-turn charge-exchange injection.
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MOPRI108	Transverse H⁻ Beam Halo Scraper System in the J-PARC L3BT	radiation, injection, proton, linac	876
	K. Okabe, M. Kinsho, K. Yamamoto, M. Yoshimoto JAEA/J-PARC, Tokai-mura, Japan
	In the Japan Proton Accelerator Research Complex (J-PARC) 3-GeV rapid cycle synchrotron (RCS), transverse beam halo scraping for the injection beam is required to increase the output beam power. The transverse collimation system at the Linac-RCS beam transport line (L3BT) was utilized in a nominal beam operation because the area of the scraper section was contaminated when scrapers were working. In the summer-autumn period of 2013, we installed a new beam-halo scraper which had optimized scraper heads for mitigation of the radiation around the scraper system. In this poster, we report a preliminary result for a halo scraper at the L3BT.
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MOPRI114	Numerical Estimation of the Equivalent Dose Rate after the Irradiation of a Tungsten Collimator by a Low Energy Proton Beam	proton, simulation, cyclotron, radiation	890
	V. Talanov, D.C. Kiselev, M. Wohlmuther PSI, Villigen PSI, Switzerland
	The issue of activation of a Tungsten collimator by protons is considered for the incident energy of 12.2 MeV. Two different simulation approaches using the Monte Carlo programs MCNPX and FLUKA are applied to estimate the equivalent remanent dose rate after the irradiation of the collimator. The results of the numerical simulation are then compared to the measured dose levels of the collimator of the COMET cyclotron at Paul Scherrer Institut (PSI).
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MOPRI115	Activation Models of the ISIS Collectors	synchrotron, simulation, controls, scattering	893
	H. V. Smith, D.J. Adams, B. Jones, C.M. Warsop STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS facility at the Rutherford Appleton Laboratory is a pulsed neutron and muon source, for materials and life science research. The 163 m circumference, 800 MeV, 50 Hz rapid cycling synchrotron accelerates up to 3·10¹³ protons per pulse. The maximum operating intensity of the synchrotron is limited by loss during acceleration, mainly due to the non-adiabatic longitudinal trapping process between 0 and 3 ms, corresponding to energies between 70 and 200 MeV. In order to minimise global machine activation and prevent component damage a beam collimation, or collector, system is installed in a five metre drift section in super-period one, to localise loss to this region. This paper summarises new results from modelling of the beam collectors using the FLUKA code [1, 2]. Understanding the current performance of the collectors is important for high intensity beam optimisation and may influence future injection upgrade plans. Residual dose rates are compared to film badge measurements, predicted energy deposition results are compared to the measured heat load on the collector cooling systems and an assessment is made of the distribution of particles exiting the collector straight.
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TUXA01	Commissioning the 400 MeV Linac at J-PARC and High Intensity Operation of the J-PARC RCS	injection, linac, dipole, emittance	899
	H. Hotchi JAEA/J-PARC, Tokai-mura, Japan
	J-PARC is currently upgrading their linac from 181MeV to 400 MEV with a new ACS section (annular coupled structure). This includes a triple frequency jump, and there should be some interesting results to report. As the result of the injector linac upgrade at J-PARC, the Rapid Cycle Synchrotron (RCS) will achieve a record-high intensity as a proton accelerator. This talk describes the recent performance of the RCS together with its beam-dynamical issues.
	Slides TUXA01 [3.611 MB]
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TUOAA01	Progress Towards Doubling the Beam Power at Fermilab's Accelerator Complex	booster, target, antiproton, proton	904
	I. Kourbanis Fermilab, Batavia, Illinois, USA
	Funding: Work supported by the Fermi Research Alliance under contract to the U.S. Department of Energy. After a 16 month shutdown to reconfigure the Fermilab Accelerators for high power operations, the Fermilab Accelerator Complex is again providing beams for numerous Physics Experiments. By using the Recycler to slip stack protons while the Main Injector is ramping, the beam power at 120 GeV can reach 700 KW, a factor of 2 increase. The progress towards doubling the Fermilab's Accelerator complex beam power will be presented.
	Slides TUOAA01 [7.059 MB]
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TUOAA02	Design of the LBNE Beamline	target, proton, shielding, extraction	907
	V. Papadimitriou, R. Andrews, J. Hylen, T.R. Kobilarcik, A. Marchionni, C.D. Moore, P. Schlabach, S. Tariq Fermilab, Batavia, Illinois, USA
	Funding: DOE, contract No. DE-AC02-07CH11359 The Long Baseline Neutrino Experiment (LBNE) will utilize a beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a wide band beam of neutrinos toward a detector placed at the Sanford Underground Research Facility in South Dakota, about 1,300 km away. The main elements of the facility are a primary proton beamline and a neutrino beamline. The primary proton beam (60-120 GeV) will be extracted from the MI-10 section of Fermilab’s Main Injector. Neutrinos are produced after the protons hit a solid target and produce mesons which are subsequently focused by a set of magnetic horns into a 204 m long decay pipe where they decay into muons and neutrinos. The parameters of the facility were determined taking into account the physics goals, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~1.2 MW, however the facility is designed to be upgradeable for 2.3 MW operation. We discuss here the status of the design and the associated challenges.
	Slides TUOAA02 [5.781 MB]
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TUOBA01	Electron Lenses for the Large Hadron Collider	electron, collider, collimation, controls	918
	G. Stancari, A. Valishev Fermilab, Batavia, Illinois, USA R. Bruce, S. Redaelli, A. Rossi, B. Salvachua CERN, Geneva, Switzerland
	Funding: Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. Research supported in part by US LARP and EU FP7 HiLumi LHC, Grant Agreement 284404. Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.
	Slides TUOBA01 [9.709 MB]
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TUZA02	THz Facility at ELBE: A Versatile Test Facility for Electron Bunch Diagnostics on Quasi-CW Electron Beams	electron, diagnostics, SRF, linac	933
	M. Gensch, B.W. Green, J. Hauser, S. Kovalev, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig HZDR, Dresden, Germany A. Al-Shemmary, V. B. Asgekar, T. Golz, H. Schlarb, N. Stojanovic, S. Vilcins DESY, Hamburg, Germany A.S. Fisher SLAC, Menlo Park, California, USA G. Geloni XFEL. EU, Hamburg, Germany A.-S. Müller, M. Schwarz KIT, Karlsruhe, Germany N.E. Neumann, D. Plettemeier TU Dresden, Dresden, Germany
	At the Helmholtz-Zentrum Dresden-Rossendorf near Dresden a quasi-cw low-energy electron linear accelerator based on superconducting radiofrequency technology is operated successfully for more than 10 years. The ELBE accelerator is driving several secondary radiation sources including 2 infrared free electron lasers. A new addition will be a THz facility that aims to make use of super-radiant THz radiation. In its final form the THz facility shall consist of one coherent diffraction radiator and one undulator source which provide high-field THz pulses at unprecedented repetition rates. While the medium term goal is to establish a unique user facility for nonlinear THz science, the THz sources are already used as a test facility for novel diagnostic techniques on quasi-cw electron beams. The progress of the developments is reported and an outlook into future challenges and opportunities is given.
	Slides TUZA02 [3.041 MB]
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TUZB02	Prospects for the use of HTS in High-field Magnets for Future Accelerator Facilities	solenoid, dipole, quadrupole, focusing	974
	A. Ballarino CERN, Geneva, Switzerland
	The enthusiasm that followed the discovery of High Temperature Superconductors (HTS) and the hope that they could replace Low Temperature Superconductors (LTS) was damped by low current-carrying capacity, short piece lengths, and fragility of the brittle oxide materials. Development of applications was mainly on devices less demanding of conductor performance. However, with continuing development, progress was made with the cuprate superconductors, and long lengths of BSCCO 2223 and REBCO tape conductors are now commercially available. Progress has also been made in the development of BSSCO 2212 round wire, where implementation of a new production process has led to a breakthrough in performance. Though still at the research level, attainments in material synthesis and theoretical understanding of iron-based materials may lead to their development into practical superconductors, featuring high upper critical field and low anisotropy. A review of the potential of HTS as applied to accelerators is presented, with a focus on using the presently available materials and on the perceived needs for further development.
	Slides TUZB02 [2.331 MB]
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TUPRO003	Fast Crab Cavity Failures in HL-LHC	simulation, optics, luminosity, synchrotron	997
	B. Yee-Rendón, R. Lopez-Fernandez CINVESTAV, Mexico City, Mexico J. Barranco García EPFL, Lausanne, Switzerland R. Calaga, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland
	Crab cavities (CCs) are a key ingredient of the High-Luminosity Large Hadron Collider (HL-LHC) to ensure head on collisions at the main experiments (ATLAS and CMS) and fully profit from the smaller β* provided by the ATS optics. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of few LHC turns and considering the large energy stored in the HL-LHC beam, CC failures represent a serious risk to the LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, necessary to dump the beam. The simulations assume a realistic steady-state distribution to assess the beam losses for the HL-LHC. Additionally, some strategies are studied to mitigate the damage caused by the failures.
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TUPRO007	LS1 “First Long Shutdown of LHC and its Injector Chains”	radiation, cryogenics, electronics, shielding	1010
	K. Foraz, S. Baird, M.B.M. Barberan Marin, M. Bernardini, J. Coupard, N. Gilbert, D. Hay, S. Mataguez, D.J. Mcfarlane CERN, Geneva, Switzerland
	The LHC and its injectors were stopped in February 2013, in order to maintain, consolidate and upgrade the different equipment of the accelerator chain, with the goal of achieving LHC operation at the design energy of 14 TeV in the centre-of-mass. Prior to the start of this Long Shutdown (LS1), a major effort of preparation was performed in order to optimize the schedule and the use of resources across the different machines, with the aim of resuming LHC physics in early 2015. The rest of the CERN complex will restart beam operation in the second half of 2014. This paper presents the schedule of LS1, describes the organizational set-up for the coordination of the works, the main activities, the different main milestones, which have been achieved so far, and the decisions taken in order to mitigate the issues encountered.
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TUPRO009	Simple Models Describing the Time-evolution of Luminosity in Hadron Colliders	luminosity, collider, hadron, proton	1017
	M. Giovannozzi CERN, Geneva, Switzerland
	In recent years, several studies have been performed to describe the evolution of the losses in circular proton machines. Considerations based on single-particle, non-linear beam dynamics allowed building models that, albeit simple, proved to be in good agreement with measurements. These initial results have been generalised, thus opening the possibility to describe the luminosity evolution in a circular hadron collider. In this paper, the focus is on the derivation of scaling laws for the integrated luminosity, taking into account both burn off and additional pseudo-diffusive effects. The proposed models are applied to the analysis of the data collected during the LHC Run I and the outcome is discussed in detail.
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TUPRO015	Update on Predictions for Yearly Integrated Luminosity for HL-LHC based on Expected Machine Availability	luminosity, radiation, electronics, cryogenics	1036
	A. Apollonio, M. Jonker, R. Schmidt, B. Todd, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland
	Machine availability is one of the key performance indicators to reach the ambitious goals for integrated luminosity in the post Long Shutdown 1 (LS1) era. Machine availability is even more important for the future High Luminosity LHC (HL-LHC) [1]. In this paper a Monte Carlo approach has been used to predict integrated luminosity as a function of LHC machine availability. The baseline model assumptions such as fault-time distributions and machine failure rate (number of fills with stable beams dumped after a failure / total number of fills with stable beams) were deduced from the observations during LHC operation in 2012. The predictions focus on operation after LS1 and its evolution towards HL-LHC. The extrapolation of relevant parameters impacting on machine availability is outlined and their corresponding impact on fault time distributions is discussed. Results for possible future operational scenarios are presented. Finally, a sensitivity analysis with relevant model parameters like fault time and machine failure rate is discussed.
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TUPRO016	Machine Protection Challenges for HL-LHC	cavity, extraction, beam-losses, luminosity	1039
	R. Schmidt, T. Bär, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland
	LHC operation requires the flawless functioning of the machine protection systems. The energy stored in the beam was progressively increased beyond the 140 MJ range at the end of 2012 at 4 TeV/c. The further increase to 364 MJ expected for 2015 at 6.5 TeV/c should be possible with the existing protection systems. For HL-LHC, additional failure modes are considered. The stored beam energy will increase by another factor of two with respect to nominal and a factor of five more than experienced so far. The maximum beta function will increase. It is planned to install crab cavities in the LHC. With crab cavities, sudden voltage decays within 100 us after e.g. cavity quenches lead to large beam oscillations. Tracking simulations predict trajectory distortions of up to 1.5 σ in the first turn after a sudden drop of the deflecting voltage in a single cavity within 3 turns. The energy of several MJ stored in halo protons that could hit the collimator in case of such events is far above damage level, even if the collimator jaws are made of robust material. In this paper we discuss the challenges for machine protection in the HL-LHC era and possible mitigation strategies.
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TUPRO020	Integration of a Neutral Absorber for the LHC Point 8	luminosity, optics, dipole, injection	1052
	A. Santamaría García, R. Alemany-Fernández, H. Burkhardt, F. Cerutti, L.S. Esposito, N.V. Shetty CERN, Geneva, Switzerland
	The LHCb detector will be upgraded during the second long shutdown (LS2) of the LHC machine, in order to increase its statistical precision significantly. The upgraded LHCb foresees a peak luminosity of L = 1-2 . 10³³ cm^-2 s⁻¹, with a pileup of 5. This represents ten times more luminosity and five times more pile up than in the present LHC. With these conditions, the pp-collisions and beam losses will produce a non-negligeable beam-induced energy deposition in the interaction region. More precisely, studies have shown that the energy deposition will especially increase on the D2 recombination dipole, which could bring them close to their safety thresholds. To avoid this, the placement of a minimal neutral absorber has been proposed. This absorber will have the same role as the TAN in the high luminosity Interaction Regions (IR) 1 and 5. This study shows the possible dimensions and location of this absorber, and how it would reduce both the peak power density and total heat load.
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TUPRO022	Implementation of Luminosity Leveling by Betatron Function Adjustment at the LHC Interaction Points	luminosity, experiment, optics, betatron	1058
	J. Wenninger, A.A. Gorzawski CERN, Geneva, Switzerland
	Growing expectations for integrated luminosity during upcoming LHC runs introduce new challenges for LHC beam operation in the scope of online luminosity control. Because some LHC experiments are limited in the maximum event rates, their luminosity is leveled to a constant value. Various techniques may be used for luminosity leveling, changing the betatron function at the interaction point is one of them. This paper explains the main operational requirements of a betatron function leveling scheme for the upcoming LHC run. Issues concerning the beam optics, orbits and collimator settings are discussed. The proposed architecture for control system integration will be discussed. A few operational scenarios with different beam configurations foreseen for the next LHC run will be presented.
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TUPRO052	Study a ‘Sum’ Linear Coupling Resonance for J-PARC Main Ring: Observations and Simulations	resonance, injection, coupling, emittance	1147
	A.Y. Molodozhentsev, S. Igarashi KEK, Ibaraki, Japan Y. Sato, J. Takano J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	J-PARC Main Ring should deliver a high-power proton beam to neutrino experiments with limited particle losses. To meet this requirement low-order machine resonances have to be compensated. The linear coupling resonance Qx+Qy=43 has been identified as the potential source for significant particle losses at the collimator. The resonance compensation scheme has been studied experimentally by using a low intensity beam. To understand this process the simulations have been performed by using the PTC-ORBIT code. The Main Ring model has been developed to reproduce the machine operation including the initial stage of the acceleration. The 6D beam model has been defined to represent the ‘pencil’ beam used for this study. In frame of this report the single and multi particle dynamics will be discussed to understand the results of measurements, performed during RUN44 (November 2012). The results of the long-term tracking for this case will be presented. The obtained results can be used to benchmark the computer modeling the ‘sum’ linear coupling resonance with the experimental results.
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TUPRO062	Improvements in the Optics Measurement Resolution for the LHC	optics, simulation, collider, dipole	1177
	A. Langner, R. Tomás CERN, Geneva, Switzerland
	Optics measurement algorithms which are based on the measurement of beam position monitor (BPM) turn-by-turn data are currently being improved in preparation for the commissioning of the LHC at higher energy. The turn-by-turn data of one BPM may be used more than once, but the implied correlations were not considered in the final error bar. In this paper the error propagation including correlations is studied for the statistical part of the uncertainty. The confidence level of the measurement is investigated analytically and with simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO062
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TUPRO068	Commisioning of the 2.4T Multipole Wiggler and the 6.5T Superconducting Wavelength Shifter at the SIAM Photon Source	emittance, betatron, optics, storage-ring	1192
	P. Sudmuang, S. Klinkhieo, P. Klysubun, S. Kongtawong, S. Krainara, N. Suradet, A. Tong-on SLRI, Nakhon Ratchasima, Thailand
	A 2.4 T hybrid multipole wiggler (MPW) and a 6.5 T superconducting wavelength shifter (SWLS) have been successfully installed and commissioned at Siam Photon Source (SPS). The influence of the two insertion devices on the electron beam dynamic at different operating points have been studied in order to determine the optimal lattice configuration for operation. In this paper, the compensation of the linear optics will be presented, and the commissioning scheme will also be described. In addition, the investigation of the difference between the model and the actual observed machine parameters will be reported in details.
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TUPRO076	Initial Experimental Analysis into the eRHIC Polarized Electron Beam Transport System	dipole, cathode, electron, network	1217
	C. Yeckel, E. Dobrin, P. Holen, R.C. Miller, M. Stangenes, K.A. Thompson, L.W. Thompson Stangenes Industries, Palo Alto, California, USA I. Ben-Zvi, R.F. Lambiase, J. Skaritka, E. Wang BNL, Upton, Long Island, New York, USA
	Stangenes Industries is working closely with Brookhaven National Lab in the United States to develop the eRHIC future ion collider. The collider requires a polarized electron source with high average current, short bunch length and small emittance. An array of photocathodes with their beams funneled into a common trajectory is utilized to achieve the required beam current and cathode lifetime. Stangenes Industries is charged with delivering the prototype injector for preliminary beam studies that will lead to full implementation by 2020. This study focuses on the development of the of beam transport system extending from cathode to beam dump. A majority of the complexity involves the so called "combiner magnet" that acts as a high frequency-rotating dipole to bend each beam into the final common trajectory. Preliminary experiments into the feasibility of such a system are analyzed.
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TUPRO092	Magnetic-field Variable Permanent Dipole Magnet for Future Light Sources	permanent-magnet, dipole, simulation, emittance	1253
	T. Watanabe, K. Fukami, T. Nakanishi, S. Sasaki JASRI/SPring-8, Hyogo, Japan
	Permanent dipole magnets with variable magnetic field have been designed, fabricated, and tested at SPring-8. Permanent magnets can be advantageous over electromagnets in terms of reliability, stability and compactness in addition to the small power consumption. No unexpected down of an accelerator due to power supply failure is supposed to happen. There is no cooling water flow that can induce a fluctuation of the magnetic field. These features may become important for future light sources, where a very reliable, stable, and compact ring is required. In addition, the power consumption is now one of the most important issues after the 3.11 disaster in Japan. One of critical issues to realize such a magnet is that a magnetic field has to be tuned. In the future, combined-functioned and longitudinally gradient magnets will play a key role in achieving extremely small emittance. In such a case, changing a gap will not work any more. We have designed and fabricated a permanent dipole magnet of which magnetic field can be tuned without changing the gap. The results of the performance test will be presented and a possibility to apply it for future light sources will be discussed.
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TUPRO093	Numerical Study of Intrinsic Ripples in J-PARC Main-ring Magnets	simulation, damping, synchrotron, acceleration	1256
	Y. Shirakabe, A.Y. Molodozhentsev, M. Muto KEK, Tsukuba, Japan
	Beam ripples are one of the critical problems in high power proton synchrotrons. Magnet field ripples are considered as a main origin of the beam ripples among various possible sources. Although magnet power supply ripples are generally treated as the dominating ripple source, the load circuit parameters of the magnets and their interconnections are also playing critical roles in defining the ripple amplitudes and frequencies. In this viewpoint, the magnet power supplies are treated as simplified current sources, and the ripples generated in the circuit systems are investigated both in analytical and numerical ways. One of the findings in this direction of investigation is the existence of intrinsic ripples. The intrinsic ripples occur inevitably in the synchrotron magnets, no matter how the power supplies are producing idealistic current ramp patterns. Their amplitudes are defined by the circuit parameters such as inductance and capacitance, and the ramp parameters such as ramp rates. Some of the analytical mechanisms in generating the magnet field ripples are presented as well as the studied examples.
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TUPRO098	Design and Test of Dipole and Quadrupole Magnets for PAL-XFEL	dipole, quadrupole, multipole, FEL	1271
	H.S. Suh, M.-H. Cho, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park PAL, Pohang, Kyungbuk, Republic of Korea
	PAL-XFEL, currently under construction in Pohang, Korea, will consist of a 10 GeV linac, three hard X-ray branches and two soft X-ray branches. As the first phase of this project, one hard X-ray (HX1) and one soft X-ray (SX1) branches will be constructed. This facility requires 6 different families of dipole magnets, and 11 families of quadrupole magnets included steering functions. We are designing these magnets with the water cooling or the heat sink system now. In this presentation, we describe the modified design of the magnets for efficient manufacturing, and the magnetic and thermal analysis with the test results.
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TUPRO104	Design of the Beam Transfer Line Magnets for HIE-ISOLDE	dipole, quadrupole, linac, lattice	1289
	J. Bauche, A.V. Aloev CERN, Geneva, Switzerland
	This paper describes the design of the beam transfer line magnets of the HIE-ISOLDE facility. The technical solutions selected to face the challenges associated with the machine requirements are presented, and the final design parameters and field quality are reported.
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TUPRO106	Status of the ELENA Magnet System	quadrupole, dipole, simulation, antiproton	1295
	D. Schoerling CERN, Geneva, Switzerland
	ELENA, the Extra Low ENergy Antiproton ring, will be a CERN facility with the purpose to deliver antiprotons at lowest energies aiming to enhance the study of antimatter. It will be a hexagonal shaped ring with a circumference of about 30 m decelerating antiprotons from energies of 5.3 MeV to 100 keV. Due to the extra-low beam rigidity the design of the magnet system is especially challenging because even small fields, for example arising from residual magnetization and hysteresis, will have a major impact both on the beam trajectory and beam dynamics. In this paper the design approach for such an extra-low beam rigidity magnet system is presented. The main challenges are outlined and solutions for the design of the magnet system are discussed.
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TUPRO117	Magnet Design for the SNS Laser Stripping Experiment	laser, electron, ion, experiment	1328
	A.V. Aleksandrov, A.A. Menshov ORNL, Oak Ridge, Tennessee, USA
	Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation. The first step in the three-step laser assisted H⁻ beam stripping for charge exchange injection is to remove one electron in a strong magnetic field. In order to preserve the beam emittance for the subsequent laser induced stripping of the second electron the magnetic field has to have large gradient of about 40 T/m along the beam trajectory. The required magnetic field strength for stripping 1GeV H⁻ beam is 1.2 T in 29 mm aperture. In order to allow for undisturbed passage of high power beam during the nominal SNS operation the stripping magnet made of permanent magnet material resides in vacuum chamber and can move in and out of the beam line. This presentation describes requirements and design and the magnetic field calculation results for a stripping magnet for the Laser Stripping Experiment at SNS.
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TUPME009	A Sub-micron Resolution, Wide-band, Stripline BPM System for Driving Bunch-by-bunch Feed-back and Feed-forward Systems at ATF	feedback, kicker, cavity, extraction	1358
	G.B. Christian, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, M.R. Davis, Y.I. Kim, C. Perry JAI, Oxford, United Kingdom
	A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used as part of a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage RF down-mixer and a position resolution below 400 nm has been demonstrated for beam intensities of ~1 nC, with single-pass beam. The BPM position data are digitised by fast ADCs on an FPGA-based digital feedback controller, which is used to drive either a pair of kickers local to the BPMs and nominally orthogonal in phase, in closed-loop feedback mode, or a downstream kicker in the ATF2 final focus region, in feedforward mode. The beam jitter is measured downstream of the final focus system with high resolution, low-Q, cavity BPMs, and the relative performance of both systems in stabilising the beam is compared.
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TUPME013	Thermo-mechanical Tests for the CLIC Two-beam Module Study	alignment, vacuum, linac, experiment	1370
	A. Xydou, G. Riddone, A.L. Vamvakas CERN, Geneva, Switzerland E. Daskalaki NTUA, Athens, Greece
	The luminosity goal of CLIC requires micron level precision with respect to the alignment of the components on its two-meter long modules, composing the two main linacs. The power dissipated inside the module components introduces mechanical deformations affecting their alignment and therefore the resulting machine performance. Several two-beam prototype modules must be assembled to extensively measure their thermo-mechanical behavior under different operation modes. In parallel, the real environmental conditions present in the CLIC tunnel should be studied. The air conditioning and ventilation system providing specified air temperature and flow has been installed in the dedicated laboratory. The power dissipation occurring in the modules is being reproduced by the electrical heaters inserted inside the RF structure mock-ups and the quadrupoles. The efficiency of the cooling systems is being verified and the alignment of module components is monitored. The measurement results will be compared to finite element analysis model and propagated back to engineering design. Finally, simulation of the most possible CLIC machine cycles is accomplished and preliminary results are analysed.
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TUPME017	Design and Simulation of a Matching System into the Helical Cooling Channel	solenoid, emittance, collider, simulation	1382
	C.Y. Yoshikawa MuPlus, Inc., Newport News, Virginia, USA Y.I. Alexahin, D.V. Neuffer, K. Yonehara Fermilab, Batavia, Illinois, USA C.M. Ankenbrandt, R.P. Johnson, S.A. Kahn, F. Marhauser Muons, Inc, Illinois, USA Y.S. Derbenev, V.S. Morozov, A.V. Sy JLab, Newport News, Virginia, USA
	Funding: Work supported in part by DOE STTR grant DE-SC 0007634. Muon colliders could provide the most sensitive measurement of the Higgs mass and return the US back to the Energy Frontier. Central to the capabilities of muon colliders are the cooling channels that provide the extraordinary reduction in emittance required for the precise Higgs mass measurement and increased luminosity for enhanced discovery potential of an Energy Frontier Machine. The Helical Cooling Channel (HCC) is able to achieve such emittance reduction and matching sections within the HCC have been successfully designed in the past with lossless transmission and no emittance growth. However, matching into the HCC from a straight solenoid poses a challenge, since a large emittance beam must cross transition. We elucidate on the challenge and present evaluations of two solutions, along with concepts to integrate the operations of a Charge Separator and match into the HCC.
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TUPME028	Flat Bunches in the LHC	impedance, emittance, luminosity, synchrotron	1413
	E.N. Shaposhnikova, T. Argyropoulos, P. Baudrenghien, J. F. Esteban Müller, T. Mastoridis, G. Papotti, B. Salvant, H. Timko CERN, Geneva, Switzerland C.M. Bhat, A.V. Burov Fermilab, Batavia, Illinois, USA
	A high-harmonic RF system that could serve multiple purposes was proposed for the LHC. Possible applications of the second harmonic RF system include beam stabilisation in the longitudinal plane in the absence of wide-band longitudinal feedback and reduction of bunch peak line-density. Apart from other useful features, flat bunches are expected to produce less beam-induced heating at frequencies below 1 GHz, the frequency region critical for some LHC equipment. The latter, however, can also be achieved by de-populating the bunch centre. This was demonstrated during the dedicated machine development session in the LHC using RF phase modulation. In this paper the results of tests with single bunches and nominal LHC beams are presented and the possible use of this technique in LHC operation is discussed.
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TUPME045	Development of a High-Energy Short-pulse 5-μm Parametric Source for Dielectric Laser Acceleration	laser, acceleration, detector, optics	1460
	G. Xu, I. Jovanovic, S.F. Wandel Penn State University, University Park, Pennsylvania, USA
	A compact, high-peak-power 5-μm laser source with pulse duration of sub-100 fs has been designed and being constructed for pumping a dielectric photonic structure to produce an acceleration gradient of order GV/m in dielectric laser acceleration. Breakdown of dielectric structure induced by multiphoton ionization can be mitigated by adopting long wavelength driver laser. Since the dielectric structure scales with the laser wavelength, fabrication tolerances for dielectric structure are relaxed as well. The 5-μm laser source is based on two cascaded optical parametric amplifiers (OPA): a 2-μm BBO OPA with a mixed phase matching scheme is used as a pump source, and a type-I phase-matched ZGP OPA is designed to produce sub-mJ, <100 fs 5-μm laser pulses. The two-stage 2-μm OPA is pumped by a Ti:sapphire amplifier and produces pulse energy of ~2.2 mJ with a pulse duration of 42 fs (~6 optical cycles), and excellent pulse stability and beam quality. Preliminary result of ~50 μJ pulse energy at 5-μm is demonstrated by using single-stage ZGP OPA, and an improved two-stage OPA scheme for production of higher pulse energy at 5-μm is under development.
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TUPRI030	Beam Coupling Impedance of the New Beam Screen of the LHC Injection Kicker Magnets	impedance, coupling, kicker, injection	1627
	H.A. Day, M.J. Barnes, F. Caspers, E. Métral, B. Salvant, J.A. Uythoven CERN, Geneva, Switzerland
	The LHC injection kicker magnets experienced significant beam induced heating of the ferrite yoke, with high intensity beam circulating for many hours, during operation of the LHC in 2011 and 2012. The causes of this beam coupling impedance were studied in depth and an improved beam screen implemented to reduce the impedance. Results of measurements and simulations of the new beam screen design are presented in this paper: these are used to predict power loss and temperature of the ferrite yoke for operation after long shutdown 1 and for proposed HL-LHC operational parameters.

Paper

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MOYAA01

Innovative Ideas for Single-pass FELs

electron, FEL, undulator, photon

12

T. Hara
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

SASE FELs are a powerful light source in short wavelengths from VUV to X-ray regions to investigate matters and phenomena. SASE was first experimentally obtained in 2000 at DESY TTF with an output wavelength of 10⁹ nm. Subsequently, FLASH, LCLS and SACLA have achieved lasing in VUV, soft X-rays and hard X-rays. Although SASE has already been widely used for many application experiments in broad scientific fields, its spiky spectrum and time structures due to the lack of longitudinal coherence sometimes become problematic. To improve its longitudinal coherence, various ideas have been proposed and some of them are already demonstrated experimentally, such as a self-seeded scheme, high-gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG). There is also another direction of developments to enhance the capability and potentiality of SASE, for example short pulse generation and two-color lasing. This talk will review recent innovative ideas of short wavelength FELs together with their experimental results.

Slides MOYAA01 [10.701 MB]

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MOZA02

Advanced RF Design and Tuning Methods of RFQ for High Intensity Proton Linacs

rfq, linac, coupling, dipole

34

A. France
CEA/IRFU, Gif-sur-Yvette, France

The injector of high intensity linacs includes a Radio Frequency Quadrupole (RFQ) which must sustain high surface fields and thermal effects while accelerating intense low energy beams. For this purpose, the modelisation, realisation and tuning of accurate field laws is mandatory to preserve beam emittances and minimize beam losses. This presentation reviews the progress of advanced methods for the RF design, RF measurements during fabrication and final tuning of RFQ for high intensity linacs. It reports the ongoing developments on the injectors of high intensity demonstrators and of the linacs under construction such as SPIRAL2, LINAC4 or IFMIF-EVEDA.

Slides MOZA02 [2.026 MB]

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MOOCA01

High Power Test Results of the SPARC C-Band Accelerating Structures

controls, accelerating-gradient, klystron, vacuum

39

D. Alesini, M. Bellaveglia, M.E. Biagini, R. Boni, P. Chimenti, R. Clementi, G. Di Pirro, R. D. Di Raddo, M. Ferrario, A. Gallo, V.L. Lollo
INFN/LNF, Frascati (Roma), Italy
M. Brönnimann, R. Kalt, T. Schilcher
PSI, Villigen PSI, Switzerland
L. Ficcadenti
INFN-Roma, Roma, Italy
L. Palumbo
URLS, Rome, Italy

The energy upgrade of the SPARC photo-injector at LNF-INFN (Italy) from 150 to more than 240 MeV will be done by replacing a low gradient S-Band accelerating structure with two C-band structures. The structures are Traveling Wave (TW) and Constant Impedance (CI), have symmetric axial input couplers and have been optimized to work with a SLED RF input pulse. In the paper we present the results of the low and high power RF tests on the two final fabricated structures that shown the feasibility of the operation at accelerating gradients larger than 35 MV/m.

Slides MOOCA01 [6.242 MB]

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MOOCA02

RF Design and Operation of a Modular Cavity for Muon Ionization Cooling R&D

cavity, instrumentation, solenoid, vacuum

42

Y. Torun
IIT, Chicago, Illinois, USA
D.L. Bowring, M.A. Palmer, K. Yonehara
Fermilab, Batavia, Illinois, USA

Funding: Supported by the US Department of Energy Office of Science through the Muon Accelerator Program.
Ionization cooling channel designs call for the operation of high-gradient, normal-conducting RF cavities in multi-Tesla solenoidal magnetic fields. However, strong magnetic fields have been shown in some cases to limit the maximum achievable gradient in RF cavities. This gradient limit is characterized by RF breakdown and damage to the cavity surface. To study this issue, we have developed an experimental program at Fermilab's MuCool Test Area (MTA) based on a modular pillbox cavity operating at 805 MHz. The modular cavity design allows for the evaluation of different cavity geometries and materials – such as beryllium – which may ameliorate or circumvent RF breakdown triggers. We present a summary of recent results and plans for the future of the MTA normal conducting RF cavity program.

Slides MOOCA02 [32.552 MB]

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MOOCB02

A Common Operation Metrics for Third Generation Light Sources

experiment, feedback, survey, insertion

56

A. Lüdeke
PSI, Villigen PSI, Switzerland
M. Bieler
DESY, Hamburg, Germany
J.-F. Lamarre
SOLEIL, Gif-sur-Yvette, France
M. Pont
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

High reliability is a very important goal for third generation light sources. Very often the beam availability is used as the operation metrics to measure the reliability of the accelerator. A survey at several light sources revealed that the calculation of this statistics varies significantly between facilities. This prevents a useful comparison of their reliabilities. The authors propose a specific metrics for the reliability of third generation light sources; a metrics that will allow a detailed and meaningful comparison of these particle accelerators.

Slides MOOCB02 [0.701 MB]

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MOPRO002

The Momentum Distribution of the Decelerated Drive Beam in CLIC and in the Two-beam Test Stand at CTF3

emittance, simulation, distributed, controls

62

Ch. Borgmann, M. Jacewicz, J. Ögren, M. Olvegård, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden

We present analytical calculations of the momentum spectrum of the drive beam in CLIC and the CLIC Test Facility CTF3 after part of its kinetic energy is converted to microwaves for the acceleration of the main beam. The resulting expressions are used to determine parameters of the power conversion process in the Power Extraction Structure (PETS) installed in the Two-beam Test Stand in CTF3.

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MOPRO019

Energy Deposition and Quench Level Calculations for Millisecond and Steady-state Quench Tests of LHC Arc Quadrupoles at 4 TeV

simulation, proton, beam-losses, quadrupole

105

N.V. Shetty, B. Auchmann, V. Chetvertkova, A. Lechner, A. Priebe, M. Sapinski, A.P. Verweij, D. Wollmann
CERN, Geneva, Switzerland

In 2013, beam-induced quench tests with 4 TeV protons were performed to probe the quench level of LHC arc quadrupole magnets at timescales corresponding to millisecond beam losses and steady-state losses. As the energy deposition in magnet coils cannot be measured directly, this study presents corresponding FLUKA simulations as well as estimates of quench levels derived with the QP3 code. Furthermore, beam loss monitor (BLM) signals were simulated and benchmarked against the measurements. Simulated and measured BLM signals are generally found to agree within 30 percent.

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MOPRO021

Power Deposition in LHC Magnets With and Without Dispersion Suppressor Collimators Downstream of the Betatron Cleaning Insertion

proton, simulation, dipole, collimation

112

A. Lechner, B. Auchmann, R. Bruce, F. Cerutti, P.P. Granieri, A. Marsili, S. Redaelli, N.V. Shetty, E. Skordis, G.E. Steele, A.P. Verweij
CERN, Geneva, Switzerland

The power deposited in dispersion suppressor (DS) magnets downstream of the LHC betatron cleaning insertion is governed by off-momentum protons which predominantly originate from single-diffractive interactions in primary collimators. With higher beam energy and intensities anticipated in future operation, these clustered proton losses could possibly induce magnet quenches during periods of short beam lifetime. In this paper, we present FLUKA simulations for nominal 7 TeV operation, comparing the existing layout with alternative layouts where selected DS dipoles are substituted by pairs of shorter higher-field magnets and a collimator. Power densities predicted for different collimator settings are compared against present estimates of quench limits. Further, the expected reduction factor due to DS collimators is evaluated.

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MOPRO028

Measurements on Prototype Inductive Adders with Ultra-flat-top Output Pulses for CLIC DR Kickers

kicker, flattop, damping, high-voltage

128

J. Holma, M.J. Barnes
CERN, Geneva, Switzerland
C. Belver-Aguilar
IFIC, Valencia, Spain

The CLIC study is investigating the technical feasibility of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the DR extraction kickers call for a 160 ns duration flat-top pulses of ±12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications because this topology allows the use of both passive and analogue modulation methods to adjust the output waveform. Recently, two five-layer, 3.5 kV, prototype inductive adders have been built at CERN. The first of these has been used to test the passive and active analogue modulation methods to compensate voltage droop and ripple of the output pulses. Pulse waveforms have been recorded with ±0.05 % relative (±1.0 V) stability for 160 ns flat-top duration at 1.823 kV.

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MOPRO030

Changes to the LHC Beam Dumping System for LHC Run 2

dumping, kicker, controls, vacuum

134

J.A. Uythoven, M.G. Atanasov, J. Borburgh, E. Carlier, S. Gabourin, B. Goddard, N. Magnin, V. Senaj, N. Voumard, W.J.M. Weterings
CERN, Geneva, Switzerland

The LHC beam dumping system performed according to expectations during Run 1 of the LHC (2009 – 2013). A brief overview of the experience is given, including a summary of the observed performance in comparison to expectations. An important number of changes are applied to the beam dumping system during the present Long Shutdown on order to further improve its system safety and performance. They include the addition of a direct link between the Beam Interlock System and the re-triggering system of the dump kickers, the modification of the uninterrupted electrical power distribution architecture, the upgrade of the HV generators, the consolidation of the trigger synchronization system, the modifications to the triggering system of the power switches and the changes to the dump absorbers TCDQ.

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MOPRO031

Abort Gap Cleaning for LHC Run 2

luminosity, emittance, extraction, quadrupole

138

J.A. Uythoven, A. Boccardi, E. Bravin, B. Goddard, G.H. Hemelsoet, W. Höfle, D. Jacquet, V. Kain, S. Mazzoni, M. Meddahi, D. Valuch
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

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MOPRO044

Construction and Bench Testing of a Prototype Rotatable Collimator for the LHC

vacuum, impedance, collimation, controls

178

T.W. Markiewicz, E.L. Bong, L. Keller
SLAC, Menlo Park, California, USA
O. Aberle, A. Bertarelli, P. Gradassi, A. Marsili, S. Redaelli, A. Rossi, B. Salvachua, G. Valentino
CERN, Geneva, Switzerland

Funding: This work partially supported by the U.S. Department of Energy through the US LHC Accelerator Research Program (LARP) and contract DE-AC02-76SF00515.
A second generation prototype rotatable collimator has been fabricated at SLAC and delivered to CERN for further vacuum, metrology, function and impedance tests. The design features two cylindrical Glidcop jaws designed to each absorb 12kW of beam in steady state and up to 60kW in transitory beam loss with no damage and minimal thermal distortion. The design is motivated by the use of a radiation resistant high Z low impedance readily available material. A vacuum rotation mechanism using the standard LHC collimation jaw positioning motor system allows each jaw to be rotated to present a new 2cm high surface to the beam if the jaw surface were to be damaged by multiple full intensity beam bunch impacts in a asynchronous beam abort. Design modifications to improve on the first generation prototype, pre-delivery functional tests performed at SLAC and post-delivery test results at CERN are presented.

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MOPRO050

Status of the ASTRID2 Synchrotron Light Source

controls, wiggler, insertion, insertion-device

197

J.S. Nielsen, N. Hertel, S.P. Møller
ISA, Aarhus, Denmark

With regular user beam delivered to experiments, the commissioning of the ASTRID2 synchrotron light source is now mostly completed. The ring is running stable in top-up mode for beam currents up to 90 mA, with a lifetime of ~0.8 h at 90 mA. The orbit is controlled by a 10 Hz feedback loop, which includes feed forward loops when the insertion devices change gap. A similar 10 Hz loop compensates tune and beta function changes from the insertion devices. Some issues are still remaining. These include installation of a Landau cavity for lifetime improvements, a reduction in the heating of the in-vacuum ferrites of the injection bumpers, and a shielding of the stray magnetic field from the booster dipoles.

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MOPRO051

SOLEIL Operation and On-going Projects

injection, storage-ring, vacuum, photon

200

L.S. Nadolski, C. Benabderrahmane, P. Betinelli-Deck, F. Bouvet, P. Brunelle, A. Buteau, L. Cassinari, M.-E. Couprie, X. Delétoille, C. Herbeaux, N. Hubert, M. Labat, J.-F. Lamarre, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, J.L. Marlats, A. Nadji, R. Nagaoka, P. Prigent, J.P. Ricaud, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

The 2.75 GeV synchrotron light source SOLEIL delivers photons to 27 beamlines; 2 new ones are under construction together with the FEMTOSLICING project of which commissioning started in January 2014. Five filling patterns are available for the users in Top-up injection mode. The storage ring is running with an upgraded optics less sensitive to insertion device (ID) configurations and giving both better beam lifetime and injection efficiency. The beam position stability remains excellent with a focus on electron vertical beam-size stability for the new very long beamlines. A gating system during Top-up injection improves significantly the quality of the spectrum on an infrared beamline. Several heavy actions of maintenance and upgrades on crucial subsystem equipment are underway. Others accelerator projects are going on such as the design and construction of new IDs, new Multipole Injection Kicker, radiation damage studies as well as R&D on solid-state amplifiers.

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MOPRO059

Fluka Calculations of Gamma Spectra at BESSY

injection, radiation, synchrotron, vacuum

219

K. Ott, Y. Bergmann
HZB, Berlin, Germany

Funding: Funded by the Bundesministerium für Bildung und Forschung and by the Land Berlin
Since 22nd October 2012 BESSY is operated in top-up mode. Losses of electrons during injection cause an electromagnetic cascade, that consists of high energetic photons of the bremsstrahlung, and secondary electrons and positrons from the pair creations. The bremsstrahlung spectrum has a maximum at 1.022 MeV owing to pair creations. The spectrum has a high energetic tail, that reaches up to the electron energy of 1.7 GeV at BESSY. The low energy part of the electromagnetic cascade is produced by compton scattering or the photo - effect. Due to the opened beamshutters during top-up injections, the low energetic part of the bremsstrahlung spectrum can reach the experimental hall. We used the particle interaction and transport code FLUKA for the calculations of both the fluence and the dose distribution. We calculated the gamma spectra of the radiation through the shielding walls and through the front-ends. We discuss the question whether additional safety measures are necessary for top-up operation due to the low energy part of the spectrum. From our calculations we determined the correction factors for our ionisation chambers of the ambient dose measurement system.

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MOPRO063

Studies of Bursting CSR in Multi-bunch Operation at the ANKA Storage Ring

radiation, storage-ring, synchrotron, detector

225

V. Judin, M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schuh, N.J. Smale, J.L. Steinmann, M. Weber
KIT, Karlsruhe, Germany

The ANKA storage ring can generate brilliant coherent synchrotron radiation (CSR) in the THz range due to a dedi- cated low-αc -optics with reduced bunch lengths. At higher electron currents the radiation is not stable, but occurs in powerful bursts caused by micro-bunching instabilities. This intense THz radiation is very attractive for users. However, the reproducibility of the experimental conditions is very low due to those power fluctuations. Systematic studies of bursting CSR in multi-bunch operation were performed with fast THz detectors at ANKA using a dedicated, ultra-fast DAQ-FPGA board. The technique and preliminary results of these studies are presented in this paper.

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MOPRO068

Fluctuation of Bunch Length in Bursting CSR: Measurement and Simulation

simulation, synchrotron, storage-ring, optics

237

P. Schönfeldt, A. Borysenko, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, S. Naknaimueang, M. Schuh, M. Schwarz, J.L. Steinmann
KIT, Karlsruhe, Germany

The ANKA electron storage ring of the Karlsruher Institute of Technology (KIT, Germany) is regularly operated in low-alpha mode to produce short bunches for the generation of coherent synchrotron radiation (CSR). This paper evaluates systematic bunch length measurements taken in low-alpha operation of the ANKA storage ring. Above the bursting threshold not only the emission of CSR occurs in bursts, but also a continuous fluctuation of the bunch's length is observed. The measurements were carried out using concurrent multi turn (using a streak camera) as well as single shot (using electro-optical spectral decoding) methods. Furthermore, we compare information obtained on the fluctuation to simulations.

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MOPRO070

Study on Ground Vibration Characteristics of Iranian Light Source Facility

site, ground-motion, synchrotron, data-analysis

243

A. Iraji, B. Kamkari, J. Rahighi, M. Rahimi, N. Ranjbar, F. Saeidi
ILSF, Tehran, Iran

In this study the results of ground vibration measurement for the site of Iranian Light Source Facility (ILSF) has been investigated. Light source buildings are very sensitive to the ground weak motions. Sources for the ground vibrations could be Cultural noise from human activities like traffic and industrial works. In order to satisfy requirements for level of the ground vibrations, a perfect ground vibration survey has been conducted and compared with other same projects. Two broad-band seismometers were utilized for surveying the ground vibration at ILSF site. The raw data were pre-processed as well as analyzed in term of seismology and engineering aspects. Spectrum amplitudes along with powers of the vibration amplitudes were calculated at the time domain. The power spectral density of vibration displacements were extracted from the measurements and were compared with results of other synchrotron projects. The results show that the dedicated site for ILSF is in the appropriate condition in the point view of ground vibration issues.

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MOPRO076

Elettra Status and Upgrades

controls, coupling, dipole, emittance

261

E. Karantzoulis, A. Carniel, S. Krecic
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the latest studies and upgrades.

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MOPRO080

Fast Beam Orbit Monitoring System during Beam Abort at SPring-8 Storage Ring

closed-orbit, storage-ring, betatron, electronics

274

T. Fujita, T. Masuda, S. Sasaki
JASRI/SPring-8, Hyogo-ken, Japan
H. Sumitomo
SES, Hyogo-pref., Japan

SPring-8 is a 3rd generation light source which has been operated stably. During user operation, an interlock system which turns off the RF acceleration signal if the beam orbit at insertion devices exceed a window is in operation. Beam abort events due to the interlock system have occurred as a rare event at SPring-8. Though in most cases we find trouble in accelerator devices as the source of the beam orbit shift, sometimes we cannot find any evidence after the beam abort. In order to identify the sources of such aborts, we have developed a system which observe beam orbit along the storage ring during beam abort. The system was realized by modification of the digital part of the existing COD measurement system. Every 1 ms, the system measures beam position at all BPMs with the position resolution of 1 micron or less. This system enabled us to identify the source when a beam abort due to an orbit shift with a time constant of longer than a few milliseconds. Furthermore, this system is applicable to survey sources of beam orbit fluctuations during stable operation. In this proceeding, we describe the system, beam orbit data during beam abort and source analysis.

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MOPRO082

Suppression of Stored Beam Oscillation at Injection by Fast Kicker in the SPring-8 Storage Ring

kicker, timing, injection, storage-ring

280

C. Mitsuda, K. Fukami, K. Kobayashi, M. Masaki, H. Ohkuma, S. Sasaki, K. Soutome
JASRI/SPring-8, Hyogo-ken, Japan
T. Nakanishi
SES, Hyogo-pref., Japan

When the injection bump orbit is not closed perfectly at the beam injection, the horizontal stored beam oscillation is excited. In the SPring-8 storage ring, many efforts had been paid to reduce the beam oscillation by adjusting the temporal shape and timing of four bump magnets and by applying a counter kick to the residual oscillation, whose amplitude is as large as 0.4mm and the width is as narrow as 500ns. Now, the averaged oscillation amplitude has successfully been suppressed to the level of less than 0.1mm. To confirm the suppression effect, we observed the turn-by-turn photon beam profile at the diagnostics beamline with the insertion device. We confirmed that the light axis oscillation was significantly suppressed by a factor of 5 comparing by applying a counter kick. We also found that the oscillation shape and the oscillation amplitude, which were caused by the timing shift of firing bump magnets, are drastically changed by only timing shift of one magnet. We are considering the feedback scheme to keep the suppression effect at the initial level during the user-time.

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MOPRO084

Recent Development and Operational Status of PF-Ring and PF-AR

undulator, vacuum, injection, photon

286

T. Honda, M. Adachi, S. Asaoka, K. Haga, K. Harada, Y. Honda, M. Izawa, T. Kageyama, Y. Kamiya, Y. Kobayashi, K. Marutsuka, T. Miyajima, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, M. Ono, T. Ozaki, H. Sagehashi, H. Sakai, S. Sakanaka, H. Sasaki, Y. Sato, M. Shimada, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Ma. Yoshida, S.I. Yoshimoto
KEK, Ibaraki, Japan

Update of the first-generation undulators installed in 1980s is pushed forward at PF-Ring, a 2.5-GeV SR source of KEK, taking advantage of the expanded straight sections reconstructed in 2005. New undulators have been designed as elliptically polarizing undulators each has 6 magnetic arrays to obtain various polarization states, not only circular polarization but also linear (horizontal and vertical) polarization. Three undulators will be installed in FY2013 and FY2014 for BL02, BL13 and BL28. For BL02, the longest straight section of about 9 m, the new undulator will be installed in tandem with the existing planar undulator, in order to cover the wide photon energy range from 15 eV to 2 keV. At PF-AR, a 6.5-GeV SR source, a new direct beam transport (BT) line from the injector LINAC is under construction. Super KEKB which shares the injector LINAC with PF-Ring and PF-AR will be commissioned at the end of FY2014. The full-energy continuous injection of PF-AR will be available as a simultaneous injection with the 7-GeV HER, the 4-GeV LER and PF-Ring not so later than the commissioning of Super KEKB.

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MOPRO087

High Voltage Generators Upgrade of Siberia-2 Injection System

kicker, injection, high-voltage, power-supply

292

S.I. Tomin, A. Belkov, V. Korchuganov, I. Kuzmin, K. Kuznetsov
NRC, Moscow, Russia

The injection system is one of the important systems which determine efficiency and reliability of the accelerator facility. The spark gap switches (SGS), which were used before at Siberia-2 in high voltage nanosecond pulse generators, are the critical components requiring permanent maintenance. SGS has a series of limitations such as a relatively large pulse jitter and a work at a high pressure nitrogen atmosphere. The new injection system uses new half-sine microsecond pulse generators which based on Pseudo-Spark Switches. Some technical aspects of the new injection system are considered and results of generators operation are shown in the article.

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MOPRO089

Towards a Low Alpha Lattice for the ALBA Storage Ring

lattice, quadrupole, sextupole, storage-ring

298

M. Carlà, G. Benedetti, Z. Martí, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

Funding: CELLS-ALBA
A proposal of a low alpha lattice for the ALBA third generation light source is presented. Opposed to most of other machines, belonging to the same category, ALBA employs an optimized lattice making use of combined function dipoles. This has permitted a very compact design stripped out of all not strictly necessary quadrupoles resulting in a lack of flexibility. For such a reason the common approaches used in many other synchrotrons can not be directly applied to ALBA and a different strategy has to worked out.

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MOPRO090

Top-up Operation at ALBA Synchrotron Light Source

injection, radiation, storage-ring, simulation

301

M. Pont, G. Benedetti, J. Moldes, R. Muñoz Horta, A. Olmos, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA light source has been operating in decay mode since May 2012. Now it is ready for top-up operation, which should become the standard operation mode for users from mid 2014. In this paper we are going to summarise the different steps that have taken place before the start of top-up operation: radiation safety simulations and measurements, upgrade of hardware and software interlocks, control software and injection optimisation.

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MOPRO116

Mechanical Engineering and Design of Novel Collimators for HL-LHC

impedance, proton, experiment, collimation

369

F. Carra, A. Bertarelli, A. Dallocchio, L. Gentini, P. Gradassi, A. Manousos, N. Mariani, G. Maîtrejean, N. Mounet, E. Quaranta, S. Redaelli, V. Vlachoudis
CERN, Geneva, Switzerland

In view of LHC intensity upgrades, collimator materials may become a limit to the machine performance: the high RF impedance of Carbon-Carbon composites can lead to beam instabilities, while the Tungsten alloy adopted in tertiary collimators exhibits low robustness in case of beam-induced accidents. An R&D program has been pursued to develop new materials overcoming such limitations. Molybdenum-Graphite, in addition to its outstanding thermal conductivity, can be coated with pure molybdenum, reducing collimator impedance by a factor of 10. A new secondary collimator is being designed around this novel composite. New high-melting materials are also proposed to improve the robustness of tertiary collimators. All the new collimators will be equipped with BPMs, significantly enhancing the alignment speed and the beta-star reach. This implies additional constraints of space, as well as detailed static and fatigue calculations on cables and connectors. This paper describes the mechanical design and the engineering calculations of such future collimators, focusing on the study via state-of-the-art numerical methods of interactions between the particle beams and the new materials adopted.

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MOPME011

Matrix Integration of ODEs for Spin-orbit Dynamics Simulation

simulation, lattice, quadrupole, resonance

400

A.N. Ivanov, Y. Senichev
FZJ, Jülich, Germany

MODE (Matrix integration of Ordinary Differential Equations) is a software package that provides nonlinear matrix maps building for spin-orbit beam dynamics simulation. In this article we briefly describe the developed integrated development environment features and present computational comparison with other simulation tools. MODE mathematical model is based on Newton-Lorentz and T-BMT equations that are expanded to Taylor series up to the necessary order of nonlinearity. The numerical algorithm is based on matrix presentation of Lie propagator. Spin-orbit simulation results of MODE are compared with results of COSY Infinity and OptiM. MODE provides a flexible graphic user interface, code auto complete technology and visual designer for accelerators. There is also a possibility to generate codes in different programming languages and parallelization techniques.

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MOPME022

Investigation of the Breakdown and RF Sheath Potential for EAST ICRF Antenna

plasma, ion, experiment, simulation

424

H. Yang, S. Dong, L. Shang, K. Tang, C.-F. Wu
USTC/NSRL, Hefei, Anhui, People's Republic of China

A new ion cyclotron range of frequency (ICRF) antenna was designed with four current straps in Experimental Advanced Superconducting Tokamak (EAST). It is to provide heating, current drive and some physics experiments in EAST. The breakdown and RF sheath potential for the antenna are investigated by a three dimension electromagnetic code in the paper. The plasma is simulated by a slab with high relative permittivity approximating the plasma loading of the antenna. Calculations show that the maximum of electric field is around the end of the coaxial feeds and the strip line and the electric field is strongly dependent on antenna phasing. Especially the maximum of electric field is decreased to 27.5 KV/cm with the (0,π,π,0) phasing between toroidal straps while the value is 32.8 KV/cm with (0,0,π,π) phasing. A challenge in ICRF is the impurity contamination which is related to sheath potential. The topology of the radio frequency (RF) sheath is optimized to reduce the potential for EAST ICRF antenna. The RF potential is mitigated obviously with the broader side limiter by a factor of 2.

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MOPME025

New Possibilities of MultP-M Code

simulation, multipactoring, electron, RF-structure

433

M. Gusarova, S. Khudyakov, I.I. Petrushina, Ya.V. Shashkov
MEPhI, Moscow, Russia

Implementation and Testing of the new module package for geometry import of the MultP-M 3D code for multipacting prediction was performed. The results of simulations for the coaxial line specimen using this new module are presented. These results are compared with analytical calculations and experimental data.

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MOPME035

Current Status of the GPU-Accelerated ELEGANT

GPU, simulation, acceleration, linac

454

I.V. Pogorelov, K.M. Amyx, J.R. King
Tech-X, Boulder, Colorado, USA
M. Borland, R. Soliday
ANL, Argonne, Ilinois, USA

Funding: Work supported by the DOE Office of Science, Office of Basic Energy Sciences grant No. DE-SC0004585, and in part by Tech-X Corporation.
Efficient implementation of general-purpose particle tracking on GPUs can result in significant performance benefits to large-scale tracking simulations. This presentation is an update on the current status of our work on accelerating Argonne National Lab’s particle accelerator simulation code ELEGANT using CUDA-enabled GPU. We summarize the performance of beamline elements ported to GPU, and discuss optimization techniques for some important collective effects kernels, in particular our methods of avoiding costly thread contention. We also present preliminary results of a scaling study of the GPU-accelerated version of the code.

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MOPME046

Supervision Software for the Integration of the Beam Interlock System with the CERN Accelerator Complex

software, monitoring, hardware, linac

476

M. Audrain, D. Anderson, M. Dragu, K. Fuchsberger, J.C. Garnier, A.A. Gorzawski, M. Koza, K.H. Krol, A. Moscatelli, B. Puccio, K. Stamos, M. Zerlauth
CERN, Geneva, Switzerland

The Accelerator complex at the European Organisation for Nuclear Research (CERN) is composed of many systems which are required to function in a valid state to ensure safe beam operation. One key component of machine protection, the Beam Interlock System (BIS), was designed to interface critical systems around the accelerator chain, provide fast and reliable transmission of beam dump requests and trigger beam extraction in case of malfunctioning of equipment systems or beam losses. Numerous upgrades of accelerator and controls components during the Long Shutdown 1 (LS1) are followed by subsequent software updates that need to be thoroughly validated before the restart of beam operation in 2015. In parallel, the ongoing deployments of the BIS hardware in the PS booster (PSB) and the future LINAC4 give rise to new requirements for the related controls and monitoring software due to their fast cycle times. This paper describes the current status and ongoing work as well as the long-term vision for the integration of the Beam Interlock System software into the operational environment.

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MOPME048

CLIC Decelerator - Machine Protection

emittance, quadrupole, alignment, collider

482

L.M. Hein, J. Esberg, M. Jonker
CERN, Geneva, Switzerland

The Compact Linear Collider CLIC is based on a four beam scheme, two colliding beams (main beams) and two drive beams, which are used to accelerate the main beams. The intended drive beam parameters exceed the "safe beam" threshold by a factor of 100. Hence, in case of a beam impact serious structural damages of the accelerator equipment are expected. In order to avoid structural damages caused by the drive beam detailed studies of its beam dynamics are on-going. In this paper the major characteristics of the drive-beam beam-dynamics and preliminary machine protection results are summarised.

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MOPME054

Upgrade of the Elettra Magnet Power Supply Controllers

controls, interface, power-supply, electronics

495

S. Cleva, M. Cautero, T.M. Cieśla, M. Lonza, L. Pivetta, C. Scafuri, R. Visintini
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Ageing of devices and components phasing-out, as well as the increasing maintenance costs, affect particle accelerators similarly to any industrial plant. A careful maintenance plan can cope with these problems in the medium-term, but then a complete update of the oldest parts is required. The most recent technologies available on the market together with a modular and open design approach are the basis of an upgrade program aimed at replacing the existing controllers of the Elettra storage ring magnet power supplies. The design considerations, the constraints and the first results are reported.

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MOPME059

Design of a Multi-harmonic Buncher for LINCE

ion, rfq, bunching, linac

508

J. Labrador, C. Bonțoiu, J.A. Dueñas, I. Martel
University of Huelva, Huelva, Spain
M.A. Carrera, A. Garbayo
AVS, Elgoibar, Spain
A.C.C. Villari
FRIB, East Lansing, Michigan, USA

Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA.
Continuous beams delivered by the LINCE ECR ion source will be bunched by a multi-harmonic buncher consisting of two copper-made electrodes. Its numerical design is reported here along with electric and magnetic field maps. Multi-frequency operation is proven by tracking a continuous beam and optimizing the its longitudinal phase space bunching for various ion species under the influence of space charge effects. A thermo-mechanical study carried out in order to estimate the needed water flow through the electrodes is presented as well.

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MOPME061

Design of a Three Legs and Phase Shift AC to DC Converter for Taiwan Photon Light Source

controls, feedback, power-supply, electronics

511

Y.S. Wong, K.-B. Liu
NSRRC, Hsinchu, Taiwan
J.F. Chen, W.C. Hsu, W.C. Hung, P.H. Tseng
NCKU, Tainan city, Taiwan

A novel low voltage high current AC/DC converter will be achieved which input is utility power supplies a low voltage DC output to load. The new three legs phase shift AC / DC power supply, can divided to five parts : diode full bridge rectifier, three legs phase shift control circuits, transformers, double inductor circuit and feedback circuit. Circuit operates as a single-phase 110 Vrms AC mains power input three legs phase shift control mode from the diode bridge rectifier circuit, the output voltage through the transformer and the phase shift control method converts to low voltage DC 12V output and supplies to loading, feedback circuit are using a feedback resistor across the filter capacitor voltage to product a feedback signal. Digital signal processing (DSP) control board by a feedback voltage determines the three legs phase shift displacement in order to control the output voltage keep a constant value 12V. For this circuit have a zero voltage switching characteristics of the three legs phase shift mode power supply, the input voltage for single phase 110Vac and output load power is 12V/20A.

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MOPME066

Development of 400 kA Pulsed Power Supply for Magnetic Horn at FAIR Antiproton Target

antiproton, radiation, power-supply, coupling

517

S.S. Mohite, R. Hettinger, K. Knie, I.J. Petzenhauser
GSI, Darmstadt, Germany

This report presents an overview of the magnetic horn and its pulsed power system at the upcoming FAIR (Facility for Antiproton and Ion Research) complex at GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. In the planned antiproton (pbar) separator scheme a magnetic horn will be used as a device for collection and focusing of highly divergent antiprotons emerging from the target with energies around 3 GeV and within a cone of about 80 mrad .To achieve the desired focusing effect, the horn needs to be powered with a current pulse of 400 kA peak amplitude at the same repetition rate as the primary proton beam, i.e. 0.1 Hz. In future, operation up to 0.2 Hz is planned without major design alterations. Due to civil construction and radiation protection limitations, possible technical realization of this system has some key design issues. The aim is to develop a reliable and efficient magnetic horn system for effective focusing of antiprotons by producing a very strong pulsed magnetic field.

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MOPME069

Upgrade of the Injection Kicker System for J-PARC Main Ring

injection, kicker, timing, feedback

526

T. Sugimoto, K. Fan, K. Ishii, H. Matsumoto
KEK, Ibaraki, Japan

Four lumped inductance injection kicker magnets for the J-PARC main ring (MR) produce a kick of 0.1096 T·m with a 1% to 99% rise-time of about 400 nsec. A residual field of about 6% of the flat-top exists at the tail of the pulse due to an impedance mismatching. The residual field is required to be suppressed less than 1% to reduce injection losses. For a higher intensity beam operation, the kicker rise-time of less than 300nsec is required to inject longer beam bunches which reduces a space charge effect. During the long shutdown in FY2013, 140Ω resistor and 7nF capacitor were connected to the thyratron to improve the post-pulse shape. In addition, an optimization of a capacitance in the matching circuit was carried out to optimize the waveform. As the result, the rise-time of 195nsec and the residual tail field of 2% were achieved. However, another reflection peak of about 9% is appeared. We plan to compensate the effect of the new peak by using a new small kicker magnet. This paper discusses the detail of the circuit and the beam test results.

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MOPME074

High Voltage Performance of the Beam Screen of the LHC Injection Kicker Magnets

injection, kicker, vacuum, impedance

541

M.J. Barnes, P. Adraktas, G. Bregliozzi, S. Calatroni, P. Costa Pinto, H.A. Day, L. Ducimetière, V. Gomes Namora, T. Kramer, V. Mertens, M. Taborelli
CERN, Geneva, Switzerland

The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wakefields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. The design of the beam screen has been upgraded to overcome limitations and permit LHC operation with increasingly higher bunch intensity and short bunch lengths: the new design also significantly reduces the electric field associated with the screen conductors, decreasing the probability of electrical breakdown. The high voltage conditioning process for the upgraded kicker magnets is presented and discussed. In addition a test setup has been utilized to study flashover, on the inner wall of the ceramic tube, as a function of both applied voltage and vacuum pressure: results from the test setup are presented.

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MOPME075

Cooling of the LHC Injection Kicker Magnet Ferrite Yoke: Measurements and Future Proposals

vacuum, kicker, injection, simulation

544

M.J. Barnes, S. Bouleghlimat, L. Ducimetière, M. Garlaschè, V. Gomes Namora, T. Kramer, R. Noulibos, Y. Sillanoli, Z.K. Sobiech, W.J.M. Weterings
CERN, Geneva, Switzerland

LHC operation with high intensity beam, stable for many hours, resulted in significant heating of the ferrite yoke of the LHC Injection Kicker Magnets. For one kicker magnet the ferrite yoke approached its Curie temperature. As a result of a long thermal time-constant the yoke can require several hours to cool sufficiently to allow re-injection of beam, thus limiting the running efficiency of the LHC. The beam screen, which screens the ferrite yoke from wakefields, has been upgraded to limit ferrite heating. In addition it is important to improve the cooling of the ferrite yoke: one method is to increase the internal emissivity of the cylindrical vacuum tank, in which the kicker magnet is installed. This paper describes a method developed for measuring the emissivity of the inside of the tanks, which has been benchmarked against measurements of the ferrite yoke temperature during heat treatment in an oven and transient thermal simulations. Conclusions are drawn regarding an ion bombardment technique evaluated for improving emissivity without degrading vacuum properties. In addition initial concepts for improved cooling are presented.

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MOPME082

ILC-Class Marx Modulator at KEK

controls, high-voltage, damping, flattop

562

M.P.J. Gaudreau, N. Silverman, B.E. Simpson
Diversified Technologies, Inc., Bedford, Massachusetts, USA
J.A. Casey
Rockfield Research Inc., Las Vegas, Nevada, USA

Funding: US Department of Energy, Award DE-FG02-05ER84352 KEK, High Energy Accelerator Research Organization
In October 2013, Diversified Technologies, Inc. (DTI) successfully installed and began operation of a 120 kV, 120 A, 1.7 ms Marx modulator for the High Energy Accelerator Research Organization (KEK) in Japan. Originally conceived, and built under a DOE SBIR grant to support SLAC (completed in 2010), the Marx bank modulator demonstrates a new technology for compact and economic ILC-class performance; the design meets the performance requirements for ILC, does so in a more compact form factor than other known technologies, and, we believe, will be more economic than other technologies. The basic concept of a Marx modulator is that it charges an array of capacitors in parallel (low voltage), then erects them in series to form a high-voltage discharge. Using DTI’s solid-state switches (instead of traditional spark gaps or SCRs) to construct a Marx modulator enables it to open and close; thus the capacitors serve as storage capacitors rather than fully exhausting during each pulse. The opening capability of the DTI switches also provides for arc protection of the load, exactly as they would in a hard-switch. Such a system requires no crowbar protection to protect the load against arcs.

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MOPRI004

SuperKEKB Positron Source Construction Status

positron, electron, target, solenoid

579

T. Kamitani, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, Y. Funakoshi, K. Furukawa, T. Higo, H. Honma, N. Iida, M. Ikeda, E. Kadokura, H. Kaji, K. Kakihara, H. Katagiri, M. Kikuchi, H. Koiso, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, Y. Ohnishi, S. Ohsawa, M. Sato, T. Shidara, A. Shirakawa, M. Suetake, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, M. Tawada, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

The KEKB positron source is under the upgrade for SuperKEKB. The previous positron production target and capture section have been removed and the new system is constructed at a location forty meters upstream to have sufficient energy margin for beam injection to the newly introduced damping ring. A flux concentrator is introduced in the new capture section to make an adiabatic matching system. Large aperture (30mm in diameter) S-band accelerating structures are introduced in the capture section and in the subsequent accelerator module to enlarge the transverse phase space acceptance. The beam focusing system of quadrupoles is also upgraded for a comparable beam acceptance to that of the capture section. This paper reports on the status of the SuperKEKB positron source construction and the preliminary positron beam commissioning.

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MOPRI017

Status of AREAL RF Photogun Test Facility

gun, electron, laser, emittance

620

B. Grigoryan, G.A. Amatuni, V.S. Avagyan, H. Avdishyan, H. Davtyan, A.A. Gevorgyan, L.H. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, A. Lorsabyan, M. Manukyan, I.N. Margaryan, N. Martirosyan, T.H. Mkrtchyan, S. Naghdalyan, V.H. Petrosyan, H. Poladyan, V. Sahakyan, A. Sargsyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, V. V. Vardanyan, G.S. Zanyan
CANDLE SRI, Yerevan, Armenia
T.K. Sargsyan
LT-PYRKAL cjsc, Yerevan, Armenia

Advanced Research Electron Accelerator Laboratory (AREAL) is a 20 MeV laser driven RF linear accelerator which is being constructed in the CANDLE institute. The construction of phase-1 is finished and at present the machine commissioning is in progress. In phase-1 a photocathode RF gun provides a 5 MeV small emittance electron beam with the 100 pC bunch charge and variable electron bunch length from 0.5 to 8 ps. Two main operation modes are foreseen for this phase – single and multibunch regimes to satisfy experimental demands. We report the status of linac, first experience and nearest machine run schedule. The brief review of the facility, main parameters, performance and first results are presented.

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MOPRI021

Laser Systems Generating Short Polarized Electron Bunches at the S-DALINAC

laser, electron, experiment, cathode

633

M. Espig, J. Enders, Y. Fritzsche, A. Kaiser, M. Wagner
TU Darmstadt, Darmstadt, Germany

Funding: Supported by DFG within CRC634 and by the state of Hesse through the LOEWE center HIC for FAIR.
The source of polarized electrons at the superconducting Darmstadt electron linear accelerator S-DALINAC uses photo-emission from strained-layer superlattice-GaAs and bulk-GaAs photocathodes. This system is driven by either 3 GHz gain-switched diode lasers or a short-pulse Ti:Sapphire laser system. Highly polarized electrons are generated with laser light at 780 nm, while blue laser light is used for unpolarized high-current experiments. We present the existing pulsed laser systems and the planned developments for the diode laser system, including, e.g., impedance matching of the diode lasers, gain switching with short electrical pulses and pulsing with a Mach-Zehnder modulator. The pulsed operation is aimed at generating short electron bunches (< 50 ps) at the S-DALINAC with variable repetition rates from some MHz to 3 GHz.

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MOPRI027

Dark Current Studies at Relativistic Electron Gun for Atomic Exploration – REGAE

electron, gun, cavity, vacuum

649

H. Delsim-Hashemi, K. Flöttmann
DESY, Hamburg, Germany

Electron diffraction is a tool for exploring structural dynamics of matter. The scattering cross section is orders of magnitude higher for electrons than for X-rays so that only a small number of electrons is required to achieve comparable results. However, the required electron beam quality is extraordinary. To study e. g. proteins a coherence length of 30 nm is required which translates into a transverse emittance of 5 nm at a spot size of 0.4mm. In addition short bunch lengths down to 10 fs and a temporal stability of the same order are required in order to study chemical reactions or phase transitions in pump probe type experiments. These are challenging parameters for an electron source, which demand improvements at many frontiers. Dark current degrades contrast of diffraction patterns in all experiments. Understanding dark-current generation and propagation can lead to better methods to decrease it. In this paper dark current studies that are performed at REGAE will be presented.

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MOPRI042

Recent Developments at the High-charge PHIN Photoinjector and the CERN Photoemission Laboratory

laser, cathode, vacuum, feedback

695

C. Heßler, E. Chevallay, S. Döbert, V. Fedosseev, I. Martini, M. Martyanov, A. Perillo Marcone, Sz. Sroka
CERN, Geneva, Switzerland

The high-charge PHIN photoinjector has originally been developed to study the feasibility of a photoinjector option for the drive beam of the CLIC Test Facility 3 (CTF3) at CERN and is now being used to investigate the feasibility of a drive beam photoinjector for CLIC. In this paper recent R&D efforts to improve the parameters of the existing system towards CLIC requirements will be discussed. This includes studies of a feedback loop for intensity stabilization, the upgrade of the PHIN vacuum system and the planned upgrade of the driving laser system. For photocathode production and R&D a dedicated photoemission laboratory is available at CERN. To increase the production rate of photocathodes and the availability of the photoemission lab for other studies, an upgrade of the photocathode preparation system with a load-lock system is under study and will also be presented.

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MOPRI056

Design and Fabrication of a VHF - CW High Repetition Rate Electron Gun

cavity, cathode, gun, vacuum

733

R.P. Wells, B. Ghiorso, F. Sannibale, J.W. Staples
LBNL, Berkeley, California, USA
T.M. Huang
IHEP, Beijing, People's Republic of China

Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
A high repetition rate, MHz, electron source is a key element in future FEL based light sources. The Advance Photo-injector Experiment (APEX) at Lawrence Berkeley National Laboratory (LBNL) consists of a high repetition rate 186 MHz (VHF-band) CW electron gun, 1 MHz UV laser source and the diagnostic components necessary to quantify the gun’s performance. The gun design is based on well established, conventional RF cavity design, with a couple notable exceptions. The basis for the selection of this technology, novel design features, fabrication techniques and measured cavity performance are presented.

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MOPRI070

2MeV Electron Cooler for COSY and HESR – First Results

electron, proton, experiment, heavy-ion

765

V. Kamerdzhiev, U. Bechstedt, F.M. Esser, O. Felden, R. Gebel, A.J. Halama, F. Klehr, G. Langenberg, A. Lehrach, B. Lorentz, R. Maier, D. Prasuhn, K. Reimers, M. Retzlaff, R. Stassen, H. Stockhorst, R. Tölle
FZJ, Jülich, Germany
N. Alinovskiy, T.V. Bedareva, E.A. Bekhtenev, O.V. Belikov, V.N. Bocharov, V.V. Borodich, M.I. Bryzgunov, A.V. Bubley, V.A. Chekavinskiy, V.G. Cheskidov, B.A. Dovzhenko, A.I. Erokhin, M.G. Fedotov, A.D. Goncharov, K. Gorchakov, V.K. Gosteev, I.A. Gusev, G.V. Karpov, Y.I. Koisin, M.N. Kondaurov, V.R. Kozak, A.M. Kruchkov, A.D. Lisitsyn, I.A. Lopatkin, V.R. Mamkin, A.S. Medvedko, V.M. Panasyuk, V.V. Parkhomchuk, I.V. Poletaev, V.A. Polukhin, A.Yu. Protopopov, D.N. Pureskin, A.A. Putmakov, V.B. Reva, P.A. Selivanov, E.P. Semenov, D.V. Senkov, D.N. Skorobogatov, N.P. Zapiatkin
BINP SB RAS, Novosibirsk, Russia
J. Dietrich
HIM, Mainz, Germany
T. Katayama
Nihon University, Narashino, Chiba, Japan
L.J. Mao
IMP, Lanzhou, People's Republic of China

The 2 MeV electron cooler was installed in the COSY ring in the spring 2013. The new system enables electron cooling in the whole energy range of COSY. The electron beam is guided by longitudinal magnetic field all the way from the electron gun to the collector. This well-proven optics scheme was chosen because of the wide electron energy range of 0.025-2 MeV. The electrostatic accelerator consists of 33 individual sections of identical design. Electrical power to each section is provided by a cascade transformer. Electron beam commissioning and first studies using proton and deuteron beams were carried out. Electron cooling of proton beam up to 1662 MeV kinetic energy was demonstrated. Maximum electron beam energy achieved so far amounted to 1.25 MeV. Voltage up to 1.4 MV was demonstrated. The cooler was operated with electron current up to 0.5 A. The paper provides insights into the recent progress in high energy electron cooling at COSY and perspectives for the HESR ring at FAIR.

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MOPRI089

Upgrade of J-PARC Fast Extraction System

septum, extraction, quadrupole, kicker

821

K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan
T. Shibata
JAEA, Ibaraki-ken, Japan

The J-PARC main ring (MR) fast extraction (FX) system has two functions: to deliver a high power beam to the neutrino experimental facility and to dump the beam at any time in case of hardware failures. The present FX system consists of five bipolar kickers and eight bipolar septa. In order to raise the beam power to the design limit, both the beam intensity and the repetition rate will increase gradually. The FX system needs to be upgraded to satisfy the new requirements. The upgrade includes FX orbit optimization and new design of devices. Firstly, two high performance eddy current septa have been designed and fabricated. Then downstream high field septa are redesigned and using ceramic beam pipe to eliminate eddy current effects, which meets the requirement of high repetition rate operation. A new large physical aperture quadrupole is needed to accommodate high intensity beam. In order to evaluate the beam loss in the new system, realistic 3D beam tracking is studied.

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MOPRI093

Technical Design of Normal Conducting Re-buncher in the MEBT for Rare Isotope Science Project

cavity, rfq, acceleration, ion

830

H.J. Kim, W.K. Han, I.S. Hong, D. Jeon
IBS, Daejeon, Republic of Korea

Funding: This work was supported by the RISP of Institute for Basic Science funded by Ministry of Science, ICT and Future Planning and National Research Foundation of Korea.(2011-0032011)
The front-end system of RISP heavy-ion accelerator(RAON) consists of an electron cyclotron resonance ion source, a low energy beam transport line, a radio frequency quadrupole accelerator and a medium energy beam transport(MEBT) line. The MEBT system, which consists of quadrupole magnets, three normal-conducting re-bunchers and diagnostic devices, is installed between the RFQ accelerator and the superconducting linac(SCL). The three normal-conducting re-bunchers are used to minimize the growths of the longitudinal emittance and to manipulate the particle distribution on longitudinal phase space for beam transportation in SCL. Several combination of the number of cavities was examined, and the quarter wave resonator(QWR) type re-buncher was chosen for MEBT line in RAON. The QWR cavity has a frequency of 81.25 MHz, a maximum electric field of 2.53 MV/m on the cavity surface with an electric field of 1 MV/m on the beam axis, a geometrical beta factor of 0.032 and an effective length of 24 cm. In this presentation, I will present the results of baseline design for electro-magnetic field analysis and mechanical design for stress analysis, thermal stress analysis and cooling channel.

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MOPRI107

The Mitigation System of the Large Angle Foil Scattering Beam Loss caused by the Multi-turn Charge-exchange Injection

injection, simulation, scattering, insertion

873

S. Kato
Tohoku University, Graduate School of Science, Sendai, Japan
H. Harada, H. Hotchi, M. Kinsho, K. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

Funding: Research Fellow of Japan Society for the Promotion of Science
In the J-PARC RCS, the significant losses were observed at the branch of H⁰ dump line and the Beam Position Monitor which was put at the downstream of the H⁰ dump branch duct. These losses were caused by the large angle scattering of the injection and the circulating beam at the charge exchange foil. To realize high power operation, we have to mitigate these losses. So, we developed a new collimation system in the H⁰ branch duct and installed in October 2011. In order to optimize this system efficiently, we focused on the relative angle of collimator block from scattering particles. We developed the beam based angler regulation method by the simulation and achieved the sufficient mitigation of the loss at 181 MeV injection energy. Since the injection energy will be upgraded to 400 MeV in this year, we will start to estimate again the collimator performance by the upgraded simulation set. We present this system as one of the mitigation methods of the large angle foil scattering beam loss caused by the multi-turn charge-exchange injection.

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MOPRI108

Transverse H⁻ Beam Halo Scraper System in the J-PARC L3BT

radiation, injection, proton, linac

876

K. Okabe, M. Kinsho, K. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-mura, Japan

In the Japan Proton Accelerator Research Complex (J-PARC) 3-GeV rapid cycle synchrotron (RCS), transverse beam halo scraping for the injection beam is required to increase the output beam power. The transverse collimation system at the Linac-RCS beam transport line (L3BT) was utilized in a nominal beam operation because the area of the scraper section was contaminated when scrapers were working. In the summer-autumn period of 2013, we installed a new beam-halo scraper which had optimized scraper heads for mitigation of the radiation around the scraper system. In this poster, we report a preliminary result for a halo scraper at the L3BT.

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MOPRI114

Numerical Estimation of the Equivalent Dose Rate after the Irradiation of a Tungsten Collimator by a Low Energy Proton Beam

proton, simulation, cyclotron, radiation

890

V. Talanov, D.C. Kiselev, M. Wohlmuther
PSI, Villigen PSI, Switzerland

The issue of activation of a Tungsten collimator by protons is considered for the incident energy of 12.2 MeV. Two different simulation approaches using the Monte Carlo programs MCNPX and FLUKA are applied to estimate the equivalent remanent dose rate after the irradiation of the collimator. The results of the numerical simulation are then compared to the measured dose levels of the collimator of the COMET cyclotron at Paul Scherrer Institut (PSI).

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MOPRI115

Activation Models of the ISIS Collectors

synchrotron, simulation, controls, scattering

893

H. V. Smith, D.J. Adams, B. Jones, C.M. Warsop
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS facility at the Rutherford Appleton Laboratory is a pulsed neutron and muon source, for materials and life science research. The 163 m circumference, 800 MeV, 50 Hz rapid cycling synchrotron accelerates up to 3·10¹³ protons per pulse. The maximum operating intensity of the synchrotron is limited by loss during acceleration, mainly due to the non-adiabatic longitudinal trapping process between 0 and 3 ms, corresponding to energies between 70 and 200 MeV. In order to minimise global machine activation and prevent component damage a beam collimation, or collector, system is installed in a five metre drift section in super-period one, to localise loss to this region. This paper summarises new results from modelling of the beam collectors using the FLUKA code [1, 2]. Understanding the current performance of the collectors is important for high intensity beam optimisation and may influence future injection upgrade plans. Residual dose rates are compared to film badge measurements, predicted energy deposition results are compared to the measured heat load on the collector cooling systems and an assessment is made of the distribution of particles exiting the collector straight.

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TUXA01

Commissioning the 400 MeV Linac at J-PARC and High Intensity Operation of the J-PARC RCS

injection, linac, dipole, emittance

899

H. Hotchi
JAEA/J-PARC, Tokai-mura, Japan

J-PARC is currently upgrading their linac from 181MeV to 400 MEV with a new ACS section (annular coupled structure). This includes a triple frequency jump, and there should be some interesting results to report. As the result of the injector linac upgrade at J-PARC, the Rapid Cycle Synchrotron (RCS) will achieve a record-high intensity as a proton accelerator. This talk describes the recent performance of the RCS together with its beam-dynamical issues.

Slides TUXA01 [3.611 MB]

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TUOAA01

Progress Towards Doubling the Beam Power at Fermilab's Accelerator Complex

booster, target, antiproton, proton

904

I. Kourbanis
Fermilab, Batavia, Illinois, USA

Funding: Work supported by the Fermi Research Alliance under contract to the U.S. Department of Energy.
After a 16 month shutdown to reconfigure the Fermilab Accelerators for high power operations, the Fermilab Accelerator Complex is again providing beams for numerous Physics Experiments. By using the Recycler to slip stack protons while the Main Injector is ramping, the beam power at 120 GeV can reach 700 KW, a factor of 2 increase. The progress towards doubling the Fermilab's Accelerator complex beam power will be presented.

Slides TUOAA01 [7.059 MB]

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TUOAA02

Design of the LBNE Beamline

target, proton, shielding, extraction

907

V. Papadimitriou, R. Andrews, J. Hylen, T.R. Kobilarcik, A. Marchionni, C.D. Moore, P. Schlabach, S. Tariq
Fermilab, Batavia, Illinois, USA

Funding: DOE, contract No. DE-AC02-07CH11359
The Long Baseline Neutrino Experiment (LBNE) will utilize a beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a wide band beam of neutrinos toward a detector placed at the Sanford Underground Research Facility in South Dakota, about 1,300 km away. The main elements of the facility are a primary proton beamline and a neutrino beamline. The primary proton beam (60-120 GeV) will be extracted from the MI-10 section of Fermilab’s Main Injector. Neutrinos are produced after the protons hit a solid target and produce mesons which are subsequently focused by a set of magnetic horns into a 204 m long decay pipe where they decay into muons and neutrinos. The parameters of the facility were determined taking into account the physics goals, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~1.2 MW, however the facility is designed to be upgradeable for 2.3 MW operation. We discuss here the status of the design and the associated challenges.

Slides TUOAA02 [5.781 MB]

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TUOBA01

Electron Lenses for the Large Hadron Collider

electron, collider, collimation, controls

918

G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA
R. Bruce, S. Redaelli, A. Rossi, B. Salvachua
CERN, Geneva, Switzerland

Funding: Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. Research supported in part by US LARP and EU FP7 HiLumi LHC, Grant Agreement 284404.
Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.

Slides TUOBA01 [9.709 MB]

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TUZA02

THz Facility at ELBE: A Versatile Test Facility for Electron Bunch Diagnostics on Quasi-CW Electron Beams

electron, diagnostics, SRF, linac

933

M. Gensch, B.W. Green, J. Hauser, S. Kovalev, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig
HZDR, Dresden, Germany
A. Al-Shemmary, V. B. Asgekar, T. Golz, H. Schlarb, N. Stojanovic, S. Vilcins
DESY, Hamburg, Germany
A.S. Fisher
SLAC, Menlo Park, California, USA
G. Geloni
XFEL. EU, Hamburg, Germany
A.-S. Müller, M. Schwarz
KIT, Karlsruhe, Germany
N.E. Neumann, D. Plettemeier
TU Dresden, Dresden, Germany

At the Helmholtz-Zentrum Dresden-Rossendorf near Dresden a quasi-cw low-energy electron linear accelerator based on superconducting radiofrequency technology is operated successfully for more than 10 years. The ELBE accelerator is driving several secondary radiation sources including 2 infrared free electron lasers. A new addition will be a THz facility that aims to make use of super-radiant THz radiation. In its final form the THz facility shall consist of one coherent diffraction radiator and one undulator source which provide high-field THz pulses at unprecedented repetition rates. While the medium term goal is to establish a unique user facility for nonlinear THz science, the THz sources are already used as a test facility for novel diagnostic techniques on quasi-cw electron beams. The progress of the developments is reported and an outlook into future challenges and opportunities is given.

Slides TUZA02 [3.041 MB]

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TUZB02

Prospects for the use of HTS in High-field Magnets for Future Accelerator Facilities

solenoid, dipole, quadrupole, focusing

974

A. Ballarino
CERN, Geneva, Switzerland

The enthusiasm that followed the discovery of High Temperature Superconductors (HTS) and the hope that they could replace Low Temperature Superconductors (LTS) was damped by low current-carrying capacity, short piece lengths, and fragility of the brittle oxide materials. Development of applications was mainly on devices less demanding of conductor performance. However, with continuing development, progress was made with the cuprate superconductors, and long lengths of BSCCO 2223 and REBCO tape conductors are now commercially available. Progress has also been made in the development of BSSCO 2212 round wire, where implementation of a new production process has led to a breakthrough in performance. Though still at the research level, attainments in material synthesis and theoretical understanding of iron-based materials may lead to their development into practical superconductors, featuring high upper critical field and low anisotropy. A review of the potential of HTS as applied to accelerators is presented, with a focus on using the presently available materials and on the perceived needs for further development.

Slides TUZB02 [2.331 MB]

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TUPRO003

Fast Crab Cavity Failures in HL-LHC

simulation, optics, luminosity, synchrotron

997

B. Yee-Rendón, R. Lopez-Fernandez
CINVESTAV, Mexico City, Mexico
J. Barranco García
EPFL, Lausanne, Switzerland
R. Calaga, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland

Crab cavities (CCs) are a key ingredient of the High-Luminosity Large Hadron Collider (HL-LHC) to ensure head on collisions at the main experiments (ATLAS and CMS) and fully profit from the smaller β* provided by the ATS optics. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of few LHC turns and considering the large energy stored in the HL-LHC beam, CC failures represent a serious risk to the LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, necessary to dump the beam. The simulations assume a realistic steady-state distribution to assess the beam losses for the HL-LHC. Additionally, some strategies are studied to mitigate the damage caused by the failures.

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TUPRO007

LS1 “First Long Shutdown of LHC and its Injector Chains”

radiation, cryogenics, electronics, shielding

1010

K. Foraz, S. Baird, M.B.M. Barberan Marin, M. Bernardini, J. Coupard, N. Gilbert, D. Hay, S. Mataguez, D.J. Mcfarlane
CERN, Geneva, Switzerland

The LHC and its injectors were stopped in February 2013, in order to maintain, consolidate and upgrade the different equipment of the accelerator chain, with the goal of achieving LHC operation at the design energy of 14 TeV in the centre-of-mass. Prior to the start of this Long Shutdown (LS1), a major effort of preparation was performed in order to optimize the schedule and the use of resources across the different machines, with the aim of resuming LHC physics in early 2015. The rest of the CERN complex will restart beam operation in the second half of 2014. This paper presents the schedule of LS1, describes the organizational set-up for the coordination of the works, the main activities, the different main milestones, which have been achieved so far, and the decisions taken in order to mitigate the issues encountered.

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TUPRO009

Simple Models Describing the Time-evolution of Luminosity in Hadron Colliders

luminosity, collider, hadron, proton

1017

M. Giovannozzi
CERN, Geneva, Switzerland

In recent years, several studies have been performed to describe the evolution of the losses in circular proton machines. Considerations based on single-particle, non-linear beam dynamics allowed building models that, albeit simple, proved to be in good agreement with measurements. These initial results have been generalised, thus opening the possibility to describe the luminosity evolution in a circular hadron collider. In this paper, the focus is on the derivation of scaling laws for the integrated luminosity, taking into account both burn off and additional pseudo-diffusive effects. The proposed models are applied to the analysis of the data collected during the LHC Run I and the outcome is discussed in detail.

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TUPRO015

Update on Predictions for Yearly Integrated Luminosity for HL-LHC based on Expected Machine Availability

luminosity, radiation, electronics, cryogenics

1036

A. Apollonio, M. Jonker, R. Schmidt, B. Todd, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

Machine availability is one of the key performance indicators to reach the ambitious goals for integrated luminosity in the post Long Shutdown 1 (LS1) era. Machine availability is even more important for the future High Luminosity LHC (HL-LHC) [1]. In this paper a Monte Carlo approach has been used to predict integrated luminosity as a function of LHC machine availability. The baseline model assumptions such as fault-time distributions and machine failure rate (number of fills with stable beams dumped after a failure / total number of fills with stable beams) were deduced from the observations during LHC operation in 2012. The predictions focus on operation after LS1 and its evolution towards HL-LHC. The extrapolation of relevant parameters impacting on machine availability is outlined and their corresponding impact on fault time distributions is discussed. Results for possible future operational scenarios are presented. Finally, a sensitivity analysis with relevant model parameters like fault time and machine failure rate is discussed.

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TUPRO016

Machine Protection Challenges for HL-LHC

cavity, extraction, beam-losses, luminosity

1039

R. Schmidt, T. Bär, J. Wenninger, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

LHC operation requires the flawless functioning of the machine protection systems. The energy stored in the beam was progressively increased beyond the 140 MJ range at the end of 2012 at 4 TeV/c. The further increase to 364 MJ expected for 2015 at 6.5 TeV/c should be possible with the existing protection systems. For HL-LHC, additional failure modes are considered. The stored beam energy will increase by another factor of two with respect to nominal and a factor of five more than experienced so far. The maximum beta function will increase. It is planned to install crab cavities in the LHC. With crab cavities, sudden voltage decays within 100 us after e.g. cavity quenches lead to large beam oscillations. Tracking simulations predict trajectory distortions of up to 1.5 σ in the first turn after a sudden drop of the deflecting voltage in a single cavity within 3 turns. The energy of several MJ stored in halo protons that could hit the collimator in case of such events is far above damage level, even if the collimator jaws are made of robust material. In this paper we discuss the challenges for machine protection in the HL-LHC era and possible mitigation strategies.

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TUPRO020

Integration of a Neutral Absorber for the LHC Point 8

luminosity, optics, dipole, injection

1052

A. Santamaría García, R. Alemany-Fernández, H. Burkhardt, F. Cerutti, L.S. Esposito, N.V. Shetty
CERN, Geneva, Switzerland

The LHCb detector will be upgraded during the second long shutdown (LS2) of the LHC machine, in order to increase its statistical precision significantly. The upgraded LHCb foresees a peak luminosity of L = 1-2 . 10³³ cm^-2 s⁻¹, with a pileup of 5. This represents ten times more luminosity and five times more pile up than in the present LHC. With these conditions, the pp-collisions and beam losses will produce a non-negligeable beam-induced energy deposition in the interaction region. More precisely, studies have shown that the energy deposition will especially increase on the D2 recombination dipole, which could bring them close to their safety thresholds. To avoid this, the placement of a minimal neutral absorber has been proposed. This absorber will have the same role as the TAN in the high luminosity Interaction Regions (IR) 1 and 5. This study shows the possible dimensions and location of this absorber, and how it would reduce both the peak power density and total heat load.

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TUPRO022

Implementation of Luminosity Leveling by Betatron Function Adjustment at the LHC Interaction Points

luminosity, experiment, optics, betatron

1058

J. Wenninger, A.A. Gorzawski
CERN, Geneva, Switzerland

Growing expectations for integrated luminosity during upcoming LHC runs introduce new challenges for LHC beam operation in the scope of online luminosity control. Because some LHC experiments are limited in the maximum event rates, their luminosity is leveled to a constant value. Various techniques may be used for luminosity leveling, changing the betatron function at the interaction point is one of them. This paper explains the main operational requirements of a betatron function leveling scheme for the upcoming LHC run. Issues concerning the beam optics, orbits and collimator settings are discussed. The proposed architecture for control system integration will be discussed. A few operational scenarios with different beam configurations foreseen for the next LHC run will be presented.

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TUPRO052

Study a ‘Sum’ Linear Coupling Resonance for J-PARC Main Ring: Observations and Simulations

resonance, injection, coupling, emittance

1147

A.Y. Molodozhentsev, S. Igarashi
KEK, Ibaraki, Japan
Y. Sato, J. Takano
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

J-PARC Main Ring should deliver a high-power proton beam to neutrino experiments with limited particle losses. To meet this requirement low-order machine resonances have to be compensated. The linear coupling resonance Qx+Qy=43 has been identified as the potential source for significant particle losses at the collimator. The resonance compensation scheme has been studied experimentally by using a low intensity beam. To understand this process the simulations have been performed by using the PTC-ORBIT code. The Main Ring model has been developed to reproduce the machine operation including the initial stage of the acceleration. The 6D beam model has been defined to represent the ‘pencil’ beam used for this study. In frame of this report the single and multi particle dynamics will be discussed to understand the results of measurements, performed during RUN44 (November 2012). The results of the long-term tracking for this case will be presented. The obtained results can be used to benchmark the computer modeling the ‘sum’ linear coupling resonance with the experimental results.

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TUPRO062

Improvements in the Optics Measurement Resolution for the LHC

optics, simulation, collider, dipole

1177

A. Langner, R. Tomás
CERN, Geneva, Switzerland

Optics measurement algorithms which are based on the measurement of beam position monitor (BPM) turn-by-turn data are currently being improved in preparation for the commissioning of the LHC at higher energy. The turn-by-turn data of one BPM may be used more than once, but the implied correlations were not considered in the final error bar. In this paper the error propagation including correlations is studied for the statistical part of the uncertainty. The confidence level of the measurement is investigated analytically and with simulations.

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TUPRO068

Commisioning of the 2.4T Multipole Wiggler and the 6.5T Superconducting Wavelength Shifter at the SIAM Photon Source

emittance, betatron, optics, storage-ring

1192

P. Sudmuang, S. Klinkhieo, P. Klysubun, S. Kongtawong, S. Krainara, N. Suradet, A. Tong-on
SLRI, Nakhon Ratchasima, Thailand

A 2.4 T hybrid multipole wiggler (MPW) and a 6.5 T superconducting wavelength shifter (SWLS) have been successfully installed and commissioned at Siam Photon Source (SPS). The influence of the two insertion devices on the electron beam dynamic at different operating points have been studied in order to determine the optimal lattice configuration for operation. In this paper, the compensation of the linear optics will be presented, and the commissioning scheme will also be described. In addition, the investigation of the difference between the model and the actual observed machine parameters will be reported in details.

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TUPRO076

Initial Experimental Analysis into the eRHIC Polarized Electron Beam Transport System

dipole, cathode, electron, network

1217

C. Yeckel, E. Dobrin, P. Holen, R.C. Miller, M. Stangenes, K.A. Thompson, L.W. Thompson
Stangenes Industries, Palo Alto, California, USA
I. Ben-Zvi, R.F. Lambiase, J. Skaritka, E. Wang
BNL, Upton, Long Island, New York, USA

Stangenes Industries is working closely with Brookhaven National Lab in the United States to develop the eRHIC future ion collider. The collider requires a polarized electron source with high average current, short bunch length and small emittance. An array of photocathodes with their beams funneled into a common trajectory is utilized to achieve the required beam current and cathode lifetime. Stangenes Industries is charged with delivering the prototype injector for preliminary beam studies that will lead to full implementation by 2020. This study focuses on the development of the of beam transport system extending from cathode to beam dump. A majority of the complexity involves the so called "combiner magnet" that acts as a high frequency-rotating dipole to bend each beam into the final common trajectory. Preliminary experiments into the feasibility of such a system are analyzed.

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TUPRO092

Magnetic-field Variable Permanent Dipole Magnet for Future Light Sources

permanent-magnet, dipole, simulation, emittance

1253

T. Watanabe, K. Fukami, T. Nakanishi, S. Sasaki
JASRI/SPring-8, Hyogo, Japan

Permanent dipole magnets with variable magnetic field have been designed, fabricated, and tested at SPring-8. Permanent magnets can be advantageous over electromagnets in terms of reliability, stability and compactness in addition to the small power consumption. No unexpected down of an accelerator due to power supply failure is supposed to happen. There is no cooling water flow that can induce a fluctuation of the magnetic field. These features may become important for future light sources, where a very reliable, stable, and compact ring is required. In addition, the power consumption is now one of the most important issues after the 3.11 disaster in Japan. One of critical issues to realize such a magnet is that a magnetic field has to be tuned. In the future, combined-functioned and longitudinally gradient magnets will play a key role in achieving extremely small emittance. In such a case, changing a gap will not work any more. We have designed and fabricated a permanent dipole magnet of which magnetic field can be tuned without changing the gap. The results of the performance test will be presented and a possibility to apply it for future light sources will be discussed.

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TUPRO093

Numerical Study of Intrinsic Ripples in J-PARC Main-ring Magnets

simulation, damping, synchrotron, acceleration

1256

Y. Shirakabe, A.Y. Molodozhentsev, M. Muto
KEK, Tsukuba, Japan

Beam ripples are one of the critical problems in high power proton synchrotrons. Magnet field ripples are considered as a main origin of the beam ripples among various possible sources. Although magnet power supply ripples are generally treated as the dominating ripple source, the load circuit parameters of the magnets and their interconnections are also playing critical roles in defining the ripple amplitudes and frequencies. In this viewpoint, the magnet power supplies are treated as simplified current sources, and the ripples generated in the circuit systems are investigated both in analytical and numerical ways. One of the findings in this direction of investigation is the existence of intrinsic ripples. The intrinsic ripples occur inevitably in the synchrotron magnets, no matter how the power supplies are producing idealistic current ramp patterns. Their amplitudes are defined by the circuit parameters such as inductance and capacitance, and the ramp parameters such as ramp rates. Some of the analytical mechanisms in generating the magnet field ripples are presented as well as the studied examples.

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TUPRO098

Design and Test of Dipole and Quadrupole Magnets for PAL-XFEL

dipole, quadrupole, multipole, FEL

1271

H.S. Suh, M.-H. Cho, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park
PAL, Pohang, Kyungbuk, Republic of Korea

PAL-XFEL, currently under construction in Pohang, Korea, will consist of a 10 GeV linac, three hard X-ray branches and two soft X-ray branches. As the first phase of this project, one hard X-ray (HX1) and one soft X-ray (SX1) branches will be constructed. This facility requires 6 different families of dipole magnets, and 11 families of quadrupole magnets included steering functions. We are designing these magnets with the water cooling or the heat sink system now. In this presentation, we describe the modified design of the magnets for efficient manufacturing, and the magnetic and thermal analysis with the test results.

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TUPRO104

Design of the Beam Transfer Line Magnets for HIE-ISOLDE

dipole, quadrupole, linac, lattice

1289

J. Bauche, A.V. Aloev
CERN, Geneva, Switzerland

This paper describes the design of the beam transfer line magnets of the HIE-ISOLDE facility. The technical solutions selected to face the challenges associated with the machine requirements are presented, and the final design parameters and field quality are reported.

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TUPRO106

Status of the ELENA Magnet System

quadrupole, dipole, simulation, antiproton

1295

D. Schoerling
CERN, Geneva, Switzerland

ELENA, the Extra Low ENergy Antiproton ring, will be a CERN facility with the purpose to deliver antiprotons at lowest energies aiming to enhance the study of antimatter. It will be a hexagonal shaped ring with a circumference of about 30 m decelerating antiprotons from energies of 5.3 MeV to 100 keV. Due to the extra-low beam rigidity the design of the magnet system is especially challenging because even small fields, for example arising from residual magnetization and hysteresis, will have a major impact both on the beam trajectory and beam dynamics. In this paper the design approach for such an extra-low beam rigidity magnet system is presented. The main challenges are outlined and solutions for the design of the magnet system are discussed.

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TUPRO117

Magnet Design for the SNS Laser Stripping Experiment

laser, electron, ion, experiment

1328

A.V. Aleksandrov, A.A. Menshov
ORNL, Oak Ridge, Tennessee, USA

Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation.
The first step in the three-step laser assisted H⁻ beam stripping for charge exchange injection is to remove one electron in a strong magnetic field. In order to preserve the beam emittance for the subsequent laser induced stripping of the second electron the magnetic field has to have large gradient of about 40 T/m along the beam trajectory. The required magnetic field strength for stripping 1GeV H⁻ beam is 1.2 T in 29 mm aperture. In order to allow for undisturbed passage of high power beam during the nominal SNS operation the stripping magnet made of permanent magnet material resides in vacuum chamber and can move in and out of the beam line. This presentation describes requirements and design and the magnetic field calculation results for a stripping magnet for the Laser Stripping Experiment at SNS.

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TUPME009

A Sub-micron Resolution, Wide-band, Stripline BPM System for Driving Bunch-by-bunch Feed-back and Feed-forward Systems at ATF

feedback, kicker, cavity, extraction

1358

G.B. Christian, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, M.R. Davis, Y.I. Kim, C. Perry
JAI, Oxford, United Kingdom

A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used as part of a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage RF down-mixer and a position resolution below 400 nm has been demonstrated for beam intensities of ~1 nC, with single-pass beam. The BPM position data are digitised by fast ADCs on an FPGA-based digital feedback controller, which is used to drive either a pair of kickers local to the BPMs and nominally orthogonal in phase, in closed-loop feedback mode, or a downstream kicker in the ATF2 final focus region, in feedforward mode. The beam jitter is measured downstream of the final focus system with high resolution, low-Q, cavity BPMs, and the relative performance of both systems in stabilising the beam is compared.

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TUPME013

Thermo-mechanical Tests for the CLIC Two-beam Module Study

alignment, vacuum, linac, experiment

1370

A. Xydou, G. Riddone, A.L. Vamvakas
CERN, Geneva, Switzerland
E. Daskalaki
NTUA, Athens, Greece

The luminosity goal of CLIC requires micron level precision with respect to the alignment of the components on its two-meter long modules, composing the two main linacs. The power dissipated inside the module components introduces mechanical deformations affecting their alignment and therefore the resulting machine performance. Several two-beam prototype modules must be assembled to extensively measure their thermo-mechanical behavior under different operation modes. In parallel, the real environmental conditions present in the CLIC tunnel should be studied. The air conditioning and ventilation system providing specified air temperature and flow has been installed in the dedicated laboratory. The power dissipation occurring in the modules is being reproduced by the electrical heaters inserted inside the RF structure mock-ups and the quadrupoles. The efficiency of the cooling systems is being verified and the alignment of module components is monitored. The measurement results will be compared to finite element analysis model and propagated back to engineering design. Finally, simulation of the most possible CLIC machine cycles is accomplished and preliminary results are analysed.

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TUPME017

Design and Simulation of a Matching System into the Helical Cooling Channel

solenoid, emittance, collider, simulation

1382

C.Y. Yoshikawa
MuPlus, Inc., Newport News, Virginia, USA
Y.I. Alexahin, D.V. Neuffer, K. Yonehara
Fermilab, Batavia, Illinois, USA
C.M. Ankenbrandt, R.P. Johnson, S.A. Kahn, F. Marhauser
Muons, Inc, Illinois, USA
Y.S. Derbenev, V.S. Morozov, A.V. Sy
JLab, Newport News, Virginia, USA

Funding: Work supported in part by DOE STTR grant DE-SC 0007634.
Muon colliders could provide the most sensitive measurement of the Higgs mass and return the US back to the Energy Frontier. Central to the capabilities of muon colliders are the cooling channels that provide the extraordinary reduction in emittance required for the precise Higgs mass measurement and increased luminosity for enhanced discovery potential of an Energy Frontier Machine. The Helical Cooling Channel (HCC) is able to achieve such emittance reduction and matching sections within the HCC have been successfully designed in the past with lossless transmission and no emittance growth. However, matching into the HCC from a straight solenoid poses a challenge, since a large emittance beam must cross transition. We elucidate on the challenge and present evaluations of two solutions, along with concepts to integrate the operations of a Charge Separator and match into the HCC.

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TUPME028

Flat Bunches in the LHC

impedance, emittance, luminosity, synchrotron

1413

E.N. Shaposhnikova, T. Argyropoulos, P. Baudrenghien, J. F. Esteban Müller, T. Mastoridis, G. Papotti, B. Salvant, H. Timko
CERN, Geneva, Switzerland
C.M. Bhat, A.V. Burov
Fermilab, Batavia, Illinois, USA

A high-harmonic RF system that could serve multiple purposes was proposed for the LHC. Possible applications of the second harmonic RF system include beam stabilisation in the longitudinal plane in the absence of wide-band longitudinal feedback and reduction of bunch peak line-density. Apart from other useful features, flat bunches are expected to produce less beam-induced heating at frequencies below 1 GHz, the frequency region critical for some LHC equipment. The latter, however, can also be achieved by de-populating the bunch centre. This was demonstrated during the dedicated machine development session in the LHC using RF phase modulation. In this paper the results of tests with single bunches and nominal LHC beams are presented and the possible use of this technique in LHC operation is discussed.

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TUPME045

Development of a High-Energy Short-pulse 5-μm Parametric Source for Dielectric Laser Acceleration

laser, acceleration, detector, optics

1460

G. Xu, I. Jovanovic, S.F. Wandel
Penn State University, University Park, Pennsylvania, USA

A compact, high-peak-power 5-μm laser source with pulse duration of sub-100 fs has been designed and being constructed for pumping a dielectric photonic structure to produce an acceleration gradient of order GV/m in dielectric laser acceleration. Breakdown of dielectric structure induced by multiphoton ionization can be mitigated by adopting long wavelength driver laser. Since the dielectric structure scales with the laser wavelength, fabrication tolerances for dielectric structure are relaxed as well. The 5-μm laser source is based on two cascaded optical parametric amplifiers (OPA): a 2-μm BBO OPA with a mixed phase matching scheme is used as a pump source, and a type-I phase-matched ZGP OPA is designed to produce sub-mJ, <100 fs 5-μm laser pulses. The two-stage 2-μm OPA is pumped by a Ti:sapphire amplifier and produces pulse energy of ~2.2 mJ with a pulse duration of 42 fs (~6 optical cycles), and excellent pulse stability and beam quality. Preliminary result of ~50 μJ pulse energy at 5-μm is demonstrated by using single-stage ZGP OPA, and an improved two-stage OPA scheme for production of higher pulse energy at 5-μm is under development.

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TUPRI030

Beam Coupling Impedance of the New Beam Screen of the LHC Injection Kicker Magnets

impedance, coupling, kicker, injection

1627

H.A. Day, M.J. Barnes, F. Caspers, E. Métral, B. Salvant, J.A. Uythoven
CERN, Geneva, Switzerland

The LHC injection kicker magnets experienced significant beam induced heating of the ferrite yoke, with high intensity beam circulating for many hours, during operation of the LHC in 2011 and 2012. The causes of this beam coupling impedance were studied in depth and an improved beam screen implemented to reduce the impedance. Results of measurements and simulations of the new beam screen design are presented in this paper: these are used to predict power loss and temperature of the ferrite yoke for operation after long shutdown 1 and for proposed HL-LHC operational parameters.

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TUPRI041

Study of Collective Beam Instabilities for Sirius

impedance, vacuum, undulator, feedback

1653

F.H. de Sá, H.O.C. Duarte, L. Liu, N. Milas, X.R. Resende
LNLS, Campinas, Brazil

In this paper we present the on going work of construction of the Sirius impedance budget and instability threshold estimates for several machine operation scenarios.

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TUPRI053

Transverse Beam Instabilities in the MAX IV 3 GeV ring

impedance, emittance, damping, storage-ring

1689

G. Skripka, P.F. Tavares
MAX-lab, Lund, Sweden
M. Klein, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France

Collective effects in MAX IV 3 GeV storage ring are strongly enhanced by the combination of low emittance, high current and small effective aperture. Three passive harmonic cavities (HC) are introduced to lengthen the bunches, by which beam stabilization is anticipated via decoupling to high frequency wakes, along with Landau damping. The role of the ransverse impedance budget of the MAX IV 3 GeV storage ring as a source of collective beam instabilities was determined. With the help of the macroparticle multi-bunch tracking code mbtrack that directly uses the former as input, we studied the influence of geometric and resistive wall impedance in both transverse planes, as well as that of chromaticity shifting. A fully dynamic treatment of the passive harmonic cavities developed for this study allowed us to evaluate their effectiveness under varying beam conditions.

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TUPRI057

Review of the Transverse Impedance Budget for the CLIC Damping Rings

impedance, damping, wiggler, simulation

1701

E. Koukovini-Platia, G. Rumolo
CERN, Geneva, Switzerland

Single bunch instability thresholds and the associated coherent tune shifts have been evaluated in the transverse plane for the damping rings (DR) of the Compact Linear Collider (CLIC). A multi-kick version of the HEADTAIL code was used to study the instability thresholds in the case where different impedance contributions are taken into account such as the broad-band resonator model in combination with the resistive wall contribution from the arcs and the wigglers of the DR. Simulations performed for positive values of chromaticity showed that higher order bunch modes can be potentially dangerous for the beam stability.

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TUPRI072

Status and Performance of Bunch-by-bunch Feedback at BESSY II and MLS

feedback, synchrotron, diagnostics, beam-loading

1733

A. Schälicke, P. Goslawski, M. Ries, M. Ruprecht
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung and Land Berlin.
Bunch-by-bunch feedback systems provide an important component in the reliable operation of electron storage rings. Modern digital bunch-by-bunch feedback systems allow efficient mitigation of multi-bunch instabilities, and at the same time offer valuable beam diagnostics. In this contribution, setup and performance of the bunch-by-bunch feedback systems at BESSY II and the MLS are presented. Longitudinal and transverse instabilities are studied under different machine conditions. The developed data analysis techniques and experimental measurements are discussed.

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TUPRI074

First Results of the New Bunch-by-bunch Feedback System at ANKA

injection, feedback, insertion, insertion-device

1739

E. Hertle, N. Hiller, E. Huttel, B. Kehrer, A.-S. Müller, A.-S. Müller, N.J. Smale
KIT, Eggenstein-Leopoldshafen, Germany
M. Höner
DELTA, Dortmund, Germany
D. Teytelman
Dimtel, San Jose, USA

A new digital three dimensional fast bunch by bunch feedback system has been installed and commissioned at ANKA. Immediate improvements to stored current and lifetime were achieved for normal user operation. For this, the feedback has to be running during the injection and the energy ramp to 2.5 GeV. Additionally, the feedback system was also incorporated into the diagnostic tool-set at ANKA and opened up new possibilities of automated and continuous measurements of certain beam parameters. The system can operate in different modes such as the low alpha operation mode, which has different requirements on the feedback system compared to normal user operation. Results on the various aspects will be presented as well as future improvements.

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TUPRI075

Beam Orbit Stability at Elettra

feedback, injection, electron, storage-ring

1742

G. Gaio, S. Cleva, E. Karantzoulis, S. Krecic, M. Lonza
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The top-up operation established since 2010 at the Elettra third-generation synchrotron light source has solved the problems related to thermal drifts and beam current dependence, and a series of feedback loops acting on the machine optics and radio-frequency systems made easier to setup and operate the ring. Those systems together with the fast orbit feedback in operation since 2007, contributed to a very high electron beam orbit stability. A description of the active systems and their performance, future perspectives as well as some still open issues will be presented and discussed.

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TUPRI079

Test Results of the Libera Sync 3 CW Reference Clock Transfer System

detector, controls, FEL, instrumentation

1751

P. Orel, E. Janezic, P.L. Lemut, S. Zorzut
I-Tech, Solkan, Slovenia
S. Hunziker, V. Schlott
PSI, Villigen PSI, Switzerland

The new Libera Sync 3 CW reference clock transfer system has been specifically designed to meet the strict requirements of the latest fourth generation light sources, such as the Swiss FEL. The system has been co-developed with the Paul Scherrer Institute (PSI). It has been produced and tested at Instrumentation Technologies (I-Tech) and later installed at PSI. In this article we give a general overview of the system and its functionalities. We also present a brief overview of the supporting products that have been developed in order to enable testing at the level of performance discussed. Finally, we focus on presenting some of the test results obtained at I-Tech and PSI showing the performance capabilities and limitations of the system.

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TUPRI092

Improvement of the Position Monitor using White Light Interferometer for Measuring Precise Movement of Compact ERL Superconducting Cavities in Cryomodule

target, cryomodule, cavity, linac

1787

H. Sakai, K. Enami, T. Furuya, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
T. Aoto, K. Hayashi, K. Kanzaki
Tokyo Seimitsu Co. Ltd, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

Alignment of superconducting cavities is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to liquid He temperature more precisely, we newly developed the position monitor by using white light interferometer. This monitor is based on the measurement of the interference of light between the measurement target and the reference point. It can measure the position from the outside of the cryomodule. We applied this monitor to the main linac cryomodule of Compact ERL (cERL) and successfully measured the displacement during 2K cooling with the resolution of 10um. However, some drift come from outer temperature and humidity were observed. In this paper, we describe the upgraded version of this monitor to suppress these drift for cERL beam operation.

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TUPRI098

The New PLC based Radiation Safety Interlock System at S-DALINAC

electron, radiation, linac, status

1802

M. Arnold, J. Birkhan, M. Brunken, J. Conrad, M. Hess, F. Hug, N. Pietralla, S.T. Sievers, P. von Neumann-Cosel
TU Darmstadt, Darmstadt, Germany

Funding: Supported by a HGS-HIRe travel grant
The Superconducting Darmstadt Linear Electron Accelerator S-DALINAC has been running since 1991. It consists of an injector linac, a main linac with two recirculations and is mainly used for in-house nuclear physics experiments as well as accelerator physics and technology. Radiation safety regulations demand an interlock system during operation of the accelerator. Amongst other major projects increasing the versatility and operation stability of the S-DALINAC, the existing, hardware based, interlock system is going to be replaced in the next shutdown period. The new interlock system is based on a PLC (Programmable Logic Controller) and will provide two subsystems, a personnel interlock system as well as a machine safety interlock system. Whereas the first subsystem is to protect staff and visitors from being harmed by ionizing radiation, the latter subsystem prohibits the S-DALINAC beam transport and vacuum elements from being damaged due to malfunctioning of any components during accelerator operation. This contribution will give an overview on this new system and will show the latest status.

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TUPRI103

Neutronics Analyses to Support Waste Management for SNS

target, proton, neutron, radiation

1817

I.I. Popova, F.X. Gallmeier
ORNL, Oak Ridge, Tennessee, USA
M.J. Dayton, S.M. Trotter
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: Work supported by the Division of Materials Science, U.S. Department of Energy, under contract number DE-AC05-96OR22464 with UT-Battelle Corporation for ORNL
According to the Spallation Neutron Source (SNS) operations plan the facility components are replaced, when they reach their end-of-life due to radiation induced material damage or burn-up or because of mechanical failure or design improvements. During operation these components are exposed to a severe radiation environment and builds up significant activity during its service lifetime. These components must be safely removed, placed in a container for storage, and transported from the site. In order to classify components and suggest appropriate shipping container an accurate estimate of the radionuclide inventory is performed. On the base of calculated radionuclide inventory the spent component is classified and appropriate container for transport and storage is suggested. Container it is being modelled with the facility component, placed inside, in order to perform transport calculations to ensure that the container is compliant with the waste management regulations. Dose rate analyses are performed as well for the exposure prediction of personnel during components change out.

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TUPRI104

A Beam Arrival Time Cavity for REGAE at DESY

cavity, electron, coupling, gun

1820

M. Hansli, A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
K. Flöttmann, D. Lipka, H. Schlarb, S. Vilcins
DESY, Hamburg, Germany
F.J. Grüner, B. Zeitler
CFEL, Hamburg, Germany

Funding: Kindly funded by BMBF within FSP302.
REGAE (Relativistic Electron Gun for Atomic Exploration) at DESY in Hamburg is a linear accelerator for electron diffraction experiments. It is upgraded to allow for laser driven wake field accelerator experiments. The bunch length is around 10 fs and the wakefield structure is about 100 fs and the synchronization of the laser and the electron bunch needs to be in order of the bunch length. To achieve this, a RFbased scheme will be used, comparing the phase of a beam induced signal with the reference clock. To improve the performance for the operation with charges well below 1 pC a beam arrival time cavity (BAC) at 3.025 GHz is foreseen as a highly sensitive pickup. To provide the maximum energy to the measurement electronics, the cavity needs a high R=Qvalue and an optimized coupling. An over-coupled setting might be beneficial as it provides a higher signal-to-noise ratio for the first samples. In this paper the concept of the beam arrival time cavity, the influence of the dark current on the measurement and parameter studies and optimization of the cavity itself are presented.

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TUPRI113

Integration of the Timing System for TPS

timing, injection, booster, gun

1833

C.Y. Wu, J. Chen, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.S. Huang, D. Lee, C.Y. Liao
NSRRC, Hsinchu, Taiwan

Timing system for the Taiwan Photon Source (TPS) were setup and ready for accelerator system commissioning. Event based timing system was chosen to satisfy various requirements for the machine and experiments. The system consist of event generator and multiple event receivers which installed local control nodes. The system is ready in the first quarter of 2014. Performance and functionality are investigated systematically. Parameters like delay, skew, latency, drift due to ambient temperature variation, etc. will be addressed. This report wills summary progress of TPS timing system before system delivery for accelerator commissioning.

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WEOBA01

Status of the FAIR Synchrotron Projects SIS18 Upgrade and SIS100

ion, quadrupole, dipole, heavy-ion

1857

P.J. Spiller, R. Balß, A. Bleile, L.H.J. Bozyk, J. Ceballos Velasco, T. Eisel, E.S. Fischer, P. Forck, P. Hülsmann, M. Kauschke, O.K. Kester, H. Klingbeil, H.G. König, H. Kollmus, P. Kowina, A. Krämer, J.P. Meier, A. Mierau, C. Omet, D. Ondreka, N. Pyka, H. Ramakers, P. Schnizer, H. Welker, St. Wilfert
GSI, Darmstadt, Germany
A. Iluk
WRUT, Wrocław, Poland
H.G. Khodzhibagiyan
JINR, Dubna, Moscow Region, Russia
D. Urner
FAIR, Darmstadt, Germany

The upgrade of the existing heavy ion synchrotron SIS18 as booster for the FAIR synchrotron SIS100 has been partly completed. With the achieved technical status, a major increase of the accelerated number of heavy ions could be reached. This progress especially demonstrates the feasibilty of acceleration of medium charge state heavy ions with high intensity and and the succesfull control of dynamic vaccuum effects and correlated charge exchange loss. Two further upgrade measures, the installation of additional MA acceleration cavities and the exchange of the main dipole power converter are in progress. For the FAIR synchrotron SIS100 all major components with long production times have been ordered. With several pre-series components, outstanding technical developments have been completed and the readiness for series production reached. The technical project status will be summarized.

Slides WEOBA01 [6.107 MB]

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WEOCA03

DAΦNE Operation with the Upgraded KLOE-2 Detector

luminosity, detector, collider, coupling

1883

C. Milardi, D. Alesini, M.E. Biagini, M. Boscolo, B. Buonomo, S. Cantarella, A. De Santis, G.O. Delle Monache, G. Di Pirro, A. Drago, L.G. Foggetta, O. Frasciello, A. Gallo, A. Ghigo, F. Guatieri, S. Guiducci, F. Iungo, C. Ligi, G. Mazzitelli, L. Pellegrino, R. Ricci, U. Rotundo, C. Sanelli, G. Sensolini, M. Serio, A. Stecchi, A. Stella, M. Zobov
INFN/LNF, Frascati (Roma), Italy
R. Gargana, A. Michelotti
Consorzio Laboratorio Nicola Cabibbo, Frascati, Italy
D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia
M. Tobiyama
KEK, Ibaraki, Japan
A. Valishev
Fermilab, Batavia, Illinois, USA

The DAΦNE collider has been successfully commissioned after the experimental detector modification and a major upgrade and consolidation program involving a large part of the accelerator complex. This paper presents the Φ-Factory setup and the achieved performances in terms of beam currents, luminosity, detector background and related aspects.

Slides WEOCA03 [2.424 MB]

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WEOBB02

Status of Single-shot EOSD Measurement at ANKA

laser, wakefield, electron, storage-ring

1909

N. Hiller, A. Borysenko, E. Hertle, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, M. Schuh, P. Schönfeldt, N.J. Smale, J.L. Steinmann
KIT, Karlsruhe, Germany
P. Peier, B. Steffen
DESY, Hamburg, Germany
V. Schlott
PSI, Villigen PSI, Switzerland

Funding: This work is funded by the BMBF contract numbers: 05K10VKC, 05K13VKA.
ANKA is the first storage ring in the world with a near-field single-shot electro-optical (EO) bunch profile monitor. The method of electro-optical spectral decoding (EOSD) uses the Pockels effect to modulate the longitudinal electron bunch profile onto a long, chirped laser pulse passing through an EO crystal. The laser pulse is then analyzed with a single-shot spectrometer and from the spectral modulation, the temporal modulation can be extracted. The setup has a sub-ps resolution (granularity) and can measure down to bunch lengths of 1.5 ps RMS for bunch charges as low as 30 pC. With this setup it is possible to study longitudinal beam dynamics (e. g. microbunching) occurring during ANKA's low-alpha-operation, an operation mode with compressed bunches to generate coherent synchrotron radiation in the THz range. In addition to measuring the longitudinal bunch profile, long-ranging wake-fields trailing the electron bunch can also be studied, revealing bunch-bunch interactions.

Slides WEOBB02 [12.753 MB]

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WEIB01

Global Industrial Development of Accelerators for Charged Particle Therapy

cyclotron, proton, hadron, hadrontherapy

1912

M. Schillo
VMS-PT, Bergisch Gladbach, Germany

This paper describes the current situation concerning industrial accelerators for medical hadron therapy facilities. Starting from high level requirements and considerations for a therapy facility more specific requirements for the accelerator will be deduced. The Varian ProBeam cyclotron is shown as an example of a medical accelerator and a statistical overview on other accelerators in us is given. The focus is strictly on industrially available equipment. As hadron facilities are extremely complex systems, in the confined space of this paper some simplifications are unavoidable.

Slides WEIB01 [4.218 MB]

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WEIB04

Challenges of the XFEL Cryomodule Integration and Industry Transfer

cryomodule, cavity, alignment, target

1929

F. Chastel, P. Pluvy, H. Rocipon
ALSYOM, Argebteuil, France

The construction of the European XFEL Accelerator is based on in-kind contributions shared by several institutes throughout Europe and Russia. Within the French contribution, CEA is responsible for the assembly, in a dedicated facility located in Saclay, of the up to 100 cryomodules constituting the Linac. Since 2012, ALSYOM has been selected as the industrial partner for such assembly works. This presentation will detail the organization set up for this partnership and the related challenges of this transfer to Industry.

Slides WEIB04 [1.962 MB]

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WEIB05

Big Science Projects - What is it that makes some a success and others to fail?

factory, collider, plasma, heavy-ion

4099

J.H. Yeck
ESS, Lund, Sweden

This presentation analyses the driving forces behind big science projects (which are very different compared to similarly complex but totally commercial projects). This presentation should be enlightening and a big help for anyone wanting to make business with big science projects.

Slides WEIB05 [3.312 MB]

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WEPRO027

W164: A Wiggler Dedicated to the PUMA Beamline and the FEMTOSLICING Project at SOLEIL

wiggler, laser, electron, photon

1998

O. Marcouillé, H.B. Abualrob, P. Brunelle, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, M. Labat, J.L. Marlats, F. Marteau, A. Mary, A. Nadji, K. Tavakoli, M.-A. Tordeux, M. Valléau
SOLEIL, Gif-sur-Yvette, France

The W164 out-vacuum wiggler was designed and built at SOLEIL with the double goal of producing high energy photons for the PUMA beamline (10 keV to 70 keV) and to be used as a modulator for the FEMTOSLICING project. The insertion device requires simultaneously reaching low resonant energy (1.55 eV) and high critical energy of photons (above 10 keV), leading to the choice of high field and large periods. The 3.28 m long wiggler is composed of 20 periods of 164 mm made of NdFeB magnets and vanadium permendur poles. The required effective field for the FEMTOSLICING is 1.53 T and the maximum total field reaches 1.8T at the minimum gap of 14.5 mm. The small transverse size of the poles was optimized to minimize the magnetic forces (8 tons maximum) resulting, together with the large field produced at minimum gap, to a large vertical dynamic field integral (DFI) inside the horizontal physical aperture of the chamber. A dedicated permanent magnet system was designed, constructed and installed at both wiggler ends to cancel the DFI at minimum gap. The construction of the wiggler, the results of the magnetic measurements and the effects on dynamics measured on electron beam are presented.

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WEPRO031

Design and Commissioning of the FLASH2 Undulators

undulator, FEL, controls, vacuum

2007

A. Schöps, O. Bilani, T. Ramm, M. Tischer, S. Tripathi, P. Vagin
DESY, Hamburg, Germany

This paper reports about aspects of design, manufacturing, and commissioning of the 12 FLASH2 variable gap undulator segments. The accuracy of gap drive and encoder systems was tested by magnetic measurements; changes in the phase error proved to be a highly sensitive probe to verify a reproducibility of 1 μm. After magnetic tuning of the IDs, the remaining gap dependence in the field integrals could be successfully compensated by corrector coils. Inconsiderate handling of components during assembling necessitated an elaborate demagnetisation process before the tuning could start.

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WEPRO032

Phase Shifters for the FLASH2 FEL

undulator, electron, quadrupole, FEL

2010

M. Tischer, P. Neumann, A. Schöps, P. Vagin
DESY, Hamburg, Germany

The FLASH2 SASE undulator section consists of 12 IDs. Each of them is followed by an intersection component comprising a phase shifter and various parts for diagnostics and beam steering. The phase shifter is a compact and simple electromagnetic chicane and has to assure constructive interference of the radiation of adjacent undulators for all wavelengths. The magnetic performance, field errors and the hysteresis behavior have been investigated and were found to be within the required accuracy. The results are discussed in relation to the undulator conditions. From these data tables for steering the phase shifter current as function of undulator gap were derived and implemented in the control system.

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WEPRO047

A New Cooling System for Cryocooled Permanent Magnet Undulators at Diamond Light Source

vacuum, undulator, cryogenics, electron

2047

E.C. Longhi, A.G. Miller, E.C.M. Rial, A.J. Rose, J.C. Schouten, C.W. Thompson, A. Thomson, J.H. Williams
DLS, Oxfordshire, United Kingdom
C. Monroe
Monroe Brothers Ltd., Moreton-in-Marsh, United Kingdom

Cryocooled permanent magnet undulators (CPMUs) using NdFeB magnets around 150K were first proposed by Hara*. These are cooled by using either GM cryocoolers or circulating sub-cooled liquid nitrogen. Due to the heat load from radiation and wakefield heating from the electron beam, temperature gradients can develop along the length of the magnet girders which could be as large as several degrees for the Diamond Light Source (DLS) storage ring operating parameters. Some grades of the magnetic material (NdxPr1-x)2Fe14B have remanence curves versus temperature which increase significantly for temperatures below 150K with peaks below 80K**. This means that the operating temperature of a CPMU using this material can be close to the boiling point of liquid nitrogen. The proposed cooling system for the new DLS CPMU is based on a thermosiphon allowing nitrogen to boil inside the cooling channels without a circulating pump. This has the advantage of absorbing large amounts (>250W) of heat with very small temperature gradients. We report here the results of a prototype magnet beam cooled with a thermosiphon producing a temperature gradient of less than 0.05K along a 2m beam at ~77K.
* T. Hara et al., Phys Rev Spec Top. Accelerator & Beam, Vol 7, 2004.
** J. Bahrdt et al., AIP Conf. Proc., SRI 2009, Melbourne Australia, vol. 1234, pp. 499-502, 2010.

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WEPRO049

Experience of Operating a Superconducting Undulator at the Advanced Photon Source

undulator, photon, storage-ring, vacuum

2053

Y. Ivanyushenkov, K.C. Harkay
ANL, Argonne, Ilinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
A superconducting test undulator SCU0 was installed into the storage ring of the Advanced Photon Source (APS) in December 2012 and has been in user operation since January 2013. The first year's experience of operating such a novel insertion device at the APS is summarized in this paper. The performance of the SCU0 as a photon source is presented. The measured heat load from the electron beam is described together with the observed cryogenic behavior of the device. The effect of the SCU0 on the APS electron beam is also presented.

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WEPRO050

Cryogenically Cooled 1J, ps Yb:YAG Slab Laser for High-brightness Laser-Compton X-Ray Source

laser, photon, electron, booster

2056

A. Endo, M. Chyla, T. Miura, T. Mocek, P. Sikocinski
Czech Republic Academy of Sciences, Institute of Physics, Prague, Czech Republic
K. Sakaue, M. Washio
RISE, Tokyo, Japan

Funding: This work benefitted from the support of the Czech Republic’s Ministry of Education, Youth and Sports to the HiLASE and DPSSLasers projects cofinanced from the European Regional Development Fund.
Laser Compton X-ray source is studied as an accelerator-laser hybrid technology to realize a compact source from soft X-ray to gamma ray*. It is critical to design a solid state laser of 1J pulse energy with 1ps pulse length, and a high beam quality for 10 microμm diameter interaction. The required M2 is less than 1.5 in a standard normal incidence configuration. X-ray total photon number is ~10⁹ with 1nC, 3ps 43MeV electron bunch for each shot. HiLASE project is committed to make a progress in the field of new generation solid state laser based on Yb-doped materials, to deliver 1J at 120Hz of 1-2ps with M2<1.5. The laser system consists of a seed fiber laser and two amplifier stages, an Yb:YAG thin disk regenerative amplifier, and a cryogenically cooled single slab booster amplifier. We have obtained output energy of 45mJ from the regenerative amplifier at 1 kHz with M2 <1.2. Booster amplifier is designed by a conduction cooling to build a compact system. Gain bandwidth was 1.2nm at 120K, enough to obtain 1-2ps pulses. Improvement of the crystal holder and the experimental results are presented to indicate the available pulse energy and M2.
*Endo, A. et.al. “Characterization of the monochromatic laser Compton X-ray beam with picosecond and femtosecond pulse widths”, Proceedings SPIE 4502, pp100-108 (2001)

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WEPRO059

Analysis and Design of a New Kirkpatrick-Baez Mirror System for Microbeams

focusing, experiment

2081

K.H. Gil, H. J. Choi, J.Y. Huang, M.H. Jung, J.H. Lim
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This research is part of the results of the Basic Science Research Program performed by the support of the NRF of Korea funded by the Korean Ministry of Education (2013R1A1A2012390).
In this research, a new K-B mirror system was developed for focusing a microbeam to 1 μm x 1 μm at the 4B beamline of the Pohang Light Source-II. The new K-B mirror system consists of a pair of assemblage having three mechanisms that adjust the position, pitch, and curvature of each vertically and horizontally focusing mirrors and stages that support both the assemblages to enable translations along two orthogonal axes and rotation on the horizontal plane. Both the pitch- and curvature-adjusting mechanisms were designed as flexural mechanisms driven by their respective single actuators to minimize the movement of the mirror center even when the pitch or the curvature of each mirror was adjusted. The K-B mirror system with these features will be robust against possible disturbances and will help promote easy and simple mirror adjustment. This paper describes the whole design of the new K-B mirror system in detail and the structural analysis results of the pitch- and the curvature-adjusting mechanisms, and reports the operation principle of the curvature-adjusting mechanism.

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WEPRO061

Optimization of the SIS18 Injector Operation for FAIR

acceleration, experiment, controls, space-charge

2088

D. Ondreka, H. Liebermann, B.R. Schlei
GSI, Darmstadt, Germany

In the FAIR accelerator complex, the existing synchrotron SIS18 will serve as an injector, supplying intense beams of heavy ions and protons for further acceleration in the synchrotron SIS100. In order to satisfy the intensity requirements for FAIR, SIS18 has to be operated routinely at the space charge limit. Particularly demanding requirements arise from the operation with medium charge state heavy ions due to the dynamic vacuum created by ions lost through charge exchange reactions. It is therefore crucial to avoid losses in SIS18 as much as possible while confining unavoidable losses onto low desorption surfaces. In this contribution we report on the ongoing activities related to minimizing the losses by means of a better quantitative understanding and control of the beam. This includes the development of more accurate theoretical models, benchmarked with machine experiments, as well as the practical integration of the models into the control system, using beam instrumentation data in the calculation of set values whenever possible.

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WEPRO062

Reacceleration of Ion Beams for Particle Therapy

synchrotron, ion, extraction, acceleration

2091

C. Schömers, R. Cee, E. Feldmeier, M. Galonska, Th. Haberer, A. Peters, S. Scheloske
HIT, Heidelberg, Germany

At the Heidelberg Ion-Beam Therapy Centre (HIT) cancer patients are treated using the raster-scanning method. A synchrotron provides pencil beams in therapy quality for 255 energy steps per ion type allowing to vary the penetration depth and thus to irradiate tumors slice-by-slice. So far, changing the beam energy necessitates a new synchrotron cycle, including all phases without beam extraction. As the no. of ions that can be accelerated in the synchrotron usually exceeds the required no. of ions for one energy slice, treatment time could be significantly reduced by reaccelerating or decelerating the remaining ions to the next energy level. By alternating acceleration and extraction phases several slices could be irradiated with only short interruptions. Therefore the reacceleration of a transversally blown up beam – due to RF-knockout extraction – must be investigated, beam losses have to be minimized. To estimate the benefit of this operation mode, treatment time has been simulated and compared to the time achieved in the past. A reduction of up to 65% is possible and more patients can be treated! Simulations and first tests of a reaccelerated and extracted beam are presented.

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WEPRO064

Recent Results of the HESR RF System

cavity, impedance, electron, accumulation

2094

R. Stassen, F.J. Etzkorn, R. Greven, T. Katayama, R. Maier, G. Schug, H. Stockhorst
FZJ, Jülich, Germany

The FAIR complex (Facility for Antiprotons and Ion Research) will be built in different stages. Due to the postponed RESR in the first stage, both RF-cavities of the HESR have to operate in different modes to achieve the required beam quantity and quality. The RF-system of the HESR will now consists of two identical cavities with a common low-level RF control (LLRF). Both cavities will be driven by low noise solid state amplifiers. Each cavity contains of one gap and two tanks operating in push-pull mode and each tank will house 6 ring cores wound of modern magnetic nano-alloy ribbon. Meanwhile all ring cores were delivered and first results at low power and at high power will be presented. The construction of the new air cooling concept is now in the final stage.

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WEPRO065

New Design of J-PARC Main Ring Injection System for High Beam Power Operation

injection, kicker, septum, space-charge

2097

K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto, T. Shibata, T. Sugimoto
KEK, Ibaraki, Japan

The present J-PARC main ring (MR) injection system has worked for 6 years since 2008, and the performance has been improved a lot by correcting the original design faults. But there are still problems in the existing injection system that affects the daily operation. In order to realize the MR beam power to the design limit, a high performance injection system is crucial. The remaining problems may have severe effects on high intensity beam, and become a big block to the realization of high beam power operation. Thus, upgrade the present injection system to satisfy the demands of high beam power operation is extremely important. The upgrade will redesign injection septa to obtain high performance, which will reduce the leakage field greatly. The kicker rise time will be reduced greatly by optimizing the configuration and using speed-up circuit. A compensation kicker magnet is being studied for reflection tail field cancelation. Careful 3D electromagnetic field simulations and 3D particle tracking are performed to ensure the accuracy of magnets design.

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WEPRO068

SPS Beam Steering for LHC Extraction

extraction, quadrupole, simulation, closed-orbit

2106

E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA
H. Bartosik, K. Cornelis, L.N. Drøsdal, B. Goddard, V. Kain, M. Meddahi, Y. Papaphilippou, J. Wenninger
CERN, Geneva, Switzerland

The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

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WEPRO089

Latest Developments of a C-band 2MeV Accelerator

experiment, linac, status, detector

2165

W. Bai, M. Li, L.J. Shan, X.M. Shen, Z. Xu
CAEP/IAE, Mianyang, Sichuan, People's Republic of China

A C-band 2MeV accelerator is developped at CAEP in China. This research is aimmed at developing an compact accelerator used as X ray source for industrial useage. At present, the C-band accelerator has been developed successfully. we have carried out a lot of research work based on the accelerator, including test of X ray energy, focus and dose rate etc. This paper shows the latest experimental results and application research status on the C-band accelerator.

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WEPRO113

Status of the Radiation Source ELBE Upgrade

laser, electron, radiation, klystron

2233

P. Michel, T.E. Cowan, U. Lehnert, U. Schramm
HZDR, Dresden, Germany

ELBE is based on a 40 MeV superconducting Electron Linac able to operate in CW mode and provides manifold secondary user beams. The suite of secondary beams include: two free electron lasers operating in the IR/THz regime; a fast neutron beam; a Bremsstrahlung gamma-ray beam; a low-energy positron beam; and patented single-electron test beams. The primary electron beam is also used for radiobiology research, or in interaction with ultra-intense PW-class lasers. Through 2014 ELBE will be upgraded to a Centre for High Power Radiation Sources. The ELBE beam current was increased to 1.6 mA by using novel solid state RF amplifiers. The concept also contains additional broad and narrow band coherent THz sources and the development of a 500 TW TiSa Laser and even a 1.5 PW diode pumped laser system. Laser plasma electron acceleration and proton acceleration experiments for medical applications are planned. Additionally, coupled electron laser beam experiments like Thomson scattering or injection of ELBE electron into the laser plasma will be done.

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WEPME001

Virtual Cathode Drive Laser Diagnostics with a Large Dynamic Range for a Continuous Wave SRF Photoinjector

laser, cathode, electron, diagnostics

2251

E. Panofski, A. Jankowiak, T. Kamps, G. Klemz
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
In a SRF photoinjector the close relationship between the laser pulse and the generated electron bunch parameters requires continuous monitoring of some of the laser pulse parameters. A laser diagnostic system, called virtual cathode, is a key part of a system that controls the stability of the laser. One of the main challenges for the virtual cathode is to cover the large dynamic range of the photocathode laser between commissioning at 120 Hz and operation at 1.3 GHz repetition rate with constant laser pulse parameters. The design of the virtual cathode as well as first measurements with a photocathode drive laser for the SRF injector test facility GunLab of BERLinPro will be presented.

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WEPME003

Two Years Experience with the Upgraded ELBE RF System Driven by 20kW Solid State Amplifier Blocks (SSPA)

klystron, linac, cavity, SRF

2257

H. Büttig, A. Arnold, A. Büchner, M. Justus, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig, G.S. Staats, J. Teichert
HZDR, Dresden, Germany

Since January 2012 the Superconducting CW Linac ELBE is equipped and in permanent operation with four 20 kW Solid State Amplifier Blocks. The poster gives an overview on the design of the new RF system and the experience gained within the first two years of operation.

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WEPME008

72 MHz Solid-state Amplifier Power Test

cavity, cyclotron, controls, impedance

2270

A.Yu. Smirnov, E.V. Ivanov, A.A. Krasnov, S.A. Polikhov, I. Řežanov
Siemens Research Center, Moscow,, Russia
G.B. Sharkov
Siemens LLC, Moscow, Russia

In this paper, we present the performance of 72 MHz 18 kW RF power source developed for cyclotrons. The machine is equipped with 9 class-AB power amplifier modules (each with up to 2 kW output) based on highly reliable LDMOS transistors. The whole system is arranged inside a single 19" cabinet and has coaxial 50 Ω output. The test environment and high power measurement results are described.

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WEPME010

Implementation of Single Klystron Working Mode at the ALBA Linac

klystron, linac, booster, synchrotron

2276

R. Muñoz Horta, J.M. Gómez Cordero, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a third generation synchrotron light source whose injector consists of a 100 MeV Linac and a Booster that accelerates the beam up to the full energy, 3 GeV. Two pulsed klystrons are used to feed the Linac cavities. Klystron 1 feeds the bunching section and also the first accelerating structure. Klystron 2 feeds exclusively the second accelerating structure. Recently, a S-band switching system installed in the waveguide system allows us to use also Klystron 2 to power the low-energy section and operate the Linac at lower energy, around 65 MeV. So that injection into the Booster is still possible while, in the meantime, Klystron 1 can be connected to a dummy load for reparation. Therefore, the time response after a klystron failure is improved. Details of the waveguide upgrade and the results of the ALBA Linac operated with only one klystron are presented.

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WEPME011

2 kW Balanced Amplifier Module for a 30 kW Solid-State Pulsed RF Power Amplifier at 352 MHz

controls, linac, proton, vacuum

2279

A. Kaftoosian, P.J. González
ESS Bilbao, LEIOA, Spain

Design and development of a 30 kW, 352 MHz pulsed RF solid-state power amplifier to be utilized for feeding re-bunching cavities in proton linac, is in progress at ESS-Bilbao. This modular transmitter is based on in-phase combination of compact, water-cooled 2 kW RF power modules, each one consists of two combined LDMOS transistors in balanced configuration. The modules include individual bias control, measurement and supply circuits. Gate modulation is foreseen to increase efficiency in pulsed regime that is up to 3ms RF pulse width and 10% duty cycle. The 2 kW RF power module has been developed and the test results are discussed.

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WEPME012

Solid-State Amplifier Development at FREIA

impedance, cryomodule, network, vacuum

2282

D.S. Dancila, A. Rydberg
Uppsala University, Department of Engineering Sciences, Uppsala, Sweden
A. Eriksson, V.A. Goryashko, L.F. Haapala, R.J.M.Y. Ruber, R. Wedberg, R.A. Yogi, V.G. Ziemann
Uppsala University, Uppsala, Sweden

The FREIA laboratory is a Facility for REsearch Instrumentation and Accelerator development at Uppsala University, Sweden, constructed recently to test and develop superconducting accelerating cavities and their high power RF sources. FREIA's activity target initially the European Spallation Source (ESS) requirements for testing spoke cavities and RF power stations, typically 400 kW per cavity. Different power stations will be installed at the FREIA laboratory. The first one is based on vacuum tubes and the second on a combination of solid state modules. In this context, we investigate different related aspects, such as power generation and power combination. For the characterization of solid-state amplifier modules in pulsed mode, at ESS specifications, we implemented a Hot S-parameters measurement set-up, allowing in addition the measurement of different parameters, such as gain and efficiency. We developed also a new solid-state amplifier module at 352 MHz, using commercially available LDMOS transistors. Preliminary results show a drain efficiency of 71% at 1300 W pulsed output power.

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WEPME018

CERN Vacuum System Activities during the Long Shutdown 1: The LHC’s injector chain.

vacuum, linac, ion, gun

2291

J.A. Ferreira Somoza, P. Chiggiato
CERN, Geneva, Switzerland

During the long shutdown 1 (LS1), several maintenance, consolidation and upgrade activities have been carried out in LHC’s injector chain. Each machine has specific vacuum requirements and different history, which determine the present status of the vacuum components, their maintenance and consolidation needs. The present work presents the priorities agreed at the beginning of the LS1 period and their implementation. Of particular relevance are the interventions in radioactive controlled areas where several leaks due to stress corrosions stopped the operations in the past years. The strategy to reduce the collective dose is presented, in particular the use of remote controlled robots. An important part of the work performed during this period involves supporting other teams (acceptance tests, new equipment installation, etc.). Finally, as a result of the LS1 experience, a medium to long term strategy is depicted, focusing on the preparation of the next shutdown (LS2) and the integration of LINAC4 in the injector chain during the same period.

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WEPME019

Heat Distribution Analysis of Planar Baluns for 1kW Solid-state Amplifiers and Power Combining for 1.8kW

impedance, storage-ring, booster, controls

2294

T.-C. Yu, L.-H. Chang, M.H. Chang, L.J. Chen, F.-T. Chung, M.-C. Lin, Y.-H. Lin, Z.K. Liu, C.H. Lo, M.H. Tsai, Ch. Wang, T.-T. Yang, M.-S. Yeh
NSRRC, Hsinchu, Taiwan

Solid-state transmitter for booster and storage ring in synchrotron would be composed of hundreds of amplifier modules. The amplifier module is biased at class AB and constructed in push-pull operation. Recent trend of amplifier module design features higher power up to 800 Watts and equipped planar balun (balance-unbalance converter) for push-pull operation. In NSRRC, the exclusive round planar design has encounter high temperature situation at kW range. Therefore, further study on this thermal condition is carried out in this study. Four types of planar balun design and two laminate materials are used for heat analysis. The typical coaxial balun is also applied on actual amplifier design. The results bring the better design with proper laminate choice and leads to acceptable thermal distribution with 1kW output power at 500MHz. Besides, for a more compact module with higher output power, the combination of two chips on the same circuit reaching 1.8kW is also presented.

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WEPME020

Commissioning of the MICE RF System

power-supply, experiment, cavity, high-voltage

2297

A.J. Moss, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.M.H. Alsari
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
A.J. Dick, K. Ronald, D.C. Speirs, C.G. Whyte
USTRAT/SUPA, Glasgow, United Kingdom
T. Stanley
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
C.J. White
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom

The Muon Ionisation Cooling Experiment (MICE) is being constructed at Rutherford Appleton Laboratory in the UK. The muon beam will be cooled using multiple hydrogen absorbers then reaccelerated using an RF cavity system operating at 201MHz. This paper describes recent progress in commissioning the amplifier systems at their design operation conditions, installation and operation within the Ionisation Cooling Test Facility (ICTF) as part of the MICE project.

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WEPME021

Solid-state Pulsed Klystron Transmitters

klystron, high-voltage, power-supply, flattop

2300

K. Schrock, C. Chipman, M.P.J. Gaudreau, B.E. Simpson
Diversified Technologies, Inc., Bedford, Massachusetts, USA

Funding: Lawrence Berkeley National Laboratory Daresbury Laboratory
Diversified Technologies, Inc. (DTI) is currently building and will deliver in early 2014 two solid-state pulsed klystron transmitters. Though not identical, the units are similar in design, and will be delivered to Lawrence Berkeley National Laboratory (LBNL) and Daresbury Laboratory in England. DTI’s goal across these two projects is to develop a complete package which can subsequently be marketed in the high peak power laboratory transmitter market. The modulator is a pulse transformer-coupled hybrid system, including ancillary klystron components (i.e., focus coil, socket) but not the actual klystron tube. Both systems employ a relatively simple modulator, consisting of an energy storage capacitor, a high voltage series switch, a step-up pulse transformer, and a passive pulse-flattening circuit. This arrangement gives an extremely flat pulse and allows the use of a moderate value of storage capacitor. The DTI switch can open or close as commanded, so the pulse width is adjusted by the gate pulse to the system.

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WEPME022

The VSL3616, CPI’s 1.3 GHz, 700 Watt CW, GaN Solid State Power Amplifier

controls, insertion, monitoring, network

2302

G. Solomon, D. Riffelmacher, R. Snyder, M. Tracy, T.A. Treado
CPI, Beverley, Massachusetts, USA

The VSL3616 GaN SSPA is a 1.3 GHz, 700 watt CW, liquid-cooled solid state power amplifier (SSPA). It has exceptional amplitude and phase stability and is being used to drive the VKL9130A1 IOT in CPI’s VIL410 30 kW CW IOT transmitter. The VSL3616 SSPA is configured in a 19 inch rack mount enclosure. Higher power levels can be obtained by power combining multiple VSL3616 SSPAs. The VSL3616 SSPA has been designed for very tight amplitude and phase control. The amplitude ripple and phase ripple are specified to be better than 0.05% rms and better than 0.2 degrees rms, respectively. The stability of the output power is specified to be better than 0.1% over any 20 second period of time. This paper will describe the design and operation of the VSL3616 SSPA. Results from a 1000 hour life test will be presented.

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WEPME023

VIL410, CPI’s 1.3 GHz, 25 kW CW IOT Amplifier System

controls, insertion, embedded, cathode

2305

I. Igor, R. Army, P. Brown, S. Locke, R. Rizzo, R. Snyder, G. Solomon, M. Tracy, T.A. Treado
CPI, Beverley, Massachusetts, USA

The VIL10 Heatwave™ Inductive Output Tube (IOT) amplifier system has been developed to meet the requirements of superconducting RF accelerators. Two VIL410 systems were completed and delivered in April 2014. The VKL9130A1 IOT in the VIL410 provides up to 30 kW RF output power over a 5 MHz bandwidth centered at 1.30 GHz. It operates both CW and pulsed. The VIL410 amplifier has been designed to achieve very tight amplitude and phase control. The amplitude and phase ripple are specified to be better than 0.1% rms and better than 0.2 degrees rms, respectively. The stability of the output power is specified to be better than 0.2% over a 20 second period. In normal operation, smooth control of the output is accomplished via RF input from the low level system. The VIL410 uses CPI’s VSL3616 solid state power amplifier (SSPA) to drive the IOT. The VSL3616 is a 700 watt CW SSPA which operates at 250 watts CW in the VIL410. The VIL410 has an embedded processor that controls all internal functions of the amplifier system and interfaces directly to EPICS. The VIL410 can be operated locally using a LabView PC Host program or remotely by EPICS.

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WEPME028

Systematic Measurement of the Pumping Capabilities of Cryogenic Surfaces

radiation, cryogenics, vacuum, simulation

2317

F. Chill, O.K. Kester
IAP, Frankfurt am Main, Germany
L.H.J. Bozyk, O.K. Kester, P.J. Spiller
GSI, Darmstadt, Germany

The quality of the beam vacuum is crucial for the stable operation of synchrotrons with high intensity heavy ions. Cryogenic surfaces are capable of pumping residual gases by cryocondensation until the saturated vapor pressure (SVP) is reached. Even at LHe temperatures the SVP of hydrogen is too high. If the surface coverage is sufficiently low, residual gas can also be bound by cryosorption, yielding in acceptable low pressures. These pumping capabilities can be described by two parameters, both dependent on surface temperature and coverage: The sticking probability (SP), that is the chance of an impinging gas particle to be bound, and the mean sojourn time (MST) of a particle on the surface. To acquire these parameters, an experimental setup is currently built at GSI. It consists of a cryogenic chamber, cooled by a cold head and a warm part with vacuum diagnostics and gas inlet. It allows monitoring the pumping speed and also the equilibrium pressure of the cryogenic part from which the SP and the MST can be deducted. The results will be used to further improve the accuracy of the dynamic vacuum simulations in cryogenic areas of particle accelerators.

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WEPME029

Development of a Field Emitter-based Extractor Gauge for the Operation in Cryogenic Vacuum Environments

vacuum, cryogenics, ion, cathode

2320

M. Lotz, O.K. Kester, St. Wilfert
GSI, Darmstadt, Germany

This paper presents an investigation of a CNT emitter-based extractor gauge which is designed for pressure reading in cryogenic ultra-high vacuum systems. The results show that the modified gauge works well in both room temperature and cryogenic vacuum environments. Furthermore, it could be demonstrated that the modified gauge responds much more sensitive to small pressure fluctuations in cryogenic environments than the same gauge type having a hot-filament cathode.

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WEPME030

Design and Construction of a Prototype Sputter ion Pump in ILSF

ion, vacuum, cathode, electron

2323

O. Seify, H. Ghasem, S. Kashani, J. Rahighi
ILSF, Tehran, Iran
H. Ghasem
IPM, Tehran, Iran

Design and construction process of special kind of sputter ion pump is described briefly in this paper. In order to investigate the optimization of effective parameters in choosing and designing ILSF ion pumps, this pump has been designed and manufactured. By optimizing some parameters such as dimension and shape of penning cells, anode voltage, magnetic field and internal structure of pump, it is possible to significantly decrease the cost of construction and operation of synchrotron vacuum system. One of the most important advantages of this design, is that the initial parameters and finally internal structure of the prototype pump are changeable easily. The effect of parameters like anode voltage, magnetic field etc. on pumping speed and final pressure are described. With the existing optimization it is expected that an ultimate pressure of 1x10^-11 Torr could be achieved.

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WEPME032

Detailed Investigation of the Low Energy Secondary Electron Yield of Technical Cu and its Relevance for LHC

electron, gun, simulation, dipole

2329

R. Cimino, L.A. Gonzalez, A.L. Romano
INFN/LNF, Frascati (Roma), Italy
R. Cimino, G. Iadarola, G. Rumolo
CERN, Geneva, Switzerland
R. Larciprete
ISM-CNR, Rome, Italy

The detailed study of the Secondary Electron Yield (SEY) of technical Cu for very low electron landing energies (from 0 to 30 eV) is very important for electron cloud build up in high intensity accelerators and in many other fields of research. However, this question has been rarely addressed due to the intrinsic experimental complexity to control very low energy electrons. Furthermore, several results published in the past have been recently questioned for allegedly suffering from experimental systematics. In this paper, we critically review the experimental method used to study low energy SEY and define more precise energy regions, in which the experimental data can be considered valid. The new SEY curves are then fed into e-cloud simulation codes to address their impact for electron cloud predictions in the LHC.

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WEPME043

Design and Qualification of Transparent Beam Vacuum Chamber Supports for the LHCb Experiment

experiment, vacuum, factory, proton

2363

J.L. Bosch, P. Chiggiato, C. Garion
CERN, Geneva, Switzerland

Beryllium beam vacuum chambers pass through the aperture of the large dipole magnet and particle acceptance region of the LHCb experiment, coaxial to the LHC beam. At the interior of the magnet, a system of rods and cables supports the chambers, holding them rigidly in place, in opposition to the vacuum forces caused by their conical geometry. In the scope of the current upgrade program, the steel and aluminium structural components are replaced by a newly designed system, making use of Beryllium, in addition to a number of organic materials, and are optimized for overall transparency to incident particles. Presented in this paper are the design criteria, along with the unique design developments carried out at CERN, and furthermore, a description of the technologies procured from industrial partners, specifically in obtaining the best solution for the cable components.

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WEPME045

Assessment of New Components to be Integrated in the LHC Room Temperature Vacuum System

vacuum, experiment, injection, ion

2369

G. Bregliozzi, V. Baglin, P. Chiggiato
CERN, Geneva, Switzerland

Integration of new equipment in the long straight sections (LSS) of the LHC must be compatible with the TiZrV non-evaporable getter thin film that coats most of the 6-km-long room-temperature beam pipes. This paper focus on two innovative accelerator devices to be installed in the LSS during the long shutdown 1 (LS1): the beam gas vertex (BGV) and a beam bending experiment using crystal collimator (LUA9). The BGV necessitates a dedicated pressure bump, generated by local gas injection, in order to create the required rate of inelastic beam-gas interactions. The LAU9 experiments aims at improving beam cleaning efficiency with the use of a crystal collimator. New materials like fibre optics, piezoelectric components, and glues are proposed in the original design of the two devices. The integration feasibility of these set-ups in the LSS is presented. In particular outgassing tests of special components, X-rays photoelectron spectroscopy, analysis of NEG coating behaviour in presence of glues during bake-out, and pressure profile simulations will be presented.

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WEPME046

The HIE-Isolde Vacuum System

vacuum, linac, cryomodule, controls

2372

G. Vandoni, S. Blanchard, P. Chiggiato, K. Radwan
CERN, Geneva, Switzerland

The High Intensity and Energy Isolde (HIE-Isolde) project aims at increasing the energy and intensity of the radioactive ion beams (RIB) delivered by the present Rex-Isolde facility. Energy up to 10MeV/amu will be reached by a new post-accelerating, superconducting (SC) linac. Beam will be delivered via a HEBT to three experimental stations for nuclear physics. To keep the SC linac compact and avoid cold-warm transitions, the cryomodules feature a common beam and insulation vacuum. Radioactive ion beams require a hermetically sealed vacuum, with transfer of the effluents to the nuclear ventilation chimney. Hermetically sealed, dry, gas transfer vacuum pumps are preferred to gas binding pumps, for an optimized management of radioactive contamination risk during maintenance and intervention. The vacuum system of the SC-linac is isolated by two fast valves, triggered by fast reacting cold cathode gauges installed on the warm linac, the HEBT and the experimental stations. Rough pumping is distributed, while the HEBT turbomolecular pumps also share a common backing line. Slow pumpdown and ventilation of the cryomodules are studied to avoid particulate movement in the viscous regime.

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WEPME062

A New Digital LLRF System for a Fast Ramping Storage Ring

cavity, LLRF, feedback, injection

2418

M. Schedler, F. Frommberger, W. Hillert, D. Proft, D. Sauerland
ELSA, Bonn, Germany
D. Teytelman
Dimtel, San Jose, USA

At the Electron Stretcher Facility ELSA of Bonn University, an upgrade of the maximum stored beam current from 20 mA to 200 mA is planned. The storage ring operates applying a fast energy ramp of 6 GeV/s from 1.2 GeV to 3.5 GeV and a slow extraction afterwards over a few seconds to the hadron physics experiments. The intended upgrade is mainly limited by the coupled-bunch instabilities and the ability of bunch-by-bunch feedback systems to suppress such instabilities. In order to achieve optimum bunch-by-bunch feedback performance, the beam phase with respect to the master oscillator and the synchrotron frequency have to stay constant. This paper reports on a new high performance low level RF (LLRF) system. The system stabilizes the cavity field and is capable of executing fast voltage and phase ramps. The LLRF uses FPGA-based digital signal processing and includes cavity tuner control as well as fast interlocks and extensive diagnostics.

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WEPME066

High Speed Digitial LLRF Feedbacks for Normal Conducting Cavity Operation

LLRF, gun, cavity, klystron

2430

M. Hoffmann, L. Butkowski, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany
W. Köhler
DESY Zeuthen, Zeuthen, Germany
A. Piotrowski
TUL-DMCS, Łódź, Poland
I. Rutkowski, R. Rybaniec
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland

In the first half of the year 2014, the MTCA.4 based LLRF control system will be installed at several facilities (FLASH RF Gun, REGAE, PITZ, FLUTE/KIT). First tests during the last year show promising results in optimizing the system for high speed digital llrf feedbacks (reducing system latency, increase internal controller processing speed). In this contribution we will present further improvements in latency and performance optimization of the system, results and gained experience from the commisioning of the system at the metioned facilities.

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WEPME067

Performance of the MTCA.4 Based LLRF System at FLASH

LLRF, electron, laser, free-electron-laser

2433

Ch. Schmidt, V. Ayvazyan, J. Branlard, L. Butkowski, M.K. Grecki, M. Hoffmann, F. Ludwig, U. Mavrič, K.P. Przygoda, H. Schlarb, H.C. Weddig, B.Y. Yang
DESY, Hamburg, Germany
W. Cichalewski, D.R. Makowski, A. Piotrowski
TUL-DMCS, Łódź, Poland
K. Czuba, I. Rutkowski, D. Sikora, M. Żukociński
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
I.M. Kudla
NCBJ, Świerk/Otwock, Poland
K. Oliwa, W. Wierba
IFJ-PAN, Kraków, Poland

The Free Electron Laser in Hamburg (FLASH) is the first linac which is equipped with a MTCA.4 based low level RF control system. Precise regulation of RF fields is essential for stable and and reproducible photon generation. Flash benefits from the performance increase using the new developments like, accurate and precise field detection devices. Further enourmous increase of processing capabilities allow for more sophisticated controller applications which better the overall performance of the regulation.

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WEPME069

Performance of a Compact LLRF System using Analog RF Backplane in MTCA.4 Crates

controls, distributed, LLRF, timing

2438

U. Mavrič, M. Fenner, M. Hoffmann, F. Ludwig, A.T. Rosner, H. Schlarb
DESY, Hamburg, Germany
K. Czuba, T.P. Leśniak
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
A. Rohlev
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

In order to increase system compactness, mitigate cabling problems, increase rack space, minimize points of failure in the system and reduce digital distortion leakage into the sensitive analog signals, the concept of the RF backplane located in the rear section of the MTCA.4 crate has been introduced. Besides signal distribution, the concept includes a signal generation module and backplane management module. The generation and splitting of the analog signals is taking place in slots 15 and 14 on the rear side in theμLO generation module (uLOG). This module generates the local oscillator signal, the clocks and feeds through the master reference signal over the RF backplane to the slots. In this paper we present the recent results of such system.

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WEPME075

Real-time Estimation of Superconducting Cavities Parameters

cavity, controls, FPGA, LLRF

2456

R. Rybaniec
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
V. Ayvazyan, J. Branlard, L. Butkowski, S. Pfeiffer, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany
W. Cichalewski, K.P. Przygoda
TUL-DMCS, Łódź, Poland

Performance of accelerators based on the superconductive cavities including FLASH and XFEL facilities at DESY is affected by cavity parameters variation over time. High gradient electromagnetic field inside cavities causes detuning due to the Lorentz force. In addition the quality factor of cavities can change during the RF field pulse. Currently used method for estimation of those parameters is based on the post-processing of the data recorded during operation of the RF. External servers calculate cavity parameters using cavity equation, forward power and probe signals collected during previous pulse. A novel approach* based on the component implemented in FPGA is presented. In the new method loaded quality factor and detuning are estimated in real-time during the RF pulse for increased reliability and better exception handling. Modified firmware of the LLRF control system based on the Micro Telecommunications Computing Architecture (MTCA) platform has been used for the method verification.
*”Development of Control System for Fast Frequency Tuners of Superconducting Resonant Cavities for FLASH and XFEL Experiments”, K. Przygoda, PhD thesis, Technical University of Łódź, Poland, 2010.

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WEPRI002

Status and First Results of Two High Beta Prototype Elliptical Cavities for ESS

cavity, cryomodule, accelerating-gradient, niobium

2477

F. Peauger, P. Bosland, P. Carbonnier, G. Devanz, F. Éozénou, X. Hanus, P. Hardy, V.M. Hennion, J. Plouin, D. Roudier, C. Servouin
CEA/DSM/IRFU, France
C. Darve, S. Molloy
ESS, Lund, Sweden
L. Maurice
CEA/IRFU, Gif-sur-Yvette, France
G. Olivier
IPN, Orsay, France

Two prototypes of elliptical superconducting cavities have been designed and manufactured in the frame of the French-Swedish agreement for ESS. These 5-cell cavities have a beta value of 0.86 and their frequency is 704.42 MHz. The nominal accelerating gradient on the ESS accelerator is 19.9 MV/m at 2K. We present the manufacturing status of the cavities by two different vendors as well as the specific means which have been developed for the cavity treatments performed at CEA after delivery. We emphasis the activities performed on the first bare cavities recently received at CEA such as the RF measurement and tuning operations, the cleaning and chemical treatments and the clean room assembly including high pressure rinsing. Finally, first test results at 2K in vertical cryostat are reported.

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WEPRI004

Operational Experience and Upgrades of the SOLEIL Storage Ring RF System

cavity, vacuum, cryogenics, SRF

2480

P. Marchand, J.P. Baete, R.C. Cuoq, H.D. Dias, M. Diop, J.L. Labelle, R. Lopes, M. Louvet, C.M. Monnot, L.S. Nadolski, S. Petit, F. Ribeiro, T. Ruan, R. Sreedharan, K. Tavakoli
SOLEIL, Gif-sur-Yvette, France

In the SOLEIL storage ring, two cryomodules provide to the electron beam an accelerating voltage of 3-4 MV and a power of 575 kW at 352 MHz. Each cryomodule contains a pair of superconducting cavities, cooled with liquid Helium at 4.5 K, which is supplied by a single 350 W cryogenic plant. The RF power is provided by four solid state amplifiers, each delivering up to 180 kW. The parasitic impedances of the high order modes (HOM) are strongly mitigated by means of four coaxial couplers, located on the central pipe connecting the two cavities. Eight years of operational experience with this system, as well as its upgrades, are reported.

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WEPRI005

Processing and Testing of the SRF Photoinjector Cavity for BERLinPro

cavity, SRF, electron, niobium

2484

A. Burrill, W. Anders, A. Frahm, J. Knobloch, A. Neumann
HZB, Berlin, Germany
G. Ciovati, W.A. Clemens, P. Kneisel, L. Turlington
JLab, Newport News, Virginia, USA
E.N. Zaplatin
FZJ, Jülich, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
The BERLinPro project is a compact, c.w. SRF energy recovery linac (ERL) that is being built to develop the accelerator physics and technology required to operate the next generation of high current ERLs. The machine is designed to produce a 50 MeV 100 mA beam, with better than 1 mm-mrad emittance. The electron source for the ERL will be a SRF photoinjector equipped with a multi-alkali photocathode. In order to produce a SRF photoinjector to operate reliably at this beam current HZB has undertaken a 3 stage photoinjector development program to study the operation of SRF photoinjectors in detail. The 1.4 cell cavity being reported on here is the second stage of this development, and represents the first cavity designed by HZB for use with a high quantum efficiency multi-alkali photocathode. This paper will describe the work done to prepare the cavity for RF testing in the vertical testing dewar at Jefferson Laboratory as well as the results of these RF tests.

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WEPRI012

Euclid Modified SRF Conical Half-wave Resonator Design

cavity, vacuum, simulation, controls

2502

E.N. Zaplatin
FZJ, Jülich, Germany
T.L. Grimm, A. Rogacki
Niowave, Inc., Lansing, Michigan, USA
A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: This Work is supported by the DOE SBIR Program, contract # DE-SC0006302.
The new low-beta conical Half-Wave Resonator (cHWR) is suggested for CW proton accelerators of new generation with relatively low beam loading, where frequency detune caused by microphonics and helium pressure fluctuations is essential. This particular design, considered in the paper, has operation frequency of 162.5 MHz, b=v/c=0.11, and is suitable for the first section of the PIP-II superconducting accelerator which is under development at Fermilab. The main idea of the cHWR design is to provide a self-compensation cavity design together with its helium vessel to minimize the resonant frequency dependence on external loads. A unique cavity side-tuning option is also under development. Niowave, Inc. proposed a series of cavity and helium vessel modifications to simplify their manufacturing. The whole set of numerical simulations has been generated to verify that the main parameters of the initial structure design were not affected by the proposed modifications. Here we present the main results of the cavity and helium vessel modified design.

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WEPRI013

Investigation of Cryomodules for the Mainz Energy-recovering Superconducting Accelerator MESA

cryomodule, linac, HOM, higher-order-mode

2505

F. Schlander, K. Aulenbacher, R.G. Heine, D. Simon
IKP, Mainz, Germany
A. Arnold
HZDR, Dresden, Germany

Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA"
For the multiturn accelerator MESA it is planned to employ superconducting technology for the main linac, which is supposed to provide an energy gain of 50 MeV per turn. As continuous wave operation is mandatory for the experiments, it is important to minimise the cryogenic losses, hence to find cavities and the corresponding cryomodule meeting the framework conditions for the accelerator. The findings and the current statuts will be reported.

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WEPRI016

Status of the Vertical Testing of the XFEL Third Harmonic Cavity Series

cavity, HOM, coupling, linac

2508

J.F. Chen, M. Bertucci, A. Bosotti, M. Fusetti, C. Maiano, P. Michelato, L. Monaco, M. Moretti, C. Pagani, R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy

The prototype cavities of the XFEL 3rd harmonic system at the XFEL injector have been tested vertically before their final integration into the He tank. The Vertical Test facility has been upgraded in preparation of the series and the results so far obtained are presented.

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WEPRI026

Mechanical Vibration Search of Compact ERL Main Linac Superconducting Cavities in Cryomodule

cavity, LLRF, cryomodule, linac

2531

M. Satoh, K. Enami, T. Furuya, S. Michizono, T. Miura, F. Qiu, H. Sakai, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

In 2014, we will start the beam operation in Compact ERL(cERL) by using main linac cryomodule, which contained the two 9-cell cavities. In principle, thanks to the mechanism of energy recovery, the input power of main linac of cERL is very small even if the beam current will be higher than 100mA. Therefore, the coupling is very weak. However, this coupling is perfectly not matched to the unloaded Q-value of the superconducting cavity like 1x10¹⁰. The minimum input power will be restricted by the cavity detuning due to the microphonics from the cryomodule itself. We designed the lower loaded Q-valued of (1-4)x10⁷ to reduce the effect of the michrophonics from the expected outer disturbance At present, we successfully suppressed the michrophonics to meet our requirement. However we found the enhancement of the detuning angle when we did not optimize the feedback loop of LLRF. This enhancement will be expected coming from the mechanical resonance frequencies of cavity and/or cryomodule. In this paper, we reported the correlation between the measured microphincs spectrum with LLRF in a beam operation and the results of the measured resonance frequencies spectrum at the test bench.

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WEPRI027

Performance Evaluation of ERL Main Linac Tuner

linac, cavity, controls, feedback

2534

K. Enami, D.A. Arakawa, T. Furuya, S. Michizono, T. Miura, F. Qiu, H. Sakai, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

cERL project is now progressing. We are carrying on R&D for cERLmain linac consisted of 1.3GHz superconductive cavity. We evaluate slide jack tuner, which is component part of cryomodule. A slide jack tuner has 2 mechanism to tune frequency. One is slide jack mechanism that tunes roughly and the other is piezo mechanism that tunes finely. We carried out basic experiment and cold experiment. We finally confirmed that slide jack tuning system can tuning to target frequency 1.3GHz.

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WEPRI028

Operation Status of Compact ERL Main Linac Cryomodule

linac, radiation, cavity, cryomodule

2537

K. Umemori, K. Enami, T. Furuya, S. Michizono, T. Miura, F. Qiu, H. Sakai, M. Satoh, K. Shinoe
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

We have developed a main linac cryomodule, in which two nine-cell HOM damped SRF cavities were mounted, for the Compact ERL (cERL) project in Japan. The main linac cryomodule is operated by a 2K refrigerator system, whose cooling ability is 80W. RF power is fed to each cavity from an IOT or a solid state amplifier. Amplitude and phase of RF stabilization is done by using a digital LLRF system. Cavity resonant frequency is controlled by using mechanical and piezo tuners. Before beam operation, performance test of the cryomodule has been carried out. Generally the cryomodule works well, but heavy field emission is rather problem. After construction of cERL circulation ring, we have a plan to do first beam operation with energy recovery mode, in this winter. Electron beam are accelerated up to 20 MeV. Heavy heat load to 2K Helium, caused by field emission, restrict cavity operation voltage. We report about a series of performance tests and a first experiment from beam operation.

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WEPRI035

Stiffening Structure of the HWR at RISP

cavity, simulation, target, controls

2552

G.-T. Park, H.J. Cha, H. Kim, H.J. Kim, W.K. Kim
IBS, Daejeon, Republic of Korea

The HWR being developed in RISP, Korea is in its final stage of the design. We consider the effects of the stiffeners in the presence of the helium vessel on the various detunings such as cool down, helium pressure fluctuation, Lorentz pressure. The interaction of the stiffened cavity with the helium jacket is studied via the coupled simulation by ANSYS and the optimal specification of the stiffeners are determined. In addition, the expected frequency shift is predicted to establish the target frequency bfor the manufacturing. The effect of the vibrational motion is also studied.

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WEPRI039

LIPAc SRF Linac Couplers Conditioning

vacuum, linac, SRF, electron

2562

D. Regidor, I. Kirpitchev, J. Mollá, P. Méndez, M. Weber, C. de la Morena
CIEMAT, Madrid, Spain
S. Chel, M. Desmons, G. Devanz, H. Jenhani
CEA/IRFU, Gif-sur-Yvette, France
H. Dzitko
CEA, Pontfaverger-Moronvilliers, France

The LIPAc SRF Linac is a cryomodule with eight superconducting HWR cavities at 175 MHz powered by RF couplers capable of transmitting up to 200 kW in CW. To prepare the couplers for operation, cleaning and high power RF processing are needed. When performed, the couplers will be ready for integration in the cryomodule. The Couplers Test Bench has been designed to perform the RF conditioning by pairs, providing good matching, low losses and the required UHV level. To preserve the cleanliness of the internal surfaces, after the test bench manufacturing, an ISO5 clean room has been used for the vacuum parts assembly. The size and number of particles was carefully controlled during the assembly process. The RF conditioning was performed at the IFMIF-EVEDA RF Integration Facility using the Prototype RF Module in travelling wave and standing wave modes. The process started with short pulses at low power and finished when full power CW was reached. Vacuum, multipacting, arcs and matching were continuously monitored to control the process avoiding damages. An overview of the process applied to the prototypes and the RF conditioning results are presented in this paper.

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WEPRI049

Optimization of Window Position on Diamond SCRF Cavities

cavity, coupling, simulation, impedance

2592

S.A. Pande, C. Christou
DLS, Oxfordshire, United Kingdom

The Diamond storage ring uses CESR type superconducting cavities. These cavities have a fixed coupling resulting in fixed Qext which is considerably higher than the optimum. We use 3 stub tuners to match the cavities under these non-optimum conditions. Diamond Cavity-1 will soon be refurbished. This opportunity could be used to lower the Qext on the cavity. One of the options is to modify the coupling tongue geometry along with a matching section. This may require cutting off the beam tube with the coupler for rework or it may need to be newly fabricated. We investigated another option to lower the Qext of the cavity by optimising the location of the window with respect to the cavity, maintaining the same coupling tongue geometry. The height of the waveguide on the vacuum side of the window differs from that of the coupling waveguide on the cavity resulting in a step. The location of window with respect to the cavity makes a significant difference to the ultimate Qext obtained after putting the window in place. In this paper we present the results of our numerical simulations comparing the present and the proposed window position under different operating conditions.

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WEPRI052

SRF Systems for ASTA at Fermilab

cavity, cryomodule, SRF, electron

2601

E.R. Harms, C.M. Baffes, K. Carlson, B. Chase, D.J. Crawford, E. Cullerton, D.R. Edstrom, M. Geynisman, A. Hocker, A.L. Klebaner, M.J. Kucera, J.R. Leibfritz, J.N. Makara, D. McDowell, S. Nagaitsev, O.A. Nezhevenko, D.J. Nicklaus, H. Pfeffer, Y.M. Pischalnikov, P.S. Prieto, J. Reid, W. Schappert, P. Stabile, P. Varghese
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The Advanced Superconducting Test Accelerator (ASTA) at Fermilab now being commissioned is comprised of a number of superconducting RF systems including single-cavity cryomodules and a TESLA/ILC style 8-cavity cryomodule. Two of them, 'Capture Cavity 2' and 'Cryomodule 2', have been cooled to 2 Kelvin and brought into operation. We provide an overview of the unique characteristics of each of the systems, commissioning experience, and latest results including their respective operating characteristics.

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WEPRI054

Medium Field Q-Slope Studies in Low Beta Resonators

cavity, radiation, niobium, controls

2608

O.S. Melnychuk, A. Grassellino, A.I. Sukhanov
Fermilab, Batavia, Illinois, USA

Studies of the phenomenon of Medium field Q-slope (MFQS, 30-80 mT) have been focused predominantly on high beta superconducting cavities. Complementing research on cavity losses with the analysis of low beta cavity data can provide additional insights into the nature of MFQS. We present MFQS measurements of 325MHz β=0.2 single spoke resonators and 650MHz β=0.9 elliptical single cell resonators at vertical test facility at FNAL. We compare our findings with those obtained for high frequency 1.3GHz cavities tested both at the same facility and other laboratories.

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WEPRI067

Multi-Physics Analysis of CW Superconducting Cavity for the LCLS-II using ACE3P

cavity, simulation, feedback, vacuum

2645

Z. Li, C. Adolphsen, O. Kononenko, T.O. Raubenheimer, C.H. Rivetta, M.C. Ross, L. Xiao
SLAC, Menlo Park, California, USA

Funding: Work was supported by the U.S. DOE contract DE-AC02-76SF00515 and used the resources of NERSC at LBNL under US DOE Contract No. DE-AC03-76SF00098.
The LCLS-II linac utilizes superconducting technology operating at continuous wave to accelerate the 1-MHz electron beams to 4 GeV to produce tunable FELs. The TESLA 9-cell superconducting cavity is adopted as the baseline design for the linac. The design gradient is approximately 16 MV/m. The highest operating current is 300 μA. Assuming that the RF power is matched at the highest current, the optimal loaded QL of the cavity is found to be around 4·10⁷. Because of the high QL, the cavity bandwidth approaches the background microphonic detuning, and the performance of the cavity is tightly coupled to the mechanical perturbations of the cavity/cryomodule system. The resulting large phase and amplitude variations in the cavity require active feedback to achieve the 0.01% amplitude and phase stability requirements. To understand the cavity RF response and feedback requirements to the microphonics and Lorentz Force detuning, we have developed a simulation model of the RF-mechanical coupled system using parameters obtained with the multi-physics solver ACE3P. We will present the simulation results of the LCLS-II linac under different power feed scenarios and feedback schemes.

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WEPRI074

Status of SRF Facilities at SNS

cavity, SRF, cryomodule, controls

2663

J. Saunders, R. Afanador, B. DeGraff, C.J. McMahan
ORNL RAD, Oak Ridge, Tennessee, USA
M.T. Crofford, M. Doleans, M.P. Howell, S.-H. Kim, S.W. Lee, T.S. Neustadt, S.E. Stewart, W.H. Strong
ORNL, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
As a part or an ongoing process to maintain and improve the performance of its Superconducting Linac (SCL) the Spallation Neutron Source (SNS) is building facilities for processing and testing Superconducting Radio Frequency (SRF) cavities. Recently both a High Pressure Rinse (HPR) tool and a Vertical Test Apparatus (VTA) have been built and commissioned. The HPR is a commercially fabricated piece of equipment which is customized for the SNS application. The VTA was specified, designed and developed by the SNS. This paper will outline the design features as well as the commissioning results for both systems.

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WEPRI083

The SIS100 Superconducting Fast Ramped Dipole Magnet

dipole, controls, quadrupole, magnet-design

2681

E.S. Fischer, A. Bleile, J.P. Meier, A. Mierau, P. Schnizer
GSI, Darmstadt, Germany
P.G. Akishin
JINR, Dubna, Moscow Region, Russia

The first dipole magnet of the superconducting SIS100 accelerator was delivered by industry and its thermodynamic, electrical and magnetic field performance was measured. We describe the build of the test facility, the infrastructure and its performance, outline the chosen measurement methods along with the optimisation of the magnet end required for obtaining the requested integral field quality. The measured ac loss parameters will be discussed in respect of the possible operation performance of the whole machine, the relevant cooling conditions of the main dipole magnet.

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WEPRI092

Test and Simulation Results for Quenches Induced by Fast Losses on a LHC Quadrupole

injection, quadrupole, simulation, proton

2706

C. Bracco, B. Auchmann, W. Bartmann, M. Bednarek, A. Lechner, M. Sapinski, R. Schmidt, N.V. Shetty, M. Solfaroli Camillocci, A.P. Verweij
CERN, Geneva, Switzerland

A test program for beam induced quenches was started in the LHC in 2011 in order to reduce as much as possible BLM-triggered beam dumps, without jeopardizing the safety of the superconducting magnets. A first measurement was performed to assess the quench level of a quadrupole located in the LHC injection region in case of fast (ns) losses. It consisted in dumping single bunches onto an injection protection collimator located right upstream of the quadrupole, varying the bunch intensity up to 3·10¹⁰ protons and ramping the quadrupole current up to 2200 A. No quench was recorded at that time. The test was repeated in 2013 with increased bunch intensity (6·10¹⁰ protons); a quench occurred when powering the magnet at 2500 A. The comparison between measurements during beam induced and quench heaters induced quenches is shown. Results of FLUKA simulations on energy deposition, calculations on quench behaviour using QP3 and the respective estimates of quench levels are also presented.

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WEPRI093

Welding and Quality Control for the Consolidation of the LHC Superconducting Magnets and Circuits

controls, superconducting-magnet, vacuum, monitoring

2709

S. Atieh, M. Bernardini, F.F. Bertinelli, P. Cruikshank, J.M. Dalin, G. Favre, V. Kain, D. Lombard, A. Perin, M. Pojer, G. Rasul, D. Rey, R. Rizwan, F. Savary, J.Ph. G. L. Tock
CERN, Geneva, Switzerland

The first LHC long shutdown was driven by the need to consolidate the 13 kA splices between the superconducting magnets to safely attain its center of mass design energy of 14 TeV. Access to the splices requires the opening of welded sleeves by machining. After consolidation, the sleeves are re-welded using a TIG orbital welding. The welding process has been modified from the original “as-new” installation in order to better adapt to the “as repaired” situation. The intervention has been thoroughly prepared through qualifications, organisation of teams, their training and follow-up. Quality control is based on the qualification of equipment, process and operators; the recording of production parameters; regular process audits and production witness samples; visual inspection through an official certifying body. The paper also describes welding and quality control of special intervention cases, with issues of difficult access requiring innovative solutions. This work concerns over 10 000 welds and a team of 40 engineers and technicians over a period of 18 months. The experience and lessons learnt will be applicable to similar large complex projects.

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WEPRI094

Conceptual Design Study of the High Luminosity LHC Recombination Dipole

dipole, target, luminosity, insertion

2712

G.L. Sabbi, X. Wang
LBNL, Berkeley, California, USA
G. Arduini, M. Giovannozzi, E. Todesco
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. DOE LHC Accelerator Research Program. The HiLumi LHC Design Study is partly funded by the European Commission within the Framework Programme 7.
The interaction region design of the High-Luminosity LHC requires replacing the recombination dipole magnets (D2) with new ones. The preliminary specifications include an aperture of 10⁵ mm, with 186 mm separation between the twin-aperture axes, and an operating field in the range of 3.5 to 4.5 T. The main design challenge is to decouple the magnetic field in the two apertures and ensure good field quality. In this paper, we present a new approach to address these issues, and provide expected harmonics for geometric, saturation and persistent current effects. The feasibility of an operating field at the high end of the range considered is also discussed, to minimize the D2 magnet length and facilitate the space allocation for other components.

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WEPRI101

Iron Shims outside the Helium Vessel to Adjust Field Quality at High Fields

sextupole, dipole, insertion, quadrupole

2734

R.C. Gupta, M. Anerella, J.P. Cozzolino, A.K. Jain, J.F. Muratore, P. Wanderer
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by the U.S. Department of Energy under Contract No. DE¬AC02-98CH10886.
This paper describes the development and demonstration of a novel technique of adjusting measured field quality at the design field in superconducting magnets. The technique is based on placing iron shims of variable stack thicknesses, variable width and/or variable length on the outer surface of the stainless steel shell at strategic locations. Since the shims are placed outside the helium vessel, adjustments can be made without involving major operations such as opening the helium vessel. It is a simple and economical technique which is suitable for long magnets with a fast turn-around. This allows one to reduce field errors well beyond the normal construction errors. The technique has recently been successfully applied in two 3.8 T, 80 mm aperture, 9.45 m long dipoles. These magnets were built at Brookhaven National Laboratory (BNL) for the APUL project (Accelerator Project to Upgrade the LHC) as a part of US contribution to LHC. The paper will present the design, measurement and adaptation of this technique which, when used in combination with the coil shims, produced near zero sextupole harmonic at high fields and small harmonics throughout the range of operation.

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WEPRI110

The HNOSS Horizontal Cryostat and the Helium Liquefaction Plant at FREIA

cavity, cryogenics, vacuum, linac

2759

R. Santiago Kern, T.J.C. Ekelöf, K.J. Gajewski, L. Hermansson, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
P. Bujard, N.R. Chevalier, T. Junquera, J.P. Thermeau
Accelerators and Cryogenic Systems, Orsay, France

A horizontal cryostat to test superconducting cavities and magnets at liquid helium temperatures is installed at FREIA (Facility for REsearch Instrumentation and Accelerator development) at Uppsala University, Sweden. The cryostat allows full testing of superconducting spoke and elliptical accelerating cavities without the need of a specialized cryomodule per cavity. Because horizontal cryostats are custom-built, their number in the accelerator world is very limited. The FREIA horizontal cryostat is one of a kind as it has been designed to be versatile: it is able to house either two ESS double-spoke, or two ESS/TESLA type elliptical cavities, or superconducting magnets or a combination of these with all the ancillary equipment (power couplers, tuners, etc) and test them at the same time, reducing installation time but requiring extra design effort and cryogens supply. In order to achieve this, a helium liquefier with a capacity of 140 l/h delivers liquid helium to the horizontal cryostat while the return gases are directed towards a recovery system, connected in closed loop with the liquefier.

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WEPRI111

Investigation of Moisture Contamination in the Cryogenic System at NSRRC

cryogenics, controls, cavity, storage-ring

2762

F. Z. Hsiao, S.-H. Chang, W.-S. Chiou, H.C. Li, T.F. Lin, C.P. Liu, H.H. Tsai
NSRRC, Hsinchu, Taiwan

In NSRRC the helium cryogenic plant began its normal operation in year 2002. Several events of moisture contamination forced the cryogenic plant to cease operation because the cooling performance degraded evidently. After long-term observation we found, through internal inspection of the helium gas buffer tank, maintenance of the compressor station, and warming the superconductive magnet, that moisture contamination occurred. This paper presents the effect of those conditions on the moisture contamination. The solution to decrease the moisture contamination is demonstrated here.

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WEPRI113

Operation of SLRI Cryogenic System for a 6.5 T Superconducting Wavelength Shifter

cryogenics, synchrotron, insertion, controls

2765

S. Srichan, Ch. Dhammatong, P. Klysubun, V. Sooksrimuang, K. Takkrathoke, A. Tong-on
SLRI, Nakhon Ratchasima, Thailand

The cryogenic plant at Synchrotron Light Research Institute was designed to be used as the main liquid helium supply for a superconducting wavelength shifter, in order to generate high-energy X-rays from the relatively low-energy 1.2 GeV Siam Photon Source storage ring. The plant was installed and successfully commissioned in the year 2009. During the past three years since commissioning, the cryogenic system had been in operation to perform helium liquefaction without a superconducting magnet. Since the installation of a 6.5 T SWLS in September 2013, the cryogenic system has begun its operation with a full-time load. In this work, the first operation of the cryogenic system with a superconducting insertion device is presented.

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THXA01

BPMs From Design to Real Measurement

electronics, simulation, cavity, vacuum

2774

D. Lipka, S. Vilcins
DESY, Hamburg, Germany

Beam Position Monitors (BPM) are an essential tool for the operation of an accelerator. Therefore BPM systems have to be already included from the beginning in the design of a new machine. This contribution describes the development of a new BPM system up to the operation with a focus on the mechanical design. It includes the collection of the requirements and boundary conditions which defines the kind of BPM system. Following the mechanical designing process is described where simulations are used to predict the signals. These results are input parameters for the design and optimization of the electronics. Several contributions are considered which can modify the BPM signal like feedhroughs, heating due to wake losses, holders, cables and so on. The steps from the design, the prototypes and series production including laboratory and test accelerator measurements up to the commissioning are described as well.

Slides THXA01 [4.844 MB]

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THXB01

Accelerators for Medical Application: what is so special?

controls, cyclotron, proton, ion

2807

J.M. Schippers, M. Seidel
PSI, Villigen PSI, Switzerland

The specific requirements of accelerators for radiation therapy will be discussed. The focus will be on accelerator and beam transport design, but also on operational and formal aspects. We will discuss the special requirements to reach a high reliability for patient treatments as well as an accurate delivery of the dose at the correct position in the patient using modern techniques like pencil beam scanning. The requirements of the beam are quite different from those in a nuclear physics laboratory, such as a special matching of the emittance of the accelerated beam, requirements on beam intensity and stability and prevention of activation. The way of operating a medical device requires not only operators, but also the possibility to have a safe machine operation by non accelerator specialists at different operating sites. Size, weight and price are important for a in a hospital based facility. This is encouraging the application of new developments in superconductivity and has stimulated novel accelerator types and beam sharing schemes. Since certification and legal aspects play an important role in a medical device, these topics will also be discussed.

Slides THXB01 [2.017 MB]

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THOAB01

Recent Progress and Future Plan of Heavy-ion Radiotherapy Facility, HIMAC

ion, synchrotron, heavy-ion, flattop

2812

K. Noda, T. Furukawa, Y. Hara, Y. Iwata, N. Kanematsu, K. Katagiri, A. Kitagawa, K. Mizushima, S. Mori, T. Murakami, M. Muramatsu, M. Nakao, A. Noda, S. Sato, T. Shirai, E. Takada, Y. Takei
NIRS, Chiba-shi, Japan

The first clinical trial with a carbon-ion beam generated from HIMAC was conducted in June 1994. Based on more than ten years of experience with HIMAC, a pilot facility of a standard carbon-ion radiotherapy facility in Japan, was constructed at Gunma University. Owing to the successfully operation of the pilot facility, Saga-HIMAT and i-ROCK in Kanagawa have been progressed. In addition, NIRS has developed the new treatment research project for the further development of radiotherapy with, based on the pencil-beam 3D scanning for both the static and moving targets. This treatment procedure has been successfully carried out with a pencil-beam 3D scanning since May 2011. Owing to the development of NIRS 3D scanning, the i-ROCK project decided to employ the NIRS 3D scanning. As a future plan, further, NIRS has developed a superconducting rotating gantry, and we are going to just start a study of a superconducting accelerator for the ion radiotherapy. The recent progress and the future plan of HIMAC for the heavy-ion cancer radiotherapy will be reported.

Slides THOAB01 [10.523 MB]

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THOBB02

Superconducting Cavity Cryomodule Designs for the Next Generation of CW Linacs: Challenges and Options

cavity, cryomodule, vacuum, cryogenics

2831

T.H. Nicol, Y.O. Orlov, T.J. Peterson, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: Supported by FRA under DOE Contract DE-AC02-07CH11359
The designs of nearly all superconducting RF (SRF) linacs over the last several years, with one notable exception being CEBAF at Jefferson Lab, have assumed pulsed beam operation with relatively low duty factors. These include the XFEL at DESY, the ILC, the original configuration for Project X at Fermilab, as well as several others. Recently proposed projects, on the other hand, including the LCLS-II at SLAC, the newly configured low and medium energy sections for Project X, and FRIB at Michigan State, to name a few, assume continuous wave or CW operation on quite a large scale with ambitious gradients and cavity performance requirements. This has implications in the cavity design as well as in many parts of the overall cryomodule due to higher dynamic heat loads in the cavities themselves and higher heat loads in the input and high-order-mode (HOM) couplers. Piping internal to the cryomodule, the effectiveness of thermal intercepts, the size of integrated heat exchangers, and many other aspects of the overall design are also affected. This paper will describe some of these design considerations as we move toward the next generation of accelerator projects.

Slides THOBB02 [8.388 MB]

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THPPA00

EPS-AG Prize d) Presentation

cryogenics, electron, simulation, synchrotron

2837

J.F. Esteban Müller
EPFL, Lausanne, Switzerland
J.F. Esteban Müller
CERN, Geneva, Switzerland

EPS-AG Prize d) Presentation. The Prize d) winner will present the work for which the prize is awarded, on the basis of the judging by the EPS-AG Prizes Selectin Committee.

Slides THPPA00 [3.432 MB]

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THPRO003

Progress of the LUNEX5 demonstator Project

FEL, electron, undulator, laser

2856

M.-E. Couprie, C. Benabderrahmane, P. Berteaud, C. Bourassin-Bouchet, F. Bouvet, L. Cassinari, L. Chapuis, J. Daillant, M. Diop, M.E. El Ajjouri, C. Evain, C. Herbeaux, N. Hubert, M. Labat, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, J.L. Marlats, C. Miron, P. Morin, A. Nadji, F. Polack, F. Ribeiro, J.P. Ricaud, P. Roy, K. Tavakoli, M. Valléau, D. Zerbib
SOLEIL, Gif-sur-Yvette, France
S. Bielawski, E. Roussel, C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
B. Carré, D. Garzella
CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
X. Davoine
CEA/DAM/DIF, Arpajon, France
N. Delerue
LAL, Orsay, France
G. Devanz
CEA/DSM/IRFU, France
A. Dubois, J. Lüning
CCPMR, Paris, France
G. Lambert, R. Lehé, V. Malka, A. Rousse, C. Thaury
LOA, Palaiseau, France
C. Madec, A. Mosnier
CEA/IRFU, Gif-sur-Yvette, France

LUNEX5 (free electron Laser Using a New accelerator for the Exploitation of X-ray radiation of 5th generation) aims at investigating the production of short, intense, coherent pulses in the 40-4 nm spectral range [1]. It comprises two types of accelerators connected to a single Free Electron Laser (FEL) for advanced seeding configurations (seeding with High order Harmonic in Gas, echo). A 400 MeV superconducting Linear Accelerator, adapted for studies of advanced FEL schemes, will enable future upgrade towards high repetition rate and multi-user operation by splitting part of the macropulse to different FEL lines. A 0.4 - 1 GeV Laser Wake Field Accelerator (LWFA) [2] will also be qualified by the FEL application. After the Conceptual Design Report, R&D has been launched on different sub components. Following transport theoretical studies of longitudinal and transverse manipulation of a LWFA electron beam enabling to provide theoretical amplification, a test experiment is under preparation.

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THPRO009

Harmonic Lasing in X-ray FELs

undulator, FEL, electron, photon

2873

E. Schneidmiller, M.V. Yurkov
DESY, Hamburg, Germany

Contrary to nonlinear harmonic generation, harmonic lasing in a high-gain FEL can provide much more intense, stable, and narrow-band FEL beam which is easier to handle if the fundamental is suppressed. We perform a parametrization of the solution of eigenvalue equation for lasing at odd harmonics, and present explicit expression for FEL gain length, taking into account all essential effects. We propose and discuss methods for suppression of the fundamental. We also suggest a combined use of harmonic lasing and lasing at the retuned fundamental wavelength in order to reduce bandwidth and to increase brilliance of X-ray beam. We discover that in a part of the parameter space, corresponding to the operating range of soft X-ray beamlines of X-ray FEL facilities, harmonics can grow faster than the fundamental. We suggest that harmonic lasing can be widely used in the existing or planned X-ray FEL facilities. LCLS after a minor modification can lase at the 3rd harmonic up to the photon energy of 25-30 keV providing multi-gigawatt power level. At the European XFEL the harmonic lasing would allow to extend operating range up to 100 keV, to reduce bandwidth and increase brilliance.

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THPRO046

100 MHz RF System as an Alternative for the Iranian Light Source Facility

cavity, HOM, storage-ring, emittance

2968

S. Pirani, H. Ghasem, M. Moradi, Kh.S. Sarhadi
ILSF, Tehran, Iran

The Iranian Light Source Facility (ILSF) RF system was conceptually designed based on ILSF requirements for a 3GeV storage ring and 400 mA beam current at 500 MHz RF frequency. The development of HOM damped cavity with simpler structure at 100MHz and advantages of reducing frequency as investigated at MAX Lab, provided an alternative of 100MHz RF system to be explored for ILSF. RF frequency change and its effects on the beam and machine parameters as well as the availability and cost of RF system components have been studied for ILSF. The conceptual design of a 100MHz RF system and the comparison between 500 MHz and 100 MHz RF frequencies are presented in this report. This paper, furthermore, provides details about the 100MHz RF cavity designed by ILSF RF group based on MAX Lab cavity.

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THPRO057

Advanced Magnetic Field Description and Measurements on Curved Accelerator Magnets

multipole, dipole, quadrupole, magnet-design

3002

P. Schnizer, E.S. Fischer, A. Mierau
GSI, Darmstadt, Germany
P.G. Akishin
JINR, Dubna, Moscow Region, Russia
B. Schnizer
TUG/ITP, Graz, Austria

The SIS100 accelerator will be built within the first realisation phase of the FAIR project. The series production of its superconducting bending magnets was started without any test model in 2013. This time saving strategy requires a careful investigation of the magnetic field quality for the first manufactured dipole. The consequences of the curved magnet design was analysed developing advanced multipoles for elliptical and toroidal magnet geometries. We present the theoretical results together with measured data obtained for the first of series dipole. A description of the rotating coil probe based measurement method will be given together with the achieved field quality as well as an estimation of the limits of the chosen field representation and its beam dynamics interpretation.

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THPRO060

Beam-beam Effect on the BTF in Bunched Beams

electron, simulation, damping, beam-beam-effects

3011

P.A. Görgen, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
W. Fischer
BNL, Upton, Long Island, New York, USA

We present studies on the transverse baseband Beam Transfer Functions (BTFs) in bunched beams at high energies. The goal of the work is to evaluate whether transverse BTFs can be used to diagnose the tune spread arising from transverse nonlinearities such as the beam-beam effect and space charge. We employ an analytic expression to the BTFs of beams under a transverse nonlinear lens arising from a bi-Gaussian charge distribution. We obtain agreement between a simulation model of an electron-lens like configuration and the analytic results. The tune spread for this scenario can be recovered by means of a fit against the analytic expectation. The results are compared with measurements where the beam-beam effect acts as a substitute for the electron lens. A similar behaviour of the BTF is observed. This allows the conclusion that the transverse BTF can be used to diagnose tune spread from an electron-lens. Finally we discuss the problems that arise when trying to recover the tune spread from BTFs of arbitrary non-Gaussian beams and in the presence of coherent beam-beam modes.

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THPRO067

Modeling Slow Extraction Process For J-PARC Main Ring

extraction, controls, quadrupole, experiment

3032

A.Y. Molodozhentsev
KEK, Ibaraki, Japan

J-PARC Main Ring has to deliver the proton beam to ‘hadron’ experiments by using ‘slow extraction’ technique, base on the 3rd order horizontal resonance. The spill quality during the full extraction period is one of the most important requirements as well as the beam quality. The computer modeling of the slow extraction process for J-PARC Main Ring is based on a realistic machine model, which includes measured imperfections of the machine in addition to dynamic variation of the machine elements to perform the slow extraction. In frame of this report we represent the results of the modeling the slow extraction process from J-PARC Main Ring by using the PTC-ORBIT combined code. The resonance extraction has been controlled by changing the betatron tune. Control the horizontal emittance of the extracted beam has been performed by using ‘dynamic’ bumps. Control the spill quality of the extracted beam has been performed by using dedicated quadrupole magnets and the transverse RF signal (RF knockout). In addition, the spill quality can be improved by suppressing effect of the power supply ripple. On the request, the collective effects can be introduced into the model.

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THPRO080

The FiDeL Model at 7 TeV

quadrupole, optics, injection, dipole

3069

N. Aquilina, M. Giovannozzi, P. Hagen, M. Lamont, A. Langner, E. Todesco, R. Tomás, J. Wenninger
CERN, Geneva, Switzerland
N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta

After the long shut down of 2013-2014, the LHC energy will be pushed toward 7 TeV. In this range of energy, the main magnets will enter a new regime. For this reason, this paper will present a detailed study of the performance of the FiDeL model that could be critical for the operation in 2015. In particular this paper will study the saturation component and its precision in the model, together with the hysteresis error. The effect of these two components and their errors on the beta-beating is also given. Furthermore, an estimate of the dynamic effects visible in the tune and chromaticity will be presented for the 7 TeV operation.

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THPRO099

Toward a Virtual Accelerator Control System for the MYRRHA Linac

linac, controls, lattice, cryomodule

3122

J.-P. Carneiro
Fermilab, Batavia, Illinois, USA
J.-L. Biarrotte
IPN, Orsay, France
F. Bouly
LPSC, Grenoble Cedex, France
L. Medeiros Romão, R. Salemme, D. Vandeplassche
SCK•CEN, Mol, Belgium
D. Uriot
CEA/DSM/IRFU, France

The MYRRHA project currently under development at Mol, Belgium, is an Accelerator Driven System expected to be operational in 2023 with the primary purpose to study the feasibility of efficiently transmuting nuclear waste products into isotopes with much shorter lifetimes. The reactor, which is expected to have a thermal power of ~70 MW, may be operated in subcritical mode when fed by spallation neutrons obtained from a 600 MeV superconducting proton linac hitting a Liquid Pb-Bi eutectic (LBE) target with an average current of 4 mA. The challenging aspect of the MYRRHA linac resides in its very high availability (close to 100%) with a Mean Time Between Failure expected to be higher than 250 hours. This paper presents the strategic approach taken during the design of the linac and its foreseen operation to fulfill this stringent requirement. In particular we will describe the concept of a beam dynamics based control system also called Virtual Accelerator which will be mandatory for the operation of such linac.

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THPRO101

Setup of a History Storage Engine based on Hypertable at ELSA

database, controls, interface, distributed

3128

D. Proft, F. Frommberger, W. Hillert
ELSA, Bonn, Germany

The electron stretcher facility ELSA serves external hadron physics experiments with a beam of unpolarized and polarized electrons of up to 3.2 GeV energy. Its in house developed control system is able to provide real time beam diagnostics as well as steering tasks in one homogeneous environment. The existing archive engine, a simple application logging parameter changes to a file storage, was unable to cope with the rising amount of parameter updates per second. Therefore a new storage system based on the non-relational database system hypertable has been introduced. It is capable of storing huge amounts of data to distributed storage systems, thus being able to handle the recording of every parameter change at any given time. The data can be read back with low latency to a newly developed graphical data browser using a C++ interface. This contribution will give details on the setup and performance of the history storage engine on top of hypertable.

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THPRO111

Control System for BEPCII Linac Power Sub-system

controls, power-supply, EPICS, linac

3156

X. Wu, X.C. Kong, Q. Le, S. Sun, Y. Zou
IHEP, Beijing, People's Republic of China

Power subsystem has been upgraded for energy improvement of the BEPCII Linac. As a result, new control system was in need. This paper proposes the designing and implementation about the power-supply control system. There are 156 sets of power supply in the system, which is divided into 6 parts, according to function. The control system is intended to make operations more convenient and efficient in beam regulation, which provides functions to meet such situations, like single regulation; restore the beam configures from data files; one-button to switch the electronic polarity (E-/E+). What’s more, the software provides a method of slow-change to protect the power supplies, when value change is too steep. Compare to the old system, this new software is more maintainable and extensible. This software is based on Qt, the GUI library for C++, and connects to the control box through the EPICS (Experimental Physics and Industrial Control System). The whole 156 sets of power supply are controlled by control boxes, which is ARM+FPGA (CPLD)-Structure front-end IO. This control system has assembled in BEPCII LINAC in September, which plays an important part in the following working.

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THPRO116

Control System of a Miniature 12 MeV Race-Track Microtron

controls, vacuum, detector, microtron

3165

Yu.A. Kubyshin, V. Blasco, J.A. Romero, A. Sanchez
UPC, Barcelona, Spain
G. Montoro
UPC-EETAC-TSC, Castelldefels, Spain
V.I. Shvedunov
MSU, Moscow, Russia

A simple control system has been developed for the commissioning of a compact 12 MeV race-track microtron which is under construction at the Technical University of Catalonia. It is of modular structure and is based on LabView programs at a conventional PC and ATmega microcontrollers. Apart from modules to monitor different RTM systems it also includes an Automatic Frequency Control of the magnetron frequency and interlocks. The architecture and main features of the modules are described and results of their operation are reported. Further developments of the control system and interfaces are on the way.

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THPRO117

Infrastructure Controls Integration at ESS

interface, controls, monitoring, PLC

3168

D.P. Piso, J. Lundgren, M. Reščič, R. Sjöholm
ESS, Lund, Sweden
T. Ranstorp
ÅF, Malmö, Sweden
R. Schmidt
CERN, Geneva, Switzerland

The European Spallation Source (ESS) project is starting the construction of buildings June 2014. When the access to linac tunnel and gallery building is ready, the commissioning of the first sections of the accelerator starts. A proper operation of the machine relies on the services provided by different infrastructure systems (water cooling, electrical power system, ventilation, etc.) These systems will be used long before beam operation starts and need to be operated via the Integrated Control System (ICS) from the Control Room. Due to the number and variety of these systems, their heterogeneous characteristics and the different teams of designers, the integration process into ICS is challenging. Experience in other facilities [2,3] shows that a late integration produces higher maintenance and operation costs, and even impact on the reliability of the machine. This paper presents the strategy developed by two partners, the Controls and Conventional Facilities Division (CF). It is planned to capture the requirements for the interfaces and to ensure an early integration of Infrastructure Systems into the EPICS environment. First results of this approach are shown for some systems.

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THPRO127

Current Status of TARLA Control System

controls, EPICS, LabView, gun

3192

E. Kazancı, A.A. Aksoy, A. Aydin, C. Kaya, B. Tonga, O. Yavaş
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
S. Özkorucuklu
Istanbul University, Istanbul, Turkey

Funding: This study was funded by Ministry of Development of Turkey by grant id DPT2006K-120470
Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) is a Free Electron Laser (FEL) facility designed to generate Free Electron Laser (FEL) in 3-250 um wavelength range, based on four 9-cell Super Conducting (SC) cavities with 10MeV/m gradient each. TARLA electron gun has been in operation since 2012. Control system studies with EPICS are being run as test stand control and permanent system and each are running as individual projects while test stand control is in stable revision. The aim of the system design is to create a fast and reliable control system which is easy to operate and extensible for future upgrades/improvements. Now, the development and implementation of control system is ongoing in a parallel manner with the rest of the accelerator as well as the architectural design, In this study, the permanent and the test stand control systems of TARLA will be discussed.
On behalf of TARLA Team

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THPRO130

MaRIE Injector Test-Stand Instrumentation & Control System Conceptual Design

controls, timing, EPICS, diagnostics

3198

M. Pieck, D. Baros, E. Björklund, J.A. Faucett, J.D. Gilpatrick, J.D. Paul, F.E. Shelley
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by LANL for the U.S. Department of Energy under contract W-7405-ENG-36.
Los Alamos National Laboratory (LANL) has defined a signature science facility Matter-Radiation Interactions in Extremes (MaRIE) that builds on the existing Los Alamos Neutron Science Center (LANSCE) facility to provide unique experimental tools to develop next-generation materials that will perform predictably and on demand for currently unattainable lifetimes in extreme environments. At its core a new 42 keV XFEL will be coupled with a MW class proton accelerator. While the larger MaRIE project is working on a pre-conceptual design a smaller LANL team is working on an injector test-stand to be constructed at LANL in the course of preparation for MaRIE. The test stand will consist of a photo injector and an initial accelerating section with a bunch compression section. The goal of this facility will be to carry out studies that will determine optimal design parameters for the prototype injector, and to facilitate a direct demonstration of the required beam characteristics for MaRIE. This paper will give a brief overview of the proposed MaRIE facility and present the conceptual design for the injector test stand with the focus on the instrumentation and control system.

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THPME008

New Reference Design of the European ADS RFQ Accelerator for MYRRHA

rfq, emittance, simulation, bunching

3223

C. Zhang
GSI, Darmstadt, Germany
H. Podlech
IAP, Frankfurt am Main, Germany

For demonstrating the technical feasibility of nuclear waste transmutation in an Accelerator Driven System (ADS), the MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) proton driver is under intensive studies. Good performance of the 2 – 4 mA, 1.5MeV RFQ (Radio-Frequency Quadrupole), the start of the accelerator chain, is essential to the reliability of the whole facility, so it must be very well designed. On the basis of the first reference design, further improvements with respect to electrode aperture, emittance growths and output distributions have been performed. The simulation results of the new reference design are presented in this paper.

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THPME010

A 325 MHz High Gradient CH – Test Cavity for β=0.16

cavity, linac, focusing, DTL

3229

A. Almomani, U. Ratzinger
IAP, Frankfurt am Main, Germany

Funding: BMBF, contract no. 05P12RFRB9
This pulsed linac activity aims on compact designs, which means a considerable increase in voltage gain per meter. At IAP – Frankfurt, a CH – cavity was developed for these studies, where mean effective accelerating fields well above 10 MV/m are expected at 325 MHz, β=0.164. This cavity is developed within a funded project. Currently, the cavity is under construction and expected to be ready for copper plating in autumn 2014. The results might influence the rebuilt of the UNILAC – Alvarez section, which aims on achieving the beam intensities specified for the GSI – FAIR project. The new GSI 3 MW Thales klystron test stand will be very important for these investigations. Detailed investigations for two different types of copper plating can be performed on this cavity. In this work, the status of the cavity fabrication will be presented. Moreover, low temperature operation of copper cavities is discussed for the case of very short RF pulses.

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THPME022

Recent Progress of the SSC-LINAC RFQ

rfq, cavity, linac, pick-up

3265

G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu
PKU, Beijing, People's Republic of China
H. Du, Y. He, P. Jiang, X.N. Li, Z.S. Li, J.X. Wu, J.W. Xia, Y.Q. Yang, X. Yin, Y.J. Yuan, X.H. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Funding: NFSC(11079001)
The project of SSC-LINAC RFQ has important progresses in the past year. The machine has been moved to the Institute of Modern Physics in the first season of 2013. The cavity measurement including tests of RF performance and field distribution is carried out again in the laboratory. The Q0 is 6440, and the unflatness of the electric field in longitudinal is ±2.5%. The results demonstrated a good agreement with simulation. The RF and beam commissioning of the RFQ has been carried out in the first half of 2014. The duty factor rose from 5% to CW gradually. By now, the cavity has been operated with 35 kW on CW mode. The measurement of the bremsstrahlung spectrum reveals that the 35 kW power is needed to generate the 70 kV inter-vane voltage. The beam transmission efficiency and energy spread has been obtained in beam commissioning by accelerating 16O⁵⁺ and 40Ar⁸⁺ beams. The efficiency of 40Ar⁸⁺ is as high as 94%, and the output energy is 142.78 keV/u. All the processes and results of the experiments will be discussed in details.

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THPME023

CPHS Linac Status at Tsinghua University

rfq, target, linac, neutron

3268

Q.Z. Xing, C. Cheng, L. Du, T. Du, X. Guan, C. Jiang, X.W. Wang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China

Funding: Work supported by National Natural Science Foundation of China (Major Research Plan Grant No. 91126003 and 11175096).
We present, in this paper, the operation status of the 3 MeV high current proton Linac for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. Proton beam with the peak current of 30 mA, pulse length of 100 μs and repetition rate of 50 Hz has been delivered to the Beryllium target to produce the neutron since July 2013. The pulse length will be further increased to 500 μs. The proton beam energy is expected to be enhanced to the designed value of 13 MeV after the Drift Tube Linac is ready in 2015.

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THPME024

Cooling Design for the FRIB RFQ Cavity at Michigan State University

rfq, simulation, cavity, linac

3271

J. Zeng, L. Du, X. Guan, Q.Z. Xing, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, J. Li
NUCTECH, Beijing, People's Republic of China

Funding: Work supported by the Major Research plan of the National Natural Science Foundation of China (Grant No. 91126003)
We present, in this paper, the cooling design for the Radio Frequency Quadrupole (RFQ) cavity of the Facility for Rare Isotope Beams (FRIB) at Michigan State University. The locations and radius of the cooling passages are optimized, which exist in the five-meter-long copper cavity, tuners, dipole-mode stabilizing rods and end-plates. A three-dimensional RF, thermal, and structural analysis by ANSYS has been performed to carry out the design and verify that the present design can meet the requirement for water velocity, stress, deformation and frequency shift.

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THPME055

RF Tuning of the IPHI RFQ

coupling, rfq, dipole, quadrupole

3355

O. Piquet, M. Desmons, A. France
CEA/DSM/IRFU, France

The construction of IPHI (High Power Proton Accelerator) is in its final step of installation. The RFQ will accelerate beam up to 100 mA with energy up to 3 MeV. The RFQ, made of six modules, one meter each, is of the four-vane type. The RFQ is divided in 2-meter long segments with capacitive coupling. It is also equipped with 96 fixed tuners and four waveguide RF ports located in the fourth module. This paper describes the procedure used to tune the accelerating field and power couplers of the RFQ.

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THPME059

Preparation of the Coupled RFQ-IH-cavity for FRANZ

rfq, DTL, coupling, cavity

3367

M. Heilmann, C. Claessens, O. Meusel, D. Mäder, U. Ratzinger, A. Schempp, M. Schwarz
IAP, Frankfurt am Main, Germany

The Frankfurt neutron source at the Stern-Gerlach-Zentrum (FRANZ) will provide ultra-short neutron pulses at high intensities and repetition rates. The neutrons will be produced using the 7Li(p, n)7Be reaction induced by a proton beam. The 175 MHz IH-type drift tube linac with 8 gaps succeeds a 4-rod-RFQ. Together they form a coupled linac combination with a length of 2.3 m and accelerate the protons from 120 keV to 2.03 MeV. As the RF losses add up to 200 kW, the cooling of both accelerators is a central challenge. The RFQ-IH combination is powered by a radio frequency amplifier, which couples the RF power into the RFQ. The two structures are connected via inductive coupling. The initial beam operation of the accelerators is configured for 50 mA in cw mode. The IH-components were fabricated, RF tuning measurements are underway. The RFQ and the IH-DTL will be conditioned separately and then be connected, aiming for a beam operation at the end of 2014. A main challenge in fabrication was the precise welding required for the water cooled drift tubes and stems.

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THPME061

Present Status of J-PARC - after the Shutdown due to the Radioactive Material Leak Accident-

linac, power-supply, injection, target

3373

T. Koseki
KEK, Ibaraki, Japan
K. Hasegawa
JAEA/J-PARC, Tokai-mura, Japan

In J-PARC, a radioactive material leak accident occurred at the Hadron Experimental Facility on May 23, 2013. The accident was triggered by a malfunction of the slow extraction system of the Main Ring synchrotron. After seven-month long shutdown due to the accident, beam operation of the linac was restarted in December 2013. In this paper, the most recent status of the beam operation is presented.

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THPME062

Status of the J-PARC Ring RF Systems

cavity, proton, extraction, impedance

3376

M. Yoshii, M. Nomura, T. Shimada, F. Tamura, M. Yamamoto
KEK/JAEA, Ibaraki-Ken, Japan
E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, K. Takata, M. Toda
KEK, Ibaraki, Japan
A. Schnase
GSI, Darmstadt, Germany

The high intensity proton accelerator complex (J-PARC) consists of the Linac, the 25Hz rapid cycling synchrotron (RCS) and the 50GeV main synchrotron (MR). During the long shutdown of 2013, the Linac energy was upgraded from 181MeV to the design value of 400MeV. In the RCS, we have installed the last 12th RF system. In operation from January 2014, beam commissioning aimed at 1 MW operation will be started. In the MR, the upgrade plan of the beam power, realizing by raising the repetition, has been started. For this reason the accelerating voltage must be increased, and all MR RF systems will be replaced with more efficient systems. A new magnetic alloy material (FT3L) has been developed. Manufacturing of the FT3L accelerating cavities has proceeded. It becomes possible to increase the accelerating voltage from 280 kV to 540 kV, using the new cavities in combination with the existing RF power supplies. We have started the developments of a 2nd harmonic system loaded with air-cooled FT3L cores and a high-Q VHF cavity system, too. Both systems are used for longitudinal dilution increase the bunching factor of the circulating high intensity proton beam.

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THPME063

Residual Dose with 400 MeV Injection Energy at J-PARC Rapid Cycling Synchrotron

injection, vacuum, linac, synchrotron

3379

K. Yamamoto, N. Hayashi, M. Kinsho
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Last summer shutdown J-PARC RCS injection energy was upgraded from 181 MeV to 400 MeV. We report the effect of the injection energy upgrade on the residual dose in the RCS.

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THPME064

Progress and Status of the J-PARC 3GeV RCS

injection, linac, vacuum, power-supply

3382

M. Kinsho
JAEA/J-PARC, Tokai-mura, Japan

Big issue for the J-PARC 3GeV RCS was displacement of main magnets caused by last big earthquake because this made beam loss more than 400 kW beam power. Since realignment of main magnet and other components was essential to realize higher beam power and stable operation, this work has been done last maintenance period. To minimize amount of realignment work, we decided that not all components moved to designed regular potions but also minimum components moved to the position which was secured design acceptance 486 π mm mrad. Almost all components which are main magnets, rf cavities, and extraction magnets had to be moved in the range of 10 mm for horizontal, 3 mm for vertical and 9 mm for longitudinal, respectively. It was not necessary for the components installed in injection straight line to move because displacement of these components was less than ± 0.2 mm. At same time 400 MeV injection upgrade work should be done. Beam commissioning is planned from the middle of January 2014. The progress and status of the RCS in J-PARC are presented.

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THPME069

Performance Studies of the SPS Beam Dump System for HL-LHC Beams

proton, kicker, simulation, optics

3394

F.M. Velotti, O. Aberle, C. Bracco, E. Carlier, F. Cerutti, K. Cornelis, L. Ducimetière, B. Goddard, V. Kain, R. Losito, C. Maglioni, M. Meddahi, F. Pasdeloup, V. Senaj, G.E. Steele
CERN, Geneva, Switzerland

The Super Proton Synchrotron (SPS) beam dump system is a concern for the planned High Luminosity LHC (HL-LHC) operation. The system has initially been designed for very different beam parameters compared to those which will reign after the completion of the LHC injectors upgrade, when the SPS will have to operate with unprecedented beam brightness. This paper describes the relevant operational and failure modes of the dump system together with the expected beam loading levels. Tracking studies are presented, considering both normal operation and failure scenarios, with particular attention on the location and level of proton losses. First FLUKA investigations and thermo-mechanical analysis of the high-energy absorber block are described

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THPME075

FNAL - The Proton Improvement Plan (PIP)

booster, linac, proton, rfq

3409

W. Pellico, K.A. Domann, F.G. Garcia, K. E. Gollwitzer, K. Seiya, R.M. Zwaska
Fermilab, Batavia, Illinois, USA

Funding: The United States Department of Energy
The FNAL Proton Source is currently undergoing a major improvement effort. A plan has been developed and is underway to increase Proton Source throughput while maintaining good availability and acceptable residual activation. The plan addresses hardware modifications to increase repetition rate and improve beam loss while ensuring viable operation of the proton source through 2025. The PIP goals will enable Linac/Booster to: Deliver 2.25·10¹⁷ protons per hour with a 15 HZ cycle rate Availability greater than 85% Maintain residual activation at acceptable levels. The work has been progressing on schedule and is expected to finished by 2018.

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THPME077

Complex Beam Profile Reconstruction, A Novel Rotating Array of Vibrating Wires

vacuum, extraction, instrumentation, detector

3415

S.G. Arutunian
ANSL, Yerevan, Armenia
J.R. Alonso
LBNL, Berkeley, California, USA

Proton/ion beams of multiple charge/mass ratio can be very complex. Orthogonal X-Y projections are often inappropriate to represent these profiles. An array of vibrating wires, rotating around the beam axis is under development. The mechanical implementation is described. An algorithm to reconstruct the profile is proposed. The tradeoffs between the number of wires, the rotation angles, the response time and the profile resolution are discussed.

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THPME086

Optical Fiber Beam Loss Monitor for the PHIL and ThomX Facilities

beam-losses, radiation, vacuum, photon

3433

I. Chaikovska, L. Burmistrov, N. Delerue, A. Variola
LAL, Orsay, France

Fiber beam loss monitor (FBLM) is an attractive solution to measure intensity and position of the beam losses in the real time. It is a very useful tool, especially, for the commissioning and beam alignment. In this article we report on the development of the FBLM at PHIL (PHotoinjector at LAL, Orsay, France) as a prototype of the beam loss monitor for the ThomX machine, the compact Compton based X-ray source being in the construction phase in Orsay.

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THPME103

Beam Current Monitors for FAIR

synchrotron, ion, proton, cryogenics

3483

M. Schwickert, H. Bräuning, F. Kurian, H. Reeg, A. Reiter
GSI, Darmstadt, Germany
R. Geithner, W. Vodel
HIJ, Jena, Germany
R. Neubert
FSU Jena, Jena, Germany

The FAIR (Facility for Antiproton and Ion Research) accelerator facility presently under construction at GSI will supply a wide range of beam intensities for physics experiments. Design beam intensities range from 2.5·10¹³ protons/cycle to be delivered to the pBar-target and separator for production of antiprotons, to beams of e.g. 10⁹ ions/s in the case of slowly extracted beams. The large intensity range demands for dedicated beam current monitors for precise, non-destructive beam intensity measurements in the synchrotrons, transport lines and storage rings of the FAIR facility. This report describes GSI developments of purpose-built beam current monitors for the SIS100 synchrotron and high-energy beam transport lines (HEBT) of FAIR. Prototype measurements with a SQUID-based Cryogenic Current Comparator and a resonant beam charge transformer are presented, and possibilities for further upgrades are discussed.

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THPME109

EOS at CW Beam Operation at ELBE

electron, laser, FEL, diagnostics

3492

Ch. Schneider, M. Gensch, M. Kuntzsch, P. Michel, W. Seidel
HZDR, Dresden, Germany
P.E. Evtushenko
JLab, Newport News, Virginia, USA
Ç. Kaya
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
A. Shemmary, N. Stojanovic
DESY, Hamburg, Germany

The ELBE accelerator is a super conduction electron cw machine located at the Helmholtz Center Dresden Rossendorf Germany with 1 mA current, now tested for up to 2 mA. Besides other important diagnostics for setting up the machine for user beam time and further improvement of the machine – a THz source is momentary under commissioning – a EOS measuring station for bunch length measurements is locate right behind the second super conducting Linac. Measuring with a crystal in the vicinity of an up to 2 mA cw beam implies higher beam loss and also higher radiation exposure of the crystal and hence also a safety risk for the UHV conditions of the super conducting cavities in the case of crystal damage. Therefore the EOS measuring principle is adapted to larger measuring distances and also for beam requirements with lower bunch charge at ELBE. A description of the setup, considerations of special boundary conditions and as well results for 13 MHz cw beam operation are presented.

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THPME117

First Tests with the Self-triggered Mode of the New MicroTCA-based Low-charge Electronics for Button and Stripline BPMs at FLASH

timing, electronics, status, interface

3509

F. Schmidt-Föhre, N. Baboi, G. Kuehn, B. Lorbeer, D. Nölle, K. Wittenburg
DESY, Hamburg, Germany

The FLASH facility at DESY is currently enhanced by a second beamline (FLASH2) to extend the capacity for user experiments. In addition, certain support systems like the timing system and the BPM system at the existing FLASH accelerator have been partly renewed and are now under commissioning. New button BPM electronics based on the MTCA.4 for physics standard is provided for the FLASH2 beamline and is foreseen as a replacement of the old BPM electronics at FLASH. Compared to the predecessor of the FLASH button BPM electronics, the new system has been specifically designed for low charge operation exceeding a wide dynamical charge range between 100pC and 3nC. Special provisions have been made to enable single bunch measurements in a self-triggered mode, enabling timing-system-independent measurements during commissioning and at fallback during normal operation.

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THPME124

Spectral Analysis of Micro-Bunching Instabilities using Fast THz Detectors

detector, radiation, synchrotron, bunching

3530

J.L. Steinmann, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, M. Schuh, P. Schönfeldt, P. Schütze
KIT, Karlsruhe, Germany
E. Bründermann
Ruhr-Universität Bochum, Bochum, Germany

Micro-bunching instabilities occur at synchrotron light sources when the particle density rises due to compression of the electron bunches. They lead to powerful bursts of coherent synchrotron radiation (CSR) in the THz range at the cost of very unstable intensity and spectral properties, highly fluctuating on a millisecond time scale. For interferometry this changing source demands a long averaging time to achieve a reasonably high signal-to-noise ratio or balancing by the use of an additional reference detector. In this study we present measurements taken by a Martin-Puplett-interferometer in the bursting regime with ultra-fast THz-detectors.

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THPME125

Electrical Field Sensitive High-Tc YBCO Detector for Real-time Observation of CSR

detector, real-time, electron, synchrotron

3533

J. Raasch, K.S. Ilin, Y.-L. Mathis, A.-S. Müller, A. Scheuring, M. Siegel, N.J. Smale, P. Thoma
KIT, Karlsruhe, Germany
S. Bielawski, C. Evain, E. Roussel, C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
B. Holzapfel
Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
M. Hosaka, N. Yamamoto
Nagoya University, Nagoya, Japan
K. Iida
Leibniz Institute for Solid State and Materials Research Dresden, Dresden, Germany
M. Katoh, S.I. Kimura, T. Konomi
UVSOR, Okazaki, Japan
H. Zen
Kyoto University, Kyoto, Japan

Funding: We thank Agilent Technologies & Tektronix for supplying oscilloscopes. The work was supported by BMBF (05K2010), ANR (2010 blanc 042301), MEXT (Quantum Beam Tech. Prog.), IMS (Int. Collab. Prog.).
High-Tc thin-film YBa2Cu3O7-x (YBCO) detectors were deployed for the real-time observation of Coherent Synchrotron Radiation (CSR). Due to enhanced fabrication techniques enabling the patterning of sub-μm sized detector areas responsivity values as high as 1V/pJ for pulsed THz excitations have been achieved at the ANKA synchrotron facility at the Karlsruhe Institute of Technology (KIT). Response of the detectors is linear over the whole dynamic range of the IR1 beamline. Combining the picosecond scaled response mechanism of the high-temperature superconductor YBa2Cu3O7-x (YBCO) to THz excitations with broad-band readout a temporal resolution of 15 ps full width at half maximum (FWHM) was reached. Real-time resolution of CSR single shots was observed at ANKA and UVSOR-III, the synchrotron facility of the Institute of Molecular Science in Okazaki, Japan.

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THPME130

Development of New Data-taking System for Beam Loss Monitors of J-PARC MR

feedback, monitoring, detector, extraction

3547

K. Satou, N. Kamikubota, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
S.Y. Yoshida
Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan

A new data acquisition system has been developed to improve band-width and dynamic range of the beam loss monitor systems. It consists of isolation current amplifiers with the gain of 1M and the band-width of DC-100kHz, and VME-based 24bit ADCs with the band-width of DC-300kHz and the noise level of 100uV peak to peak. The waveform data of 1MS/s and 1KS/s, and the charge count which is the integrated waveform data are generated and these are compared with alarm levels for the machine protection system. Long-term ground-level stability is essential to monitor residual dose activities. Some beam loss signals include effect of radiations from activated devices, and thus its fractions should be excluded. If the residual dose activities just before the beam injections can be monitored, these fractions would be roughly estimated. Furthermore, on-line monitoring of the residual dose activities after a beam operation will be useful for activation control of the devices at the high level activation area like the collimator and the slow-extraction area. A shot by shot DC offset cancellation is adopted to ensure high ground level stability.

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THPME147

The High Position Resolution Cavity BPM Developments and Measurement for ILC Final Focus System

cavity, electronics, resonance, alignment

3599

S.W. Jang, J.G. Hwang, E.-S. Kim, L. Lee
KNU, Deagu, Republic of Korea
P. Bambade, O.R. Blanco-García, F. Bogard, S. Wallon
LAL, Orsay, France
Y. Honda, T. Okugi, T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

An ultra high position resolution cavity BPM was developed for the final focus system of ATF2, which is a accelerator test facility for ILC final focus system. The main purpose of ATF2 are achievement of 37 nm beam size and nano-meter beam orbit stability at IP(Interaction Point). For these purposes, a few nano meter beam position resolution was required for this cavity BPM, which is called the IP-BPM. The IP-BPM was fabricated 2 blocks of IP-BPM, the first block consists of two cavities in one block and second block consists of single cavity. IP-BPM can measure beam position in vertical and horizontal independently by using rectangular shape single cavity. Three IP-BPMs were installed at ATF IP region inside IP-chamber, and its position resolution was measured. We will present the detailed results on the beam tests.

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THPME157

Radiation of a Charged Particle Bunch Moving in the Presence of Planar Wire Structure

radiation, diagnostics, electronics, vacuum

3629

V.V. Vorobev, S.N. Galyamin, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: Work was supported by "Dynasty" Foundation, the Grant of the President of Russian Federation (No. 273.2013.2) and the Russian Foundation for Basic Research (Grant No. 12-02-31258).
The structure under consideration represents a set of long thin parallel wires which are placed in a plane with fixed spacing. The wires can exhibit a limited conductivity. If the period of the structure is much less than the typical wavelength, the structure’s influence can be described with help of the averaged boundary conditions*. The main attention is given to the case when the bunch flies through the grid in the orthogonal direction. Radiation of charged particle bunch which have small transversal size and limited longitudinal one is studied. Analytical expressions for volume and surface waves are given for the bunches with arbitrary longitudinal profile. A separate analysis is performed for the particular case of the plane which is ideally conducting in only one direction. It is shown that the surface wave is similar, in some way, to the radiation field of the bunch moving in a wire metamaterial**. It is demonstrated that the detection of surface waves can be used to estimate the longitudinal sizes of bunches. Typical numerical results for bunches of different shapes and structures with different parameters are given.
* M.I. Kontorovich et al, Electrodynamics of Grid Structures (Moscow, 1987).
** V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Let., 108, 184801 (2012).

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THPME174

High-accuracy Diagnostic Tool for Electron Cloud Observation in the LHC based on Synchronous Phase Measurements

cryogenics, electron, simulation, synchrotron

3677

J.F. Esteban Müller, P. Baudrenghien, T. Mastoridis, E.N. Shaposhnikova, D. Valuch
CERN, Geneva, Switzerland

Electron cloud effects such as heat load in the cryogenic system, pressure rise and beam instabilities are among the main limitations for the LHC operation with 25 ns spaced bunches. A new observation tool was developed to monitor the e-cloud activity and has been successfully used in the LHC during Run 1 (2010-2012). The power loss of each bunch due to the e-cloud can be estimated using very precise bunch-by-bunch measurement of the synchronous phase shift. In order to achieve the required accuracy, corrections for reflection in the cables and some systematic errors need to be applied followed by a post-processing of the measurements. Results show clearly the e-cloud build-up along the bunch trains and its evolution during each LHC fill as well as from fill to fill. Measurements during the 2012 LHC scrubbing run reveal a progressive reduction in the e-cloud activity and therefore a decrease in the secondary electron yield (SEY). The total beam power loss can be computed as a sum of the contributions from all bunches and compared with the heat load deposited in the cryogenic system. The plan to use this method in the LHC operation is also presented.

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THPME176

CERN Antiproton Decelerator Beam Instrumentation for the ELENA Era

antiproton, pick-up, instrumentation, electron

3684

M. Ludwig, L. Bojtár, M.F. Fernandes, M. Gąsior, L. Søby, G. Tranquille
CERN, Geneva, Switzerland

CERN is currently constructing an Extra Low ENergy Antiproton ring (ELENA), which will allow the further deceleration of antiprotons from the currently exploited Antiproton Decelerator (AD). In order to meet the challenges of ELENA the beam instrumentation systems of the CERN AD are being consolidated and upgraded. An updated controls architecture with a more flexible timing system needs to be adopted and obsolete systems must be replaced. This paper presents the status and plans for improved performance and measurement availability of the AD beam instrumentation with a decreased risk of failure.

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THPME180

Vibration Measurement Experiment at TLS

photon, interface, electron, synchrotron

3697

C.C. Liang, C.K. Chou, S. Fann, C.K. Kuan, D. Lin, T.F. Lin, Y.-C. Liu, T.-C. Yu
NSRRC, Hsinchu, Taiwan
Y.-C. Liu
NTHU, Hsinchu, Taiwan

The oncoming completion of Taiwan Photon Source is closely constructed beside Taiwan Light Source (TLS). Few civil works are continuously under construction. Building the measurement, recording and analysis platform of software and hardware is the one of the main directions of operation group. To diagnose the instability problem of the light source, the external influence must be eliminated. One of the factors causing the instability is the physical vibration. Vibration measurement helps to evaluate if newly installed equipments are suited for adding on or the influence of the earthquake to the stability of TLS and to improve the light source quality for users. Software has been developed to provide assistance to do some preliminary diagnoses at TLS. In this article, some actual cases in routine operation are also presented.

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THPME185

Design and First Operation of a Silicon-based Non–invasive Beam Monitor

detector, proton, experiment, electronics

3712

T. Cybulski, L.J. Devlin, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
T. Cybulski, L.J. Devlin, K.P. Hennessy, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Kacperek, B. Marsland, I. Taylor, A. Wray
The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom

Funding: Work supported by the EU under contract PITN-GA-2008-215080 and the STFC Cockcroft Institute Core Grant No. ST/G008248/1.
Non–invasive, highly accurate and reliable beam monitors are a desired aim of any beam diagnostics design. Knowledge of beam parameters is essential in fundamental research, industry or medical applications with varying demands. It is critical for the optimization of ion beams used for cancer treatment. Ocular tumor treatment at the Clatterbridge Cancer Center (CCC) uses a 60 MeV proton beam. Disturbances introduced to a beam by intercepting devices risk affecting its energy and energy spread, thereby limiting its effectiveness for treatment. The advantageous semi-circular structure of the LHCb Vertex Locator (VELO) detector has been investigated in the QUASAR Group. It is an interesting option for a non-invasive online beam monitor relying on beam ‘halo’ measurements without disturbing the part of the beam used for treatment. This contribution discusses the measurement method, setup design and integration within the CCC treatment beam line.

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THPME195

Nondestructive Beam Current Monitor for the 88-inch Cyclotron

cyclotron, ion, ion-source, heavy-ion

3738

M. Kireeff Covo
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director, Office of Science, Office of Nuclear Physics, Division of Nuclear Physics, US Department of Energy under Contract No. DE-AC02-05CH11231.
A fast current transformer is mounted in the staging line of the Berkeley 88-inch isochronous cyclotron. The measured signal is amplified and connected to the input of a lock-in amplifier. The lock-in amplifier detects the signal vector from the input signal at the RF reference frequency of the cyclotron second harmonic. The magnitude of the signal detected is calibrated against a Faraday cup and shows the beam current leaving the cyclotron.

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THPME196

Low Energy Coded Aperture Performance at the CesrTA x-Ray Beam Size Monitor

detector, electron, synchrotron, photon

3741

D.P. Peterson, J.P. Alexander, A. Chatterjee, M. P. Ehrlichman, B.K. Heltsley, A. Lyndaker, N.T. Rider, D. L. Rubin, R.D. Seeley, J.P. Shanks
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J.W. Flanagan
KEK, Ibaraki, Japan

Funding: U.S. National Science Foundation PHY-0734867, PHY-1002467, PHYS-1068662, U.S. Department of Energy DE-FC02-08ER41538, DE-SC0006505
We report on the design and performance of coded aperture optics elements in the CesrTA x-ray beam size monitor (xBSM). Resolution must be sufficient to allow single-turn measurements of vertical beam sizes of order 10um by imaging synchrotron radiation photons onto a one-dimensional photodiode array. Measurements with beam energies above 2.1GeV and current above 0.1mA can be performed with a single-slit (pinhole) optic. At lower energy or current, small beam size measurements are limited by the diffractive width of a pinhole image and counting statistics. A coded aperture is a multi-slit mask that can improve on the resolution of a pinhole in two ways: higher average transparency improves counting statistics; and the slit pattern and masking transparency can be designed to obtain a diffractive image with narrower features. We have previously implemented coded apertures that are uniform redundant arrays (URA). A new coded aperture design is optimized for imaging with 1.8 GeV beam energy (1.9keV average x-ray energy) and with beam sizes below 20um. Resolution measurements were made in December 2013. Performance of the new coded aperture is compared to the pinhole and the URA.

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THPME197

Power Saving Status in the NSRRC

controls, synchrotron, synchrotron-radiation, status

3744

J.-C. Chang, Y.C. Chang, Y.F. Chiu, Y.-C. Chung, C.W. Hsu, Y.-C. Lin, C.Y. Liu, Y.-H. Liu, Z.-D. Tsai, T.-S. Ueng
NSRRC, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC), Taiwan has completed the construction of the civil and utility system engineering of the Taiwan Photon Source (TPS) in 2013 and 2014, respectively. The contract power capacities of the Taiwan Light Source (TLS) and the TPS with the Taiwan Power Company (TPC) are 5.5MW and 3MW currently, respectively. The ultimate power consumption of the TPS is estimated about 12.5MW. To cope with increasing power requirement in the near future, we have been conducting several power saving schemes for years. They include power consumption control, optimization of chillers operation, air conditioning system improvement, power factor improvement, application of heat pump, and promotion for power saving.

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THPME200

Status of the Utility System Construction for the 3 GeV TPS Storage Ring

storage-ring, booster, controls, power-supply

3751

J.-C. Chang, W.S. Chan, C.S. Chen, J.-R. Chen, Y.-C. Chung, C.W. Hsu, K.C. Kuo, Y.-C. Lin, C.Y. Liu, Y.-H. Liu, Z.-D. Tsai, T.-S. Ueng
NSRRC, Hsinchu, Taiwan

The construction of the utility system for the 3.0 GeV Taiwan Photon Source (TPS) was started in the end of 2009. The utility building for the TPS ring had been completed in the end of 2013. The building use license had been approved in Sep. 2013. The whole construction engineering has been completed. The acceptance test is scheduled on July 2014. Total budget of this construction is about four million dollars. This utility system presented in this paper includes the cooling water, air conditioning, electrical power, and compressed air systems.

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THPRI014

Modular Stand-Alone Pulse Current Measurement System for Kicker and Septa at BESSY II and MLS

controls, EPICS, storage-ring, kicker

3794

O. Dressler, J. Kuszynski, M. Markert
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung and Land Berlin.
Pulse current measurement systems are introduced for all pulsed deflection magnets in the BESSY II and MLS storage rings which acquire data autonomously. The measured pulse currents are displayed locally or remotely as single values or graphs. The data acquisition systems utilize commercial PXI chassis by National Instruments (NI), controllers and 2-channel 14bit, 100MHz high-speed digitizer cards. Measurement routines are programmed with LabVIEW 2012. Special in-house custom made ‘CA-Lab’ client software provides interface for the independent systems to write values into pre-assigned process variables of the EPICS control system. The retrieved data can be displayed in the machine control system and stored in a data archive. This allows shot to shot assessment of the pulse currents for accelerator operation and troubleshooting as well as long term data evaluation in correlation with other relevant machine parameters. This report also describes the set-up for the pulse current measurements and the structured programming for the data acquisition. Limits of the applied measurement technique and experience with the information gained for the accelerator operation will be explained.

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THPRI019

Reliability and Availability Modeling for Accelerator Driven Facilities

software, simulation, vacuum, linac

3803

O. Rey Orozko, E. Bargalló, A. Nordt
ESS, Lund, Sweden
A. Apollonio, R. Schmidt
CERN, Geneva, Switzerland

Accelerator driven facilities are and will have to be designed to a very high level of reliability and beam availability to meet expectations of the users and experiments. In order to fulfill these demanding requirements on reliability and overall beam availability, statistical models have been developed. We compare different statistical reliability models as well as tools in terms of their performance, capacity and user-friendliness. In addition we also benchmarked some of the existing models. We will present in detail a tool being used for LHC and LINAC4 which is based on the commercially available software package Isograph and a tool using Excel, which was developed in house for ESS-systems. The impact of an early reliability modeling on the design of mission critical systems will be presented as well.

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THPRI020

Availability Studies for Linac4 and Machine Protection Requirements for Linac4 Commissioning

linac, target, hardware, ion

3807

A. Apollonio, S. Gabourin, C. Martin, B. Mikulec, B. Puccio, J.L. Sanchez Alvarez, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

Linac4 is one of the key elements in the upgrade program of the LHC injector complex at CERN, assuring beams with higher bunch intensities and smaller emittance for the LHC and many other physics experiments on the CERN site. Due to the demand of continuous operation, the expected availability of Linac4 needs to be carefully studied already during its design phase. In this paper an overview of the relevant systems impacting on Linac4 machine availability is given: the various system failure modes are outlined as well as their impact on the total yearly machine downtime. Machine Protection Systems (MPS) play a significant role in reducing the risk associated to each failure mode and are therefore important for reaching the target availability. The Linac4 MPS requirements, with particular focus on the different commissioning phases, are discussed.

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THPRI021

Implementation of a Direct Link between the LHC Beam Interlock System and the LHC Beam Dumping System Re-triggering Lines

dumping, extraction, kicker, electronics

3810

S. Gabourin, E. Carlier, R. Denz, N. Magnin, J.A. Uythoven, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
M. Bartholdt, B. Bertsche, V. Vatansever, P. Zeiler
Universität Stuttgart, Stuttgart, Germany

To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump blocks must be guaranteed at all times. When a beam dump is demanded, the Beam Interlock System communicates this request to the Trigger Synchronisation and Distribution System of the LHC Beam Dumping System. Both systems were built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the Trigger Synchronisation and Distribution System, a new direct link from the Beam Interlock System to the re-triggering lines of the LHC Beam Dumping System will be implemented for the start-up with beam in 2015. The link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called asynchronous beam dumps nor compromise machine availability. This paper describes the implementation choices of this link. Furthermore the results of a reliability analysis to quantify its impact on LHC machine availability are presented.

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THPRI022

The Accelerator Reliability Forum

HOM, controls, instrumentation, software

3813

A. Lüdeke
PSI, Villigen PSI, Switzerland
R. Giachino
CERN, Geneva, Switzerland
L. Hardy
ESRF, Grenoble, France

A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum (http://reliability.forumotion.com). This contribution will describe the forum and advertise it's usage in the community.

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THPRI024

Finding Your Happy-User-Index

proton, target, feedback, electron

3816

A. Lüdeke
PSI, Villigen PSI, Switzerland

Reliability is defined as the ability of a system or component to perform its required functions under stated conditions for a specified period of time. If we are talking about accelerator reliability then we have to know what the required functions are. Many accelerator facilities restrict their analysis to the beam availability: how reliable is beam provided to the users? We will show that this metrics is often not fully adequate. Specific metrics can be much more useful to allow you to optimize your facility to the needs of your users. The three accelerator user facilities at PSI will serve as examples for these happy-user-indexes.

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THPRI025

Accelerator Reliability Reporting at the Swiss Light Source

feedback, interlocks, injection, insertion

3819

A. Lüdeke
PSI, Villigen PSI, Switzerland

Third generation light sources do aim for a very high reliability of the accelerator. This contribution describes the reliability reporting of the Swiss Light Source at the Paul Scherrer Institut, as it has been performed in the past decade. We will highlight the importance of a formal reporting on the accelerator reliability to support the long term optimization of the reliability of an accelerator facility.

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THPRI026

A Review on Accelerator Operator Training

survey, ISAC, controls, proton

3822

A. Lüdeke, E. Zimoch
PSI, Villigen PSI, Switzerland

Operators of accelerator facilities have to be trained in order to safely operate their machines. While the amount of training varies between the different types of accelerators, many best-practices could be applied to the training of operators for a variety of different facilities. The aim of our study is to survey the best-practices for operator training for a larger number of accelerator facilities. The results may provide useful insights to advance the training-plans for operators of particle accelerators.

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THPRI031

Design and Commissioning of S-Band RF Station for AREAL Test Facility

gun, electron, LLRF, klystron

3834

A. Vardanyan, H. Avdishyan, H. Davtyan, B. Grigoryan, L.H. Hakobyan, H. Poladyan
CANDLE SRI, Yerevan, Armenia

The RF station has been designed and constructed for AREAL Linac. The constructional features and commissioning results of RF system are presented. The whole RF system is designed to work at 3GHz frequency. The linac includes an electron gun for 0.5-8 ps electron bunch production with 1-10 Hz repetition rate. For linac RF control system a Libera LLRF stabilization system is used. An important feature of the presented system is a high level synchronization of amplitude-phase characteristics which provide the required accuracy for particle acceleration and bunch formation.

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THPRI033

Design of New Buncher Cavity for Relativistic Electron Gun for Atomic Exploration – REGAE

cavity, simulation, emittance, electron

3840

M. Fakhari, H. Delsim-Hashemi, K. Flöttmann, M. Hüning, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
J. Roßbach
Uni HH, Hamburg, Germany

The Relativistic Electron Gun for Atomic Exploration, REGAE, is a small electron accelerator build and operated at DESY. Its main application is to provide high quality electron bunches for time resolved diffraction experiments. The RF system of REGAE contains different parts such as low level RF, preamplifier, modulator, phase shifter, and cavities. A photocathode gun cavity to produce the electrons and a buncher cavity to compress the electron bunches in the following drift tube. Since the difference between the operating mode of the existing buncher and its adjacent mode is too small, the input power excites the other modes in addition to the operating mode which affects the beam parameters. A new buncher cavity is designed in order to improve the mode separation. Furthermore the whole cavity is modeled by a circuit which can be useful especially during the tuning process. Beam dynamics simulations have been performed in order to compare the new designed cavity with the old one which declare that the effects of the adjacent modes on the beam parameters are decreased.

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THPRI041

Twenty Years of Operation of the Elettra RF System

klystron, cavity, storage-ring, booster

3853

C. P. Pasotti, M. Bocciai, P. Pittana, M. Rinaldi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Six thousand hours per year is the typical running scheduled time of the user-dedicated Elettra facility and twenty years is a significant amount of operating hours for the RF system. Failure and weak points of the installed equipment is discussed as well as the up-time statistic. The effectiveness of the predictive versus the extraordinary maintenance is presented. The gained operational experience has allowed the planning of the priorities to refit the installed components within a reasonable budget, in compliance with the user-operation time schedule and following the technical need of upgrading to improve the RF system performance.

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THPRI042

Design and RF Test of Damped C-Band Accelerating Structures for the ELI-NP Linac

HOM, damping, linac, vacuum

3856

D. Alesini, S. Bini, R. D. Di Raddo, V.L. Lollo, L. Pellegrino
INFN/LNF, Frascati (Roma), Italy
L. Ficcadenti, V. Pettinacci
INFN-Roma, Roma, Italy
L. Palumbo
URLS, Rome, Italy
L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy

The linac energy booster of the European ELI-NP proposal foresees the use of 12 traveling wave C-Band structures, 1.8 m long with a field phase advance per cell of 2pi/3 and a repetition rate of 100 Hz. Because of the multi-bunch operation, the structures have been designed with a damping of the HOM dipoles modes in order to avoid beam break-up (BBU). They are quasi-constant gradient structures with symmetric inputs couplers and a strong damping of the HOM in each cell. An optimization of the electromagnetic and mechanical design has been done to simplify the fabrication and to reduce their cost. In the paper we shortly review the whole design criteria and we illustrate the low and high power RF test results on prototypes that shown the feasibility of the structure realization and the effectiveness of the HOM damping.

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THPRI044

Vacuum Waveguide System for SPring-8 Linac Injector Section

vacuum, linac, electron, klystron

3863

T. Taniuchi, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, S. Suzuki, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan

An SF6 waveguide system for the injector section of SPring-8 linac has been replaced in a vacuum waveguide system including a newly developed vacuum circulator and an isolator. This paper describes developed RF components, a waveguide configuration and an RF conditioning of the system.

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THPRI045

Development of a 1.3-GHz Buncher Cavity for the Compact ERL

cavity, vacuum, simulation, gun

3866

T. Takahashi, Y. Honda, T. Miura, T. Miyajima, H. Sakai, S. Sakanaka, K. Shinoe, T. Uchiyama, K. Umemori, M. Yamamoto
KEK, Ibaraki, Japan

In a high-brightness injector of the Compact ERL (cERL), a 1.3-GHz buncher cavity is used to compress the electron bunches which are produced at a 500-kV photocathode DC electron gun. An rf voltage required is about 130 kV. To elongate the lifetime of the photocathode of the DC gun which is located beside the buncher cavity, an extremely-low pressure of about 10^-9 Pa is required in the buncher cavity under operating conditions. In order to achieve such low pressures, we have developed a normal-conducting cavity which included several measures to reduce the outgas from the cavity components, together with careful rf designs to avoid any problems due to multipactor discharges or to other problems. With the developed cavity, we achieved a vacuum pressure of about 2·10^-9 Pa under rf operations at an rf voltage of about 100 kV. The buncher cavity was installed in the cERL, and it worked very well; we could demonstrate to compress the bunch length from 10 ps (FWHM) to 0.5 ps (rms) using the buncher cavity.

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THPRI047

Large-aperture Travelling-wave Accelerator Structure for Positron Capture of SuperKEKB Injector Linac

positron, acceleration, linac, solenoid

3872

S. Matsumoto, T. Higo, K. Kakihara, T. Kamitani, M. Tanaka
KEK, Ibaraki, Japan

Comparing to the previous KEKB, the four-times higher charge of 4 nC per bunch is required for the injector linac of SuperKEKB. Not only a flux concentrator will be introduced but also the physical aperture of the downstream six 2m-long accelerator structures was increased as large as 30mm in diameter. We call these structures as LAS, “Large Aperture S-band” structure. The resultant higher RF group velocity of about 3% makes the acceleration gradient lower. In the nominal acceleration system, a 40MW klystron with SLED feeds four 2m-long accelerator structures producing 20MV/m acceleration field. The acceleration gradient higher than 14 MV/m is required for the very first two LAS structures to suppress the satellite bunches. This gradient is obtained by feeding only two LAS structures. Initially, ten LAS structures were installed and the RF processing has partly started. In the present paper, we firstly describe the acceleration system design and then present the processing characteristics through the RF processing without beam and with beam.

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THPRI049

Engineering Design of the RF Input Couplers for C-ADS RFQ

rfq, cavity, linac, impedance

3878

L.P. Sun, Y. He, A. Shi, C. Zhang, Z.L. Zhang
IMP, Lanzhou, People's Republic of China

A new coupler with the special ceramic window has been developed at IMP, CAS (Institute of Modern Physics, Chinese Academy of Sciences), operating at 30 kW/162.5 MHz in CW mode for an one-meter prototype cavity, which can provide all kinds of experiences to the real four-meter cavity including EM simulation, power conditioning, cooling consideration and so on. Now, the beam experiments on prototype cavity have been completed and the results show the simulation and the measurements of coupler were in the good agreement. The special bowl-type ceramic window can promote S parameter and reduce sparking risk for beam commissioning stably. A detailed electromagnetic design and measured results of the coupler will be presented in the paper.

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THPRI050

Calculation and Design of the Re-buncher Cavities for the LIPAc Deuteron Accelerator

cavity, pick-up, vacuum, beam-transport

3881

D. Gavela, I. Podadera, F. Toral
CIEMAT, Madrid, Spain

Funding: This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under project AIC-A-2011-0654
Two re-buncher cavities are necessary for the LIPAc (Linear IFMIF Prototype Accelerator), presently being built at Rokkasho (Japan). They are placed at the Medium Energy Beam Transport (MEBT) line to longitudinally focus a 5 MeV CW deuteron beam. Due to the strong space charge and the compactness of the beamline, the cavity has several space restrictions. In order to minimize the power loss, an IH-type cavity with 5 gaps was selected. It provides an effective voltage of 350 kV at 175 MHz with a power loss of 6.6 kW. First, electromagnetic calculations have been done with HFSS to compute the resonant frequency, the S-parameters, the electric and magnetic field maps, the power losses and the proper geometry for a magnetic input coupler and a pickup probe. Then, a mechanical Ansys model has been used to analyze the stresses and deformations due to vacuum, the cooling circuit and the temperature distribution, taking into account the power losses imported from the electromagnetic model. Finally, the fluid dynamics in the cooling circuits of the stems has been carefully studied.

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THPRI086

Beam Dumps of the New LCLS-II

shielding, electron, neutron, radiation

3973

M. Santana-Leitner, A. Ibrahimov, L.Y. Nicolas, S.H. Rokni, D.R. Walz, J.J. Welch
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515.
In 2013 the design of the new LCLS-II new hard X-FEL facility at the SLAC National Accelerator Laboratory was rescoped to operate two parallel variable gap undulator lines at repetition rates up to 1MHz and above. A new superconducting RF structure will be installed in the first third of the SLAC two-mile Linac to provide a few hundred kWof beam power at energies of up to 4 GeV. This paper describes the radiological aspects of the dumps that are being designed for the end of the electron beam lines. A layered arrangement of shielding materials is being optimized to reduce instantaneous dose leakage to occupied areas, minimum cool-down time to access the tunnel, and impact to equipment and to the environment. Calculations deal with numerous constraints, as legacy beam components will be used, and the existing tunnel structure was designed for beam powers fifty times below those envisaged for LCLS-II.

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THPRI093

CSCM: EXPERIMENTAL AND SIMULATION RESULTS

simulation, dipole, extraction, network

3988

S. Rowan, B. Auchmann, K. Brodzinski, Z. Charifoulline, R. Denz, V. Roger, I. Romera, R. Schmidt, A.P. Siemko, J. Steckert, H. Thiesen, A.P. Verweij, G.P. Willering, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
H. Pfeffer
Fermilab, Batavia, Illinois, USA

The copper-stabilizer continuity measurement - or CSCM - was devised to obtain a direct and complete qualification of the continuity in the 13 kA bypass circuits of the LHC, especially in the copper-stabilizer of the busbar joints and the bolted connections in the diode-leads. The circuit under test is brought to ~20 K, a voltage is applied to open the diodes, and the low-inductance circuit is powered with a pre-defined series of current profiles. The profiles are designed to successively increase the thermal load on the busbar joints up to a level that corresponds to worst-case operating conditions at nominal energy. In this way, the circuit is tested for thermal runaways in the joints - the very process that could prove catastrophic if it occurred under nominal conditions with the full circuit energy. Surveillance software and a numerical model were devised to carry out the analysis and ensure complete protection of the circuit from over-heating. A type test of the CSCM was successfully carried out in April 2013 on one main dipole and one main quadrupole circuit of the LHC. This paper describes the analysis procedure, the numerical model, and results of this first type test.

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THPRI095

Testing Quality and Metrics for the LHC Magnet Powering System throughout Past and Future Commissioning

framework, hardware, interface, embedded

3995

D. Anderson, M. Audrain, Z. Charifoulline, M. Dragu, K. Fuchsberger, J.C. Garnier, A.A. Gorzawski, M. Koza, K.H. Krol, S. Rowan, K. Stamos, M. Zerlauth
CERN, Geneva, Switzerland

The LHC magnet powering system is comprised of thousands of individual components to assure a safe operation when operating with stored energies as high as 10GJ in the superconducting LHC magnets. Each of these components has to be thoroughly commissioned following interventions and machine shutdown periods to assure their protection function in case of powering failures. As well as a dependable tracking of test executions it is vital that the executed commissioning steps and applied analysis criteria adequately represent the operational state of each component. The Accelerator Testing (AccTesting) framework in combination with a domain specific analysis language provides the means to quantify and improve the quality of analysis for future campaigns. Dedicated tools were developed to analyse in detail the reasons for failures and success of commissioning steps in past campaigns and to compare the results with newly developed quality metrics. Observed shortcomings and discrepancies are used to propose additional verification and mitigation for future campaigns in an effort to improve the testing quality and hence assure the overall dependability of subsequent operational periods.

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THPRI097

A Retrospective View to the Magnet Interlock Systems at CERN

PLC, interlocks, software, linac

4001

I. Romera, P. Dahlen, R. Mompo, B. Puccio, M. Zerlauth
CERN, Geneva, Switzerland

Several thousands of both, superconducting and normal conducting magnets are in charge of guiding the particle beams in CERN’s accelerator complex. In order to protect the magnet and powering equipment from damage, dedicated magnet interlock and protection systems are deployed throughout the various accelerators and transfer lines. These systems have worked extremely well during the first years of LHC operation, providing highly dependable interlocking of magnet powering based on industrial COTS components. This paper reviews the performance of the more than 70 individual installations during the first LHC running period and compares the operational experience with the initial expectations of dependability. Additional improvements required to address specific operational needs and observed shortcomings are presented. Finally, we review the existing magnet interlock infrastructure in the LHC injector complex and the ongoing renovation works during the first long shutdown.

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THPRI100

Distributed Cooling System for the AREAL Test Facility

gun, klystron, electron, controls

4010

V. V. Vardanyan, G.A. Amatuni, V.S. Avagyan, A.A. Gevorgyan, B. Grigoryan, T.H. Mkrtchyan, V. Sahakyan, A.S. Simonyan, A.V. Tsakanian, A. Vardanyan
CANDLE SRI, Yerevan, Armenia

Following the design specifications of the Advanced Research Electron Accelerator Laboratory (AREAL), a reliable distributed cooling system for the AREAL linear accelerator has been developed. The cooling system provides a high accuracy temperature control for the electron gun, klystron and the magnets. The main requirements and technical solutions for various accelerator components cooling units are presented, including the local and remote control.

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THPRI102

Energy Effciency of Particle Accelerators - A Networking Effort within the EUCARD² Program

network, quadrupole, focusing, luminosity

4016

J. Stadlmann, P.J. Spiller
GSI, Darmstadt, Germany
R. Gehring
KIT, Karlsruhe, Germany
E. Jensen
CERN, Geneva, Switzerland
T.I. Parker
ESS, Lund, Sweden
M. Seidel
PSI, Villigen PSI, Switzerland

Funding: EuCARD² is co-funded by the partners and the European Commission under Capacities 7th Framework Programme, Grant Agreement 312453
EuCARD² is an Integrating Activity Project for coordinated Research and Development on Particle Accelerators, co-funded by the European Commission under the FP7 Capacities Programme. Within the network EnEfficient we address topics around energy efficiency of research accelerators. The ambitious scientific research goals of modern accelerator facilities lead to high requirements in beam power and beam quality for those research accelerators. In conjunction with the user’s needs the power consumption and environmental impact of the research facilities becomes a major factor in the perception of both funding agencies and the general public. In this Network we combine and focus the R&D done individually at different research centers into a series of workshops. We cover the topics “Energy recovery from cooling circuits “, “Higher electronic efficiency RF power generation“, “Short term energy storage systems”, “Virtual power plants” and “Beam transfer channels with low power consumption”. Our network activities are naturally open to external participants. With this work we will introduce our energy efficiency topics to interested participants and contributors from the whole community.

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THPRI103

Improvement of the Run-time of 35 mbar Helium Gas Pumping Units for the Superconducting Linear Accelerator S-DALINAC

coupling, controls, experiment, vacuum

4019

J. Conrad, F. Hug, T. Kürzeder, N. Pietralla
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by DFG through SFB 634
The superconducting Darmstadt linear accelerator S-DALINAC has been designed to provide electron beams of up to 130 MeV for nuclear and astrophysical experiments. The accelerating cavities are operated in a liquid helium bath at 2 K. To achieve this temperature the cryostat has to be pumped down to a pressure of 35 mbar which was done by a system of pumping units connected in series, when the accelerator started its operation in 1991. In 2005 this system was replaced by four parallel switched pumping stations. In the first three years of their operation, the reliability of the accelerator was very poor due to repeated breakdowns of the pumping stations caused by overheating. In addition the high temperatures lead to an early decay of the gaskets used. The problem was solved by installing oil cooling systems and more appropriate shaft sleeves at the pumping stations. We will report on the technical efforts we made and thereby further increased the availability of the accelerator significantly. Also we will give a review on our experiences in maintenance procedures.

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THPRI113

Spallation Neutron Source Cryogenic Test Facility Horizontal Test Apparatus Operation

cavity, cryogenics, plasma, SRF

4043

B. DeGraff, B.S. Hannah, T.S. Neustadt, J. Saunders
ORNL RAD, Oak Ridge, Tennessee, USA
R. Afanador, M. Doleans, M.P. Howell, S.-H. Kim, C.J. McMahan
ORNL, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
The Spallation Neutron Source (SNS) has built Superconducting Radio Frequency (SRF) processing and testing facilities to support improvement programs and future upgrades. The Cryogenic Test Facility (CTF) system is capable of delivering liquid helium at 4.5K to different test apparatus in support of SRF testing. This paper describes the final stages of fabrication, commissioning and the initial operation of the Horizontal Test Apparatus (HTA). The HTA allows for cold testing of single jacketed medium-beta or high-beta SRF cavities. Heat loads, capacities, and other performance data collected during operation will be presented. Cavity testing lifecycle for plasma processing research and development will be discussed. System changes to allow for 2K helium operation in the HTA will also be addressed.

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FRXCA01

State-of-the-art and Future Challenges for Machine Protection Systems

injection, linac, monitoring, diagnostics

4060

J. Wenninger
CERN, Geneva, Switzerland

Current frontier accelerators explore regimes of increasing power and stored energy, with beam energies spanning more than three orders of magnitude from the GeV to the TeV scale. In many cases the high beam power has to cohabit with superconducting equipment in the form of magnets or RF cavities requiring careful control of losses and of halos to mitigate quenches. Despite their large diversity in physics goals and operation modes, all facilities depend on their “Machine Protection Systems” (MPS) for safe and efficient running. This presentation will aim to give an overview of current MPS and on how the MPS act on or control the beams. Lessons from the LHC and other accelerators show that ever tighter monitoring of accelerator equipment and of beam parameters is required in the future. Such new monitoring systems must not only be very accurate but also be extremely reliable to minimize false alarms. Novel MPS ideas and concepts for linear colliders, high intensity hadron accelerators and to other high power accelerators will be presented.

Slides FRXCA01 [5.507 MB]

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FRXAB01

Trends in RF Technology for Applications to Light Sources with Great Average Power

klystron, rf-amplifier, high-voltage, power-supply

4065

Ch. Wang
NSRRC, Hsinchu, Taiwan

RF systems are a major part of both the capital and operating costs of contemporary light sources and directly impact their capability, reliability and availability. The RF community has been discussing for many years the best choice of CW RF power source for light sources. In the domain of great average power, the choice is among a klystron, inductive-output tube, and solid-state RF amplifier. Here we review their current development and challenges and offer a perspective from a point of view of operating a light source with high reliability and availability.

Slides FRXAB01 [4.033 MB]

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