IPAC2013 - List of Keywords (vacuum)

Paper	Title	Other Keywords	Page
MOZB102	Undulator Technologies for Future Free Electron Laser Facilities and Storage Rings	undulator, radiation, electron, wiggler	26
	M.-E. Couprie SOLEIL, Gif-sur-Yvette, France
	Insertion devices (undulators and wigglers) are key components for high brightness third generation synchrotron sources and for the amplifying medium of free electron lasers. Different technological developments carried out worldwide lead to improved undulator performance. In particular, the advances concerning the in vacuum permanent magnet systems, in particular for short period ones with the operation at cryogenic temperature with NdFeB or PrFeB magnets or for long period ones where in vacuum wigglers will be described. Secondly, progress in Elliptical Polarised Undulators (EPU) will be discussed, such as the DELTA undulator. Recent progress in superconducting undulators will also be reported. Finally, the effect of the insertion devices on the light source operation is analysed, either with the strategies to compensate unwanted effects or in viewing taking advantage of them as for Robinson or damping wigglers for reducing storage ring horizontal emittance.
	Slides MOZB102 [8.940 MB]

MOZB202	The First Long Shutdown (LS1) for the LHC	dipole, ion, luminosity, radiation	44
	F. Bordry, S. Baird, K. Foraz, A.-L. Perrot, R.I. Saban, J.Ph. G. L. Tock CERN, Geneva, Switzerland
	The LHC has been delivering data to the physics experiments since the first collisions in 2009. The first long shutdown (LS1), which started on 14 February 2013, was triggered by the need to consolidate the magnet interconnections so as to allow the LHC to operate at the design energy of 14 TeV in the centre-of-mass. It has now become a major shutdown which, in addition, includes other repairs, consolidation, upgrades and cabling across the whole accelerator complex and the associated experimental facilities. LS1 will see a massive programme of maintenance for the LHC and its injectors in the wake of more than three years of operation without the long winter shutdowns that were the norm in the past. The main driving effort will be the consolidation of the 10,170 high-current splices between the superconducting magnets. The presentation describes first the preparation phase with the prioritisation of the activities, the building of the teams and the detailed planning of the operation. Then, it gives the status after 3 months and the restart plans for all CERN accelerators. First lessons learnt for the 2nd long shutdown (LS2) will conclude the presentation.
	Slides MOZB202 [13.675 MB]

MOPEA003	Status and Very First Commissioning of the ASTRID2 Synchrotron Light Source	quadrupole, lattice, cavity, booster	64
	S.P. Møller, N. Hertel, J.S. Nielsen ISA, Aarhus, Denmark
	ASTRID2 is the new 10 nm UV and soft x-ray light source at Aarhus University. It will replace the ageing source ASTRID, which will be used as the full-energy (580 MeV) booster for ASTRID2. An upgrade of the beamlines at ASTRID are presentlytaking place before being transferred to ASTRID2 until the end of 2013. In addition new beamlines and insertion devices are being procured. Presently, ASTRID2 commissioning is alternating with ASTRID operation to continue during 2013. Status in spring 2013 includes operation of most sub-systems resulting in top-up mode operation to 150 mA. The lattice have been qualifies although a re-alignment is planned. The poster will present experiences from the first commissioning and give the status of the project.

MOPEA004	Beam Lifetime in the ASTRID and ASTRID2 Synchrotron Light Sources: Excitations and Vacuum Dependences	synchrotron, ion, emittance, electron	67
	J.S. Nielsen, N. Hertel, S.P. Møller ISA, Aarhus, Denmark
	The beam lifetime is a very important parameter for synchrotron light sources without top-up, and sometimes more important than the lowest possible vertical beam emittance. At the ASTRID synchrotron light source, we have for many years routinely applied a phase modulation of the accelerating RF field, together with a vertical excitation of the beam at the first vertical betatron frequency. These two effects increase the beam lifetime from about 3 hours to more than 100 hours at 150 mA. Lifetime measurements as function of modulation and excitation parameters will be presented. Additionally, measurements of the beam lifetime in ASTRID and ASTRID2 as function of vacuum pressure will be presented.

MOPEA006	Operation and Performance Upgrade of the SOLEIL Storage Ring	feedback, power-supply, dipole, injection	73
	A. Nadji, F. Bouvet, P. Brunelle, A. Buteau, L. Cassinari, M.-E. Couprie, N. Hubert, M. Labat, J.-F. Lamarre, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, J.L. Marlats, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	SOLEIL delivers photons to 26 beamlines and 3 new ones are under construction together with the femtoslicing project. Up to 5 filling patterns are available for the users including a low alpha mode; all of them are in Top-up injection. The beam current for the users has been increased to 430 mA in the multibunch mode. The Storage Ring (SR) is running with a new optics incorporating an additional quadrupole triplet in one long straight section. The beam position stability remains excellent. Vertical positions from the dipole X-BPMs have been included in the orbit feedbacks loop with very encouraging results. A feedback loop maintaining the emittance coupling close to 1% for any Insertion Devices (IDs) configuration has been implemented. Up to 25 very diverse IDs are now installed on the SR, and several others are under design or construction. In house developments are being carried out in several domains such as construction of SR dipole power supply spare and of 70 kW-500 MHz solid state amplifiers, design of a pulsed multipole magnet for injection, and a Robinson wiggler, as well as a feasibility study of a local reduction of the emittance in one of the long straight sections.

MOPEA016	The Main Stochastic Cooling System of the HESR	kicker, pick-up, accumulation, simulation	100
	R. Stassen, R. Greven, R. Maier, G. Schug, H. Stockhorst FZJ, Jülich, Germany
	The main stochastic cooling system of the High-Energy Storage Ring HESR (1.5-15 GeV/c) for antiprotons at the FAIR complex (Facility for Antiprotons and Ion Research) in Darmstadt (GSI) will work in the frequency range of 2 - 4 GHz. The design work on pickup and kicker is now finished and the production of the first cooling tank has been started. The whole system layout will be presented taking into account new additional requirements concerning the accumulation and the cooling of heavy ions. All beam-coupling structures are nearly identical and contain several ring-slot blocks. These blocks consist of eight wall-current monitors coupled out by eight electrodes each. Most of the signal combining and splitting take place within the vacuum envelope to reduce the number of vacuum RF feed throughs. The long-distance transmission of the signals and the filters containing long signal delays work with near infrared optical elements.

MOPEA021	Status of the HESR Electron Cooler Test Set-up	electron, simulation, cathode, controls	115
	M.W. Bruker, K. Aulenbacher, J. Dietrich, S. Friederich, A. Hofmann, T. Weilbach HIM, Mainz, Germany K. Aulenbacher IKP, Mainz, Germany
	For the proposed High Energy Storage Ring (HESR) at FAIR, it is foreseen to install an electron cooling device with a beam current of 3 A and a beam energy of 8 MeV. A test set-up was built at Helmholtz-Insitut Mainz (HIM) to conduct a feasibility study. One of the main goals of the test set-up is to evaluate the gun design proposed by TSL (Uppsala) with respect to vacuum handling, EM fields and the resulting beam parameters. Another purpose of the set-up is to achieve an energy recuperation efficiency of 1 - 10^-5. To measure this quantity, a Wien filter has to be employed, which will also prove capable of mitigating collection losses. The current status of the project will be presented.

MOPEA029	Status of UVSOR III	injection, undulator, sextupole, quadrupole	139
	T. Konomi, M. Adachi, K. Hayashi, M. Katoh, J. Yamazaki UVSOR, Okazaki, Japan M. Adachi, M. Katoh Sokendai - Okazaki, Okazaki, Aichi, Japan
	UVSOR-III is the 750 MeV synchrotron light source. In 2012, three new components were installed in the storage ring. First one is combined function bending magnets to reduce the emittance from 27 nm-rad to 17 nm-rad. These magnets can produce dipole, quadrupole and sextupole fields at the same time. Second ones are an in-vacuum undulator and a beam line. It was installed at 1.5 m straight section, which is the last section reserved for insertion devices. As a result, UVSOR-III is now equipped with six undulators. It would provide soft X-rays to a scanning transmission X-ray microscope (STXM) beam-line. Last one is a newly designed pulse sextupole magnet at the injection point. This is beneficial to the user experiments in the top-up operation mode. Fine machine tuning is in progress.

MOPEA030	Status of UVSOR-III	injection, undulator, cavity, sextupole	142
	N. Yamamoto Nagoya University, Nagoya, Japan T. Konomi UVSOR, Okazaki, Japan
	Construction of the Central Japan Synchrotron Radiation (SR) Facility has been completed in the Aichi area of Japan, and the beam commissioning was started in Spring of 2012. Up to now, it is confirmed that the 1.2 GeV storage ring works with 300 mA Top-up mode. The key equipments of the accelerators are a compact electron storage ring with the ability to supply hard X-rays and full energy injectors for the top-up operation. The accelerators consist of an electron storage ring, a booster synchrotron ring, and an injector linac. In this prezentation, the present status of the accelerators are reported.

MOPEA037	Theoretical Study on the Two-stage Collimation System Design	collimation, scattering, simulation, space-charge	157
	N. Wang, S. Wang IHEP, Beijing, People's Republic of China
	Two-stage collimation system is widely used in high intensity machines to localize the beam losses in a restricted area. In the well-known theory, the optical constrains are expressed by the betatronic phase advances between primary and secondary collimators, which minimize the size of the secondary halo. In this paper, the physical model is developed considering the characteristic of the space charge dominated beams. Numerical studied are performed to verify the theoretical model.

MOPEA040	Study of Geometry Dependent Multipacting of a Superconducting QWR	accelerating-gradient, electron, simulation, cavity	166
	K. Zhou, X.Y. Lu, X. Luo, S.W. Quan, L. Yang, Z.Y. Yao PKU, Beijing, People's Republic of China
	Funding: The Major Research Plan of National Natural Science Foundation of China A superconducting quarter wave resonator (QWR) of frequency=162.5 MHz and β=0.085 has been designed at Peking University. This paper focus on the multipacting (MP) study for the QWR with CST Particle Studio. The simulation results for the initial designed model reveal that there is no sign of MP with its normal operating accelerating gradients in the range of 6-8 MV/m. The accelerating gradient range that may incur MP is from about 1.4 MV/m to 3.2 MV/m, and the places where MP may be encountered are mainly located at the top part of the QWR. So the effect of different top geometries on MP has also been studied in depth. Our results show that inward convex round roof is better than other round roofs, and plane roofs have an obvious advantage over round roofs on the suppression of MP in general. While considering the optimization of its electromagnetic (EM) design, our initial designed model is also acceptable.

MOPEA046	Solaris Project Progress	storage-ring, linac, injection, klystron	181
	A.I. Wawrzyniak, C.J. Bocchetta, P.B. Borowiec, D. Einfeld, P.P. Goryl, M. Młynarczyk, R. Nietubyć, M.P. Nowak, W. Soroka, M.J. Stankiewicz, P. Szostak, P.S. Tracz, Ł. Walczak, K. Wawrzyniak, J.J. Wiechecki, M. Zając, L. Żytniak Solaris, Kraków, Poland D. Einfeld MAX-lab, Lund, Sweden R. Nietubyć NCBJ, Świerk/Otwock, Poland
	Funding: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program:POIG.02.01.00-12-213/09 Solaris is a 3rd generation light source facility being built in Kraków, Poland at the Jagiellonian University Campus. The project is being accomplished in a tight collaboration with the MAX IV Laboratory in Lund, Sweden. The Solaris 1.5 GeV storage ring is a replica of the MAX IV 1.5 GeV machine, whereas the injector and the transfer line although based on the same components, are unique for Solaris. One of the main differences is the 600 MeV injection energy requiring an energy ramp in the storage ring to the final operating energy of 1.5 GeV. The construction of the facility started in early 2010 and is planned to be finished in the autumn 2014. Up to now, 70% of the components have been procured and construction of the buildings in progress with expected handover in autumn 2013. This paper will give an update on infrastructure progress and design choices for shielding, service area placement of racks and routing of piping and cables. An update is also presented of machine layout that includes the injector, transfer line and storage ring.

MOPEA053	Status of NSLS-II Booster	booster, dipole, controls, septum	196
	S.M. Gurov, A.I. Erokhin, S.E. Karnaev, V.A. Kiselev, E.B. Levichev, A. Polyansky, A.M. Semenov, S.V. Shiyankov, S.V. Sinyatkin, V.V. Smaluk BINP SB RAS, Novosibirsk, Russia H.-C. Hseuh, T.V. Shaftan BNL, Upton, Long Island, New York, USA
	The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized 3 GeV electron storage ring, linac pre-injector and full-energy injector-synchrotron. Budker Institute of Nuclear Physics build booster for NSLS-II. The booster should accelerate the electron beam continuously and reliably from a minimum 170 MeV injection energy to a maximum energy of 3.15 GeV and average beam current of 20 mA. The booster shall be capable of multi-bunch and single bunch operation. Pre-comissioning test results of booster components and system are reviewed.

MOPEA055	First Year Operation of the ALBA Synchrotron Light Source	storage-ring, interlocks, kicker, feedback	202
	F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3 GeV, 3rd generation, light source located in Cerdanyola, Barcelona, Spain, which started users operation in May 2012. In this paper we will report about the transition from commissioning to operation, the main problems faced during this first year, the actual status of the accelerators and we will provide an outlook to the next steps.

MOPEA056	Measuring and Improving the Momentum Acceptance and Horizontal Acceptance at MAX III	cavity, lattice, electron, storage-ring	205
	A. Hansson, Å. Andersson, J. Breunlin, G. Skripka, E.J. Wallén MAX-lab, Lund, Sweden
	Lifetime measurements for varying horizontal scraper positions performed at different RF frequencies suggested a horizontal aperture restriction in the MAX III synchrotron light source. A combination of local orbit distortions and horizontal scraper measurements pinpointed the location of the horizontal aperture restriction to the center of the main cavity straight section. The aperture restriction was determined to be located 10.4 ± 0.3 mm from the beam center. The precise result was achieved by measurements and calculations of the Touschek lifetime as a function of the main cavity voltage. Realignment of the main cavity increased the average lattice momentum acceptance from 0.0116 ± 0.0003 to 0.0158 ± 0.0003 and the horizontal acceptance from 26 ± 2 × 10^-6 m to larger than 44 ± 2 × 10^-6 m. The increase in momentum acceptance increased the lifetime in MAX III by a factor of two.

MOPEA057	Studies of the Electron Beam Lifetime at MAX III	scattering, cavity, electron, emittance	208
	A. Hansson, Å. Andersson, J. Breunlin, G. Skripka, E.J. Wallén MAX-lab, Lund, Sweden
	MAX III is a 700 MeV 3rd generation synchrotron light source located at the MAX IV Laboratory in Sweden. The lifetime in the storage ring is lower than originally envisaged. From vertical scraper measurements the lifetime contributions at 300 mA stored current have been determined. The lifetime is mainly limited by the Touschek lifetime, which is lower than its design value, whereas the vacuum lifetime is close to the expected value. The low Touschek lifetime is explained by a lower than design emittance ratio and momentum acceptance in the storage ring.

MOPEA059	The Optimization of Transverse Stripline Kicker	kicker, simulation, impedance, insertion	214
	H.P. Hsueh, C.-C. Chang, Y.P. Chang, J.-R. Chen, Y.T. Cheng, G.-Y. Hsiung, Y.C. Yang NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	The construction of a new 3 GeV synchrotron facility, Taiwan Photon Source, is ongoing. It is required to install stripline kickers to suppress instability generated by mismatch between injection kickers or imperfect installation of vacuum components all around. First, the design philosophy will be described for transverse stripline kickers. HFSS electromagnetic simulation software is used to optimize all structure parameters like electrode dimensions, electrode distance from vacuum chambers etc. to make transverse stripline kicker working more efficiently and effectively. All simulation results will be presented in this paper and all structure dimension choices will be discussed and the final prototype structure dimensions will be selected from the discussion.

MOPEA068	Novel Lattice Upgrade Studies for Diamond Light Source	lattice, dipole, optics, quadrupole	240
	R. Bartolini, C.P. Bailey, M.P. Cox, N.P. Hammond, J. Kay, R.P. Walker Diamond, Oxfordshire, United Kingdom R. Bartolini, T. Pulampong JAI, Oxford, United Kingdom
	Many synchrotron radiation facilities are studying lattice upgrades in order to lower the natural emittance and hence increase the radiation brightness. At Diamond we are pursuing a novel alternative, not targeting the minimum possible emittance but instead introducing additional insertion device (ID) straights and hence increasing the capacity of the facility, while still possibly achieving a more limited reduction in emittance. The new scheme involves converting some of the DBA lattice cells into a double-DBA or DDBA, with a new ID straight between the two achromats. This then allows existing or future bending magnet ports (which in Diamond are taken from near the entrance to the second dipole of the DBA lattice) to be served by a much more powerful insertion device. We present here the design concept and preliminary lattice design, and discuss the challenging magnet, vacuum and engineering issues.

MOPEA078	Commissioning and Operation of Wiggler Switchyard System for Duke FEL and HIGS	wiggler, FEL, storage-ring, lattice	267
	Y.K. Wu, M.D. Busch, M. Emamian, J.F. Faircloth, H. Hao, J.Y. Li, S.F. Mikhailov, V. Popov, G. Swift, P.W. Wallace, P. Wang, J. Yan FEL/Duke University, Durham, North Carolina, USA A.L. Wu USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033. To enable the Duke storage ring FEL to operate in VUV with adequate gain, a major storage ring upgrade was carried out in 2012 to install two additional helical FEL wigglers with a wiggler switchyard system. Using the switchyard, a quick changeover can be made between two planar OK-4 wigglers and two helical OK-5 wigglers in the middle of the FEL straight section. This system preserves the linear polarization capabilities of the Duke FEL and gamma-ray beams at the High Intensity Gamma-ray Source (HIGS), while enabling VUV FEL operation with a higher gain using a longer FEL with as many as four helical wigglers. The wiggler switchyard upgrade was completed in Summer 2012, followed by a rapid and successful commissioning of the Duke storage ring, FEL system, and HIGS. In this paper, we will present the results of accelerator and light source commissioning with the wiggler switchyard. We will also present preliminary results of operating the OK-5 FEL in different configurations. With the wiggler switchyard, we are well positioned to realize the operation of a VUV FEL below 190 nm and production of Compton gamma-ray beams above 100 MeV in circular polarization.

MOPFI005	XPS and UHV-AFM Analysis of the K2CsSb Photocathodes Growth	cathode, electron, background, factory	291
	S.G. Schubert HZB, Berlin, Germany I. Ben-Zvi, M. Ruiz-Osés Stony Brook University, Stony Brook, USA X. Liang SBU, Stony Brook, New York, USA H.A. Padmore, T. Vecchione LBNL, Berkeley, California, USA T. Rao, J. Smedley BNL, Upton, Long Island, New York, USA
	Funding: This work is funded by the Department of Energy, under Contract No. KC0407-ALSJNT-I0013, DE-SC0005713, the Bundesministerium für Bildung und Forschung (BMBF) and the state of Berlin, Germany. Next generation light sources, based on Energy Recovery Linac and Free Electron Laser technology will rely on photoinjector based electron sources. Successful operation of such sources requires reliable photocathodes with long operational life, uniform and high quantum efficiency, low thermal emittance and low dark current. The goal of this project is to construct a cathode which meets these requirements. Advances in photocathode research must take a combined effort. The materials have to be analyzed by means of chemical composition, surface structure and these findings have to be correlated to the quantum efficiency and performance in the injector. The presented work focuses on the chemical composition and surface structure of K2CsSb photocathodes. The XPS and AFM measurements were performed at the Center of Functional Nanomaterials at BNL. K2CsSb photocathodes were grown under UHV conditions. The components were adsorbed one at a time and after each growth step the corresponding XPS spectra was taken. During growth the quantum efficiency was recorded. As last step the sample was moved into the AFM without exposure to air to determine the surface roughness.

MOPFI006	A New Load Lock System for the Source of Polarised Electrons at ELSA	electron, polarization, laser, ion	294
	D. Heiliger, W. Hillert, B. Neff ELSA, Bonn, Germany
	Funding: supported by DFG (SFB/TR16) The inverted source of polarized electrons at the electron stretcher accelerator ELSA routinely provides a pulsed beam with a current of 100 mA and a polarization degree of about 80%. One micro-second long pulses with 100 nC charge are produced by irradiating a GaAs strained-layer superlattice photocathode (8 mm in diameter) with laser light. Future accelerator operation requires a significantly higher beam intensity, which can be achieved by using photocathodes with sufficiently high quantum efficiency. Therefore, and in order to enhance the reliability and uptime of the source, a new extreme high-vacuum (XHV) load lock system was installed and commissioned. It consists of a loading chamber in which an atomic hydrogen source is used to remove any remaining surface oxidation, an activation chamber for heat cleaning of the photocathodes and activation with cesium and oxygen and a storage chamber in which up to five different types of photocathodes with various diameters of the emitting surface can be stored under XHV conditions. Additionally, tests of the photocathodes' properties can be performed during accelerator operation.

MOPFI010	Initial Beam Loss and Control of Dynamic Vacuum Effects in SIS18	injection, ion, collimation, synchrotron	300
	Y. El-Hayek FIAS, Frankfurt am Main, Germany M.M. Kirk, D. Ondreka, P.J. Spiller GSI, Darmstadt, Germany U. Ratzinger IAP, Frankfurt am Main, Germany
	To stabilize the dynamic pressure in the SIS18, the systematic initial beam loss must be minimized. Beam Particles, which are lost on the vaccum chamber cause a local pressure increase. Thereby the collision rate between beam ions and residual gas particles and consequently beam loss by ionization is enhanced. The reduction and control of beam loss in the injection channel, during multiturn injection and during the Rf capture process has an outstanding importance for the vacuum dynamics. One way to minimize the initial losses in the synchrotron is to displace the beam loss into the transfer channel (TK) between UNILAC and SIS. In the transfer channel, the beam edges are trimmed by means of a collimator system and a sharply defined phase space area can be injected into SIS18. The effect of reduced initial beam loss on the vaccum dynamics is presented.

MOPFI012	Measurement of Adsorption Rates of Residual Gases for NEA-GaAs Surface	electron, cathode, ion, emittance	306
	M. Kuriki, H. Iijima, K. Miyoshi, K.U. Uchida HU/AdSM, Higashi-Hiroshima, Japan
	A GaAs photocathode activated the surface to negative-electron-affinity (NEA) is an important device for high-average-current electron accelerators such as a next-generation light source based on an energy recovery linac. The NEA surface is normally formed by a yo-yo technique in which cesium and oxygen are applied onto the surface alternately. Although the initial quantum efficiency is relatively larger than that of another cathode, the lifetime is shorter. The degradation with time elapsing even if the electron beam is not extracted is mainly caused by adsorption of residual gases in a vacuum chamber. We have evaluated the adsorption rates of various gases for the NEA surface by measuring the dark lifetime in sample gases such as hydrogen, carbon oxide and carbon dioxide.

MOPFI013	A Lifetime Study of CsK2Sb Cathode	cathode, laser, electron, brightness	309
	M. Kuriki, H. Iijima, K. Miyoshi, N. Norihito HU/AdSM, Higashi-Hiroshima, Japan
	Funding: Cooperative and Supporting Program for Researches and Educations in　Universities by High energy accelerator research organization (KEK) CsK2Sb multi-alkali cathode is one of the candidates of robust and high efficiency cathode for high brightness electron source. CsKSb can be driven by green laser and it is a big advantage comparing to Cs2Te cathode which is widely used as a robust photo-cathode and driven by UV light. In Hiroshima University, a test chamber for CsK2Sb photo-cathode study is developed. In the chamber, CsK2Sb photo-cathode is formed by evaporation on SUS base plate. During the evaporation, amount is monitored by quartz meter. We devised good locations of the evaporation source, base plate, and thickness monitor, so that all evaporation processes for Cs, K, and Sb are under control. The base plate temperature is also controlled during the cathode formation. More than 2.0% quantum efficiency was achieved at the first activation test. The cathode lifetime was more than 200 hours and more than 20C in charge. The latest experimental result will be reported.

MOPFI014	A Charge Lifetime Study of NEA GaAs Cathode by Ion Back-bombardment	electron, cathode, ion, simulation	312
	M. Kuriki KEK, Ibaraki, Japan L. Guo, H. Iijima, K. Miyoshi HU/AdSM, Higashi-Hiroshima, Japan
	Funding: Quantum beam project by the Ministry of Education, Culture, Sports, Science and Technology; The title is High Brightness Photon Beam by Laser-Compton Scattering. NEA GaAs cathode is one of the most important techniques for advanced future projects based on linac. Up to 90% polarized beam can be generated with high quantum efficiency, 0.1 – 10%. The extremely low emittance beam can be generated driven by optimized wavelength laser. Although these remarkable features, the less robustness has been the biggest issue on the real operation of this cathode. According to past experiments, there are three sources of the cathode degradation; gas absorption, thermal desorption, and ion-back bombardment. First two processes could be controlled by less vacuum pressure in order of 10^-10Pa and keeping the cathode temperature low. The ion back-bombardment is the last issue which should be solved for high brightness operation in such as ERL. We observed the cathode quantum efficiency evolution in various laser power density and bias voltage. We found that the cathode degradation was due to the ion back-bombardment quantitatively and the deactivation coefficient of NEA surface by one ion collision did not depend on the bias voltage. We report the experimental results and its analysis based on the ion back-bombardment hypothesis.

MOPFI027	The Progress of the BRISOL Facility at CIAE	ion, target, ion-source, diagnostics	339
	B. Tang, L.H. Chen, B.Q. Cui, Q.H. Huang, W. Jiang, R. Ma, Y.J. Ma, Z. Peng CIAE, Beijing, People's Republic of China
	Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line (BRISOL), aiming to generate short life radioactive ion beam (RIB) on-line, is being constructed at China Institute of Atomic Energy(CIAE). Up to now, construction of major equipment for BRISOL is completed, including ion source, vacuum system, separator, optical element, and beam diagnostic system, and assembling is underway in laboratory. The on-site installation of all the beam line will be carried out soon. All the major element prototype including surface ion source, quadrupole, hexapole, multipole and beam diagnostic system have been studied off-line on a test-bench for BRISOL. A Li beam was generated and separated . The primary tests show that the ion source and the optical elements work well. The test charge exchange cell (CEC) is under way. BRISOL will be commissioned next year.

MOPFI029	The Construction Progress of Beijing Radioactive Ion-beam Facility	ion, cyclotron, ISOL, ion-source	345
	T.J. Zhang, Shizhong. An, B.Q. Cui, Z.G. Li, Y.L. Lu, C.H. Peng, F. Yang CIAE, Beijing, People's Republic of China
	The Beijing Radioactive Ion-Beam Facility (BRIF) is being constructed at CIAE. The project consists of a 100 MeV high intensity cyclotron CYCIAE-100, an ISOL system with a mass resolution of 20000, and a superconducting booster. The construction of the building was started on April 28, 2011 and the roof was sealed on Jan. 16, 2012. The on-site installation conditions have been ready since Sept. 27, 2012. Up to now, the fabrication of all major components for CYCIAE-100 have been completed, including the main magnet system, the RF system, ion source and injection, main vacuum, etc. The equipment fabrication for the ISOL system has been completed and magnetic mapping and shimming is being performed on the large-scale analysis magnet. The fabrication of the major components for the superconducting booster has been accomplished, and the work on copper-niobium sputtering is under way. At present, the installation and assembly is in full swing and the beam commissioning is to predicted to be finished in mid 2013. Taking advantage of the experiences accumulated on the CRM cyclotron with beam up to 430 uA, it is likely that the first beams of 100 MeV can be achieved by the end of 2013.

MOPFI044	VHF Gun Research at SINAP	gun, cavity, electron, FEL	380
	Q. Gu, L. Chen, W. Fang, G.Q. Lin SINAP, Shanghai, People's Republic of China
	The R&D work on the high power THz based on energy recovery linac (ERL) has been carried out in Shanghai Institute of Applied Physics (SINAP). One of the key components for the ERL is the high brightness electron source. The low frequency gun technology has been adopted, by comparing with the SRF gun and DC gun. In this paper, the design and cold test of a 250MHz gun will be presented.

MOPFI053	Upgrades of the SPS, Transfer Line and LHC Injection Protection Devices for the HL-LHC Era	injection, kicker, coupling, extraction	401
	Ö. Mete, O. Aberle, F. Cerutti, K. Cornelis, B. Goddard, V. Kain, R. Losito, F.L. Maciariello, M. Meddahi, A. Mereghetti, J.A. Uythoven, F.M. Velotti CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	The challenging High Luminosity LHC (HL-LHC) beam requirements will lead in the future to unprecedented beam parameters along the LHC injector chain. In the SPS accelerator these requests translate into about a factor two higher intensity and brightness than the present design performance. In addition to the challenge of producing and accelerating such beams, these parameters affect the resistance of the existing equipment against beam impact. Most of the protection devices in the SPS ring, its transfer lines and the LHC injection areas will be put under operational constraints which are beyond their design specification. The equipment concerned has been reviewed and their resistance to the HL-LHC beams checked. Theoretical and simulation studies have been performed for the SPS beam scraping system, the protection devices and the dump absorbers of the SPS-to-LHC transfer lines, as well as for the LHC injection protection devices. The first results of these studies are reported, together with the future prospects.

MOPFI058	Studies of Cs3Sb Cathodes for the CLIC Drive Beam Photoinjector Option	cathode, gun, laser, electron	413
	I. Martini, E. Chevallay, S. Döbert, V. Fedosseev, C. Heßler, M. Martyanov CERN, Geneva, Switzerland
	Within the CLIC (Compact Linear Collider) project, feasibility studies of a photoinjector option for the drive beam as an alternative to its baseline design using a thermionic electron gun are on-going. This R&D program covers both the laser and the photocathode side. Whereas the available laser pulse energy in ultra-violet (UV) is currently limited by the optical defects in the 4th harmonics frequency conversion crystal induced by the 0.14 ms long pulse trains, recent measurements of Cs3Sb photocathodes sensitive to green light showed their potential to overcome this limitation. Moreover, using visible laser beams leads to better stability of produced electron bunches and one can take advantages of the availability of higher quality optics. The studied Cs3Sb photocathodes have been produced in the CERN photoemission laboratory using the co-deposition technique and tested in a DC gun set-up. The analysis of data acquired during the cathode production process will be presented in this paper, as well as the results of life-time measurements in the DC gun.

MOPFI061	Concept for Elena Extraction and Beam Transfer Elements	extraction, septum, kicker, quadrupole	422
	J. Borburgh, B. Balhan, W. Bartmann, T. Fowler, L. Sermeus, G. Vanbavinckhove CERN, Geneva, Switzerland R.A. Baartman TRIUMF, Vancouver, Canada D. Barna University of Tokyo, Tokyo, Japan V. Pricop Transilvania University of Brasov, Brasov, Romania
	In 2011 the ELENA decelerator was approved as a CERN project. Initially one extraction was foreseen, which should use a kicker and a magnetic septum which can be recuperated from an earlier installation. Since then a second extraction has been approved and a new solution was studied using only electric fields to extract the beam. This will be achieved by fast pulsing a separator, allowing single-bunch but also a full single-turn extraction from ELENA towards the experiments. The extraction and transfer requirements of ELENA are described, followed by the principal differences between the magnetic and electric field concepts. The design of electrostatic focussing and bending devices for the transfer lines will be presented. Finally the field quality which can be achieved with the separator and the concept of its power supply will be discussed.

MOPFI080	Fabrication, Transport and Characterization of Cesium Potassium Antimonide Cathode in Electron Guns	cathode, gun, laser, SRF	461
	T. Rao, S.A. Belomestnykh, I. Ben-Zvi, X. Liang, I. Pinayev, B. Sheehy, J. Skaritka, J. Smedley, E. Wang, T. Xin BNL, Upton, Long Island, New York, USA R.R. Mammei, J.L. McCarter, M. Poelker JLAB, Newport News, Virginia, USA M. Ruiz-Osés Stony Brook University, Stony Brook, USA
	a number of accelerator applications need high current, low emittance and high brightness electron beams. Recent studies have shown cesium potassium antimonide to be a robust photocathode capable of producing high peak and average currents. However, for some applications, the UHV conditions required for producing these cathodes necessitate their fabrication site to be physically removed from the gun location and the cathode to be transferred between the two sites in UHV load-lock chambers. We have fabricated two cathodes at BNL, transported and tested them in DC gun at JLab at 100 kV and 200 kV. These cathodes have delivered up to 8A/cm² without significant degradation. Localized changes in the QE have been attributed to heating due to laser, increasing the QE at lower laser power, but damaging the cathode at higher power. Two more load-lock chambers have been built to transport and insert similar cathodes in SRF guns operating at 700 MHz and 112 MHz for the first time. In this paper, we will describe the design of the load-lock chambers, transfer mechanisms, transport of the cathodes over ~ 1000 km and the cathode performance in gun environment.

MOPFI081	Correlating Structure and Function - In situ X-ray Analysis of High QE Alkali-antimonide Photocathodes	cathode, scattering, emittance, controls	464
	J. Smedley, K. Attenkofer, S.G. Schubert BNL, Upton, Long Island, New York, USA I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Osés Stony Brook University, Stony Brook, USA T. Forrest, H.A. Padmore, T. Vecchione, J.J. Wong LBNL, Berkeley, California, USA J. Xie ANL, Argonne, USA
	Funding: The authors wish to acknowledge the support of the US DOE, under Contract No. KC0407-ALSJNT-I0013, DE-AC02-98CH10886 and DE-SC0005713. Use of CHESS is supported by NSF award DMR-0936384. Alkali antimonide photocathodes have high quantum efficiency and low emittance when illuminated by visible light, and are thought to be well suited for use in high-brightness photoinjectors of 4th generation light sources. Here we report on the growth of multi-alkali K2CsSb cathodes on [100] silicon substrates measured using in-situ X-ray diffraction (XRD) and X-ray reflection (XRR). Correlations between cathode structure and growth parameters and the resulting quantum efficiency (QE) are also explored. The best cathodes have a QE at 532 nm in excess of 6% and are structurally textured K2CsSb with grain sizes in excess of 20 nm. In an attempt to reduce the complexity of the current growth methodology we are also making alkali antimonides in parallel via the reaction of bulk materials in an inert environment. This approach has the advantage that the desired stoichiometry can be obtained exactly. Initial diffraction results from prepared bulk materials are promising and show the formation of well reacted K3Sb. In the future we intend to transfer this material to smooth thin photocathode films by either sputtering or pulsed laser deposition.

MOPFI082	Redesign and Development of the Shanghai Electron Beam Ion Trap	electron, ion, alignment, cryogenics	467
	D. Lu, Y. Shen, Z. Shi, J. Xiao, Y. Yang, Y. Zou Fudan University, Shanghai, People's Republic of China
	Over the last few years the Shanghai Electron Beam Ion Trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Nuclear and Applied Physics, first generated an electron beam in 2005. Shanghai EBIT could be operated with electron beam energies between 1 and 130 keV and currents up to 160 mAmps. After several years of operation, it was found that some improvements/modifications to the old design were necessary. This contribution will discuss several of the main aspects of the redesigned Shanghai EBIT. So far it has been operated up to an electron energy of 40 keV with an current density of over 2400 A per square cm. The new EBIT is made primarily from Titanium instead of Stainless Steel and has an order of magnitude better background vacuum, a more efficient and economical cryogenic system, and also excellent optical alignment. Finally the magnetic field in the central drift tube region can reach up till 4.8 T.

MOPME003	Development of Diamond Sensors for Beam Halo and Compton Spectrum Diagnostics After The Interaction Point of ATF2	collimation, electron, simulation, photon	470
	S. Liu, P. Bambade LAL, Orsay, France S. Bai IHEP, Beijing, People's Republic of China T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major issue at ATF2 and in linear colliders is to control the beam halo, which consists of tails extending far beyond the Gaussian core of the beam. At present there is no dedicated collimation for the beam halo at ATF2, and the transverse distribution near the interaction point is not well known. The development of a sensor based on CVD diamond to scan the beam halo in the vacuum chamber a few meters after the interaction point is presented. This system also aims to detect the Compton recoil electrons generated by the laser interferometer (Shintake monitor) used to measure the beam size at the interaction point of ATF2.

MOPME007	High Resolution Synchrotron Light Analysis at ELSA	synchrotron, diagnostics, optics, electron	482
	S. Zander, F. Frommberger, P. Hänisch, W. Hillert, M.T. Switka ELSA, Bonn, Germany
	Funding: Funded by the DFG within the SFB/ TR 16 The Electron Stretcher Facility ELSA provides polarized electrons with energies up to 3.5 GeV for external hadron experiments. In order to suffice the need of stored beam intensities towards 200 mA, advanced beam instability studies need to be carried out. An external diagnostic beamline for synchrotron light analysis has been set up and provides the space for multiple diagnostic tools including a streak camera with time resolution of < 1 ps. Beam profile measurements are expected to identify instabilities and reveal their thresholds. The effect of adequate countermeasures is subject to analysis. The current status of the beamline development will be presented.

MOPME021	Ionization Profile Monitor (IPM) of J-PARC 3-GeV RCS	electron, ion, injection, acceleration	515
	H. Harada, K. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan S. Kato Tohoku University, Graduate School of Science, Sendai, Japan
	Ionization profile monitors (IPM) were installed in the 3-GeV RCS ring of J-PARC and used to observe the beam-profile for the transverse plane in beam commissioning. These electrodes and MCPs of IPMs were upgraded in 2012 summer shutdown in order to improve the external electric field for leading the electrons and ions to MCPs. This presentation will be described the results of observed beam profile in beam commissioning and be discussed the new issues for the ion and electron collection mode.

MOPME025	Production of Extraction Kicker Magnet of the J-PARC 3-GeV RCS	kicker, high-voltage, extraction, proton	526
	M. Kinsho, N. Ogiwara, K. Suganuma JAEA/J-PARC, Tokai-mura, Japan
	The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been provided proton beam to the Material and Life Science Facility (MLF)as well as to the 50 GeV Main Ring (MR). Proton beam is accelerated from 181 MeV to 3GeV in the RCS and immediately extracted it to the beam transport line to the MLF and the MR. Extraction kicker magnets are used for this fast extraction. To improve reliability of the RCS for user operation, production of a reserve kicker magnet has been performed. The kicker magnet mainly consists of Ni-Zn ferrite cores and Aluminum alloy plates, and these parts are installed in vacuum chamber to prevent discharge because a high voltage is applied to the magnet for a short period. Since it is important to reduce the outgassing of water vapor form these parts to prevent discharge, we has been produced the reserve magnet with low outgassing at high voltage discharge. Since assemble of the kicker magnet already finished and vacuum test has been performed, the result of vacuum test is reported.

MOPME027	Bunch Length Measurement of 181 MeV Beam in J-PARC Linac	electron, linac, target, simulation	532
	A. Miura, H. Oguri, N. Ouchi, J. Tamura JAEA/J-PARC, Tokai-mura, Japan A. Feschenko, A.N. Mirzojan RAS/INR, Moscow, Russia K. Futatsukawa, T. Miyao KEK, Ibaraki, Japan M. Ikegami J-PARC, KEK & JAEA, Ibaraki-ken, Japan T. Maruta KEK/JAEA, Ibaraki-Ken, Japan
	In J-PARC Linac, an energy and intensity upgrade project has started since 2009 using Annular Coupled Structure (ACS) cavities. Because the longitudinal matching before ACS cavities is additionally required, we decided to employ the bunch shape monitors (BSMs) to measure the longitudinal beam profile. After three years from the start of BSM project, three BSMs were fabricated. All three BSMs were installed during the summer shutdown of 2012. We tried to measure the longitudinal beam profile exited from SDTL cavities. In this paper, we introduce the outline of BSM project, the first data acquisition and related small problems.

MOPME038	A New Theoretical Design of BLM System for HLS II	electron, scattering, monitoring, emittance	553
	Y.K. Chen, L.J. He, J. Li, W. Li, Y. Li USTC/NSRL, Hefei, Anhui, People's Republic of China
	Beam loss monitoring (BLM) system has been commonly used to detect the vacuum leakage. The existing BLM system for Hefei Light Source (HLS) was built in 2000. It played an important role in analyzing beam loss distribution and regulating the machine operation parameters. Recently, HLS is being upgraded to HLS II. The emittance will be decreased to increase the brilliance of synchrotron radiation. The Touschek lifetime will be much shorter than before, and dominate the total beam lifetime. It is necessary to redesign the BLM system for HLS II. The most important part of this work is to find a better method of monitoring Touschek lifetime by BLM system while keeping its general functions. According to the results of our research, a preliminary theoretical design for the new BLM system is proposed in this paper. This new system will play an important role in the storage ring commissioning, troubleshooting, and beam lifetime studying.

MOPME044	A Novel Type of Forward Coupler Slotted Stripline Pickup Electrode for CSRe Stochastic Cooling	impedance, pick-up, kicker, simulation	571
	J.X. Wu, X.J. Hu, M. Li, J.W. Xia, J.C. Yang, Y. Zhang, G. Zhu IMP, Lanzhou, People's Republic of China F. Caspers CERN, Geneva, Switzerland
	A novel type of slotted or perforated strip-line pick-up or kicker electrode structure for CSRe stochastic cooling for non relativistic particle beams with b=v/c values around 0.7 is presented. This slotted structure is to be used as a forward coupler with the output signal taken from the downstream end and has a rather large relative bandwidth of several octaves. The electrode structure and pickup tank, as well as the beam test result will be presented in this paper.

MOPME045	Design and Test Status of Beam Position Monitors for ADS Injector II Proton LINAC	proton, linac, cryomodule, alignment	574
	Y. Zhang, H. Jia, X.C. Kang, M. Li, J.X. Wu, G. Zhu IMP, Lanzhou, People's Republic of China
	Beam Position Monitors (BPM) based on capacitive pick-ups are designed for Accelerator-Driven System (ADS) Injector II proton LINAC. This LINAC is aiming to produce a maximum design current of 15 mA at the 10 MeV energy with an operating frequency of 162.5 MHz. Non-interceptive BPM will be installed to measure the transverse beam position and beam phase in the vacuum chamber. Depending on the location, the response of the BPMs must be optimized for a beam with an energy range from 2.1 up to 10 MeV and an average current between 0.01 and 15 mA. Apart from the broadening of the electromagnetic field due to the low-beta beam, specific issues are affecting some of the BPMs: tiny space in the transport line between the RFQ and the cryomodule and the cryogenic temperature inside the cryomodule. For this reason two types of BPMs are being designed for each location (MEBT and cryomoudle). In this contribution, the present status of the design and measured results for each BPM will be presented in room and cold temperature, focusing on the electromagnetic response for low-beta beams.

MOPME049	Status of Non-destructive Bunch Length Measurement based on Coherent Cherenkov Radiation	radiation, electron, target, diagnostics	583
	H.X. Deng, S.L. Lu, T. Yu, J.B. Zhang SINAP, Shanghai, People's Republic of China G.A. Naumenko, A. Potylitsyn, M.V. Shevelev, D.A. Shkitov TPU, Tomsk, Russia
	Funding: This work was supported by the joint Russian-Chinese grant (RFBR 110291177 and NSFC 11111120065) and partially by the Program of Russian MES “Nauka” and the Chinese NSFC 11175240. As a novel non-destructive bunch length diagnostic of the electron beam, an experimental observation of the coherent Cherenkov radiation generated from a dielectric caesium iodide crystal with large spectral dispersion was proposed for the 30MeV femtosecond linear accelerator at Shanghai Institute of Applied Physics (SINAP). In this paper, the theoretical design, the experimental setup, the terahertz optics, the first angular distribution observations of the coherent Cherenkov radiation, and the future plans are presented. * Shevelev M. et al., Journal of Physics: Conf. Ser. 357 (2012) 012023.

MOPME064	SLM and Flags for Booster of NSLS-II	booster, radiation, synchrotron, synchrotron-radiation	622
	O.I. Meshkov, V. Smalyuk BINP SB RAS, Novosibirsk, Russia V.L. Dorokhov BINP, Novosibirsk, Russia
	Set of diagnostics of booster of NSLS-II includes 6 fluorescent screens (flags) and 2 synchrotron light monitors (SLM). The flags will be applied during booster commissioning for closing of the beam turn. They are also a useful tool in case of malfunction elimination. SLM will be used both for booster comissioning and for operation. The details of calibration and design of the devices are discussed.

MOPME065	Approximate Method of Calculation of a Bunch Radiation in Presence of Complex Dielectric Object	radiation, optics, diagnostics, scattering	625
	A.V. Tyukhtin, E.S. Belonogaya, S.N. Galyamin Saint-Petersburg State University, Russia
	Funding: Work supported by the Grant of President of Russian Federation, Russian Foundation for Basic Research, and the Dmitry Zimin "Dynasty" Foundation. Cherenkov radiation is widely used for detection of charged particles and can be also applied for particle bunch diagnostics. As a rule, dielectric objects applied for these goals have complex forms. Therefore development of methods of calculation of bunch radiation in presence of complex dielectric objects is now of a great interest. The approximate method developed by us allows to take into account influence of the object boundaries closed to the charge trajectory as well as "external" boundaries of the object. The case of the charge crossing a dielectric plate was considered as a test problem. The exact solution of this problem is in a good agreement with our approximate solution. Next, the cases of more complex objects were analyzed. One of them is a dielectric cone with a vacuum channel. Particularly, it was shown that radiation can be convergent under certain conditions, that is the field outside the cone can be more intensive than on the cone boundary. Radiation of the bunch in the case of dielectric prism was considered as well. A.P. Potylitsyn, Yu.A. Popov, L.G. Sukhikh, G.A. Naumenko, M.V. Shevelev, Journal of Physics: Conference Series 236 (2010) 012025.

MOPME066	Radiation of a Charged Particle Bunch Moving along Boundary of Wire Metamaterial	radiation, diagnostics, lattice, optics	628
	A.V. Tyukhtin, S.N. Galyamin, V.V. Vorobev Saint-Petersburg State University, Russia
	Funding: Work supported by Russian Foundation for Basic Research and the Dmitry Zimin “Dynasty” Foundation. The material under consideration represents a periodical volume structure of long parallel conductive wires. If wavelengths are much greater than periods, the structure can be described as some anisotropic medium possessing both frequency and spatial dispersion* (so-called wire metamaterial). Earlier we considered the radiation of bunches moving in boundless wire metamaterial. It has been discovered that this radiation is nondivergent, and it is perspective for diagnostics of bunches*. Now we consider the case when the bunch moves in vacuum along the boundary of the semi-infinite metamaterial perpendicularly to the wires. Analytical and numerical analysis of the problem is performed. It is shown that radiation from a point charge concentrates in some vicinity of certain planes and propagates along the wires with speed of light. Series of computations show that the radiation under consideration can be useful for determination of sizes and shape of bunch. A.V. Tyukhtin, E.G. Doilnitsina, J. Phys. D - Appl. Phys., 44, 265401 (2011). **V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Lett., 108, 184801 (2012).

MOPME068	Feasibility Study of a 2nd Generation Smith-Purcell Radiation Monitor for the ESTB at SLAC	radiation, simulation, background, electron	634
	N. Fuster Martinez, A. Faus-Golfe, J. Resta-López IFIC, Valencia, Spain H.L. Andrews LANL, Los Alamos, New Mexico, USA F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, C. Perry, A. Reichold, S.R. Stevenson JAI, Oxford, United Kingdom J. Barros, N. Delerue, M. Grosjean LAL, Orsay, France V. Bharadwaj, C.I. Clarke SLAC, Menlo Park, California, USA
	The use of a radiative process such as the Coherent Smith-Purcell Radiation (CSPR) is a very promising non-invasive technique for the reconstruction of the time profile of relativistic electron bunches. Currently existing CSPR monitors do not have yet single-shot capability. Here we study the feasibility of using a CSPR based monitor for bunch length measurement at the End Station Test Beam (ESTB) at SLAC. The aim is to design a second-generation device with single-shot capability, and use it as a diagnostic tool at ESTB. Simulations of the spectral CSPR energy distribution and feasibility study have been performed for the optimization of the parameters and design of such a device.

MOPME077	Electro-0ptical Bunch Profile Measurement at CTF3	laser, electron, photon, polarization	658
	R. Pan, A. Andersson, W. Farabolini, A. Goldblatt, T. Lefèvre, M. Martyanov, S. Mazzoni, S.F. Rey, L. Timeo CERN, Geneva, Switzerland W.A. Gillespie, R. Pan, D.A. Walsh University of Dundee, Nethergate, Dundee, Scotland, United Kingdom S.P. Jamison STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	A new electro-optic bunch profile monitor has recently been installed in CLIC Test Facility 3 at CERN. The monitor is based on an electro-optic spectral decoding scheme which reconstructs the longitudinal profile of the electron bunch by measuring its Coulomb field. The system uses a 780 nm fibre laser system, transported over a 20m long distance to the interaction chamber, where a ZnTe crystal is positioned close to the beam. The assembly also contains a traditional OTR screen, which is coupled to a second optical line and used to adjust the temporal overlap between the laser and the electron pulse. This paper presents the detection system in detail, as well as reporting on the first measurements performed with beam.

MOPWA026	Fast Magnetic Kickers for the NSLS-II Booster-Synchrotron: Design and Test Results	kicker, booster, extraction, injection	717
	D.A. Shvedov, O. Anchugov, V.A. Kiselev, A.A. Korepanov, S.V. Sinyatkin BINP SB RAS, Novosibirsk, Russia
	For the purpose of realization of single-turn injection and extraction from the NSLS-II booster synchrotron, BINP members created nanosecond non-vacuum ferrite kickers with fronts of pulsed magnetic field of ~ 200 ns, flat-top duration of 300 nsec and its instability of 0.2/1% at most. This paper describes the design of unique kicker magnets with ceramic vacuum chambers with deposited longitudinal strips of titanium nitride (TiN) inside. The paper also presents the results of bench tests of the kickers: oscillograms of current pulse in bus bars, the shape of the pulsed magnetic field, and transverse distribution of the longitudinal field integral in the kicker aperture.

MOPWA030	Upgrade of the LHC Injection Kicker Magnets	kicker, injection, electron, impedance	729
	M.J. Barnes, P. Adraktas, V. Baglin, G. Bregliozzi, S. Calatroni, F. Caspers, H.A. Day, L. Ducimetière, M. Garlaschè, V. Gomes Namora, J.M. Jimenez, N. Magnin, V. Mertens, E. Métral, B. Salvant, M. Taborelli, J.A. Uythoven, W.J.M. Weterings CERN, Geneva, Switzerland
	The two LHC injection kicker systems, comprising 4 magnets per ring, produce a kick of 1.3 T.m with a rise-time of less than 900 ns and a flattop ripple of less than ±0.5%. A beam screen is placed in the aperture of each magnet, to provide a path for the image current of the high intensity LHC beam and screen the ferrite yoke against wake fields. The screen consists of a ceramic tube with conductors in the inner wall. The initially implemented beam screen ensured a low rate of electrical breakdowns while providing an adequate beam coupling impedance. Operation with increasingly higher intensity beams, stable for many hours at a time, now results in substantial heating of the ferrite yoke, sometimes requiring cool down over several hours before the LHC can be refilled. During the long shutdown in 2013/2014 all 8 kicker magnets will be upgraded with an improved beam screen and an increased emissivity of the vacuum tank. In addition equipment adjacent to the injection kickers and various vacuum components will also be modified to help reduce the vacuum pressure in the kickers during high-intensity operation. This paper discusses the upgrades as well as their preparation and planning.

MOPWA031	Beam Induced Ferrite Heating of the LHC Injection Kickers and Proposals for Improved Cooling	kicker, injection, simulation, impedance	732
	M.J. Barnes, S. Calatroni, F. Caspers, L. Ducimetière, M. Garlaschè, V. Gomes Namora, V. Mertens, Z.K. Sobiech, M. Taborelli, J.A. Uythoven, W.J.M. Weterings CERN, Geneva, Switzerland H.A. Day UMAN, Manchester, United Kingdom
	The two LHC injection kicker systems produce a kick of 1.3 T.m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. A beam screen is placed in the aperture of each magnet, which consists of a ceramic tube with conductors in the inner wall. The conductors provide a path for the beam image current and screen the ferrite yoke against wake fields. Recent LHC operation, with high intensity beam stable for many hours, resulted in significant heating of both the ferrite yoke and beam impedance reduction ferrites. For one kicker magnet the ferrite yoke approached its Curie temperature. As a result of a long thermal time-constant the ferrites can require several hours to cool enough to re-inject beam, thus limiting the availability of the LHC. Thermal measurement data has been analysed, a thermal model developed and emissivity measurements carried out. The effects of various measures to improve the ferrite cooling have been simulated, including an improved emissivity of the vacuum tank and active cooling on the outside of the tank.

MOPWA032	Reduction of Surface Flashover of the Beam Screen of the LHC Injection Kickers	kicker, injection, impedance, simulation	735
	M.J. Barnes, P. Adraktas, S. Calatroni, F. Caspers, L. Ducimetière, V. Gomes Namora, V. Mertens, R. Noulibos, M. Taborelli, B. Teissandier, J.A. Uythoven, W.J.M. Weterings CERN, Geneva, Switzerland
	The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wake fields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. Operation with increasingly higher bunch intensity, and narrow bunches, now requires improved ferrite screening. This will be implemented by additional conductors; however the good high-voltage behaviour of the kicker magnets must not be compromised by the supplementary screening. Extensive studies and optimisations have been carried out, to better satisfy the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time, high vacuum and good high voltage behaviour. A new configuration is proposed which reduces significantly the electric field associated with the screen conductors and the secondary electron yield of the surface of the ceramic tube. Results of high voltage test results are also presented.

MOPWA043	The HV Withstands Test for In Vacuum Booster Kicker	booster, kicker, injection, extraction	765
	Y.-H. Liu, C.K. Chan, C.S. Chen, H.H. Chen, J.-R. Chen, K.H. Hsu, H.P. Hsueh, Y.T. Huang, C.S. Yang NSRRC, Hsinchu, Taiwan
	The maximum driving voltage of TPS booster extraction kicker is close to 30 kV, the HV insulation should be carefully noticed. A DC withstand voltage tester MUSASHI 3802 (Model: IP-701G) is used to test the DC breakdown voltage, which the maximum driving voltage is 37 kV. The 10 mm gap between coil and ferrite is designed in order to increase HV break down voltage. The safety breakdown distance between HV coil and grounding plate was tested in air. Different insulation material with different thickness was tested the breakdown voltage. Thicker than 10 mm ceramic plate could effectively avoid the breakdown occurred with 37 kV DC charging. Thus HV withstand voltage will be higher in vacuum chamber and the insulation with HV will not be the problem.

MOPWA064	Microwave Resonator Diagnostics of Electron Cloud Density Profile in High Intensity Proton Beam	electron, cavity, proton, simulation	825
	Y.-M. Shin, J. Ruan, C.-Y. Tan, J.C.T. Thangaraj, R.M. Zwaska Fermilab, Batavia, USA
	We have developed an novel technique to accurately estimate the density of dilute electron clouds emitted from high intensity proton beams. The strong phase shift enhancement from multiple reflections of standing microwaves in a resonating beam pipe cavity has been demonstrated with numerical modeling using dielectric approximation and e S-parameter measurements. The equivalent dielectric simulation showed a ~ 10 times phase shift enhancement (Pi-mode, 1.516 GHz) with the cavity beam pipe compared to the waveguide model. The position-dependence of the technique is investigated by overlapping the field distributions of harmonic resonances. The simulation with various positions of dielectric insertions confirmed that resonance peaks in phase-shift spectra corresponding to the relative distance between field-nodes and electron cloud position, which allows for one-dimensional mapping. Preliminary experimental studies based on a bench-top setup confirm the results of the simulation showing that thicker reflectors enhance the phase-shift measurement of the electron cloud density.

MOPWA072	MODELING FOR TIME-RESOLVED RETARDING FIELD ANALYZER MEASUREMENTS OF ELECTRON CLOUD BUILDUP AT CesrTA	electron, positron, dipole, pick-up	846
	J.A. Crittenden, Y. Li, X. Liu, M.A. Palmer, J.P. Sikora CLASSE, Ithaca, New York, USA
	Funding: US National Science Foundation PHY-0734867, PHY-1002467, and the U.S. Department of Energy DE-FC02-08ER41538 The Cornell Electron Storage Ring Test Accelerator program includes investigations into electron cloud buildup mitigation techniques using custom vacuum chambers. Multibunch electron and positron beams of energies between 2.1 and 5.3 GeV with bunch spacings from 4 to 98 ns and bunch populations ranging from 10¹⁰ to 16·10¹⁰ provide highly differentiated sensitivity to the processes contributing to cloud buildup such as photoelectron production, cloud space-charge dynamics, and secondary electron emission. Measurements of the time dependence of cloud buildup using BPM-style shielded pickups have been shown to provide tight constraints on cloud buildup models. Recently, time-resolving retarding-field analyzers have been designed, installed and commissioned. These novel detectors combine the time-resolving feature of the shielded pickups with the fine transverse segmentation and cloud electron energy sensitivity of the time-integrating retarding-field analyzers used previously. We report on progress in modeling these measurements and quantify their sensitivity to various parameters describing the underlying physical processes contributing to cloud buildup.

MOPWA080	Design of a Fast, XFEL-quality Wire Scanner	photon, electron, radiation, instrumentation	867
	M.A. Harrison, R.B. Agustsson, P.S. Chang, T.J. Hodgetts, A.Y. Murokh, M. Ruelas RadiaBeam, Santa Monica, USA
	RadiaBeam Technologies, in collaboration with the Pohang Accelerator Laboratory, has designed and built a fast wire scanner for transverse beam size measurements in the XFEL Injector Test Facility. The wire scanner utilizes three 25-micron diameter tungsten wires mounted vertically, horizontally, and diagonally on a single alumina card to measure the transverse beam size down to 10 microns with sub-micron accuracy of a 139-MeV electron beam. A double-ended design using dual bellows for actuation is used to reduce the vibrations of the wire holder during motion and negate the effects of air pressure on positioning. The servomotor-driven system is capable of performing full horizontal, vertical, and 45-degree scans in under a minute. Algorithms are presented for removing the broadening effect of the wires' thickness from the scanning data to measure beams that are as small or smaller than the wires. Furthermore, we present formulas for determining the beam's transverse spatial sizes (horizontal and vertical spot size and correlation) from the scan data.

MOPWO022	Design and Manufacturing Description of the Prototype Striplines for the Extraction Kicker of the CLIC Damping Rings	impedance, kicker, extraction, damping	930
	C. Belver-Aguilar, A. Faus-Golfe IFIC, Valencia, Spain M.J. Barnes CERN, Geneva, Switzerland J. Gómez Trinos Vacuum Projects, Paterna, Spain D. Gutiérrez Arribas Trinos Vacuum Projects, S.L., Paterna - Valencia, Spain F. Toral CIEMAT, Madrid, Spain
	The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are needed to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are carried out by kicker systems. In order to achieve both low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. The design of the stripline kicker was previously carried out by modelling the striplines with simulation codes such as HFSS, Quickfield and CST Particle Studio. In order to have a complete analysis of the striplines, the effect of electrodes supports and coaxial feedthroughs have been studied in detail. In this paper, electromagnetic analyses of the complete striplines, including fabrication tolerances, are reported. Furthermore, a new idea for impedance matching is presented.

MOPWO031	High Energy Beam Impact Tests on a LHC Tertiary Collimator at CERN HiRadMat Facility	alignment, collimation, simulation, proton	954
	M. Cauchi, O. Aberle, R.W. Aßmann, A. Bertarelli, F. Carra, A. Dallocchio, D. Deboy, L. Lari, S. Redaelli, A. Rossi CERN, Geneva, Switzerland M. Cauchi, P. Mollicone UoM, Msida, Malta L. Lari IFIC, Valencia, Spain N.J. Sammut University of Malta, Information and Communication Technology, Msida, Malta
	The correct functioning of the collimation system is crucial to safely operate the LHC. The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs) in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN HiRadMat (High Irradiation to Materials) facility, involved 440 GeV beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained together with some first outcomes from visual inspection.

TUOAB203	ESRF Upgrade Phase II	lattice, emittance, storage-ring, brilliance	1140
	J.-L. Revol, P. Berkvens, J.C. Biasci, J-F. B. Bouteille, N. Carmignani, F. Ewald, L. Farvacque, A. Franchi, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, G. Lebec, S.M. Liuzzo, B. Nash, T.P. Perron, E. Plouviez, P. Raimondi, K.B. Scheidt, V. Serrière ESRF, Grenoble, France
	Four years after the launch of the Upgrade Programme, the ESRF is midway through its first phase (2009-2015) and has defined the objectives for the ensuing second phase. The first phase paved the way to a new generation of nano-beam X-ray beamlines fed by an X-ray source itself substantially improved in terms of reliability, stability and brilliance. The second phase envisions a major upgrade of the source to best serve the science case of this new generation of beamlines. In December 2012, the ESRF Council endorsed Management's proposal to launch the technical design study of a new 7-bend achromat lattice. This new configuration will allow the ESRF storage ring to operate with a decrease in horizontal emittance by a factor of about 30 and a consequent increase in brilliance and coherence of the photon beam. The increase will be substantially higher at X-ray energies larger than 50 keV.
	Slides TUOAB203 [3.664 MB]

TUOCB201	Recent Developments of Novel Beam Diagnostics at the ESRF	electron, dipole, diagnostics, injection	1143
	K.B. Scheidt ESRF, Grenoble, France
	A number of rather novel and particular electron beam diagnostics have seen their development in 2012 for the ESRF Storage Ring. A vertical Beam Halo detector that measures the bunch population at millimetres, i.e. hundreds of σs of nominal beam size, away from the central core. This measurement is based on X-ray synchrotron radiation from a bending magnet and is totally non-destructive to the electron beam itself. Another diagnostic use of the very hard X-rays available from the bending magnets is the detection of electron beam energy fluctuations. The detector hardware is simple and in-expensive and has shown a resolution of energy fluctuations of less than 10ppm. Also a single orbit turn measurement of the injected beam shape and size is now possible through the use of visible synchrotron light combined with a fast gateable intensifier, which can be triggered on any of the desired orbit turns after injection. Detailed results of each of these new diagnostics will be presented.
	Slides TUOCB201 [1.511 MB]

TUOCB203	In Vacuum High Accuracy Mechanical Positioning System of Nano Resolution Beam Position Monitor at the Interaction Point of ATF2	feedback, alignment, linear-collider, collider	1149
	P. Bambade, O.R. Blanco, F. Bogard, P. Cornebise, S. Wallon LAL, Orsay, France T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major goal of ATF2 is to demonstrate the ability to stabilise the beam position at the interaction point, where the beam can be focused down to about 35 nm. For this purpose, a set of new Beam Position Monitors (BPM) has been designed, with an expected resolution of about 2 nm. These BPMs must be very well aligned with respect to the beam, at the few micron level, to fully exploit their fine resolution. In this paper, the mechanical positioning system which has been developed to enable such a precise alignment is presented. It is based on a set of eight piezo actuators with nanometer range displacement resolution, mounted in a new specially made vacuum chamber. Due to the expected resolution of the piezo actuators, this system also brings a new functionality, the possibility to calibrate the BPMs by mechanically scanning the beam.
	Slides TUOCB203 [2.276 MB]

TUODB202	Experiment and Numerical Simulation Results of Plasma Window	plasma, simulation, cathode, cavity	1155
	K. Zhu, S. Huang, Y.R. Lu, B.L. Shi PKU, Beijing, People's Republic of China
	Funding: Supported by NSFC 91026012 A windowless vacuum seal technique has been widely researched and designed, which can connect high pressure cavity to a vacuum condition with rather little thickness of material. As a result, it will reduce most interaction with the particle beam penetrating through comparing to that of foil window. It is desired extensively in experiments using high-intensity heavy ion beams which will break foil window in a short time or in experiments which require the injecting beams with mono-energy and high purity for example. In this work, we study the plasma window in argon which is used as a windowless vacuum sealing device. A numerical 2D FLUENT-based magneto-hydrodynamic model has been developed to investigate the physical reasons of high pressure difference in plasma window. Further, preliminary experimental results are presented and discussed.
	Slides TUODB202 [2.180 MB]

TUPEA057	Optimization of Rectangular Dielectric Structures for the Planned Wakefield Acceleration Experiments in KIPT	wakefield, electron, accelerating-gradient, acceleration	1262
	G.V. Sotnikov, K.V. Galaydych, V. Kiselev, P.I. Markov, I.N. Onishchenko NSC/KIPT, Kharkov, Ukraine
	Funding: This study is supported by Global Initiatives for Proliferation Prevention (GIPP) program, project ANL-T2-247-UA (STCU Agreement P522). We, at the Kharkov Institute of Physics and Technology, planned experimental test of the basic principles of the multi-bunch multi-mode wakefield accelerator. For this purpose we carried out a series of calculations of wakefield excitation and dynamics of the drive and witness bunches in rectangular structures with a dielectric substrate. For optimization two rectangular vacuum waveguides of R32 (72.14mm x 34.04mm) and R26 (86.36mm x 43.18mm) which were filled with the dielectric covering two any opposite metal walls of a waveguide were chosen. As possible dielectric Alumina, Cordierite, or Teflon were tested. It was supposed that the structure will be energized by sequence of electron bunches (bunch repetition frequency is 2.805 GHz), having energy of 4.5 MeV. As the candidate for operating mode LSM-wave or LSE-wave, with frequency to equal the bunch repetition frequency or its doubled frequency were tested. The gradient of an accelerating field, small transverse deflection (or divergence) of drive and witness bunches were the main criteria of optimization. As a result of optimization we propose some dielectric structures for future wakefield experiments in KIPT.

TUPEA065	Design of a Photonic Crystal Accelerator for Basic Radiation Biology	laser, acceleration, electron, simulation	1283
	A. Aimidula, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Aimidula, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom K. Koyama, Y. Matsumura University of Tokyo, Tokyo, Japan T. Natsui, M.Y. Yoshida KEK, Ibaraki, Japan M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan G.X. Xia UMAN, Manchester, United Kingdom
	Funding: This work is supported by the EU under Grant Agreement 289485, the STFC Cockcroft Institute Core Grant No. ST/G008248/1 and KAKENHI, Grant-in-Aid for Scientific Research (C) 24510120. The application of photonic crystals to realize an on-chip electron beam source for fundamental radiation biology is highly interesting for a number of applications. The unique combination of nanometer beam size and attosecond-short pulses has a very promising potential for use in microscopic and ultra-fast analyses of damage and repair of radiation-irradiated DNA and chromosomes. Simulations studies indicate an output electron beam energy, beam intensity and device size of the order of MeVs, fCs and a few cm, respectively. In this contribution, first results from numerical studies into the design of such compact accelerator structure are presented. The dimensions of a novel dual grating-based acceleration structure are shown together with the estimated laser parameters. Finally, a system consisting of an electron injector and multi-stage accelerating structures is proposed, which corresponds to a miniaturized optical linear accelerator.

TUPEA066	Metamaterial-based Accelerating, Bending and Focusing Structures	focusing, electron, quadrupole, resonance	1286
	I. McGregor The University of Liverpool, Liverpool, United Kingdom K.M. Hock Cockcroft Institute, Warrington, Cheshire, United Kingdom
	We report on the progress of our research into metamaterial-based accelerating, bending and focusing structures at the Cockcroft Institute. The effort during the last year has been directed towards designing and investigating practical RF structures that are suitable for industrial and medical applications. We have shown that, by introducing structures based on metamaterial resonators, RF accelerating structures can be made more compact and higher gradient. This year, we will concentrate on focusing and bending structures.

TUPEA079	Experimental Search For Acceleration in the Micro-accelerator Platform	laser, electron, acceleration, coupling	1307
	J.C. McNeur, K.S. Hazra, B. Matthews, E.B. Sozer, G. Travish UCLA, Los Angeles, USA R.J. England, B. Montazeri, K. Soong, Z. Wu SLAC, Menlo Park, California, USA E.A. Peralta Stanford University, Stanford, California, USA R.B. Yoder Goucher College, Baltimore, USA
	The results of recent experimental efforts to observe acceleration in the Micro-Accelerator Platform (MAP) are detailed. The MAP is a slab-symmetric dielectric laser accelerator that when side illuminated by an optical laser, accelerates electrons via a standing wave resonance. This structure has been placed in the beamline at the NLCTA experimental hall at SLAC. A 60 MeV electron beam traverses the MAP when it is illuminated by a laser and, using a camera placed around a spectrometer bend magnet, signs of acceleration in the energy spectrum of the beam are searched for. The details of this search, as well as simulations that motivate the search, are elaborated on below.

TUPEA080	Numerical Modeling and Experimental Data Analysis for Dielectric Laser Accelerators	laser, electron, acceleration, GUI	1310
	E.B. Sozer, K.S. Hazra, J.C. McNeur, G. Travish UCLA, Los Angeles, USA R.J. England, K. Soong SLAC, Menlo Park, California, USA E.A. Peralta Stanford University, Stanford, California, USA R.B. Yoder Goucher College, Baltimore, USA
	Funding: Work supported by a grant for the US Defense Threat Reduction Agency (DTRA). Work on Dielectric Laser Accelerators (DLAs) has been ongoing for the past decade. These devices come in a variety of configurations but share the use of lasers as power sources and dielectrics as the primary building material. While these devices have many of the same characteristics and dynamics as conventional accelerating structures, they operate in a dramatically different regime. One version of these DLAs is the Micro Accelerator Platform (MAP): a slab-symmetric device operated with a standing wave (Pi-mode) and powered by a transversely coupled laser. The coupler is essentially a transmissive diffraction grating and therefore reinforced the desired mode. The remainder of the structure is composed of two Distributed Bragg Reflectors (DBRs) which serve to form a resonant cavity in an evacuated bounded by the reflectors. The MAP has now undergone experimental testing at SLAC’s E-163. As with many advanced accelerators, identifying the best data analysis approach demands extensive numerical modelling of the anticipated beam parameters and development of data visualization tools. We present the latest numerical results and data analysis tools developed for dielectric laser acceleration experiments with MAP.

TUPFI005	Synchrotron-Radiation Photon Distribution for Highest Energy Circular Colliders	photon, scattering, radiation, electron	1340
	G.H.I. Maury Cuna CINVESTAV, Mérida, Mexico G. Dugan, D. Sagan CLASSE, Ithaca, New York, USA F. Zimmermann CERN, Geneva, Switzerland
	Funding: Acknowledgements to CINVESTAV, CERN and EPLANET project. At high energies, beam-induced synchrotron radiation is an important source of heating, beam-related vacuum pressure increase, and primary photoelectrons, which can give rise to an electron cloud. The photon distribution along the beam pipe wall is a key input to codes such as ECLOUD and PyECLOUD, which model the electron cloud build-up. For future high-energy colliders, like TLEP or SHE-LHC, photon stops and antechambers are considered in order to facilitate cooling and vacuum pressure control. We use the Synrad3D code developed at Cornell to simulate the photon distribution for the LHC.

TUPFI013	LHC Long Shutdown: A Parenthesis for a Challenge	cryogenics, radiation, controls, superconducting-magnet	1355
	K. Foraz, M. Arnaud, M.B.M. Barberan Marin, C. Bedel, M. Bernardini, J. Coupard, J. Etheridge, H. Gaillard, S. Grillot, E. Paulat, A.-L. Perrot CERN, Geneva, Switzerland
	After three fruitful years of operation, the LHC will enter a long shutdown. Major works will be implemented to allow running safely at 7TeV/beam. The LHC superconducting circuits will be consolidated; mitigation measures will be carried out to reduce the single event effects occurrence in the frame of the Radiation To Electronics mitigation project (R2E); all the equipment will be fully maintained. In parallel, numerous consolidation and upgrade activities will be performed all around the 27km ring. The schedule has been optimized in order to reduce the length of the shutdown (LS1) to 22 months (including hardware commissioning). The organization of the works is therefore essential to ensure a safe and reliable plan. This paper introduces the various activities to be performed and presents the schedule and the preparation process, including the operational safety aspects.

TUPFI065	Muon Ionization Cooling Experiment Step VI	cavity, coupling, emittance, status	1499
	D. Rajaram Illinois Institute of Technology, Chicago, Illinois, USA P. Snopok IIT, Chicago, Illinois, USA
	The Muon Ionization Cooling Experiment (MICE) is a demonstration experiment to prove the viability of cooling a beam of muons for use in a Neutrino Factory and Muon Collider. The ultimate Step VI configuration of the MICE cooling channel, a section of the one proposed in the Neutrino Factory Study II, will demonstrate a 10% reduction in transverse beam emittance measured at the level of 1%. This requires measuring emittance to 0.1%. This measurement will be made using all beam line elements present in the MICE Step IV configuration with the addition of two low-Z absorber modules and two RF-Coupling Coil (RFCC) modules. The RFCC modules each contain four normal-conducting low frequency (201 MHz) RF cavities with a guiding magnetic field provided by a large diameter coupling coil. Each of these cavities will require approximately 1 MW of RF power in a 1 ms pulse at a rate of 1 Hz. The experiment can explore a variety of combinations of momentum, beta function, magnetic field flip or non-flip configurations that will prove precious in the design of future cooling channels. The current status and progress toward Step VI are discussed.

TUPME014	Coherent Synchrotron Radiation Predicted at the SuperKEKB Damping Ring	damping, linac, emittance, simulation	1595
	H. Ikeda, M. Kikuchi, K. Ohmi, K. Oide, D. Zhou KEK, Ibaraki, Japan
	The damping ring of SuperKEKB is under construction in order to inject low emittance positron beam into the main ring. We calculated the bunch lengthening and the energy spread caused by the longitudinal wake, which is dominated by the CSR wake field. The result was within the tolerance level.

TUPME022	Study on the Single Bunch Transverse Emittance Growth in BAPS	emittance, wakefield, lattice, wiggler	1619
	J. Gao, D. Wang IHEP, Beijing, People's Republic of China
	Funding: Supported by the National Foundation of Natural Sciences Contract 11175192. Beijing Advanced photon Source (BAPS) is a proposed next synchrotron radiation facility which has much smaller transverse emittance after SSRF in China, with 5 GeV energy and 1.5 km circumference. In order to explore how small the transverse emittance we can get on BAPS, this paper studies the single bunch transverse emittance growth due to short range wakefield according to J. Gao’ theory. The mechanism of wakefield induced single bunch emittance is explained first and then the transverse emittance at the design beam current is estimated. Also, the tolerances for the transverse loss factor and the vacuum chamber misalignment (or the closed orbit distortion) are presented.

TUPWA005	Study of Collective Beam Instabilities for the MAX IV 3 GeV Ring	impedance, simulation, damping, wakefield	1730
	M. Klein, R. Nagaoka SOLEIL, Gif-sur-Yvette, France G. Skripka, P.F. Tavares, E.J. Wallén MAX-lab, Lund, Sweden
	The present paper reports on a systematic simulation study made on the collective beam instability in the MAX IV 3 GeV ring. We study both single and multibunch instabilities in the longitudinal plane. Specifically, we focus on the microwave instabilities which are considered to be particularly dangerous for MAX IV, in view of its small effective radius of aperture (b_eff < 11 mm), the high intensity (500 mA) and the low emittance (0.24 nm.rad) nature of the circulating beam. Single and multibunch tracking are performed using wake fields that were numerically obtained using GdfidL for the ensemble of the vacuum components. A special effort was made to include dynamically the effect of harmonic cavities that lengthen the bunch and introduce Landau damping, whose details are described in the companion paper . The study aims to confirm the effectiveness of storing long bunches in the 100 MHz RF system, where tune spreads are further increased by the harmonic cavities, in order to fight against collective instabilities. M. Klein and R. Nagaoka "Multibunch Tracking Code Development to Account for Passive Landau Cavities", these proceedings

TUPWA008	Computation of Wakefields for an In-vacuum Undulator at PETRA III	undulator, wakefield, simulation, impedance	1736
	E. Gjonaj, L. Lünzer, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany R. Wanzenberg DESY, Hamburg, Germany
	Funding: Work supported by DESY, Hamburg, Germany At DESY the installation of an in-vacuum undulator at the synchrotron radiation facility PETRA III is under consideration. The moveable magnet array of the undulator is installed inside the vacuum chamber to achieve shorter wavelength synchrotron radiation. A thin metal foil covers the magnet structure to mitigate resistive wall wakefields. Moveable tapered transitions connect the magnet structure and the adjacent vacuum duct to reduce the geometric wakefields. Nevertheless these moveable tapered transitions contribute significantly to the impedance budget of PETRA III. The computer codes MAFIA, CST-Studio and PBCI have been used to calculate the longitudinal and transverse wakefields. The results for the loss and kick parameters are presented and compared to the corresponding parameters for a standard undulator section.

TUPWA042	Lessons Learned and Mitigation Measures for the CERN LHC Equipment with RF Fingers	impedance, resonance, damping, simulation	1802
	E. Métral, O. Aberle, R.W. Aßmann, V. Baglin, M.J. Barnes, O.E. Berrig, A. Bertarelli, G. Bregliozzi, S. Calatroni, F. Carra, F. Caspers, H.A. Day, M. Ferro-Luzzi, M.A. Gallilee, C. Garion, M. Garlaschè, A. Grudiev, J.M. Jimenez, O.R. Jones, O. Kononenko, R. Losito, J.L. Nougaret, V. Parma, S. Redaelli, B. Salvant, P.M. Strubin, R. Veness, C. Vollinger, W.J.M. Weterings CERN, Geneva, Switzerland
	Beam-induced RF heating has been observed in several LHC components when the bunch/beam intensity was increased and/or the bunch length reduced. In particular eight bellows, out of the ten double-bellows modules present in the machine in 2011, were found with the spring, which should keep the RF fingers in good electrical contact with the central insert, broken. Following these observations, the designs of all the components of the LHC equipped with RF fingers have been reviewed. The lessons learnt and mitigation measures are presented in this paper.

TUPWA052	Loss Factor and Impedance Analysis for the Diamond Storage Ring	impedance, storage-ring, wiggler, simulation	1826
	R. Bartolini, R.T. Fielder, C.A. Thomas Diamond, Oxfordshire, United Kingdom
	Diamond Light Source is investigating the possibility of increasing the storage ring operating current above the nominal 300 mA. A campaign of measurements and simulations has been carried out in order to understand the extent of the parasitic energy loss and characterise the most important items which build up the machine impedance. In this paper we report on the most recent measurements of the longitudinal loss factor and the present status of the impedance database with an initial comparison between the two.

TUPWO057	Active Shimming of Dynamic Multipoles of an APPLE II Undulator in the Diamond Storage Ring	polarization, injection, optics, undulator	1997
	B. Singh, R. Bartolini, R.T. Fielder, E.C. Longhi, I.P.S. Martin, S.P. Mhaskar, R.P. Walker Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Diamond plans to operate a 5 m, long period length, APPLE undulator in a long insertion straight section. Theoretical investigations showed a severe impact on machine dynamics especially when the device is operated in vertical polarization mode. The use of local optics corrections and/or lowering of beta functions were initially investigated as possible solutions but with limited success. Active shimming of dynamic multipoles, following the approach at BESSY-II, proved more effective. The optimum shiming has been devised using kick map approach. In this paper we review the theoretical analysis, the commissioning of the active shims and the undulator, and the net effect of the undulator after compensation.

WEIB203	Industrialization of ILC from a View Point of Industry	cavity, HOM, target, status	2110
	K. Sennyu, H. Hara, F. Inoue, K. Kanaoka, K. Okihira MHI, Hiroshima, Japan
	Cavity performance has been improved by various efforts to meet the ILC spec stably in these days. For industrialization, not only Quality but also Cost and Delivery time, that is, QCD are important. We report our activities for stable quality and cost reduction in this report.
	Slides WEIB203 [5.789 MB]

WEPWA003	Hall-Probe Bench for Cryogenic in-Vacuum-Undulators	undulator, laser, cryogenics, permanent-magnet	2126
	C. Kuhn, H.-J. Bäcker, J. Bahrdt, A. Gaupp, B. Schulz HZB, Berlin, Germany
	The Helmholtz-Zentrum Berlin (HZB) builds a 2m long in-vacuum-hall-probe-bench for the characterization of several cryogenic undulators currently under development. Short period lengths and small gaps require an accurate correlation between Hall probe position / orientation and the 3D-magnetic field. The geometric tolerances of an in-vacuum bench in the presence of strong temperature gradients do not permit a Hall probe movement along a straight line without corrections. The HZB-bench employs a system of laser interferometers and position sensitive detectors, which is used in a feed-back loop for the Hall probe position / orientation. First measurements on the accuracy and reproducibility of the new device are presented.

WEPWA007	First Tests with a Local and Integral Magnetic Field Measurement Setup for Conduction Cooled Superconducting Undulator Coils	undulator, synchrotron, radiation, synchrotron-radiation	2138
	A.W. Grau, S. Casalbuoni, S. Gerstl, N. Glamann, T. Holubek, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany
	The magnetic field quality of insertion devices (IDs) has a significant influence on their performance. Therefore it is essential to characterize their magnetic properties and perform precise field measurements before installation in synchrotron light sources. Particularly for permanent magnet IDs the magnetic field measurement technology made significant progress during the last years and pushed the capabilities of synchrotron light sources. Even though for superconducting IDs the measurement settings are far more challenging similar major developments are required. As a part of our R&D program on superconducting IDs we perform quality assessment of their magnetic field properties. This contribution describes details, challenges and the first tests with the measurement equipment configurations to perform measurements of the integral and local magnetic field distributions of superconducting undulator coils up to 2 m length, in a cold (4.2 K), in-vacuum and cryogen free environment.

WEPWA022	The Fabrication and Measurement of the New Insertion Devices of Hefei Light Source	undulator, insertion, insertion-device, radiation	2177
	Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China
	To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more new insertion devices. The new insertion devices include one elliptically polarizing undulator with 10⁴ mm period, one in-vacuum undulator with 40mm period, one wiggler with 152mm period and one quasi-periodic undulator based on a new scheme proposed by us. In this paper the fabrication and the preliminary results of the magnetic field measurements of the new insertion devices are reported.

WEPWA029	Undulator Chamber R&D for SXFEL	undulator, controls, free-electron-laser, laser	2193
	X. Hu, L. Yin SINAP, Shanghai, People's Republic of China
	The upcoming construction of Shanghai Soft X-ray Free Electron Laser Facility (SXFEL) will use 18 m small gap undulators. Each undulator is 3 meters long and will work at a minimum gap of 9 mm. This requires a vacuum chamber with an outer height of 8 mm and an elliptic inner aperture. The pressure inside of the chamber shall be less than 10^-5 Pa for the beam operation. An oxygen-free copper vacuum chamber was designed and a prototype was developed. This chamber includes three parts, a copper pipe manufactured by stretching, two flanges made of clad metal and a set of supports. The main fabrication procedure and the test results for the chamber prototype are described in this paper.

WEPWA033	The Magnetic Performance of Two Undulators for HLS	undulator, polarization, multipole, electron	2202
	W. Zhang, Q.G. Zhou SINAP, Shanghai, People's Republic of China H.F. Wang SSRF, Shanghai, People's Republic of China
	An elliptically polarized undulator and an in vacuum undulator for HLS have been built at SSRF. The magnetic design of the two Undulators is reviewed. Measurements of the complete undulators are described. Results of performance optimization, including minimization of optical phase error, trajectory wander and integrated multipoles with magic fingers are presented.

WEPWA053	Control System of In-vacuum Undulator in Taiwan Photon Source	controls, EPICS, undulator, insertion	2238
	C.Y. Wu, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, C.Y. Liao NSRRC, Hsinchu, Taiwan
	Insertion device (ID) is a crucial component in third-generation synchrotron light sources, which can produces highly-brilliant, forward-directed and quasi-monochromatic radiation over a broad energy range for various experiments. In the phase I of the Taiwan Photon Source (TPS) project, seven IU22s (In-Vacuum Undulator) will be planned, constructed, and installed. The control system for IU22 is based on the EPICS architecture. The main control components include the motor with encoder for gap adjustment, trimming power supply for corrector magnets, ion pumpers and BA gauges for vacuum system, temperature sensors for ID environmental monitoring and baking, and interlock system (limit switches, emergency button) for safety. The progress of IU22 control system will be summarized in this report.

WEPWA062	Status of the UK Superconducting Planar Undulator Project	undulator, cryogenics, wakefield, radiation	2259
	J.A. Clarke, B.J.A. Shepherd STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom V. Bayliss, T.W. Bradshaw, S.A. Brown, A.J. Brummitt, G.W. Burton, S.J. Canfer, B. Green, S.R. Watson STFC/RAL, Chilton, Didcot, Oxon, United Kingdom S.E. Hughes, E.C. Longhi, J.C. Schouten Diamond, Oxfordshire, United Kingdom
	The UK is developing a short period, narrow aperture, planar superconducting undulator that is planned to be installed and tested in the 3 GeV Diamond Light Source in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. First measurements will be presented of a 19 period test module and also the commissioning of the 2K cryogenic turret.

WEPWA081	Status of the Praseodymium Undulator with Textured Dysprosium Poles for Compact X-Ray FEL Applications	undulator, cryogenics, simulation, radiation	2298
	F.H. O'Shea, R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh, K.E. Woods RadiaBeam, Santa Monica, USA J. Park, R.L. Stillwell NHMFL, Tallahassee, Florida, USA V. Solovyov BNL, Upton, Long Island, New York, USA
	The demand for high-brightness hard x-ray fluxes from next generation light sources has spurred the development of insertion devices with shorter periods and higher fields than is feasible with conventional materials and designs. RadiaBeam Technologies is currently developing a novel high peak field, ultrashort period undulator with praseodymium-iron-boron (PrFeB) permanent magnets and textured dysprosium (Tx Dy) ferromagnetic field concentrators. This device will offer an unparalleled solution for compact x-ray light sources, as well as for demanding applications at conventional synchrotron radiation sources. A 1.4T on-axis field has already been achieved in a 9mm period undulator, demonstrating the feasibility of using Tx Dy poles in a hybrid undulator configuration with PrFeB magnets. Facets of the undulator design, optimization of the Tx Dy production and characterization process, and magnetic measurements of Tx Dy will be presented.

WEPWO001	Power Couplers for XFEL	site, pick-up, controls, monitoring	2310
	W. Kaabi, M. El Khaldi, A. Gallas, P. Lepercq, C. Magueur, A. Variola, A. Verguet LAL, Orsay, France W.-D. Möller DESY, Hamburg, Germany
	The LAL contribution to the XFEL project will be the delivery of 800 power couplers to equip 100 Cry-modules. The LAL’s tasks consist on the industrial monitoring and coupler quality control at two different production sites, in addition to the RF conditioning at LAL of the 800 produced couplers. The RF conditioning and all the coupler preparation process will be held in a 70m2 ISO5 clean room. An RF power station delivering 5MW, allow 8 couplers conditioning in the same time. Being in production control side and also RF conditioning one, the aim of LAL is to reach the rate of 8 couplers delivery per week, after a rump up phase. The starting of Coupler mass production is scheduled for beginning 2013.

WEPWO002	RF Measurements of the 1.6 Cell Lead/Niobium Photoinjector in HoBiCaT	cavity, gun, cathode, SRF	2313
	A. Burrill, W. Anders, T. Kamps, J. Knobloch, O. Kugeler, P. Lauinger, A. Neumann HZB, Berlin, Germany P. Kneisel JLAB, Newport News, Virginia, USA R. Nietubyć NCBJ, Świerk/Otwock, Poland J.K. Sekutowicz DESY, Hamburg, Germany
	The development of a simple and robust SRF photoinjector capable of delivering up to 1 mA average current in c.w. operation continues to progress with the horizontal RF testing of the 1.6 cell Pb/Nb hybrid photoinjector. This injector utilizes a sputtered lead coating on a removable Nb cathode plug as the photoelectron source and has recently been tested in the horizontal test cryostat facility, HoBiCaT, at HZB. In this paper we will report on the status of these RF measurements and compare the performance to previous vertical RF tests performed at JLab. We will also report on the experience operating this cavity with a TTF-III high power RF input coupler, as well as provide a summary of the microphonics susceptibility now that it has been installed into a helium vessel and equipped with a Saclay style tuner.

WEPWO005	Microphonics Analysis of the SC 325 MHz CH-Cavity	cavity, simulation, resonance, status	2319
	M. Amberg, M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher HIM, Mainz, Germany K. Aulenbacher IKP, Mainz, Germany
	Since the walls of superconducting (sc) cavities are kept very thin to support the cooling process, even small mechanical disturbances can detune the cavity. One of the main sources of detuning a cavity is microphonics. These low-frequent vibrations caused by vacuum pumps or underground noise are transferred to the cryostat and excite mechanical resonances of the cavity which may lead to frequency shifts larger than the bandwidth. To determine the mechanical resonance frequencies of the sc 325 MHz CH-cavity (Crossbar-H-Mode) simulations with ANSYS Workbench have been performed in a first step. Additionally, microphonics measurements were taken at room temperature as well as in a vertical cryostat at 4K in the cryo-lab of the IAP, Frankfurt University. Furthermore, the contraction of the cavity walls and the resulting frequency shift due to the cavity cool-down has been measured. A comparison between simulation results and the measured values is presented in this paper.

WEPWO011	In-vacuum Temperature Measurement of Niobium Components using Infrared Pyrometry during Electron Beam Welding Procedure	cavity, electron, controls, shielding	2334
	L. Monaco, P. Michelato, C. Pagani, D. Sertore INFN/LASA, Segrate (MI), Italy V. Battista, G. Corniani, M. Festa Ettore Zanon S.p.A., Schio, Italy
	Electron beam welding (EBW) is widely used in the construction of Niobium Superconducting RF cavities. The welding sequence of such a complex structure, foresees many welding operations. The welding parameters depend on many variables as the material thickness, but also on the component temperature before each weld. This paper presents a technique to measure the temperature of Nb components in vacuum during the EBW operation using an IR pyrometer placed outside the vacuum chamber through an appropriate vacuum viewport. With the current configuration the system can measure temperatures up to 350°C in the vacuum conditions of the EBW vacuum chamber (10-5-10^-6 mbar). The technique was used to optimize the time interval between each subsequent equatorial weld operation during Nb cavities production at Ettore Zanon, increasing the welding procedure reliability and decreasing the waiting time by control of the temperatures in the weld region. Moreover this technique can be generally used for in vacuum measurements of components from room temperature up to about 350 °C. Future developments are under way to make this technique compatible with UHV and increasing the measurement range.

WEPWO014	Rf Field-Attenuation Formulae for the Multilayer Coating Model	cavity, coupling, electromagnetic-fields	2343
	T. Kubo, T. Saeki KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan
	Formulae that describe the RF electromagnetic field attenuation in the multilayer coating model with a single superconductor layer and a single insulator layer deposited on a bulk superconductor are derived with a rigorous calculation based on the Maxwell equations and the London equation.

WEPWO018	Status of the IHEP 1.3 GHz Superconducting RF Program for the ILC	cavity, cryomodule, SRF, HOM	2355
	J. Gao, Y.L. Chi, J.P. Dai, R. Ge, T.M. Huang, S. Jin, C. H. Li, S.P. Li, Z.Q. Li, H.Y. Lin, Y. Liu, Z.C. Liu, Q. Ma, Z.H. Mi, W.M. Pan, Y. Sun, J.Y. Zhai, T.X. Zhao, H.J. Zheng IHEP, Beijing, People's Republic of China
	The 1.3 GHz superconducting radio-frequency (SRF) technology is one of the key technologies for the ILC. IHEP is building an SRF Accelerating Unit, named the IHEP ILC Test Cryomodule (IHEP ILC-TC1), for the ILC SRF system integration study, high power horizontal test and possible beam test in the future. In this paper, we report the components test results and the assembly preparation of this cryomodule. Processing and vertical test of the large grain low-loss shape 9-cell cavity is done. Performance of the in-house made high power input coupler and tuner at room temperature reaches the ILC specification.

WEPWO041	Beam Commissioning Superconducting RF Cavities for PLS-II Upgrade	SRF, cavity, storage-ring, LLRF	2390
	Y.U. Sohn, M.-H. Chun, J.Y. Huang, Y.D. Joo, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, I.H. Yu PAL, Pohang, Kyungbuk, Republic of Korea
	Two superconducting RF cavities were commissioned with electron beam at PLS-II, which is upgraded machine from PLS with 3 GeV, 20 insertion devices, and now on user service. These srf cavities have been prepared during last 3 years. Each cavity was tested with higher than 2 MV rf voltage and 125 kW standing wave power at CW mode after installation at storage ring. PLS-II is on user operation with 200 mA beam current now, and on the way of beam current improvement upto 400mA, by synchrotron conditioning for beam chamber and in-vacuum udulators. Upto 200 mA beam current no beam instability from the higher order modes is observed. With top-up mode operation, the errors of amplitude of rf field and phase are recorded as 0.3% and 0.3 degree peak to peak, respectively during one day. Successful PLS-II upgrade with hardware and its designed performance will be declared at the end of 1st half user run in 2013.

WEPWO043	IFMIF-EVEDA SRF Linac Couplers Test Bench	linac, SRF, controls, LLRF	2396
	D. Regidor, I. Kirpitchev, J. Molla, P. Méndez, A. Salom, M. Weber CIEMAT, Madrid, Spain M. Desmons, N. Grouas, P. Hardy, V.M. Hennion, H. Jenhani, F. Orsini CEA/IRFU, Gif-sur-Yvette, France
	The IFMIF-EVEDA SRF Linac is a cryomodule equipped with eight superconducting HWR cavities, operating at the frequency of 175 MHz and powered by 200kW CW RF couplers. Before assembling the couplers to the cryomodule, it is necessary to process them using high levels of RF power. In order to perform this conditioning, the power couplers must be connected to a RF network which is fed by an RF source and ended with a load or a short-circuit, depending on the conditioning mode to be applied. A test bench has been designed for the conditioning of the SRF LINAC couplers. The main component is the “test box”, a resonant cavity where two couplers will be assembled to transmit the 200 kW from the RF source to the appropriate termination. The test box includes a large pumping port allowing an efficient pumping of the entire vacuum volume limited by the coupler ceramic windows. Several diagnostics as light detectors, vacuum gauges and thermal transducers will provide information on the relevant parameters for the control of the RF conditioning process. In addition, a support frame has been designed to maintain the whole assembly and reduce the mechanical stress on the couplers.

WEPWO046	First Test Results of the 4-rod Crab Cavity	cavity, niobium, pick-up, coupling	2405
	R. Calaga, L.S. Alberty Vieira, S. Calatroni, O. Capatina, E. Ciapala, L.M.A. Ferreira, E. Jensen, P. Maesen, A. Mongelluzzo, T. Renaglia, M. Therasse CERN, Geneva, Switzerland P.K. Ambattu, D. Doherty, B.D.S. Hall, C. Lingwood Cockcroft Institute, Lancaster University, Lancaster, United Kingdom G. Burt Lancaster University, Lancaster, United Kingdom
	Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The first prototype crab cavity with the 4-rod geometry has undergone surface treatment and cold testing. Due to the complex geometry and unique fabrication procedure, RF validation of the field at beyond the nominal operating voltage at a sufficiently high Q0 is an important pre-requiste. Preliminary results of the first cold tests are presented along with cavity performance at different stages of the cavity processing is described.

WEPWO050	Mechanical Study of 400 MHz Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade	cavity, simulation, luminosity, electron	2417
	B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu BNL, Upton, Long Island, New York, USA L. Alberty Vieira, R. Calaga CERN, Geneva, Switzerland T.L. Grimm Niowave, Inc., Lansing, Michigan, USA
	A prototype double quarter wave crab cavity was designed for the Large Hadron Collider luminosity upgrade. A finite element model is used to simulate the mechanical properties of the crab cavity. The results are presented and a reinforcement concept is proposed to meet the safety requirements. The reinforcement components, as well as the cavity, are presently being fabricated at Niowave Inc.

WEPWO051	Manufacture of a Compact Prototype 4R Crab Cavity for HL-LHC	cavity, niobium, luminosity, electron	2420
	G. Burt, B.D.S. Hall, C. Lingwood Cockcroft Institute, Lancaster University, Lancaster, United Kingdom L. Alberty Vieira, R. Calaga, O. Capatina CERN, Geneva, Switzerland C.H. Boulware, D. Gorelov, T.L. Grimm, C. Krizmanich, T.S. Lamie Niowave, Inc., Lansing, Michigan, USA C. Hill, P.A. McIntosh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R.A. Rimmer, H. Wang JLAB, Newport News, Virginia, USA
	Funding: This work has been funded by the EU through EUCARD and HiLumi and by STFC via the Cockcroft Institute. A prototype compact SRF deflecting cavity has been manufactured for LHC. The base of the cavity has been machined out of large grain niobium ingot to allow the manufacture of the complex rod profile. Stiffening rods have been used to increase the mechanical strength of the outer can. Details of the cavity design and manufacture will be discussed.

WEPWO055	Fabrication and Testing of SSR1 Resonators for PXIE	cavity, cryomodule, linac, beam-transport	2429
	L. Ristori, M.H. Awida, P. Berrutti, T.N. Khabiboulline, M. Merio, D. Passarelli, A.M. Rowe, D.A. Sergatskov, A.I. Sukhanov Fermilab, Batavia, USA
	Fermilab is in the process of constructing a proton linac to accelerate a 1 mA CW beam up to 30 MeV. It will be a test for the front end of Project X and known as the Project X Injector Experiment (PXIE). The major goal of PXIE is the validation of the Project X concept and mitigation of technical risks. It is expected to be constructed in the period of 2012-2016. The PXIE linac consists of a Ion source and LEBT, a 162.5 MHz RFQ, a MEBT, a 162.5 MHz HWR cryomodule (designed and built at ANL) and a 325 MHZ SSR1 cryomodule (designed and built at FNAL). In this paper we present the recent advances in the development of the SSR1 resonators at Fermilab. Several bare SSR1 resonators have been processed, heat-treated and tested successfully in the Fermilab Vertical Test Stand. The outfitting of helium vessels is in process and the coarse-fine frequency tuning system has been designed and is currently being procured and tested. Details of the power coupler are also discussed.

WEPWO082	Ferroelectric Based High Power Tuner for L-band Accelerator Applications	controls, linac, cavity, simulation	2486
	A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA S. Kazakov, V.P. Yakovlev Fermilab, Batavia, USA A.B. Kozyrev LETI, Saint-Petersburg, Russia E. Nenasheva Ceramics Ltd., St. Petersburg, Russia
	Funding: US Department of Energy With this paper, we present our recent breakthrough with a new fast ferroelectric tuner development. The tuner is based on BST(M) ferroelectric elements (ε~150), which are designed to be used as the basis for L-band accelerator components intended for ERL, ILC, Project X and other applications. These new ferroelectric elements are to be fabricated for the new fast active tuner for SC cavities that can operate in air at low biasing DC fields. Note there were no reliable results on the long-term piezo actuators operations in CW regime. Specific features of ERL, ILC and Project X accelerator technology and challenges of the designs are high magnitude and phase stability of its operations. Mechanical vibrations, or microphonics affect the SRF resonator, while the ferroelectric tuners have shown extremely high tuning speed. We have demonstrated successful mitigation of the residual effects on the ferroelectric-metal interface along with the acceptable level of the overall loss factor of the tuner element. A new concepts of a tuning element based on low dielectric constant ferroelectrics along with fabrication technology of these new BST(M) ferroelectric elements will be presented.

WEPEA014	Recent Electron Cloud Studies in the SPS	electron, injection, emittance, simulation	2525
	G. Iadarola, H. Bartosik, M. Driss Mensi, H. Neupert, G. Rumolo, M. Taborelli CERN, Geneva, Switzerland G. Iadarola Naples University Federico II, Science and Technology Pole, Napoli, Italy
	It is important to qualify the present status of the SPS with respect to the electron cloud before the Long Shutdown of the CERN accelerator complex, which will take place in 2013-2014. Therefore several electron cloud studies were performed during the 2012 run in order to get a full characterization of the behavior of the SPS with the LHC-type beams with 25 ns bunch spacing, which can be very sensitive to electron cloud effects. The collected information should allow to understand up to which extent this long period without beam operation - and the related interventions on the machine - will degrade the present conditioning state of the SPS, which has been achieved by “scrubbing” over several years. Several measurements with different beam conditions have been collected also on the electron cloud detectors installed in the machine. These results, in combination with detailed simulation studies, will provide the basis for defining strategies of electron cloud mitigation as required for the production of future high intensity and high brightness beams within the LHC Injectors Upgrade (LIU) project.

WEPEA021	Influence of the Vacuum Chamber Limitation on Dynamic Aperture Calculations	dynamic-aperture, multipole, resonance, optics	2543
	M. Attal SESAME, Allan, Jordan
	In a storage ring the evaluation of the dynamic aperture taking into account the vacuum chamber limitation is more accurate and may display nonlinearities that could not be seen in the conventional absolute dynamic aperture calculations. This has been investigated in this paper and demonstrated in SESAME dynamic aperture case where taking into account the vacuum chamber uncovered the seriousness of a 5th order resonance mainly when errors like high order multipoles were introduced to the lattice. The destructive effect of the 5th order resonance has been avoided by changing the fractional part of the tunes. The problem has also been more investigated using the Frequency Map Analysis technique.

WEPEA062	Progress in ELENA Design	extraction, emittance, electron, antiproton	2651
	S. Maury, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, C. Carli, T. Eriksson, R. Kersevan, S. Pasinelli, G. Tranquille, G. Vanbavinckhove CERN, Geneva, Switzerland W. Oelert FZJ, Jülich, Germany
	The Extra Low Energy Antiproton ring (ELENA) is a small ring at CERN which will be built to increase substantially the number of usable (or trappable) antiprotons delivered to experiments for studies with antihydrogen. The report shows the progress in the ELENA design. The choice of optics and ring layout inside of AD hall is given. The main limitations for beam parameters at extraction like intra beam scattering and tune shift due to space charge are discussed. The electron cooler plays key role in ELENA both for efficient deceleration as well as for preparing extracted beam with parameters defined by experiments. The other important systems like beam vacuum, beam instrumentations and others are reviewed as well.

WEPEA063	Upgrades and Consolidation of the CERN AD for Operation during the Next Decades	controls, target, antiproton, electron	2654
	T. Eriksson, M. E. Angoletta, L. Arnaudon, J.A. Baillie, M. Calviani, F. Caspers, L.V. Joergensen, R. Kersevan, G. Le Godec, R. Louwerse, M. Ludwig, S. Maury, A. Newborough, C. Oliveira, G. Tranquille CERN, Geneva, Switzerland
	As the ELENA project is now well underway, focus is turned to the Antiproton Decelerator (AD) itself. Most of the machine’s key components are in operation since more than 25 years and a substantial consolidation program is now being launched in view of continued operation beyond 2025. Over the course of the next few years a progressive consolidation of the AD-Target area, the AD-ring and all associated systems will take place. Several investigations have recently been performed in the target area with the objective of establishing the radiation environment and the sensitivity of the antiproton production to potential misalignment of the production elements. Identification of reliability and serviceability issues of the AD-ring components and associated systems has been done and will continue during the 2013 shut-down. Planned and ongoing consolidation activities are also discussed with emphasis on stochastic and electron beam cooling, instrumentation, RF systems, vacuum, magnets, power converters and beam transfer equipment.

WEPFI014	Present Status and Progresses of RFQ of IFMIF/EVEDA	rfq, coupling, linac, quadrupole	2729
	R. Dima, A. Pepato, F. Scantamburlo, E. Udup INFN- Sez. di Padova, Padova, Italy F. Grespan, A. Palmieri, C. Roncolato INFN/LNL, Legnaro (PD), Italy
	The RFQ of IFMIF/EVEDA is designed to accelerate a 125 mA D⁺ beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz. The production of the modules 16, 17 and 18 necessary has been completed. In this paper the progress and improvements on the production of the modules, as well the development of the brazing procedure design will be described.

WEPFI018	Comparison of High Gradient Performance in Varying Cavity Geometries	damping, coupling, acceleration, HOM	2741
	T. Higo, T. Abe, Y. Arakida, Y. Higashi, S. Matsumoto, T. Shidara, T. Takatomi, M. Yamanaka KEK, Ibaraki, Japan A. Grudiev, G. Riddone, W. Wuensch CERN, Geneva, Switzerland
	Four types of CLIC prototype TW accelerator structures were high-gradient tested at Nextef, KEK, up to 100 MV/m level and the fifth is under test now. The ramping speed of each processing and the resultant breakdown rate were compared among them. From this comparison, it was found that the ramping speed of the structures with opening ports for HOM damping with magnetic coupling became slow and the resultant breakdown rate became high. It was also found that that with lower surface magnetic field showed faster ramping in processing and lower breakdown rate. This indicates the role of the magnetic field on vacuum breakdowns in copper structure at the region of several tens to 100 MV/m. In this paper, we review the processing stage and the high gradient performance of these structures trying to discuss the relevant parameters, surface electric field, surface magnetic field and other parameters such as Sc, “complex pointing vector”, to the performance difference.

WEPFI019	High Power Test of Kanthal-coated L-band Lossy Cavity	cavity, positron, klystron, solenoid	2744
	F. Miyahara, Y. Arakida, Y. Higashi, T. Higo, K. Kakihara, S. Matsumoto KEK, Ibaraki, Japan K. Saito Hitachi, Ltd., Energy and Environmental System Laboratory, Hitachi-shi, Japan H. Sakurabata Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken, Japan
	We have been developing a Kanthal (Al-Cr-Fe)-coated collinear load as a possible candidate of the L-band acc. structure of SuperKEKB positron capture system. In order to achieve the higher capture efficiency comparing to that of KEKB, the upgrade of the e⁺ production and capture section is required. The system consists of a W target with a flux concentrator followed by acc. structures surrounded by solenoids. The increase of the e⁺ bunch charge and the reduction of satellite bunches are the main issues for this system. The frequency choice of L-band is based on the larger transverse and longitudinal acceptances than those of the S-band one. The load is preferable to compose the system with compact magnets and to minimize the dip in the solenoid field. The design of the load was reported in previous work. We understand that the Kanthal-coated cell should be confirmed in high power to confirm the feasibility at our design field of 10 MV/m level. We are making a test cavity which consists of 3 cells and one of them is composed of Kanthal-coated disks to lower the intrinsic Q value from 20000 to the order of 1000. The cavity production and the experimental result will be reported. Development of L-band accelerating structure with Kanthal-coated collinear load for SuperKEKB, IPAC12, THLR04.

WEPFI021	Influence of Core Winding Tension and Ribbon Quality on the MA Core RF Characteristics	impedance, synchrotron, factory, cavity	2747
	M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan K. Hara, K. Hasegawa, C. Ohmori, M. Toda, M. Yoshii KEK, Tokai, Ibaraki, Japan
	J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) and Main Ring (MR) employ RF cavities loaded with Magnetic Alloy (MA) cores to generate a high field gradient. To achieve the high field gradient, the core shunt impedance is a key parameter. We found during the development of MA cores for RCS RF cavities that the core shunt impedance was increased by lowering a core winding tension. We lowered the core winding tension in order to improve the electrical insulation between MA ribbon layers. The lower winding tension reduced the core filling factor that is defined as the volume ratio of MA ribbons and geometrical dimensions. The core shunt impedance might be reduced according to the core filling factor reduction. We discuss the reason why the lower winding tension increased the core shunt impedance. We also report the influence of the ribbon quality variation on the MA core RF characteristics.

WEPFI055	Experience on Fabrication and Assembly of the First Clic Two-Beam Module Prototype	alignment, quadrupole, RF-structure, instrumentation	2815
	D. Gudkov, S. Lebet, G. Riddone, F. Rossi CERN, Geneva, Switzerland A. Samoshkin JINR, Dubna, Moscow Region, Russia
	The CLIC two-beam module prototypes are intended to prove the design of all technical systems under the different operation modes. Two validation programs are currently under way and they foresee the construction of four prototype modules for mechanical tests without beam and three prototype modules for tests with RF and beam. The program without beam will show the capability of the technical solutions proposed to fulfil the stringent requirements on radio-frequency, supporting, pre-alignment, stabilization, vacuum and cooling systems. The engineering design was performed with the use of CAD/CAE software. Dedicated mock-ups of RF structures, with all mechanical interfaces and chosen technical solutions, are used for the tests and therefore reliable results are expected. The components were fabricated by applying different technologies for the part manufacturing and joining. The first full-size prototype module was assembled in 2012. This paper is focused on the production process including the comparison of several technical solutions adopted during the realization. The description of the module assembly and quality control measurements are also recalled.

WEPFI061	Petra Cavity Vacuum RF Condition with Field Balance Mechanism for TPS Storage Ring in NSRRC	cavity, coupling, controls, storage-ring	2833
	T.-C. Yu, L.-H. Chang, M.H. Chang, L.J. Chen, F.-T. Chung, M.-C. Lin, Y.-H. Lin, Z.L. Liu, C.H. Lo, M.H. Tsai, Ch. Wang, T.-T. Yang, M.-S. Yeh NSRRC, Hsinchu, Taiwan
	In the first stage commissioning of TPS (Taiwan Photon source) storage ring in NSRRC, two room temperature Petra cavities will be used. At this commission stage, 100mA with 950keV beam loss is estimated to have 47.5kW beam loss for each cavity. In the meanwhile, the cavity loss at the specified 1.2MV of each cavity will be about 50kW. Therefore, coupling coefficient of 2 is required. However, the initial design specification of Petra cavity has only beta of about 1.7. Hence, the modification of the input coupler is done with the enhancement of its beta as well as advanced water cooling for some heat point. Besides, due to the two-tuner system of Petra cavity, special field-balance tuner control system is also developed. In RF condition for better vacuum up to 1.4MV, some modification of the tuner mechanical structure is also done to reach high vacuum condition (lower than 5*10^-9 Torr) for storage ring requirement.

WEPFI064	Prototype Refinement of the VELA Transverse Deflecting Cavity Design	cavity, simulation, target, emittance	2842
	P. Goudket, S.R. Buckley, L.S. Cowie, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	The Versatile Linear Accelerator (VELA) at Daresbury Laboratory will deliver low energy (5/6 MeV) short bunches (~40 fs) to a number of industrial experimental stations and for scientific research. In order to measure the longitudinal profile of the bunch an S-band transverse deflecting cavity will be inserted into the beamline. A transverse kick of around 5 MV is required therefore a 9 cell design has been chosen. As part of the design iteration a three-cell prototype has been built. Frequency measurements have been performed on the prototype cavity as well as Coordinate Measuring Machine to confirm that the dimensions are to the required design tolerances. Subsequently, further modelling has been performed to improve and refine the design of the 9-cell cavity, to ensure that the frequency of the final design is within the tuning range of the water thermal control system and that the field flatness requirement can be obtained.

WEPFI065	The Commissioning of the EBTF S-band Photoinjector Gun at Daresbury Laboratory	cavity, klystron, electron, laser	2845
	A.E. Wheelhouse, R.K. Buckley, S.R. Buckley, P.A. Corlett, J.W. McKenzie, B.L. Militsyn, A.J. Moss STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The first stage of the installation of the Electron Beam Test Facility (EBTF) at Daresbury Laboratory has been completed and a commissioning phase is presently underway. At the heart of the machine is a photoinjector based on a two and a half cell S-band RF gun incorporating a metallic photocathode, which is capable of delivering 4-6 MeV, low emittance, short electron pulses (10 - 250 pC). The photoinjector is driven by a UV light at 266 nm wavelength delivered by a laser system and is powered by a RF system incorporating a Low Level RF system, a high power RF modulator and a klystron. This paper describes the commissioning and conditioning of the photoinjector.

WEPFI073	A Modular Cavity for Muon Ionization Cooling R&D	cavity, simulation, coupling, solenoid	2860
	D.L. Bowring, A.J. DeMello, A.R. Lambert, D. Li, S.P. Virostek, M.S. Zisman LBNL, Berkeley, California, USA C. Adolphsen, L. Ge, A.A. Haase, K.H. Lee, Z. Li, D.W. Martin SLAC, Menlo Park, California, USA D.M. Kaplan Illinois Institute of Technology, Chicago, Illinois, USA T.H. Luo, D.J. Summers UMiss, University, Mississippi, USA A. Moretti, M.A. Palmer, R.J. Pasquinelli, Y. Torun Fermilab, Batavia, USA R.B. Palmer BNL, Upton, Long Island, New York, USA
	The Muon Accelerator Program (MAP) collaboration is developing an ionization cooling channel for muon beams. 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 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 based on a modular pillbox cavity operating at 805 MHz. The modular cavity design allows for the evaluation of different cavity materials - such as beryllium - which may ameliorate or circumvent RF breakdown triggers. Modular cavity components may furthermore be prepared with different surface treatments, such as high-temperature baking or chemical polishing. This poster presents the design and experimental status of the modular cavity, as well as future plans for the experimental program.

WEPFI075	Design of the FRIB RFQ	rfq, linac, ion, dipole	2866
	N.K. Bultman, G. Morgan, E. Pozdeyev, Y. Yamazaki, Q. Zhao FRIB, East Lansing, Michigan, USA J. Stovall, L.M. Young TechSource, Santa Fe, New Mexico, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 FRIB linac driver includes a front end and a SRF linac for all stable ion beams with energy more than 200 MeV/u, and beam power on target up to 400 kW. A 80.5 MHz FRQ at the front end accelerates heavy ion beams from 12 keV/u to 0.5 MeV/u, in CW mode. Design of the RFQ is introduced and several important technical issues are discussed in this paper.

WEPFI077	LLNL X-band Test Station Status	gun, alignment, emittance, cathode	2872
	R.A. Marsh, F. Albert, G.G. Anderson, S.G. Anderson, C.P.J. Barty, E.T. Dayton, S.E. Fisher, D.J. Gibson, F.V. Hartemann, S.S.Q. Wu LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test station is being developed to investigate accelerator optimization for future upgrades. This test station will enable work to explore the science and technology paths required to boost the current mono-energetic gamma-ray technology a higher effective repetition rate, potentially increasing the average gamma-ray brightness by two orders of magnitude. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. Detailed design of the test station including is complete, and will be presented with modeling simulations and future upgrade paths. The current status of the installation will also be discussed with future commissioning plans.

WEPFI078	LLNL X-band RF System	klystron, high-voltage, gun, cathode	2875
	R.A. Marsh, G.G. Anderson, S.G. Anderson, C.P.J. Barty, S.E. Fisher, D.J. Gibson, F.V. Hartemann LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray technology at LLNL. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The high power RF for the test station will be provided by a SLAC XL4 11.424 GHz klystron driven by a ScandiNova solid state modulator. The high power system has been installed and results of initial testing into high power loads will be presented. Performance of the system with respect to processing and stability will be discussed as well as future plans for the low level RF system.

WEPFI082	Double-tip Magnetic Field Enhancement	simulation, cavity, electron, cathode	2887
	F.Y. Wang, L. Xiao SLAC, Menlo Park, California, USA
	The local electric field enhancement factor β in an rf accelerator cavity has been studied experimentally for decades and found to be in the range from few tens up to few hundreds for various rf frequencies and materials. A large field enhancement factor is usually thought to come from sharp tips whose β is roughly the ratio of their height to their tip radius. For a β of few hundred, the corresponding tip height would need to be more than 10 microns, which should be visible in a scanning electron microscope (SEM). However, the estimated β from SEM images of cavity surfaces is around 10. Therefore, the physics of such large β values is still not clear. In this paper, we have studied differentμstructures and found that the magnetic field could be enhanced many times in the presence of two nearby tips with β of 10. The large local magnetic field enhancement could lead to large enhanced pulsed heating and thus could melt surface in a very short time and form a liquid Taylor cone.

WEPFI084	High Power S-band RF Window Optimized to Minimize Electric and Magnetic Field on the Surface	klystron, linac, simulation, positron	2893
	A.D. Yeremian, V.A. Dolgashev, S.G. Tantawi SLAC, Menlo Park, California, USA
	Funding: * Work Supported by Doe Contract No. DE-AC02-76SF00515 RF windows are used to separate vacuum from atmosphere in high power microwave systems, such as klystrons. RF breakdowns in these megawatt power environments are frequent and problematic. And S-band RF window was designed to have reduced electric and magnetic field in the ceramic and waveguide joints. Specifically the normal component of the electric field on the ceramic is minimized and a traveling wave is created inside the ceramic by optimizing the shape of the window and the geometry of the joint between the circular waveguide to the rectangular waveguide. A prototype of this window in the process of being made at SLAC for high power tests.

WEPFI086	Normal Conducting Radio Frequency X-band Deflecting Cavity Fabrication, Validation and Tuning	cavity, electron, linear-collider, collider	2899
	R.B. Agustsson, L. Faillace, A.Y. Murokh, E. Spranza, S. Storms RadiaBeam, Santa Monica, USA D. Alesini INFN/LNF, Frascati (Roma), Italy V.A. Dolgashev, J.R. Lewandowski SLAC, Menlo Park, California, USA J.B. Rosenzweig UCLA, Los Angeles, California, USA V. Yakimenko BNL, Upton, Long Island, New York, USA
	An X-band Traveling wave Deflector mode cavity (XTD) has been developed, fabricated, tuned and characterized by Radiabeam Technologies to perform longitudinal measurement of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory, and is scalable to higher energies. The XTD is designed to operate at 11.424 GHz, and features short filling time, femtosecond resolution, and a small footprint. RF design, structure fabrication, cold testing and tuning results are presented.

WEPFI088	High-power Tests of an Ultra-high Gradient Compact S-band (HGS) Accelerating Structure	klystron, coupling, monitoring, linac	2902
	L. Faillace, R.B. Agustsson, P. Frigola, A.Y. Murokh, S. Seung RadiaBeam, Santa Monica, USA S.G. Anderson LLNL, Livermore, California, USA V.A. Dolgashev SLAC, Menlo Park, California, USA J.B. Rosenzweig UCLA, Los Angeles, California, USA V. Yakimenko BNL, Upton, Long Island, New York, USA
	RadiaBeam Technologies reports on the RF design, fabrication and high-power tests of a ultra-high gradient S-Band accelerating structure (HGS) operating in the pi-mode at 2.856 GHz. The compact HGS structure offers a drop-in replacement for conventional S-Band linacs in research and industrial applications such as drivers for compact light sources, medical and security systems. The electromagnetic design (optimization of the cell shape in order to maximize RF efficiency and minimize surface fields at very high accelerating gradients) has been carried out with the codes HFSS and SuperFish while the thermal analysis has been performed by using the code ANSYS. The high-power conditioning was carried out at Lawrence Livermore National Laboratory (LLNL).

WEPFI090	An X-band Dielectric-based Wakefield Power Extractor	wakefield, simulation, damping, impedance	2908
	C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA M.E. Conde, W. Gai, J.G. Power ANL, Argonne, USA V.A. Dolgashev, J.R. Lewandowski, S.G. Tantawi, S.P. Weathersby SLAC, Menlo Park, California, USA I. Syratchev CERN, Geneva, Switzerland
	Funding: US DoE SBIR Phase II project under Contract#DE-SC0004322 An X-band dielectric-based wakefield power extractor is under development to function as a high power rf source primarily for Two Beam Accelerator applications. A low surface electric field to gradient ratio and low fabrication cost are two main advantages of the dielectric-loaded accelerating/decelerating structure. We have designed a 12 GHz dielectric-based power extractor that has similar performance parameters to the CLIC PETS (23 mm beam channel, 240 ns pulse duration, 135 MW output per structure) using the CLIC drive beam. In order to study potential rf breakdown issues, as a first step we built a 11.424 GHz dielectric-based power extractor scaled from the 12 GHz design. A high power rf test will be conducted using the SLAC 11.424 GHz high power rf source in Dec. 2012. Results of the high power testing will be reported. Meanwhile, the 12 GHz fully featured dielectric power extractor is also under construction; construction progress and bench tests will be discussed.

WEPME007	Commissioning of the Upgraded Superconducting CW Linac ELBE	cavity, klystron, linac, SRF	2935
	H. Büttig, A. Arnold, A. Büchner, M. Justus, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig, G.S. Staats, J. Teichert HZDR, Dresden, Germany
	With the expansion of the radiation source ELBE a center for high power radiation sources is being built at the Helmholtz Zentrum Dresden-Rossendorf (HZDR). In a first step (January 2012) the available CW RF-power (1.3 GHz) per superconducting 9-cell TESLA cavity at ELBE had been increased from 8.5 kW to 20 kW (CW) using solid state amplifiers. In a second step the performance of several machine components of ELBE must be redesigned to enable full power operation without risks. The poster gives an overview how these problems have been solved at ELBE and reports on the commissioning.

WEPME058	Integrated System Modeling Analysis of a Multi-cell Deflecting-mode Cavity in Cryogenic Operation	cavity, simulation, cryomodule, coupling	3064
	Y.-M. Shin, M.D. Church, J. Ruan Fermilab, Batavia, USA
	Over the past decade, multi-cell deflecting (TM110) mode cavities have been employed for experiments on six-dimensional phase-space beam manipulation ,,,,**** at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently scheduled at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretic prediction. We thus fully inspected the cavity design with theoretical calculation (based on Panofsky-Wenzel theorem) combined with RF simulations. Also, we are extensively developing an integrated computational tool with comprehensive system analysis capacity to solve complex thermodynamics and mechanical stresses of a high-Q deflecting-mode cryomodule. We will benchmark simulation analysis result with experimental data from high power RF tests in Fermilab. Successfully developed modeling tool will be potentially used for prompt assessment on RF performance of vacuum-cryomodules. * D. A. Edwards, LINAC 2002 Y.-E Sun, PRTAB 2004 * P. Piot, PRSTAB2006 ** J. Ruand et al., PRL 2011 *** Y.-E. Sun, et al., PRL 2010

THOAB102	A Pepper-pot Based Device for Diagnostics of the Single-shot Beam	ion, emittance, LabView, diagnostics	3093
	S.X. Peng, J. Chen, J.E. Chen, Z.Y. Guo, P.N. Lu, H.T. Ren, Z.H. Wang, Y. Xu, Z.X. Yuan, T. Zhang, J. Zhao PKU, Beijing, People's Republic of China A.L. Zhang Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China J. Zhao State Key Laboratory of Nuclear Physics and Technology, Beijing, Haidian District, People's Republic of China
	Generally the beam emittance can be measured by different Emittance Measurement Units (EMUs), such as the pepper-pot device, the slit-wire type facility and the Allison scanner. However, for a microsecond single-shot ion beam, the pepper-pot device is a suitable choice because of its cut-off single-shot technique without any time-consuming step. A pepper-pot based beam current & profile measurement device, which is a combination of Faraday cup technique and pepper-pot measurement facility, was developed at PKU. It consists of a main Faraday cup with a pepper-pot mask at its bottom, and a Faraday cup array locating 3 mm away from the pepper-pot mask. This device has been tested at the PKU LEBT test bench and the measurement results are consistent with the results acquired by the Allison scanner. By replacing the Faraday cup array with a fluorescent screen and a CCD camera, this device becomes a facility that not only has the ability to measure the total beam current and the beam profile, but also has the capability to measure the beam emittance for CW or pulsed ion beams. Details will be presented in this paper.
	Slides THOAB102 [5.332 MB]

Paper

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MOZB102

Undulator Technologies for Future Free Electron Laser Facilities and Storage Rings

undulator, radiation, electron, wiggler

26

M.-E. Couprie
SOLEIL, Gif-sur-Yvette, France

Insertion devices (undulators and wigglers) are key components for high brightness third generation synchrotron sources and for the amplifying medium of free electron lasers. Different technological developments carried out worldwide lead to improved undulator performance. In particular, the advances concerning the in vacuum permanent magnet systems, in particular for short period ones with the operation at cryogenic temperature with NdFeB or PrFeB magnets or for long period ones where in vacuum wigglers will be described. Secondly, progress in Elliptical Polarised Undulators (EPU) will be discussed, such as the DELTA undulator. Recent progress in superconducting undulators will also be reported. Finally, the effect of the insertion devices on the light source operation is analysed, either with the strategies to compensate unwanted effects or in viewing taking advantage of them as for Robinson or damping wigglers for reducing storage ring horizontal emittance.

Slides MOZB102 [8.940 MB]

MOZB202

The First Long Shutdown (LS1) for the LHC

dipole, ion, luminosity, radiation

44

F. Bordry, S. Baird, K. Foraz, A.-L. Perrot, R.I. Saban, J.Ph. G. L. Tock
CERN, Geneva, Switzerland

The LHC has been delivering data to the physics experiments since the first collisions in 2009. The first long shutdown (LS1), which started on 14 February 2013, was triggered by the need to consolidate the magnet interconnections so as to allow the LHC to operate at the design energy of 14 TeV in the centre-of-mass. It has now become a major shutdown which, in addition, includes other repairs, consolidation, upgrades and cabling across the whole accelerator complex and the associated experimental facilities. LS1 will see a massive programme of maintenance for the LHC and its injectors in the wake of more than three years of operation without the long winter shutdowns that were the norm in the past. The main driving effort will be the consolidation of the 10,170 high-current splices between the superconducting magnets. The presentation describes first the preparation phase with the prioritisation of the activities, the building of the teams and the detailed planning of the operation. Then, it gives the status after 3 months and the restart plans for all CERN accelerators. First lessons learnt for the 2nd long shutdown (LS2) will conclude the presentation.

Slides MOZB202 [13.675 MB]

MOPEA003

Status and Very First Commissioning of the ASTRID2 Synchrotron Light Source

quadrupole, lattice, cavity, booster

64

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

ASTRID2 is the new 10 nm UV and soft x-ray light source at Aarhus University. It will replace the ageing source ASTRID, which will be used as the full-energy (580 MeV) booster for ASTRID2. An upgrade of the beamlines at ASTRID are presentlytaking place before being transferred to ASTRID2 until the end of 2013. In addition new beamlines and insertion devices are being procured. Presently, ASTRID2 commissioning is alternating with ASTRID operation to continue during 2013. Status in spring 2013 includes operation of most sub-systems resulting in top-up mode operation to 150 mA. The lattice have been qualifies although a re-alignment is planned. The poster will present experiences from the first commissioning and give the status of the project.

MOPEA004

Beam Lifetime in the ASTRID and ASTRID2 Synchrotron Light Sources: Excitations and Vacuum Dependences

synchrotron, ion, emittance, electron

67

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

The beam lifetime is a very important parameter for synchrotron light sources without top-up, and sometimes more important than the lowest possible vertical beam emittance. At the ASTRID synchrotron light source, we have for many years routinely applied a phase modulation of the accelerating RF field, together with a vertical excitation of the beam at the first vertical betatron frequency. These two effects increase the beam lifetime from about 3 hours to more than 100 hours at 150 mA. Lifetime measurements as function of modulation and excitation parameters will be presented. Additionally, measurements of the beam lifetime in ASTRID and ASTRID2 as function of vacuum pressure will be presented.

MOPEA006

Operation and Performance Upgrade of the SOLEIL Storage Ring

feedback, power-supply, dipole, injection

73

A. Nadji, F. Bouvet, P. Brunelle, A. Buteau, L. Cassinari, M.-E. Couprie, N. Hubert, M. Labat, J.-F. Lamarre, P. Lebasque, A. Lestrade, A. Loulergue, P. Marchand, J.L. Marlats, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

SOLEIL delivers photons to 26 beamlines and 3 new ones are under construction together with the femtoslicing project. Up to 5 filling patterns are available for the users including a low alpha mode; all of them are in Top-up injection. The beam current for the users has been increased to 430 mA in the multibunch mode. The Storage Ring (SR) is running with a new optics incorporating an additional quadrupole triplet in one long straight section. The beam position stability remains excellent. Vertical positions from the dipole X-BPMs have been included in the orbit feedbacks loop with very encouraging results. A feedback loop maintaining the emittance coupling close to 1% for any Insertion Devices (IDs) configuration has been implemented. Up to 25 very diverse IDs are now installed on the SR, and several others are under design or construction. In house developments are being carried out in several domains such as construction of SR dipole power supply spare and of 70 kW-500 MHz solid state amplifiers, design of a pulsed multipole magnet for injection, and a Robinson wiggler, as well as a feasibility study of a local reduction of the emittance in one of the long straight sections.

MOPEA016

The Main Stochastic Cooling System of the HESR

kicker, pick-up, accumulation, simulation

100

R. Stassen, R. Greven, R. Maier, G. Schug, H. Stockhorst
FZJ, Jülich, Germany

The main stochastic cooling system of the High-Energy Storage Ring HESR (1.5-15 GeV/c) for antiprotons at the FAIR complex (Facility for Antiprotons and Ion Research) in Darmstadt (GSI) will work in the frequency range of 2 - 4 GHz. The design work on pickup and kicker is now finished and the production of the first cooling tank has been started. The whole system layout will be presented taking into account new additional requirements concerning the accumulation and the cooling of heavy ions. All beam-coupling structures are nearly identical and contain several ring-slot blocks. These blocks consist of eight wall-current monitors coupled out by eight electrodes each. Most of the signal combining and splitting take place within the vacuum envelope to reduce the number of vacuum RF feed throughs. The long-distance transmission of the signals and the filters containing long signal delays work with near infrared optical elements.

MOPEA021

Status of the HESR Electron Cooler Test Set-up

electron, simulation, cathode, controls

115

M.W. Bruker, K. Aulenbacher, J. Dietrich, S. Friederich, A. Hofmann, T. Weilbach
HIM, Mainz, Germany
K. Aulenbacher
IKP, Mainz, Germany

For the proposed High Energy Storage Ring (HESR) at FAIR, it is foreseen to install an electron cooling device with a beam current of 3 A and a beam energy of 8 MeV. A test set-up was built at Helmholtz-Insitut Mainz (HIM) to conduct a feasibility study. One of the main goals of the test set-up is to evaluate the gun design proposed by TSL (Uppsala) with respect to vacuum handling, EM fields and the resulting beam parameters. Another purpose of the set-up is to achieve an energy recuperation efficiency of 1 - 10^-5. To measure this quantity, a Wien filter has to be employed, which will also prove capable of mitigating collection losses. The current status of the project will be presented.

MOPEA029

Status of UVSOR III

injection, undulator, sextupole, quadrupole

139

T. Konomi, M. Adachi, K. Hayashi, M. Katoh, J. Yamazaki
UVSOR, Okazaki, Japan
M. Adachi, M. Katoh
Sokendai - Okazaki, Okazaki, Aichi, Japan

UVSOR-III is the 750 MeV synchrotron light source. In 2012, three new components were installed in the storage ring. First one is combined function bending magnets to reduce the emittance from 27 nm-rad to 17 nm-rad. These magnets can produce dipole, quadrupole and sextupole fields at the same time. Second ones are an in-vacuum undulator and a beam line. It was installed at 1.5 m straight section, which is the last section reserved for insertion devices. As a result, UVSOR-III is now equipped with six undulators. It would provide soft X-rays to a scanning transmission X-ray microscope (STXM) beam-line. Last one is a newly designed pulse sextupole magnet at the injection point. This is beneficial to the user experiments in the top-up operation mode. Fine machine tuning is in progress.

MOPEA030

Status of UVSOR-III

injection, undulator, cavity, sextupole

142

N. Yamamoto
Nagoya University, Nagoya, Japan
T. Konomi
UVSOR, Okazaki, Japan

Construction of the Central Japan Synchrotron Radiation (SR) Facility has been completed in the Aichi area of Japan, and the beam commissioning was started in Spring of 2012. Up to now, it is confirmed that the 1.2 GeV storage ring works with 300 mA Top-up mode. The key equipments of the accelerators are a compact electron storage ring with the ability to supply hard X-rays and full energy injectors for the top-up operation. The accelerators consist of an electron storage ring, a booster synchrotron ring, and an injector linac. In this prezentation, the present status of the accelerators are reported.

MOPEA037

Theoretical Study on the Two-stage Collimation System Design

collimation, scattering, simulation, space-charge

157

N. Wang, S. Wang
IHEP, Beijing, People's Republic of China

Two-stage collimation system is widely used in high intensity machines to localize the beam losses in a restricted area. In the well-known theory, the optical constrains are expressed by the betatronic phase advances between primary and secondary collimators, which minimize the size of the secondary halo. In this paper, the physical model is developed considering the characteristic of the space charge dominated beams. Numerical studied are performed to verify the theoretical model.

MOPEA040

Study of Geometry Dependent Multipacting of a Superconducting QWR

accelerating-gradient, electron, simulation, cavity

166

K. Zhou, X.Y. Lu, X. Luo, S.W. Quan, L. Yang, Z.Y. Yao
PKU, Beijing, People's Republic of China

Funding: The Major Research Plan of National Natural Science Foundation of China
A superconducting quarter wave resonator (QWR) of frequency=162.5 MHz and β=0.085 has been designed at Peking University. This paper focus on the multipacting (MP) study for the QWR with CST Particle Studio. The simulation results for the initial designed model reveal that there is no sign of MP with its normal operating accelerating gradients in the range of 6-8 MV/m. The accelerating gradient range that may incur MP is from about 1.4 MV/m to 3.2 MV/m, and the places where MP may be encountered are mainly located at the top part of the QWR. So the effect of different top geometries on MP has also been studied in depth. Our results show that inward convex round roof is better than other round roofs, and plane roofs have an obvious advantage over round roofs on the suppression of MP in general. While considering the optimization of its electromagnetic (EM) design, our initial designed model is also acceptable.

MOPEA046

Solaris Project Progress

storage-ring, linac, injection, klystron

181

A.I. Wawrzyniak, C.J. Bocchetta, P.B. Borowiec, D. Einfeld, P.P. Goryl, M. Młynarczyk, R. Nietubyć, M.P. Nowak, W. Soroka, M.J. Stankiewicz, P. Szostak, P.S. Tracz, Ł. Walczak, K. Wawrzyniak, J.J. Wiechecki, M. Zając, L. Żytniak
Solaris, Kraków, Poland
D. Einfeld
MAX-lab, Lund, Sweden
R. Nietubyć
NCBJ, Świerk/Otwock, Poland

Funding: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program:POIG.02.01.00-12-213/09
Solaris is a 3rd generation light source facility being built in Kraków, Poland at the Jagiellonian University Campus. The project is being accomplished in a tight collaboration with the MAX IV Laboratory in Lund, Sweden. The Solaris 1.5 GeV storage ring is a replica of the MAX IV 1.5 GeV machine, whereas the injector and the transfer line although based on the same components, are unique for Solaris. One of the main differences is the 600 MeV injection energy requiring an energy ramp in the storage ring to the final operating energy of 1.5 GeV. The construction of the facility started in early 2010 and is planned to be finished in the autumn 2014. Up to now, 70% of the components have been procured and construction of the buildings in progress with expected handover in autumn 2013. This paper will give an update on infrastructure progress and design choices for shielding, service area placement of racks and routing of piping and cables. An update is also presented of machine layout that includes the injector, transfer line and storage ring.

MOPEA053

Status of NSLS-II Booster

booster, dipole, controls, septum

196

S.M. Gurov, A.I. Erokhin, S.E. Karnaev, V.A. Kiselev, E.B. Levichev, A. Polyansky, A.M. Semenov, S.V. Shiyankov, S.V. Sinyatkin, V.V. Smaluk
BINP SB RAS, Novosibirsk, Russia
H.-C. Hseuh, T.V. Shaftan
BNL, Upton, Long Island, New York, USA

The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized 3 GeV electron storage ring, linac pre-injector and full-energy injector-synchrotron. Budker Institute of Nuclear Physics build booster for NSLS-II. The booster should accelerate the electron beam continuously and reliably from a minimum 170 MeV injection energy to a maximum energy of 3.15 GeV and average beam current of 20 mA. The booster shall be capable of multi-bunch and single bunch operation. Pre-comissioning test results of booster components and system are reviewed.

MOPEA055

First Year Operation of the ALBA Synchrotron Light Source

storage-ring, interlocks, kicker, feedback

202

F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3 GeV, 3rd generation, light source located in Cerdanyola, Barcelona, Spain, which started users operation in May 2012. In this paper we will report about the transition from commissioning to operation, the main problems faced during this first year, the actual status of the accelerators and we will provide an outlook to the next steps.

MOPEA056

Measuring and Improving the Momentum Acceptance and Horizontal Acceptance at MAX III

cavity, lattice, electron, storage-ring

205

A. Hansson, Å. Andersson, J. Breunlin, G. Skripka, E.J. Wallén
MAX-lab, Lund, Sweden

Lifetime measurements for varying horizontal scraper positions performed at different RF frequencies suggested a horizontal aperture restriction in the MAX III synchrotron light source. A combination of local orbit distortions and horizontal scraper measurements pinpointed the location of the horizontal aperture restriction to the center of the main cavity straight section. The aperture restriction was determined to be located 10.4 ± 0.3 mm from the beam center. The precise result was achieved by measurements and calculations of the Touschek lifetime as a function of the main cavity voltage. Realignment of the main cavity increased the average lattice momentum acceptance from 0.0116 ± 0.0003 to 0.0158 ± 0.0003 and the horizontal acceptance from 26 ± 2 × 10^-6 m to larger than 44 ± 2 × 10^-6 m. The increase in momentum acceptance increased the lifetime in MAX III by a factor of two.

MOPEA057

Studies of the Electron Beam Lifetime at MAX III

scattering, cavity, electron, emittance

208

A. Hansson, Å. Andersson, J. Breunlin, G. Skripka, E.J. Wallén
MAX-lab, Lund, Sweden

MAX III is a 700 MeV 3rd generation synchrotron light source located at the MAX IV Laboratory in Sweden. The lifetime in the storage ring is lower than originally envisaged. From vertical scraper measurements the lifetime contributions at 300 mA stored current have been determined. The lifetime is mainly limited by the Touschek lifetime, which is lower than its design value, whereas the vacuum lifetime is close to the expected value. The low Touschek lifetime is explained by a lower than design emittance ratio and momentum acceptance in the storage ring.

MOPEA059

The Optimization of Transverse Stripline Kicker

kicker, simulation, impedance, insertion

214

H.P. Hsueh, C.-C. Chang, Y.P. Chang, J.-R. Chen, Y.T. Cheng, G.-Y. Hsiung, Y.C. Yang
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

The construction of a new 3 GeV synchrotron facility, Taiwan Photon Source, is ongoing. It is required to install stripline kickers to suppress instability generated by mismatch between injection kickers or imperfect installation of vacuum components all around. First, the design philosophy will be described for transverse stripline kickers. HFSS electromagnetic simulation software is used to optimize all structure parameters like electrode dimensions, electrode distance from vacuum chambers etc. to make transverse stripline kicker working more efficiently and effectively. All simulation results will be presented in this paper and all structure dimension choices will be discussed and the final prototype structure dimensions will be selected from the discussion.

MOPEA068

Novel Lattice Upgrade Studies for Diamond Light Source

lattice, dipole, optics, quadrupole

240

R. Bartolini, C.P. Bailey, M.P. Cox, N.P. Hammond, J. Kay, R.P. Walker
Diamond, Oxfordshire, United Kingdom
R. Bartolini, T. Pulampong
JAI, Oxford, United Kingdom

Many synchrotron radiation facilities are studying lattice upgrades in order to lower the natural emittance and hence increase the radiation brightness. At Diamond we are pursuing a novel alternative, not targeting the minimum possible emittance but instead introducing additional insertion device (ID) straights and hence increasing the capacity of the facility, while still possibly achieving a more limited reduction in emittance. The new scheme involves converting some of the DBA lattice cells into a double-DBA or DDBA, with a new ID straight between the two achromats. This then allows existing or future bending magnet ports (which in Diamond are taken from near the entrance to the second dipole of the DBA lattice) to be served by a much more powerful insertion device. We present here the design concept and preliminary lattice design, and discuss the challenging magnet, vacuum and engineering issues.

MOPEA078

Commissioning and Operation of Wiggler Switchyard System for Duke FEL and HIGS

wiggler, FEL, storage-ring, lattice

267

Y.K. Wu, M.D. Busch, M. Emamian, J.F. Faircloth, H. Hao, J.Y. Li, S.F. Mikhailov, V. Popov, G. Swift, P.W. Wallace, P. Wang, J. Yan
FEL/Duke University, Durham, North Carolina, USA
A.L. Wu
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033.
To enable the Duke storage ring FEL to operate in VUV with adequate gain, a major storage ring upgrade was carried out in 2012 to install two additional helical FEL wigglers with a wiggler switchyard system. Using the switchyard, a quick changeover can be made between two planar OK-4 wigglers and two helical OK-5 wigglers in the middle of the FEL straight section. This system preserves the linear polarization capabilities of the Duke FEL and gamma-ray beams at the High Intensity Gamma-ray Source (HIGS), while enabling VUV FEL operation with a higher gain using a longer FEL with as many as four helical wigglers. The wiggler switchyard upgrade was completed in Summer 2012, followed by a rapid and successful commissioning of the Duke storage ring, FEL system, and HIGS. In this paper, we will present the results of accelerator and light source commissioning with the wiggler switchyard. We will also present preliminary results of operating the OK-5 FEL in different configurations. With the wiggler switchyard, we are well positioned to realize the operation of a VUV FEL below 190 nm and production of Compton gamma-ray beams above 100 MeV in circular polarization.

MOPFI005

XPS and UHV-AFM Analysis of the K2CsSb Photocathodes Growth

cathode, electron, background, factory

291

S.G. Schubert
HZB, Berlin, Germany
I. Ben-Zvi, M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
X. Liang
SBU, Stony Brook, New York, USA
H.A. Padmore, T. Vecchione
LBNL, Berkeley, California, USA
T. Rao, J. Smedley
BNL, Upton, Long Island, New York, USA

Funding: This work is funded by the Department of Energy, under Contract No. KC0407-ALSJNT-I0013, DE-SC0005713, the Bundesministerium für Bildung und Forschung (BMBF) and the state of Berlin, Germany.
Next generation light sources, based on Energy Recovery Linac and Free Electron Laser technology will rely on photoinjector based electron sources. Successful operation of such sources requires reliable photocathodes with long operational life, uniform and high quantum efficiency, low thermal emittance and low dark current. The goal of this project is to construct a cathode which meets these requirements. Advances in photocathode research must take a combined effort. The materials have to be analyzed by means of chemical composition, surface structure and these findings have to be correlated to the quantum efficiency and performance in the injector. The presented work focuses on the chemical composition and surface structure of K2CsSb photocathodes. The XPS and AFM measurements were performed at the Center of Functional Nanomaterials at BNL. K2CsSb photocathodes were grown under UHV conditions. The components were adsorbed one at a time and after each growth step the corresponding XPS spectra was taken. During growth the quantum efficiency was recorded. As last step the sample was moved into the AFM without exposure to air to determine the surface roughness.

MOPFI006

A New Load Lock System for the Source of Polarised Electrons at ELSA

electron, polarization, laser, ion

294

D. Heiliger, W. Hillert, B. Neff
ELSA, Bonn, Germany

Funding: supported by DFG (SFB/TR16)
The inverted source of polarized electrons at the electron stretcher accelerator ELSA routinely provides a pulsed beam with a current of 100 mA and a polarization degree of about 80%. One micro-second long pulses with 100 nC charge are produced by irradiating a GaAs strained-layer superlattice photocathode (8 mm in diameter) with laser light. Future accelerator operation requires a significantly higher beam intensity, which can be achieved by using photocathodes with sufficiently high quantum efficiency. Therefore, and in order to enhance the reliability and uptime of the source, a new extreme high-vacuum (XHV) load lock system was installed and commissioned. It consists of a loading chamber in which an atomic hydrogen source is used to remove any remaining surface oxidation, an activation chamber for heat cleaning of the photocathodes and activation with cesium and oxygen and a storage chamber in which up to five different types of photocathodes with various diameters of the emitting surface can be stored under XHV conditions. Additionally, tests of the photocathodes' properties can be performed during accelerator operation.

MOPFI010

Initial Beam Loss and Control of Dynamic Vacuum Effects in SIS18

injection, ion, collimation, synchrotron

300

Y. El-Hayek
FIAS, Frankfurt am Main, Germany
M.M. Kirk, D. Ondreka, P.J. Spiller
GSI, Darmstadt, Germany
U. Ratzinger
IAP, Frankfurt am Main, Germany

To stabilize the dynamic pressure in the SIS18, the systematic initial beam loss must be minimized. Beam Particles, which are lost on the vaccum chamber cause a local pressure increase. Thereby the collision rate between beam ions and residual gas particles and consequently beam loss by ionization is enhanced. The reduction and control of beam loss in the injection channel, during multiturn injection and during the Rf capture process has an outstanding importance for the vacuum dynamics. One way to minimize the initial losses in the synchrotron is to displace the beam loss into the transfer channel (TK) between UNILAC and SIS. In the transfer channel, the beam edges are trimmed by means of a collimator system and a sharply defined phase space area can be injected into SIS18. The effect of reduced initial beam loss on the vaccum dynamics is presented.

MOPFI012

Measurement of Adsorption Rates of Residual Gases for NEA-GaAs Surface

electron, cathode, ion, emittance

306

M. Kuriki, H. Iijima, K. Miyoshi, K.U. Uchida
HU/AdSM, Higashi-Hiroshima, Japan

A GaAs photocathode activated the surface to negative-electron-affinity (NEA) is an important device for high-average-current electron accelerators such as a next-generation light source based on an energy recovery linac. The NEA surface is normally formed by a yo-yo technique in which cesium and oxygen are applied onto the surface alternately. Although the initial quantum efficiency is relatively larger than that of another cathode, the lifetime is shorter. The degradation with time elapsing even if the electron beam is not extracted is mainly caused by adsorption of residual gases in a vacuum chamber. We have evaluated the adsorption rates of various gases for the NEA surface by measuring the dark lifetime in sample gases such as hydrogen, carbon oxide and carbon dioxide.

MOPFI013

A Lifetime Study of CsK2Sb Cathode

cathode, laser, electron, brightness

309

M. Kuriki, H. Iijima, K. Miyoshi, N. Norihito
HU/AdSM, Higashi-Hiroshima, Japan

Funding: Cooperative and Supporting Program for Researches and Educations in　Universities by High energy accelerator research organization (KEK)
CsK2Sb multi-alkali cathode is one of the candidates of robust and high efficiency cathode for high brightness electron source. CsKSb can be driven by green laser and it is a big advantage comparing to Cs2Te cathode which is widely used as a robust photo-cathode and driven by UV light. In Hiroshima University, a test chamber for CsK2Sb photo-cathode study is developed. In the chamber, CsK2Sb photo-cathode is formed by evaporation on SUS base plate. During the evaporation, amount is monitored by quartz meter. We devised good locations of the evaporation source, base plate, and thickness monitor, so that all evaporation processes for Cs, K, and Sb are under control. The base plate temperature is also controlled during the cathode formation. More than 2.0% quantum efficiency was achieved at the first activation test. The cathode lifetime was more than 200 hours and more than 20C in charge. The latest experimental result will be reported.

MOPFI014

A Charge Lifetime Study of NEA GaAs Cathode by Ion Back-bombardment

electron, cathode, ion, simulation

312

M. Kuriki
KEK, Ibaraki, Japan
L. Guo, H. Iijima, K. Miyoshi
HU/AdSM, Higashi-Hiroshima, Japan

Funding: Quantum beam project by the Ministry of Education, Culture, Sports, Science and Technology; The title is High Brightness Photon Beam by Laser-Compton Scattering.
NEA GaAs cathode is one of the most important techniques for advanced future projects based on linac. Up to 90% polarized beam can be generated with high quantum efficiency, 0.1 – 10%. The extremely low emittance beam can be generated driven by optimized wavelength laser. Although these remarkable features, the less robustness has been the biggest issue on the real operation of this cathode. According to past experiments, there are three sources of the cathode degradation; gas absorption, thermal desorption, and ion-back bombardment. First two processes could be controlled by less vacuum pressure in order of 10^-10Pa and keeping the cathode temperature low. The ion back-bombardment is the last issue which should be solved for high brightness operation in such as ERL. We observed the cathode quantum efficiency evolution in various laser power density and bias voltage. We found that the cathode degradation was due to the ion back-bombardment quantitatively and the deactivation coefficient of NEA surface by one ion collision did not depend on the bias voltage. We report the experimental results and its analysis based on the ion back-bombardment hypothesis.

MOPFI027

The Progress of the BRISOL Facility at CIAE

ion, target, ion-source, diagnostics

339

B. Tang, L.H. Chen, B.Q. Cui, Q.H. Huang, W. Jiang, R. Ma, Y.J. Ma, Z. Peng
CIAE, Beijing, People's Republic of China

Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line (BRISOL), aiming to generate short life radioactive ion beam (RIB) on-line, is being constructed at China Institute of Atomic Energy(CIAE). Up to now, construction of major equipment for BRISOL is completed, including ion source, vacuum system, separator, optical element, and beam diagnostic system, and assembling is underway in laboratory. The on-site installation of all the beam line will be carried out soon. All the major element prototype including surface ion source, quadrupole, hexapole, multipole and beam diagnostic system have been studied off-line on a test-bench for BRISOL. A Li beam was generated and separated . The primary tests show that the ion source and the optical elements work well. The test charge exchange cell (CEC) is under way. BRISOL will be commissioned next year.

MOPFI029

The Construction Progress of Beijing Radioactive Ion-beam Facility

ion, cyclotron, ISOL, ion-source

345

T.J. Zhang, Shizhong. An, B.Q. Cui, Z.G. Li, Y.L. Lu, C.H. Peng, F. Yang
CIAE, Beijing, People's Republic of China

The Beijing Radioactive Ion-Beam Facility (BRIF) is being constructed at CIAE. The project consists of a 100 MeV high intensity cyclotron CYCIAE-100, an ISOL system with a mass resolution of 20000, and a superconducting booster. The construction of the building was started on April 28, 2011 and the roof was sealed on Jan. 16, 2012. The on-site installation conditions have been ready since Sept. 27, 2012. Up to now, the fabrication of all major components for CYCIAE-100 have been completed, including the main magnet system, the RF system, ion source and injection, main vacuum, etc. The equipment fabrication for the ISOL system has been completed and magnetic mapping and shimming is being performed on the large-scale analysis magnet. The fabrication of the major components for the superconducting booster has been accomplished, and the work on copper-niobium sputtering is under way. At present, the installation and assembly is in full swing and the beam commissioning is to predicted to be finished in mid 2013. Taking advantage of the experiences accumulated on the CRM cyclotron with beam up to 430 uA, it is likely that the first beams of 100 MeV can be achieved by the end of 2013.

MOPFI044

VHF Gun Research at SINAP

gun, cavity, electron, FEL

380

Q. Gu, L. Chen, W. Fang, G.Q. Lin
SINAP, Shanghai, People's Republic of China

The R&D work on the high power THz based on energy recovery linac (ERL) has been carried out in Shanghai Institute of Applied Physics (SINAP). One of the key components for the ERL is the high brightness electron source. The low frequency gun technology has been adopted, by comparing with the SRF gun and DC gun. In this paper, the design and cold test of a 250MHz gun will be presented.

MOPFI053

Upgrades of the SPS, Transfer Line and LHC Injection Protection Devices for the HL-LHC Era

injection, kicker, coupling, extraction

401

Ö. Mete, O. Aberle, F. Cerutti, K. Cornelis, B. Goddard, V. Kain, R. Losito, F.L. Maciariello, M. Meddahi, A. Mereghetti, J.A. Uythoven, F.M. Velotti
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

The challenging High Luminosity LHC (HL-LHC) beam requirements will lead in the future to unprecedented beam parameters along the LHC injector chain. In the SPS accelerator these requests translate into about a factor two higher intensity and brightness than the present design performance. In addition to the challenge of producing and accelerating such beams, these parameters affect the resistance of the existing equipment against beam impact. Most of the protection devices in the SPS ring, its transfer lines and the LHC injection areas will be put under operational constraints which are beyond their design specification. The equipment concerned has been reviewed and their resistance to the HL-LHC beams checked. Theoretical and simulation studies have been performed for the SPS beam scraping system, the protection devices and the dump absorbers of the SPS-to-LHC transfer lines, as well as for the LHC injection protection devices. The first results of these studies are reported, together with the future prospects.

MOPFI058

Studies of Cs3Sb Cathodes for the CLIC Drive Beam Photoinjector Option

cathode, gun, laser, electron

413

I. Martini, E. Chevallay, S. Döbert, V. Fedosseev, C. Heßler, M. Martyanov
CERN, Geneva, Switzerland

Within the CLIC (Compact Linear Collider) project, feasibility studies of a photoinjector option for the drive beam as an alternative to its baseline design using a thermionic electron gun are on-going. This R&D program covers both the laser and the photocathode side. Whereas the available laser pulse energy in ultra-violet (UV) is currently limited by the optical defects in the 4th harmonics frequency conversion crystal induced by the 0.14 ms long pulse trains, recent measurements of Cs3Sb photocathodes sensitive to green light showed their potential to overcome this limitation. Moreover, using visible laser beams leads to better stability of produced electron bunches and one can take advantages of the availability of higher quality optics. The studied Cs3Sb photocathodes have been produced in the CERN photoemission laboratory using the co-deposition technique and tested in a DC gun set-up. The analysis of data acquired during the cathode production process will be presented in this paper, as well as the results of life-time measurements in the DC gun.

MOPFI061

Concept for Elena Extraction and Beam Transfer Elements

extraction, septum, kicker, quadrupole

422

J. Borburgh, B. Balhan, W. Bartmann, T. Fowler, L. Sermeus, G. Vanbavinckhove
CERN, Geneva, Switzerland
R.A. Baartman
TRIUMF, Vancouver, Canada
D. Barna
University of Tokyo, Tokyo, Japan
V. Pricop
Transilvania University of Brasov, Brasov, Romania

In 2011 the ELENA decelerator was approved as a CERN project. Initially one extraction was foreseen, which should use a kicker and a magnetic septum which can be recuperated from an earlier installation. Since then a second extraction has been approved and a new solution was studied using only electric fields to extract the beam. This will be achieved by fast pulsing a separator, allowing single-bunch but also a full single-turn extraction from ELENA towards the experiments. The extraction and transfer requirements of ELENA are described, followed by the principal differences between the magnetic and electric field concepts. The design of electrostatic focussing and bending devices for the transfer lines will be presented. Finally the field quality which can be achieved with the separator and the concept of its power supply will be discussed.

MOPFI080

Fabrication, Transport and Characterization of Cesium Potassium Antimonide Cathode in Electron Guns

cathode, gun, laser, SRF

461

T. Rao, S.A. Belomestnykh, I. Ben-Zvi, X. Liang, I. Pinayev, B. Sheehy, J. Skaritka, J. Smedley, E. Wang, T. Xin
BNL, Upton, Long Island, New York, USA
R.R. Mammei, J.L. McCarter, M. Poelker
JLAB, Newport News, Virginia, USA
M. Ruiz-Osés
Stony Brook University, Stony Brook, USA

a number of accelerator applications need high current, low emittance and high brightness electron beams. Recent studies have shown cesium potassium antimonide to be a robust photocathode capable of producing high peak and average currents. However, for some applications, the UHV conditions required for producing these cathodes necessitate their fabrication site to be physically removed from the gun location and the cathode to be transferred between the two sites in UHV load-lock chambers. We have fabricated two cathodes at BNL, transported and tested them in DC gun at JLab at 100 kV and 200 kV. These cathodes have delivered up to 8A/cm² without significant degradation. Localized changes in the QE have been attributed to heating due to laser, increasing the QE at lower laser power, but damaging the cathode at higher power. Two more load-lock chambers have been built to transport and insert similar cathodes in SRF guns operating at 700 MHz and 112 MHz for the first time. In this paper, we will describe the design of the load-lock chambers, transfer mechanisms, transport of the cathodes over ~ 1000 km and the cathode performance in gun environment.

MOPFI081

Correlating Structure and Function - In situ X-ray Analysis of High QE Alkali-antimonide Photocathodes

cathode, scattering, emittance, controls

464

J. Smedley, K. Attenkofer, S.G. Schubert
BNL, Upton, Long Island, New York, USA
I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
T. Forrest, H.A. Padmore, T. Vecchione, J.J. Wong
LBNL, Berkeley, California, USA
J. Xie
ANL, Argonne, USA

Funding: The authors wish to acknowledge the support of the US DOE, under Contract No. KC0407-ALSJNT-I0013, DE-AC02-98CH10886 and DE-SC0005713. Use of CHESS is supported by NSF award DMR-0936384.
Alkali antimonide photocathodes have high quantum efficiency and low emittance when illuminated by visible light, and are thought to be well suited for use in high-brightness photoinjectors of 4th generation light sources. Here we report on the growth of multi-alkali K2CsSb cathodes on [100] silicon substrates measured using in-situ X-ray diffraction (XRD) and X-ray reflection (XRR). Correlations between cathode structure and growth parameters and the resulting quantum efficiency (QE) are also explored. The best cathodes have a QE at 532 nm in excess of 6% and are structurally textured K2CsSb with grain sizes in excess of 20 nm. In an attempt to reduce the complexity of the current growth methodology we are also making alkali antimonides in parallel via the reaction of bulk materials in an inert environment. This approach has the advantage that the desired stoichiometry can be obtained exactly. Initial diffraction results from prepared bulk materials are promising and show the formation of well reacted K3Sb. In the future we intend to transfer this material to smooth thin photocathode films by either sputtering or pulsed laser deposition.

MOPFI082

Redesign and Development of the Shanghai Electron Beam Ion Trap

electron, ion, alignment, cryogenics

467

D. Lu, Y. Shen, Z. Shi, J. Xiao, Y. Yang, Y. Zou
Fudan University, Shanghai, People's Republic of China

Over the last few years the Shanghai Electron Beam Ion Trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Nuclear and Applied Physics, first generated an electron beam in 2005. Shanghai EBIT could be operated with electron beam energies between 1 and 130 keV and currents up to 160 mAmps. After several years of operation, it was found that some improvements/modifications to the old design were necessary. This contribution will discuss several of the main aspects of the redesigned Shanghai EBIT. So far it has been operated up to an electron energy of 40 keV with an current density of over 2400 A per square cm. The new EBIT is made primarily from Titanium instead of Stainless Steel and has an order of magnitude better background vacuum, a more efficient and economical cryogenic system, and also excellent optical alignment. Finally the magnetic field in the central drift tube region can reach up till 4.8 T.

MOPME003

Development of Diamond Sensors for Beam Halo and Compton Spectrum Diagnostics After The Interaction Point of ATF2

collimation, electron, simulation, photon

470

S. Liu, P. Bambade
LAL, Orsay, France
S. Bai
IHEP, Beijing, People's Republic of China
T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major issue at ATF2 and in linear colliders is to control the beam halo, which consists of tails extending far beyond the Gaussian core of the beam. At present there is no dedicated collimation for the beam halo at ATF2, and the transverse distribution near the interaction point is not well known. The development of a sensor based on CVD diamond to scan the beam halo in the vacuum chamber a few meters after the interaction point is presented. This system also aims to detect the Compton recoil electrons generated by the laser interferometer (Shintake monitor) used to measure the beam size at the interaction point of ATF2.

MOPME007

High Resolution Synchrotron Light Analysis at ELSA

synchrotron, diagnostics, optics, electron

482

S. Zander, F. Frommberger, P. Hänisch, W. Hillert, M.T. Switka
ELSA, Bonn, Germany

Funding: Funded by the DFG within the SFB/ TR 16
The Electron Stretcher Facility ELSA provides polarized electrons with energies up to 3.5 GeV for external hadron experiments. In order to suffice the need of stored beam intensities towards 200 mA, advanced beam instability studies need to be carried out. An external diagnostic beamline for synchrotron light analysis has been set up and provides the space for multiple diagnostic tools including a streak camera with time resolution of < 1 ps. Beam profile measurements are expected to identify instabilities and reveal their thresholds. The effect of adequate countermeasures is subject to analysis. The current status of the beamline development will be presented.

MOPME021

Ionization Profile Monitor (IPM) of J-PARC 3-GeV RCS

electron, ion, injection, acceleration

515

H. Harada, K. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
S. Kato
Tohoku University, Graduate School of Science, Sendai, Japan

Ionization profile monitors (IPM) were installed in the 3-GeV RCS ring of J-PARC and used to observe the beam-profile for the transverse plane in beam commissioning. These electrodes and MCPs of IPMs were upgraded in 2012 summer shutdown in order to improve the external electric field for leading the electrons and ions to MCPs. This presentation will be described the results of observed beam profile in beam commissioning and be discussed the new issues for the ion and electron collection mode.

MOPME025

Production of Extraction Kicker Magnet of the J-PARC 3-GeV RCS

kicker, high-voltage, extraction, proton

526

M. Kinsho, N. Ogiwara, K. Suganuma
JAEA/J-PARC, Tokai-mura, Japan

The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been provided proton beam to the Material and Life Science Facility (MLF)as well as to the 50 GeV Main Ring (MR). Proton beam is accelerated from 181 MeV to 3GeV in the RCS and immediately extracted it to the beam transport line to the MLF and the MR. Extraction kicker magnets are used for this fast extraction. To improve reliability of the RCS for user operation, production of a reserve kicker magnet has been performed. The kicker magnet mainly consists of Ni-Zn ferrite cores and Aluminum alloy plates, and these parts are installed in vacuum chamber to prevent discharge because a high voltage is applied to the magnet for a short period. Since it is important to reduce the outgassing of water vapor form these parts to prevent discharge, we has been produced the reserve magnet with low outgassing at high voltage discharge. Since assemble of the kicker magnet already finished and vacuum test has been performed, the result of vacuum test is reported.

MOPME027

Bunch Length Measurement of 181 MeV Beam in J-PARC Linac

electron, linac, target, simulation

532

A. Miura, H. Oguri, N. Ouchi, J. Tamura
JAEA/J-PARC, Tokai-mura, Japan
A. Feschenko, A.N. Mirzojan
RAS/INR, Moscow, Russia
K. Futatsukawa, T. Miyao
KEK, Ibaraki, Japan
M. Ikegami
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
T. Maruta
KEK/JAEA, Ibaraki-Ken, Japan

In J-PARC Linac, an energy and intensity upgrade project has started since 2009 using Annular Coupled Structure (ACS) cavities. Because the longitudinal matching before ACS cavities is additionally required, we decided to employ the bunch shape monitors (BSMs) to measure the longitudinal beam profile. After three years from the start of BSM project, three BSMs were fabricated. All three BSMs were installed during the summer shutdown of 2012. We tried to measure the longitudinal beam profile exited from SDTL cavities. In this paper, we introduce the outline of BSM project, the first data acquisition and related small problems.

MOPME038

A New Theoretical Design of BLM System for HLS II

electron, scattering, monitoring, emittance

553

Y.K. Chen, L.J. He, J. Li, W. Li, Y. Li
USTC/NSRL, Hefei, Anhui, People's Republic of China

Beam loss monitoring (BLM) system has been commonly used to detect the vacuum leakage. The existing BLM system for Hefei Light Source (HLS) was built in 2000. It played an important role in analyzing beam loss distribution and regulating the machine operation parameters. Recently, HLS is being upgraded to HLS II. The emittance will be decreased to increase the brilliance of synchrotron radiation. The Touschek lifetime will be much shorter than before, and dominate the total beam lifetime. It is necessary to redesign the BLM system for HLS II. The most important part of this work is to find a better method of monitoring Touschek lifetime by BLM system while keeping its general functions. According to the results of our research, a preliminary theoretical design for the new BLM system is proposed in this paper. This new system will play an important role in the storage ring commissioning, troubleshooting, and beam lifetime studying.

MOPME044

A Novel Type of Forward Coupler Slotted Stripline Pickup Electrode for CSRe Stochastic Cooling

impedance, pick-up, kicker, simulation

571

J.X. Wu, X.J. Hu, M. Li, J.W. Xia, J.C. Yang, Y. Zhang, G. Zhu
IMP, Lanzhou, People's Republic of China
F. Caspers
CERN, Geneva, Switzerland

A novel type of slotted or perforated strip-line pick-up or kicker electrode structure for CSRe stochastic cooling for non relativistic particle beams with b=v/c values around 0.7 is presented. This slotted structure is to be used as a forward coupler with the output signal taken from the downstream end and has a rather large relative bandwidth of several octaves. The electrode structure and pickup tank, as well as the beam test result will be presented in this paper.

MOPME045

Design and Test Status of Beam Position Monitors for ADS Injector II Proton LINAC

proton, linac, cryomodule, alignment

574

Y. Zhang, H. Jia, X.C. Kang, M. Li, J.X. Wu, G. Zhu
IMP, Lanzhou, People's Republic of China

Beam Position Monitors (BPM) based on capacitive pick-ups are designed for Accelerator-Driven System (ADS) Injector II proton LINAC. This LINAC is aiming to produce a maximum design current of 15 mA at the 10 MeV energy with an operating frequency of 162.5 MHz. Non-interceptive BPM will be installed to measure the transverse beam position and beam phase in the vacuum chamber. Depending on the location, the response of the BPMs must be optimized for a beam with an energy range from 2.1 up to 10 MeV and an average current between 0.01 and 15 mA. Apart from the broadening of the electromagnetic field due to the low-beta beam, specific issues are affecting some of the BPMs: tiny space in the transport line between the RFQ and the cryomodule and the cryogenic temperature inside the cryomodule. For this reason two types of BPMs are being designed for each location (MEBT and cryomoudle). In this contribution, the present status of the design and measured results for each BPM will be presented in room and cold temperature, focusing on the electromagnetic response for low-beta beams.

MOPME049

Status of Non-destructive Bunch Length Measurement based on Coherent Cherenkov Radiation

radiation, electron, target, diagnostics

583

H.X. Deng, S.L. Lu, T. Yu, J.B. Zhang
SINAP, Shanghai, People's Republic of China
G.A. Naumenko, A. Potylitsyn, M.V. Shevelev, D.A. Shkitov
TPU, Tomsk, Russia

Funding: This work was supported by the joint Russian-Chinese grant (RFBR 110291177 and NSFC 11111120065) and partially by the Program of Russian MES “Nauka” and the Chinese NSFC 11175240.
As a novel non-destructive bunch length diagnostic of the electron beam, an experimental observation of the coherent Cherenkov radiation generated from a dielectric caesium iodide crystal with large spectral dispersion was proposed for the 30MeV femtosecond linear accelerator at Shanghai Institute of Applied Physics (SINAP). In this paper, the theoretical design, the experimental setup, the terahertz optics, the first angular distribution observations of the coherent Cherenkov radiation, and the future plans are presented.
* Shevelev M. et al., Journal of Physics: Conf. Ser. 357 (2012) 012023.

MOPME064

SLM and Flags for Booster of NSLS-II

booster, radiation, synchrotron, synchrotron-radiation

622

O.I. Meshkov, V. Smalyuk
BINP SB RAS, Novosibirsk, Russia
V.L. Dorokhov
BINP, Novosibirsk, Russia

Set of diagnostics of booster of NSLS-II includes 6 fluorescent screens (flags) and 2 synchrotron light monitors (SLM). The flags will be applied during booster commissioning for closing of the beam turn. They are also a useful tool in case of malfunction elimination. SLM will be used both for booster comissioning and for operation. The details of calibration and design of the devices are discussed.

MOPME065

Approximate Method of Calculation of a Bunch Radiation in Presence of Complex Dielectric Object

radiation, optics, diagnostics, scattering

625

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

Funding: Work supported by the Grant of President of Russian Federation, Russian Foundation for Basic Research, and the Dmitry Zimin "Dynasty" Foundation.
Cherenkov radiation is widely used for detection of charged particles and can be also applied for particle bunch diagnostics*. As a rule, dielectric objects applied for these goals have complex forms. Therefore development of methods of calculation of bunch radiation in presence of complex dielectric objects is now of a great interest. The approximate method developed by us allows to take into account influence of the object boundaries closed to the charge trajectory as well as "external" boundaries of the object. The case of the charge crossing a dielectric plate was considered as a test problem. The exact solution of this problem is in a good agreement with our approximate solution. Next, the cases of more complex objects were analyzed. One of them is a dielectric cone with a vacuum channel. Particularly, it was shown that radiation can be convergent under certain conditions, that is the field outside the cone can be more intensive than on the cone boundary. Radiation of the bunch in the case of dielectric prism was considered as well.
* A.P. Potylitsyn, Yu.A. Popov, L.G. Sukhikh, G.A. Naumenko, M.V. Shevelev, Journal of Physics: Conference Series 236 (2010) 012025.

MOPME066

Radiation of a Charged Particle Bunch Moving along Boundary of Wire Metamaterial

radiation, diagnostics, lattice, optics

628

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

Funding: Work supported by Russian Foundation for Basic Research and the Dmitry Zimin “Dynasty” Foundation.
The material under consideration represents a periodical volume structure of long parallel conductive wires. If wavelengths are much greater than periods, the structure can be described as some anisotropic medium possessing both frequency and spatial dispersion* (so-called wire metamaterial). Earlier we considered the radiation of bunches moving in boundless wire metamaterial. It has been discovered that this radiation is nondivergent, and it is perspective for diagnostics of bunches**. Now we consider the case when the bunch moves in vacuum along the boundary of the semi-infinite metamaterial perpendicularly to the wires. Analytical and numerical analysis of the problem is performed. It is shown that radiation from a point charge concentrates in some vicinity of certain planes and propagates along the wires with speed of light. Series of computations show that the radiation under consideration can be useful for determination of sizes and shape of bunch.
*A.V. Tyukhtin, E.G. Doilnitsina, J. Phys. D - Appl. Phys., 44, 265401 (2011).
**V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Lett., 108, 184801 (2012).

MOPME068

Feasibility Study of a 2nd Generation Smith-Purcell Radiation Monitor for the ESTB at SLAC

radiation, simulation, background, electron

634

N. Fuster Martinez, A. Faus-Golfe, J. Resta-López
IFIC, Valencia, Spain
H.L. Andrews
LANL, Los Alamos, New Mexico, USA
F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, C. Perry, A. Reichold, S.R. Stevenson
JAI, Oxford, United Kingdom
J. Barros, N. Delerue, M. Grosjean
LAL, Orsay, France
V. Bharadwaj, C.I. Clarke
SLAC, Menlo Park, California, USA

The use of a radiative process such as the Coherent Smith-Purcell Radiation (CSPR) is a very promising non-invasive technique for the reconstruction of the time profile of relativistic electron bunches. Currently existing CSPR monitors do not have yet single-shot capability. Here we study the feasibility of using a CSPR based monitor for bunch length measurement at the End Station Test Beam (ESTB) at SLAC. The aim is to design a second-generation device with single-shot capability, and use it as a diagnostic tool at ESTB. Simulations of the spectral CSPR energy distribution and feasibility study have been performed for the optimization of the parameters and design of such a device.

MOPME077

Electro-0ptical Bunch Profile Measurement at CTF3

laser, electron, photon, polarization

658

R. Pan, A. Andersson, W. Farabolini, A. Goldblatt, T. Lefèvre, M. Martyanov, S. Mazzoni, S.F. Rey, L. Timeo
CERN, Geneva, Switzerland
W.A. Gillespie, R. Pan, D.A. Walsh
University of Dundee, Nethergate, Dundee, Scotland, United Kingdom
S.P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

A new electro-optic bunch profile monitor has recently been installed in CLIC Test Facility 3 at CERN. The monitor is based on an electro-optic spectral decoding scheme which reconstructs the longitudinal profile of the electron bunch by measuring its Coulomb field. The system uses a 780 nm fibre laser system, transported over a 20m long distance to the interaction chamber, where a ZnTe crystal is positioned close to the beam. The assembly also contains a traditional OTR screen, which is coupled to a second optical line and used to adjust the temporal overlap between the laser and the electron pulse. This paper presents the detection system in detail, as well as reporting on the first measurements performed with beam.

MOPWA026

Fast Magnetic Kickers for the NSLS-II Booster-Synchrotron: Design and Test Results

kicker, booster, extraction, injection

717

D.A. Shvedov, O. Anchugov, V.A. Kiselev, A.A. Korepanov, S.V. Sinyatkin
BINP SB RAS, Novosibirsk, Russia

For the purpose of realization of single-turn injection and extraction from the NSLS-II booster synchrotron, BINP members created nanosecond non-vacuum ferrite kickers with fronts of pulsed magnetic field of ~ 200 ns, flat-top duration of 300 nsec and its instability of 0.2/1% at most. This paper describes the design of unique kicker magnets with ceramic vacuum chambers with deposited longitudinal strips of titanium nitride (TiN) inside. The paper also presents the results of bench tests of the kickers: oscillograms of current pulse in bus bars, the shape of the pulsed magnetic field, and transverse distribution of the longitudinal field integral in the kicker aperture.

MOPWA030

Upgrade of the LHC Injection Kicker Magnets

kicker, injection, electron, impedance

729

M.J. Barnes, P. Adraktas, V. Baglin, G. Bregliozzi, S. Calatroni, F. Caspers, H.A. Day, L. Ducimetière, M. Garlaschè, V. Gomes Namora, J.M. Jimenez, N. Magnin, V. Mertens, E. Métral, B. Salvant, M. Taborelli, J.A. Uythoven, W.J.M. Weterings
CERN, Geneva, Switzerland

The two LHC injection kicker systems, comprising 4 magnets per ring, produce a kick of 1.3 T.m with a rise-time of less than 900 ns and a flattop ripple of less than ±0.5%. A beam screen is placed in the aperture of each magnet, to provide a path for the image current of the high intensity LHC beam and screen the ferrite yoke against wake fields. The screen consists of a ceramic tube with conductors in the inner wall. The initially implemented beam screen ensured a low rate of electrical breakdowns while providing an adequate beam coupling impedance. Operation with increasingly higher intensity beams, stable for many hours at a time, now results in substantial heating of the ferrite yoke, sometimes requiring cool down over several hours before the LHC can be refilled. During the long shutdown in 2013/2014 all 8 kicker magnets will be upgraded with an improved beam screen and an increased emissivity of the vacuum tank. In addition equipment adjacent to the injection kickers and various vacuum components will also be modified to help reduce the vacuum pressure in the kickers during high-intensity operation. This paper discusses the upgrades as well as their preparation and planning.

MOPWA031

Beam Induced Ferrite Heating of the LHC Injection Kickers and Proposals for Improved Cooling

kicker, injection, simulation, impedance

732

M.J. Barnes, S. Calatroni, F. Caspers, L. Ducimetière, M. Garlaschè, V. Gomes Namora, V. Mertens, Z.K. Sobiech, M. Taborelli, J.A. Uythoven, W.J.M. Weterings
CERN, Geneva, Switzerland
H.A. Day
UMAN, Manchester, United Kingdom

The two LHC injection kicker systems produce a kick of 1.3 T.m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. A beam screen is placed in the aperture of each magnet, which consists of a ceramic tube with conductors in the inner wall. The conductors provide a path for the beam image current and screen the ferrite yoke against wake fields. Recent LHC operation, with high intensity beam stable for many hours, resulted in significant heating of both the ferrite yoke and beam impedance reduction ferrites. For one kicker magnet the ferrite yoke approached its Curie temperature. As a result of a long thermal time-constant the ferrites can require several hours to cool enough to re-inject beam, thus limiting the availability of the LHC. Thermal measurement data has been analysed, a thermal model developed and emissivity measurements carried out. The effects of various measures to improve the ferrite cooling have been simulated, including an improved emissivity of the vacuum tank and active cooling on the outside of the tank.

MOPWA032

Reduction of Surface Flashover of the Beam Screen of the LHC Injection Kickers

kicker, injection, impedance, simulation

735

M.J. Barnes, P. Adraktas, S. Calatroni, F. Caspers, L. Ducimetière, V. Gomes Namora, V. Mertens, R. Noulibos, M. Taborelli, B. Teissandier, J.A. Uythoven, W.J.M. Weterings
CERN, Geneva, Switzerland

The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wake fields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. Operation with increasingly higher bunch intensity, and narrow bunches, now requires improved ferrite screening. This will be implemented by additional conductors; however the good high-voltage behaviour of the kicker magnets must not be compromised by the supplementary screening. Extensive studies and optimisations have been carried out, to better satisfy the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time, high vacuum and good high voltage behaviour. A new configuration is proposed which reduces significantly the electric field associated with the screen conductors and the secondary electron yield of the surface of the ceramic tube. Results of high voltage test results are also presented.

MOPWA043

The HV Withstands Test for In Vacuum Booster Kicker

booster, kicker, injection, extraction

765

Y.-H. Liu, C.K. Chan, C.S. Chen, H.H. Chen, J.-R. Chen, K.H. Hsu, H.P. Hsueh, Y.T. Huang, C.S. Yang
NSRRC, Hsinchu, Taiwan

The maximum driving voltage of TPS booster extraction kicker is close to 30 kV, the HV insulation should be carefully noticed. A DC withstand voltage tester MUSASHI 3802 (Model: IP-701G) is used to test the DC breakdown voltage, which the maximum driving voltage is 37 kV. The 10 mm gap between coil and ferrite is designed in order to increase HV break down voltage. The safety breakdown distance between HV coil and grounding plate was tested in air. Different insulation material with different thickness was tested the breakdown voltage. Thicker than 10 mm ceramic plate could effectively avoid the breakdown occurred with 37 kV DC charging. Thus HV withstand voltage will be higher in vacuum chamber and the insulation with HV will not be the problem.

MOPWA064

Microwave Resonator Diagnostics of Electron Cloud Density Profile in High Intensity Proton Beam

electron, cavity, proton, simulation

825

Y.-M. Shin, J. Ruan, C.-Y. Tan, J.C.T. Thangaraj, R.M. Zwaska
Fermilab, Batavia, USA

We have developed an novel technique to accurately estimate the density of dilute electron clouds emitted from high intensity proton beams. The strong phase shift enhancement from multiple reflections of standing microwaves in a resonating beam pipe cavity has been demonstrated with numerical modeling using dielectric approximation and e S-parameter measurements. The equivalent dielectric simulation showed a ~ 10 times phase shift enhancement (Pi-mode, 1.516 GHz) with the cavity beam pipe compared to the waveguide model. The position-dependence of the technique is investigated by overlapping the field distributions of harmonic resonances. The simulation with various positions of dielectric insertions confirmed that resonance peaks in phase-shift spectra corresponding to the relative distance between field-nodes and electron cloud position, which allows for one-dimensional mapping. Preliminary experimental studies based on a bench-top setup confirm the results of the simulation showing that thicker reflectors enhance the phase-shift measurement of the electron cloud density.

MOPWA072

MODELING FOR TIME-RESOLVED RETARDING FIELD ANALYZER MEASUREMENTS OF ELECTRON CLOUD BUILDUP AT CesrTA

electron, positron, dipole, pick-up

846

J.A. Crittenden, Y. Li, X. Liu, M.A. Palmer, J.P. Sikora
CLASSE, Ithaca, New York, USA

Funding: US National Science Foundation PHY-0734867, PHY-1002467, and the U.S. Department of Energy DE-FC02-08ER41538
The Cornell Electron Storage Ring Test Accelerator program includes investigations into electron cloud buildup mitigation techniques using custom vacuum chambers. Multibunch electron and positron beams of energies between 2.1 and 5.3 GeV with bunch spacings from 4 to 98 ns and bunch populations ranging from 10¹⁰ to 16·10¹⁰ provide highly differentiated sensitivity to the processes contributing to cloud buildup such as photoelectron production, cloud space-charge dynamics, and secondary electron emission. Measurements of the time dependence of cloud buildup using BPM-style shielded pickups have been shown to provide tight constraints on cloud buildup models. Recently, time-resolving retarding-field analyzers have been designed, installed and commissioned. These novel detectors combine the time-resolving feature of the shielded pickups with the fine transverse segmentation and cloud electron energy sensitivity of the time-integrating retarding-field analyzers used previously. We report on progress in modeling these measurements and quantify their sensitivity to various parameters describing the underlying physical processes contributing to cloud buildup.

MOPWA080

Design of a Fast, XFEL-quality Wire Scanner

photon, electron, radiation, instrumentation

867

M.A. Harrison, R.B. Agustsson, P.S. Chang, T.J. Hodgetts, A.Y. Murokh, M. Ruelas
RadiaBeam, Santa Monica, USA

RadiaBeam Technologies, in collaboration with the Pohang Accelerator Laboratory, has designed and built a fast wire scanner for transverse beam size measurements in the XFEL Injector Test Facility. The wire scanner utilizes three 25-micron diameter tungsten wires mounted vertically, horizontally, and diagonally on a single alumina card to measure the transverse beam size down to 10 microns with sub-micron accuracy of a 139-MeV electron beam. A double-ended design using dual bellows for actuation is used to reduce the vibrations of the wire holder during motion and negate the effects of air pressure on positioning. The servomotor-driven system is capable of performing full horizontal, vertical, and 45-degree scans in under a minute. Algorithms are presented for removing the broadening effect of the wires' thickness from the scanning data to measure beams that are as small or smaller than the wires. Furthermore, we present formulas for determining the beam's transverse spatial sizes (horizontal and vertical spot size and correlation) from the scan data.

MOPWO022

Design and Manufacturing Description of the Prototype Striplines for the Extraction Kicker of the CLIC Damping Rings

impedance, kicker, extraction, damping

930

C. Belver-Aguilar, A. Faus-Golfe
IFIC, Valencia, Spain
M.J. Barnes
CERN, Geneva, Switzerland
J. Gómez
Trinos Vacuum Projects, Paterna, Spain
D. Gutiérrez Arribas
Trinos Vacuum Projects, S.L., Paterna - Valencia, Spain
F. Toral
CIEMAT, Madrid, Spain

The Pre-Damping Rings (PDRs) and Damping Rings (DRs) of CLIC are needed to reduce the beam emittances to the small values required for the main linacs. The injection and extraction, from the PDRs and DRs, are carried out by kicker systems. In order to achieve both low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. The design of the stripline kicker was previously carried out by modelling the striplines with simulation codes such as HFSS, Quickfield and CST Particle Studio. In order to have a complete analysis of the striplines, the effect of electrodes supports and coaxial feedthroughs have been studied in detail. In this paper, electromagnetic analyses of the complete striplines, including fabrication tolerances, are reported. Furthermore, a new idea for impedance matching is presented.

MOPWO031

High Energy Beam Impact Tests on a LHC Tertiary Collimator at CERN HiRadMat Facility

alignment, collimation, simulation, proton

954

M. Cauchi, O. Aberle, R.W. Aßmann, A. Bertarelli, F. Carra, A. Dallocchio, D. Deboy, L. Lari, S. Redaelli, A. Rossi
CERN, Geneva, Switzerland
M. Cauchi, P. Mollicone
UoM, Msida, Malta
L. Lari
IFIC, Valencia, Spain
N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta

The correct functioning of the collimation system is crucial to safely operate the LHC. The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs) in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN HiRadMat (High Irradiation to Materials) facility, involved 440 GeV beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained together with some first outcomes from visual inspection.

TUOAB203

ESRF Upgrade Phase II

lattice, emittance, storage-ring, brilliance

1140

J.-L. Revol, P. Berkvens, J.C. Biasci, J-F. B. Bouteille, N. Carmignani, F. Ewald, L. Farvacque, A. Franchi, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, G. Lebec, S.M. Liuzzo, B. Nash, T.P. Perron, E. Plouviez, P. Raimondi, K.B. Scheidt, V. Serrière
ESRF, Grenoble, France

Four years after the launch of the Upgrade Programme, the ESRF is midway through its first phase (2009-2015) and has defined the objectives for the ensuing second phase. The first phase paved the way to a new generation of nano-beam X-ray beamlines fed by an X-ray source itself substantially improved in terms of reliability, stability and brilliance. The second phase envisions a major upgrade of the source to best serve the science case of this new generation of beamlines. In December 2012, the ESRF Council endorsed Management's proposal to launch the technical design study of a new 7-bend achromat lattice. This new configuration will allow the ESRF storage ring to operate with a decrease in horizontal emittance by a factor of about 30 and a consequent increase in brilliance and coherence of the photon beam. The increase will be substantially higher at X-ray energies larger than 50 keV.

Slides TUOAB203 [3.664 MB]

TUOCB201

Recent Developments of Novel Beam Diagnostics at the ESRF

electron, dipole, diagnostics, injection

1143

K.B. Scheidt
ESRF, Grenoble, France

A number of rather novel and particular electron beam diagnostics have seen their development in 2012 for the ESRF Storage Ring. A vertical Beam Halo detector that measures the bunch population at millimetres, i.e. hundreds of σs of nominal beam size, away from the central core. This measurement is based on X-ray synchrotron radiation from a bending magnet and is totally non-destructive to the electron beam itself. Another diagnostic use of the very hard X-rays available from the bending magnets is the detection of electron beam energy fluctuations. The detector hardware is simple and in-expensive and has shown a resolution of energy fluctuations of less than 10ppm. Also a single orbit turn measurement of the injected beam shape and size is now possible through the use of visible synchrotron light combined with a fast gateable intensifier, which can be triggered on any of the desired orbit turns after injection. Detailed results of each of these new diagnostics will be presented.

Slides TUOCB201 [1.511 MB]

TUOCB203

In Vacuum High Accuracy Mechanical Positioning System of Nano Resolution Beam Position Monitor at the Interaction Point of ATF2

feedback, alignment, linear-collider, collider

1149

P. Bambade, O.R. Blanco, F. Bogard, P. Cornebise, S. Wallon
LAL, Orsay, France
T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major goal of ATF2 is to demonstrate the ability to stabilise the beam position at the interaction point, where the beam can be focused down to about 35 nm. For this purpose, a set of new Beam Position Monitors (BPM) has been designed, with an expected resolution of about 2 nm. These BPMs must be very well aligned with respect to the beam, at the few micron level, to fully exploit their fine resolution. In this paper, the mechanical positioning system which has been developed to enable such a precise alignment is presented. It is based on a set of eight piezo actuators with nanometer range displacement resolution, mounted in a new specially made vacuum chamber. Due to the expected resolution of the piezo actuators, this system also brings a new functionality, the possibility to calibrate the BPMs by mechanically scanning the beam.

Slides TUOCB203 [2.276 MB]

TUODB202

Experiment and Numerical Simulation Results of Plasma Window

plasma, simulation, cathode, cavity

1155

K. Zhu, S. Huang, Y.R. Lu, B.L. Shi
PKU, Beijing, People's Republic of China

Funding: Supported by NSFC 91026012
A windowless vacuum seal technique has been widely researched and designed, which can connect high pressure cavity to a vacuum condition with rather little thickness of material. As a result, it will reduce most interaction with the particle beam penetrating through comparing to that of foil window. It is desired extensively in experiments using high-intensity heavy ion beams which will break foil window in a short time or in experiments which require the injecting beams with mono-energy and high purity for example. In this work, we study the plasma window in argon which is used as a windowless vacuum sealing device. A numerical 2D FLUENT-based magneto-hydrodynamic model has been developed to investigate the physical reasons of high pressure difference in plasma window. Further, preliminary experimental results are presented and discussed.

Slides TUODB202 [2.180 MB]

TUPEA057

Optimization of Rectangular Dielectric Structures for the Planned Wakefield Acceleration Experiments in KIPT

wakefield, electron, accelerating-gradient, acceleration

1262

G.V. Sotnikov, K.V. Galaydych, V. Kiselev, P.I. Markov, I.N. Onishchenko
NSC/KIPT, Kharkov, Ukraine

Funding: This study is supported by Global Initiatives for Proliferation Prevention (GIPP) program, project ANL-T2-247-UA (STCU Agreement P522).
We, at the Kharkov Institute of Physics and Technology, planned experimental test of the basic principles of the multi-bunch multi-mode wakefield accelerator. For this purpose we carried out a series of calculations of wakefield excitation and dynamics of the drive and witness bunches in rectangular structures with a dielectric substrate. For optimization two rectangular vacuum waveguides of R32 (72.14mm x 34.04mm) and R26 (86.36mm x 43.18mm) which were filled with the dielectric covering two any opposite metal walls of a waveguide were chosen. As possible dielectric Alumina, Cordierite, or Teflon were tested. It was supposed that the structure will be energized by sequence of electron bunches (bunch repetition frequency is 2.805 GHz), having energy of 4.5 MeV. As the candidate for operating mode LSM-wave or LSE-wave, with frequency to equal the bunch repetition frequency or its doubled frequency were tested. The gradient of an accelerating field, small transverse deflection (or divergence) of drive and witness bunches were the main criteria of optimization. As a result of optimization we propose some dielectric structures for future wakefield experiments in KIPT.

TUPEA065

Design of a Photonic Crystal Accelerator for Basic Radiation Biology

laser, acceleration, electron, simulation

1283

A. Aimidula, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Aimidula, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
K. Koyama, Y. Matsumura
University of Tokyo, Tokyo, Japan
T. Natsui, M.Y. Yoshida
KEK, Ibaraki, Japan
M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
G.X. Xia
UMAN, Manchester, United Kingdom

Funding: This work is supported by the EU under Grant Agreement 289485, the STFC Cockcroft Institute Core Grant No. ST/G008248/1 and KAKENHI, Grant-in-Aid for Scientific Research (C) 24510120.
The application of photonic crystals to realize an on-chip electron beam source for fundamental radiation biology is highly interesting for a number of applications. The unique combination of nanometer beam size and attosecond-short pulses has a very promising potential for use in microscopic and ultra-fast analyses of damage and repair of radiation-irradiated DNA and chromosomes. Simulations studies indicate an output electron beam energy, beam intensity and device size of the order of MeVs, fCs and a few cm, respectively. In this contribution, first results from numerical studies into the design of such compact accelerator structure are presented. The dimensions of a novel dual grating-based acceleration structure are shown together with the estimated laser parameters. Finally, a system consisting of an electron injector and multi-stage accelerating structures is proposed, which corresponds to a miniaturized optical linear accelerator.

TUPEA066

Metamaterial-based Accelerating, Bending and Focusing Structures

focusing, electron, quadrupole, resonance

1286

I. McGregor
The University of Liverpool, Liverpool, United Kingdom
K.M. Hock
Cockcroft Institute, Warrington, Cheshire, United Kingdom

We report on the progress of our research into metamaterial-based accelerating, bending and focusing structures at the Cockcroft Institute. The effort during the last year has been directed towards designing and investigating practical RF structures that are suitable for industrial and medical applications. We have shown that, by introducing structures based on metamaterial resonators, RF accelerating structures can be made more compact and higher gradient. This year, we will concentrate on focusing and bending structures.

TUPEA079

Experimental Search For Acceleration in the Micro-accelerator Platform

laser, electron, acceleration, coupling

1307

J.C. McNeur, K.S. Hazra, B. Matthews, E.B. Sozer, G. Travish
UCLA, Los Angeles, USA
R.J. England, B. Montazeri, K. Soong, Z. Wu
SLAC, Menlo Park, California, USA
E.A. Peralta
Stanford University, Stanford, California, USA
R.B. Yoder
Goucher College, Baltimore, USA

The results of recent experimental efforts to observe acceleration in the Micro-Accelerator Platform (MAP) are detailed. The MAP is a slab-symmetric dielectric laser accelerator that when side illuminated by an optical laser, accelerates electrons via a standing wave resonance. This structure has been placed in the beamline at the NLCTA experimental hall at SLAC. A 60 MeV electron beam traverses the MAP when it is illuminated by a laser and, using a camera placed around a spectrometer bend magnet, signs of acceleration in the energy spectrum of the beam are searched for. The details of this search, as well as simulations that motivate the search, are elaborated on below.

TUPEA080

Numerical Modeling and Experimental Data Analysis for Dielectric Laser Accelerators

laser, electron, acceleration, GUI

1310

E.B. Sozer, K.S. Hazra, J.C. McNeur, G. Travish
UCLA, Los Angeles, USA
R.J. England, K. Soong
SLAC, Menlo Park, California, USA
E.A. Peralta
Stanford University, Stanford, California, USA
R.B. Yoder
Goucher College, Baltimore, USA

Funding: Work supported by a grant for the US Defense Threat Reduction Agency (DTRA).
Work on Dielectric Laser Accelerators (DLAs) has been ongoing for the past decade. These devices come in a variety of configurations but share the use of lasers as power sources and dielectrics as the primary building material. While these devices have many of the same characteristics and dynamics as conventional accelerating structures, they operate in a dramatically different regime. One version of these DLAs is the Micro Accelerator Platform (MAP): a slab-symmetric device operated with a standing wave (Pi-mode) and powered by a transversely coupled laser. The coupler is essentially a transmissive diffraction grating and therefore reinforced the desired mode. The remainder of the structure is composed of two Distributed Bragg Reflectors (DBRs) which serve to form a resonant cavity in an evacuated bounded by the reflectors. The MAP has now undergone experimental testing at SLAC’s E-163. As with many advanced accelerators, identifying the best data analysis approach demands extensive numerical modelling of the anticipated beam parameters and development of data visualization tools. We present the latest numerical results and data analysis tools developed for dielectric laser acceleration experiments with MAP.

TUPFI005

Synchrotron-Radiation Photon Distribution for Highest Energy Circular Colliders

photon, scattering, radiation, electron

1340

G.H.I. Maury Cuna
CINVESTAV, Mérida, Mexico
G. Dugan, D. Sagan
CLASSE, Ithaca, New York, USA
F. Zimmermann
CERN, Geneva, Switzerland

Funding: Acknowledgements to CINVESTAV, CERN and EPLANET project.
At high energies, beam-induced synchrotron radiation is an important source of heating, beam-related vacuum pressure increase, and primary photoelectrons, which can give rise to an electron cloud. The photon distribution along the beam pipe wall is a key input to codes such as ECLOUD and PyECLOUD, which model the electron cloud build-up. For future high-energy colliders, like TLEP or SHE-LHC, photon stops and antechambers are considered in order to facilitate cooling and vacuum pressure control. We use the Synrad3D code developed at Cornell to simulate the photon distribution for the LHC.

TUPFI013

LHC Long Shutdown: A Parenthesis for a Challenge

cryogenics, radiation, controls, superconducting-magnet

1355

K. Foraz, M. Arnaud, M.B.M. Barberan Marin, C. Bedel, M. Bernardini, J. Coupard, J. Etheridge, H. Gaillard, S. Grillot, E. Paulat, A.-L. Perrot
CERN, Geneva, Switzerland

After three fruitful years of operation, the LHC will enter a long shutdown. Major works will be implemented to allow running safely at 7TeV/beam. The LHC superconducting circuits will be consolidated; mitigation measures will be carried out to reduce the single event effects occurrence in the frame of the Radiation To Electronics mitigation project (R2E); all the equipment will be fully maintained. In parallel, numerous consolidation and upgrade activities will be performed all around the 27km ring. The schedule has been optimized in order to reduce the length of the shutdown (LS1) to 22 months (including hardware commissioning). The organization of the works is therefore essential to ensure a safe and reliable plan. This paper introduces the various activities to be performed and presents the schedule and the preparation process, including the operational safety aspects.

TUPFI065

Muon Ionization Cooling Experiment Step VI

cavity, coupling, emittance, status

1499

D. Rajaram
Illinois Institute of Technology, Chicago, Illinois, USA
P. Snopok
IIT, Chicago, Illinois, USA

The Muon Ionization Cooling Experiment (MICE) is a demonstration experiment to prove the viability of cooling a beam of muons for use in a Neutrino Factory and Muon Collider. The ultimate Step VI configuration of the MICE cooling channel, a section of the one proposed in the Neutrino Factory Study II, will demonstrate a 10% reduction in transverse beam emittance measured at the level of 1%. This requires measuring emittance to 0.1%. This measurement will be made using all beam line elements present in the MICE Step IV configuration with the addition of two low-Z absorber modules and two RF-Coupling Coil (RFCC) modules. The RFCC modules each contain four normal-conducting low frequency (201 MHz) RF cavities with a guiding magnetic field provided by a large diameter coupling coil. Each of these cavities will require approximately 1 MW of RF power in a 1 ms pulse at a rate of 1 Hz. The experiment can explore a variety of combinations of momentum, beta function, magnetic field flip or non-flip configurations that will prove precious in the design of future cooling channels. The current status and progress toward Step VI are discussed.

TUPME014

Coherent Synchrotron Radiation Predicted at the SuperKEKB Damping Ring

damping, linac, emittance, simulation

1595

H. Ikeda, M. Kikuchi, K. Ohmi, K. Oide, D. Zhou
KEK, Ibaraki, Japan

The damping ring of SuperKEKB is under construction in order to inject low emittance positron beam into the main ring. We calculated the bunch lengthening and the energy spread caused by the longitudinal wake, which is dominated by the CSR wake field. The result was within the tolerance level.

TUPME022

Study on the Single Bunch Transverse Emittance Growth in BAPS

emittance, wakefield, lattice, wiggler

1619

J. Gao, D. Wang
IHEP, Beijing, People's Republic of China

Funding: Supported by the National Foundation of Natural Sciences Contract 11175192.
Beijing Advanced photon Source (BAPS) is a proposed next synchrotron radiation facility which has much smaller transverse emittance after SSRF in China, with 5 GeV energy and 1.5 km circumference. In order to explore how small the transverse emittance we can get on BAPS, this paper studies the single bunch transverse emittance growth due to short range wakefield according to J. Gao’ theory. The mechanism of wakefield induced single bunch emittance is explained first and then the transverse emittance at the design beam current is estimated. Also, the tolerances for the transverse loss factor and the vacuum chamber misalignment (or the closed orbit distortion) are presented.

TUPWA005

Study of Collective Beam Instabilities for the MAX IV 3 GeV Ring

impedance, simulation, damping, wakefield

1730

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

The present paper reports on a systematic simulation study made on the collective beam instability in the MAX IV 3 GeV ring. We study both single and multibunch instabilities in the longitudinal plane. Specifically, we focus on the microwave instabilities which are considered to be particularly dangerous for MAX IV, in view of its small effective radius of aperture (b_eff < 11 mm), the high intensity (500 mA) and the low emittance (0.24 nm.rad) nature of the circulating beam. Single and multibunch tracking are performed using wake fields that were numerically obtained using GdfidL for the ensemble of the vacuum components. A special effort was made to include dynamically the effect of harmonic cavities that lengthen the bunch and introduce Landau damping, whose details are described in the companion paper *. The study aims to confirm the effectiveness of storing long bunches in the 100 MHz RF system, where tune spreads are further increased by the harmonic cavities, in order to fight against collective instabilities.
* M. Klein and R. Nagaoka "Multibunch Tracking Code Development to Account for Passive Landau Cavities", these proceedings

TUPWA008

Computation of Wakefields for an In-vacuum Undulator at PETRA III

undulator, wakefield, simulation, impedance

1736

E. Gjonaj, L. Lünzer, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany
R. Wanzenberg
DESY, Hamburg, Germany

Funding: Work supported by DESY, Hamburg, Germany
At DESY the installation of an in-vacuum undulator at the synchrotron radiation facility PETRA III is under consideration. The moveable magnet array of the undulator is installed inside the vacuum chamber to achieve shorter wavelength synchrotron radiation. A thin metal foil covers the magnet structure to mitigate resistive wall wakefields. Moveable tapered transitions connect the magnet structure and the adjacent vacuum duct to reduce the geometric wakefields. Nevertheless these moveable tapered transitions contribute significantly to the impedance budget of PETRA III. The computer codes MAFIA, CST-Studio and PBCI have been used to calculate the longitudinal and transverse wakefields. The results for the loss and kick parameters are presented and compared to the corresponding parameters for a standard undulator section.

TUPWA042

Lessons Learned and Mitigation Measures for the CERN LHC Equipment with RF Fingers

impedance, resonance, damping, simulation

1802

E. Métral, O. Aberle, R.W. Aßmann, V. Baglin, M.J. Barnes, O.E. Berrig, A. Bertarelli, G. Bregliozzi, S. Calatroni, F. Carra, F. Caspers, H.A. Day, M. Ferro-Luzzi, M.A. Gallilee, C. Garion, M. Garlaschè, A. Grudiev, J.M. Jimenez, O.R. Jones, O. Kononenko, R. Losito, J.L. Nougaret, V. Parma, S. Redaelli, B. Salvant, P.M. Strubin, R. Veness, C. Vollinger, W.J.M. Weterings
CERN, Geneva, Switzerland

Beam-induced RF heating has been observed in several LHC components when the bunch/beam intensity was increased and/or the bunch length reduced. In particular eight bellows, out of the ten double-bellows modules present in the machine in 2011, were found with the spring, which should keep the RF fingers in good electrical contact with the central insert, broken. Following these observations, the designs of all the components of the LHC equipped with RF fingers have been reviewed. The lessons learnt and mitigation measures are presented in this paper.

TUPWA052

Loss Factor and Impedance Analysis for the Diamond Storage Ring

impedance, storage-ring, wiggler, simulation

1826

R. Bartolini, R.T. Fielder, C.A. Thomas
Diamond, Oxfordshire, United Kingdom

Diamond Light Source is investigating the possibility of increasing the storage ring operating current above the nominal 300 mA. A campaign of measurements and simulations has been carried out in order to understand the extent of the parasitic energy loss and characterise the most important items which build up the machine impedance. In this paper we report on the most recent measurements of the longitudinal loss factor and the present status of the impedance database with an initial comparison between the two.

TUPWO057

Active Shimming of Dynamic Multipoles of an APPLE II Undulator in the Diamond Storage Ring

polarization, injection, optics, undulator

1997

B. Singh, R. Bartolini, R.T. Fielder, E.C. Longhi, I.P.S. Martin, S.P. Mhaskar, R.P. Walker
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Diamond plans to operate a 5 m, long period length, APPLE undulator in a long insertion straight section. Theoretical investigations showed a severe impact on machine dynamics especially when the device is operated in vertical polarization mode. The use of local optics corrections and/or lowering of beta functions were initially investigated as possible solutions but with limited success. Active shimming of dynamic multipoles, following the approach at BESSY-II, proved more effective. The optimum shiming has been devised using kick map approach. In this paper we review the theoretical analysis, the commissioning of the active shims and the undulator, and the net effect of the undulator after compensation.

WEIB203

Industrialization of ILC from a View Point of Industry

cavity, HOM, target, status

2110

K. Sennyu, H. Hara, F. Inoue, K. Kanaoka, K. Okihira
MHI, Hiroshima, Japan

Cavity performance has been improved by various efforts to meet the ILC spec stably in these days. For industrialization, not only Quality but also Cost and Delivery time, that is, QCD are important. We report our activities for stable quality and cost reduction in this report.

Slides WEIB203 [5.789 MB]

WEPWA003

Hall-Probe Bench for Cryogenic in-Vacuum-Undulators

undulator, laser, cryogenics, permanent-magnet

2126

C. Kuhn, H.-J. Bäcker, J. Bahrdt, A. Gaupp, B. Schulz
HZB, Berlin, Germany

The Helmholtz-Zentrum Berlin (HZB) builds a 2m long in-vacuum-hall-probe-bench for the characterization of several cryogenic undulators currently under development. Short period lengths and small gaps require an accurate correlation between Hall probe position / orientation and the 3D-magnetic field. The geometric tolerances of an in-vacuum bench in the presence of strong temperature gradients do not permit a Hall probe movement along a straight line without corrections. The HZB-bench employs a system of laser interferometers and position sensitive detectors, which is used in a feed-back loop for the Hall probe position / orientation. First measurements on the accuracy and reproducibility of the new device are presented.

WEPWA007

First Tests with a Local and Integral Magnetic Field Measurement Setup for Conduction Cooled Superconducting Undulator Coils

undulator, synchrotron, radiation, synchrotron-radiation

2138

A.W. Grau, S. Casalbuoni, S. Gerstl, N. Glamann, T. Holubek, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany

The magnetic field quality of insertion devices (IDs) has a significant influence on their performance. Therefore it is essential to characterize their magnetic properties and perform precise field measurements before installation in synchrotron light sources. Particularly for permanent magnet IDs the magnetic field measurement technology made significant progress during the last years and pushed the capabilities of synchrotron light sources. Even though for superconducting IDs the measurement settings are far more challenging similar major developments are required. As a part of our R&D program on superconducting IDs we perform quality assessment of their magnetic field properties. This contribution describes details, challenges and the first tests with the measurement equipment configurations to perform measurements of the integral and local magnetic field distributions of superconducting undulator coils up to 2 m length, in a cold (4.2 K), in-vacuum and cryogen free environment.

WEPWA022

The Fabrication and Measurement of the New Insertion Devices of Hefei Light Source

undulator, insertion, insertion-device, radiation

2177

Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China

To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more new insertion devices. The new insertion devices include one elliptically polarizing undulator with 10⁴ mm period, one in-vacuum undulator with 40mm period, one wiggler with 152mm period and one quasi-periodic undulator based on a new scheme proposed by us. In this paper the fabrication and the preliminary results of the magnetic field measurements of the new insertion devices are reported.

WEPWA029

Undulator Chamber R&D for SXFEL

undulator, controls, free-electron-laser, laser

2193

X. Hu, L. Yin
SINAP, Shanghai, People's Republic of China

The upcoming construction of Shanghai Soft X-ray Free Electron Laser Facility (SXFEL) will use 18 m small gap undulators. Each undulator is 3 meters long and will work at a minimum gap of 9 mm. This requires a vacuum chamber with an outer height of 8 mm and an elliptic inner aperture. The pressure inside of the chamber shall be less than 10^-5 Pa for the beam operation. An oxygen-free copper vacuum chamber was designed and a prototype was developed. This chamber includes three parts, a copper pipe manufactured by stretching, two flanges made of clad metal and a set of supports. The main fabrication procedure and the test results for the chamber prototype are described in this paper.

WEPWA033

The Magnetic Performance of Two Undulators for HLS

undulator, polarization, multipole, electron

2202

W. Zhang, Q.G. Zhou
SINAP, Shanghai, People's Republic of China
H.F. Wang
SSRF, Shanghai, People's Republic of China

An elliptically polarized undulator and an in vacuum undulator for HLS have been built at SSRF. The magnetic design of the two Undulators is reviewed. Measurements of the complete undulators are described. Results of performance optimization, including minimization of optical phase error, trajectory wander and integrated multipoles with magic fingers are presented.

WEPWA053

Control System of In-vacuum Undulator in Taiwan Photon Source

controls, EPICS, undulator, insertion

2238

C.Y. Wu, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, C.Y. Liao
NSRRC, Hsinchu, Taiwan

Insertion device (ID) is a crucial component in third-generation synchrotron light sources, which can produces highly-brilliant, forward-directed and quasi-monochromatic radiation over a broad energy range for various experiments. In the phase I of the Taiwan Photon Source (TPS) project, seven IU22s (In-Vacuum Undulator) will be planned, constructed, and installed. The control system for IU22 is based on the EPICS architecture. The main control components include the motor with encoder for gap adjustment, trimming power supply for corrector magnets, ion pumpers and BA gauges for vacuum system, temperature sensors for ID environmental monitoring and baking, and interlock system (limit switches, emergency button) for safety. The progress of IU22 control system will be summarized in this report.

WEPWA062

Status of the UK Superconducting Planar Undulator Project

undulator, cryogenics, wakefield, radiation

2259

J.A. Clarke, B.J.A. Shepherd
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
V. Bayliss, T.W. Bradshaw, S.A. Brown, A.J. Brummitt, G.W. Burton, S.J. Canfer, B. Green, S.R. Watson
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
S.E. Hughes, E.C. Longhi, J.C. Schouten
Diamond, Oxfordshire, United Kingdom

The UK is developing a short period, narrow aperture, planar superconducting undulator that is planned to be installed and tested in the 3 GeV Diamond Light Source in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. First measurements will be presented of a 19 period test module and also the commissioning of the 2K cryogenic turret.

WEPWA081

Status of the Praseodymium Undulator with Textured Dysprosium Poles for Compact X-Ray FEL Applications

undulator, cryogenics, simulation, radiation

2298

F.H. O'Shea, R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh, K.E. Woods
RadiaBeam, Santa Monica, USA
J. Park, R.L. Stillwell
NHMFL, Tallahassee, Florida, USA
V. Solovyov
BNL, Upton, Long Island, New York, USA

The demand for high-brightness hard x-ray fluxes from next generation light sources has spurred the development of insertion devices with shorter periods and higher fields than is feasible with conventional materials and designs. RadiaBeam Technologies is currently developing a novel high peak field, ultrashort period undulator with praseodymium-iron-boron (PrFeB) permanent magnets and textured dysprosium (Tx Dy) ferromagnetic field concentrators. This device will offer an unparalleled solution for compact x-ray light sources, as well as for demanding applications at conventional synchrotron radiation sources. A 1.4T on-axis field has already been achieved in a 9mm period undulator, demonstrating the feasibility of using Tx Dy poles in a hybrid undulator configuration with PrFeB magnets. Facets of the undulator design, optimization of the Tx Dy production and characterization process, and magnetic measurements of Tx Dy will be presented.

WEPWO001

Power Couplers for XFEL

site, pick-up, controls, monitoring

2310

W. Kaabi, M. El Khaldi, A. Gallas, P. Lepercq, C. Magueur, A. Variola, A. Verguet
LAL, Orsay, France
W.-D. Möller
DESY, Hamburg, Germany

The LAL contribution to the XFEL project will be the delivery of 800 power couplers to equip 100 Cry-modules. The LAL’s tasks consist on the industrial monitoring and coupler quality control at two different production sites, in addition to the RF conditioning at LAL of the 800 produced couplers. The RF conditioning and all the coupler preparation process will be held in a 70m2 ISO5 clean room. An RF power station delivering 5MW, allow 8 couplers conditioning in the same time. Being in production control side and also RF conditioning one, the aim of LAL is to reach the rate of 8 couplers delivery per week, after a rump up phase. The starting of Coupler mass production is scheduled for beginning 2013.

WEPWO002

RF Measurements of the 1.6 Cell Lead/Niobium Photoinjector in HoBiCaT

cavity, gun, cathode, SRF

2313

A. Burrill, W. Anders, T. Kamps, J. Knobloch, O. Kugeler, P. Lauinger, A. Neumann
HZB, Berlin, Germany
P. Kneisel
JLAB, Newport News, Virginia, USA
R. Nietubyć
NCBJ, Świerk/Otwock, Poland
J.K. Sekutowicz
DESY, Hamburg, Germany

The development of a simple and robust SRF photoinjector capable of delivering up to 1 mA average current in c.w. operation continues to progress with the horizontal RF testing of the 1.6 cell Pb/Nb hybrid photoinjector. This injector utilizes a sputtered lead coating on a removable Nb cathode plug as the photoelectron source and has recently been tested in the horizontal test cryostat facility, HoBiCaT, at HZB. In this paper we will report on the status of these RF measurements and compare the performance to previous vertical RF tests performed at JLab. We will also report on the experience operating this cavity with a TTF-III high power RF input coupler, as well as provide a summary of the microphonics susceptibility now that it has been installed into a helium vessel and equipped with a Saclay style tuner.

WEPWO005

Microphonics Analysis of the SC 325 MHz CH-Cavity

cavity, simulation, resonance, status

2319

M. Amberg, M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher
HIM, Mainz, Germany
K. Aulenbacher
IKP, Mainz, Germany

Since the walls of superconducting (sc) cavities are kept very thin to support the cooling process, even small mechanical disturbances can detune the cavity. One of the main sources of detuning a cavity is microphonics. These low-frequent vibrations caused by vacuum pumps or underground noise are transferred to the cryostat and excite mechanical resonances of the cavity which may lead to frequency shifts larger than the bandwidth. To determine the mechanical resonance frequencies of the sc 325 MHz CH-cavity (Crossbar-H-Mode) simulations with ANSYS Workbench have been performed in a first step. Additionally, microphonics measurements were taken at room temperature as well as in a vertical cryostat at 4K in the cryo-lab of the IAP, Frankfurt University. Furthermore, the contraction of the cavity walls and the resulting frequency shift due to the cavity cool-down has been measured. A comparison between simulation results and the measured values is presented in this paper.

WEPWO011

In-vacuum Temperature Measurement of Niobium Components using Infrared Pyrometry during Electron Beam Welding Procedure

cavity, electron, controls, shielding

2334

L. Monaco, P. Michelato, C. Pagani, D. Sertore
INFN/LASA, Segrate (MI), Italy
V. Battista, G. Corniani, M. Festa
Ettore Zanon S.p.A., Schio, Italy

Electron beam welding (EBW) is widely used in the construction of Niobium Superconducting RF cavities. The welding sequence of such a complex structure, foresees many welding operations. The welding parameters depend on many variables as the material thickness, but also on the component temperature before each weld. This paper presents a technique to measure the temperature of Nb components in vacuum during the EBW operation using an IR pyrometer placed outside the vacuum chamber through an appropriate vacuum viewport. With the current configuration the system can measure temperatures up to 350°C in the vacuum conditions of the EBW vacuum chamber (10-5-10^-6 mbar). The technique was used to optimize the time interval between each subsequent equatorial weld operation during Nb cavities production at Ettore Zanon, increasing the welding procedure reliability and decreasing the waiting time by control of the temperatures in the weld region. Moreover this technique can be generally used for in vacuum measurements of components from room temperature up to about 350 °C. Future developments are under way to make this technique compatible with UHV and increasing the measurement range.

WEPWO014

Rf Field-Attenuation Formulae for the Multilayer Coating Model

cavity, coupling, electromagnetic-fields

2343

T. Kubo, T. Saeki
KEK, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan

Formulae that describe the RF electromagnetic field attenuation in the multilayer coating model with a single superconductor layer and a single insulator layer deposited on a bulk superconductor are derived with a rigorous calculation based on the Maxwell equations and the London equation.

WEPWO018

Status of the IHEP 1.3 GHz Superconducting RF Program for the ILC

cavity, cryomodule, SRF, HOM

2355

J. Gao, Y.L. Chi, J.P. Dai, R. Ge, T.M. Huang, S. Jin, C. H. Li, S.P. Li, Z.Q. Li, H.Y. Lin, Y. Liu, Z.C. Liu, Q. Ma, Z.H. Mi, W.M. Pan, Y. Sun, J.Y. Zhai, T.X. Zhao, H.J. Zheng
IHEP, Beijing, People's Republic of China

The 1.3 GHz superconducting radio-frequency (SRF) technology is one of the key technologies for the ILC. IHEP is building an SRF Accelerating Unit, named the IHEP ILC Test Cryomodule (IHEP ILC-TC1), for the ILC SRF system integration study, high power horizontal test and possible beam test in the future. In this paper, we report the components test results and the assembly preparation of this cryomodule. Processing and vertical test of the large grain low-loss shape 9-cell cavity is done. Performance of the in-house made high power input coupler and tuner at room temperature reaches the ILC specification.

WEPWO041

Beam Commissioning Superconducting RF Cavities for PLS-II Upgrade

SRF, cavity, storage-ring, LLRF

2390

Y.U. Sohn, M.-H. Chun, J.Y. Huang, Y.D. Joo, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, I.H. Yu
PAL, Pohang, Kyungbuk, Republic of Korea

Two superconducting RF cavities were commissioned with electron beam at PLS-II, which is upgraded machine from PLS with 3 GeV, 20 insertion devices, and now on user service. These srf cavities have been prepared during last 3 years. Each cavity was tested with higher than 2 MV rf voltage and 125 kW standing wave power at CW mode after installation at storage ring. PLS-II is on user operation with 200 mA beam current now, and on the way of beam current improvement upto 400mA, by synchrotron conditioning for beam chamber and in-vacuum udulators. Upto 200 mA beam current no beam instability from the higher order modes is observed. With top-up mode operation, the errors of amplitude of rf field and phase are recorded as 0.3% and 0.3 degree peak to peak, respectively during one day. Successful PLS-II upgrade with hardware and its designed performance will be declared at the end of 1st half user run in 2013.

WEPWO043

IFMIF-EVEDA SRF Linac Couplers Test Bench

linac, SRF, controls, LLRF

2396

D. Regidor, I. Kirpitchev, J. Molla, P. Méndez, A. Salom, M. Weber
CIEMAT, Madrid, Spain
M. Desmons, N. Grouas, P. Hardy, V.M. Hennion, H. Jenhani, F. Orsini
CEA/IRFU, Gif-sur-Yvette, France

The IFMIF-EVEDA SRF Linac is a cryomodule equipped with eight superconducting HWR cavities, operating at the frequency of 175 MHz and powered by 200kW CW RF couplers. Before assembling the couplers to the cryomodule, it is necessary to process them using high levels of RF power. In order to perform this conditioning, the power couplers must be connected to a RF network which is fed by an RF source and ended with a load or a short-circuit, depending on the conditioning mode to be applied. A test bench has been designed for the conditioning of the SRF LINAC couplers. The main component is the “test box”, a resonant cavity where two couplers will be assembled to transmit the 200 kW from the RF source to the appropriate termination. The test box includes a large pumping port allowing an efficient pumping of the entire vacuum volume limited by the coupler ceramic windows. Several diagnostics as light detectors, vacuum gauges and thermal transducers will provide information on the relevant parameters for the control of the RF conditioning process. In addition, a support frame has been designed to maintain the whole assembly and reduce the mechanical stress on the couplers.

WEPWO046

First Test Results of the 4-rod Crab Cavity

cavity, niobium, pick-up, coupling

2405

R. Calaga, L.S. Alberty Vieira, S. Calatroni, O. Capatina, E. Ciapala, L.M.A. Ferreira, E. Jensen, P. Maesen, A. Mongelluzzo, T. Renaglia, M. Therasse
CERN, Geneva, Switzerland
P.K. Ambattu, D. Doherty, B.D.S. Hall, C. Lingwood
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
G. Burt
Lancaster University, Lancaster, United Kingdom

Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The first prototype crab cavity with the 4-rod geometry has undergone surface treatment and cold testing. Due to the complex geometry and unique fabrication procedure, RF validation of the field at beyond the nominal operating voltage at a sufficiently high Q0 is an important pre-requiste. Preliminary results of the first cold tests are presented along with cavity performance at different stages of the cavity processing is described.

WEPWO050

Mechanical Study of 400 MHz Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade

cavity, simulation, luminosity, electron

2417

B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu
BNL, Upton, Long Island, New York, USA
L. Alberty Vieira, R. Calaga
CERN, Geneva, Switzerland
T.L. Grimm
Niowave, Inc., Lansing, Michigan, USA

A prototype double quarter wave crab cavity was designed for the Large Hadron Collider luminosity upgrade. A finite element model is used to simulate the mechanical properties of the crab cavity. The results are presented and a reinforcement concept is proposed to meet the safety requirements. The reinforcement components, as well as the cavity, are presently being fabricated at Niowave Inc.

WEPWO051

Manufacture of a Compact Prototype 4R Crab Cavity for HL-LHC

cavity, niobium, luminosity, electron

2420

G. Burt, B.D.S. Hall, C. Lingwood
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
L. Alberty Vieira, R. Calaga, O. Capatina
CERN, Geneva, Switzerland
C.H. Boulware, D. Gorelov, T.L. Grimm, C. Krizmanich, T.S. Lamie
Niowave, Inc., Lansing, Michigan, USA
C. Hill, P.A. McIntosh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R.A. Rimmer, H. Wang
JLAB, Newport News, Virginia, USA

Funding: This work has been funded by the EU through EUCARD and HiLumi and by STFC via the Cockcroft Institute.
A prototype compact SRF deflecting cavity has been manufactured for LHC. The base of the cavity has been machined out of large grain niobium ingot to allow the manufacture of the complex rod profile. Stiffening rods have been used to increase the mechanical strength of the outer can. Details of the cavity design and manufacture will be discussed.

WEPWO055

Fabrication and Testing of SSR1 Resonators for PXIE

cavity, cryomodule, linac, beam-transport

2429

L. Ristori, M.H. Awida, P. Berrutti, T.N. Khabiboulline, M. Merio, D. Passarelli, A.M. Rowe, D.A. Sergatskov, A.I. Sukhanov
Fermilab, Batavia, USA

Fermilab is in the process of constructing a proton linac to accelerate a 1 mA CW beam up to 30 MeV. It will be a test for the front end of Project X and known as the Project X Injector Experiment (PXIE). The major goal of PXIE is the validation of the Project X concept and mitigation of technical risks. It is expected to be constructed in the period of 2012-2016. The PXIE linac consists of a Ion source and LEBT, a 162.5 MHz RFQ, a MEBT, a 162.5 MHz HWR cryomodule (designed and built at ANL) and a 325 MHZ SSR1 cryomodule (designed and built at FNAL). In this paper we present the recent advances in the development of the SSR1 resonators at Fermilab. Several bare SSR1 resonators have been processed, heat-treated and tested successfully in the Fermilab Vertical Test Stand. The outfitting of helium vessels is in process and the coarse-fine frequency tuning system has been designed and is currently being procured and tested. Details of the power coupler are also discussed.

WEPWO082

Ferroelectric Based High Power Tuner for L-band Accelerator Applications

controls, linac, cavity, simulation

2486

A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Kazakov, V.P. Yakovlev
Fermilab, Batavia, USA
A.B. Kozyrev
LETI, Saint-Petersburg, Russia
E. Nenasheva
Ceramics Ltd., St. Petersburg, Russia

Funding: US Department of Energy
With this paper, we present our recent breakthrough with a new fast ferroelectric tuner development. The tuner is based on BST(M) ferroelectric elements (ε~150), which are designed to be used as the basis for L-band accelerator components intended for ERL, ILC, Project X and other applications. These new ferroelectric elements are to be fabricated for the new fast active tuner for SC cavities that can operate in air at low biasing DC fields. Note there were no reliable results on the long-term piezo actuators operations in CW regime. Specific features of ERL, ILC and Project X accelerator technology and challenges of the designs are high magnitude and phase stability of its operations. Mechanical vibrations, or microphonics affect the SRF resonator, while the ferroelectric tuners have shown extremely high tuning speed. We have demonstrated successful mitigation of the residual effects on the ferroelectric-metal interface along with the acceptable level of the overall loss factor of the tuner element. A new concepts of a tuning element based on low dielectric constant ferroelectrics along with fabrication technology of these new BST(M) ferroelectric elements will be presented.

WEPEA014

Recent Electron Cloud Studies in the SPS

electron, injection, emittance, simulation

2525

G. Iadarola, H. Bartosik, M. Driss Mensi, H. Neupert, G. Rumolo, M. Taborelli
CERN, Geneva, Switzerland
G. Iadarola
Naples University Federico II, Science and Technology Pole, Napoli, Italy

It is important to qualify the present status of the SPS with respect to the electron cloud before the Long Shutdown of the CERN accelerator complex, which will take place in 2013-2014. Therefore several electron cloud studies were performed during the 2012 run in order to get a full characterization of the behavior of the SPS with the LHC-type beams with 25 ns bunch spacing, which can be very sensitive to electron cloud effects. The collected information should allow to understand up to which extent this long period without beam operation - and the related interventions on the machine - will degrade the present conditioning state of the SPS, which has been achieved by “scrubbing” over several years. Several measurements with different beam conditions have been collected also on the electron cloud detectors installed in the machine. These results, in combination with detailed simulation studies, will provide the basis for defining strategies of electron cloud mitigation as required for the production of future high intensity and high brightness beams within the LHC Injectors Upgrade (LIU) project.

WEPEA021

Influence of the Vacuum Chamber Limitation on Dynamic Aperture Calculations

dynamic-aperture, multipole, resonance, optics

2543

M. Attal
SESAME, Allan, Jordan

In a storage ring the evaluation of the dynamic aperture taking into account the vacuum chamber limitation is more accurate and may display nonlinearities that could not be seen in the conventional absolute dynamic aperture calculations. This has been investigated in this paper and demonstrated in SESAME dynamic aperture case where taking into account the vacuum chamber uncovered the seriousness of a 5th order resonance mainly when errors like high order multipoles were introduced to the lattice. The destructive effect of the 5th order resonance has been avoided by changing the fractional part of the tunes. The problem has also been more investigated using the Frequency Map Analysis technique.

WEPEA062

Progress in ELENA Design

extraction, emittance, electron, antiproton

2651

S. Maury, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, C. Carli, T. Eriksson, R. Kersevan, S. Pasinelli, G. Tranquille, G. Vanbavinckhove
CERN, Geneva, Switzerland
W. Oelert
FZJ, Jülich, Germany

The Extra Low Energy Antiproton ring (ELENA) is a small ring at CERN which will be built to increase substantially the number of usable (or trappable) antiprotons delivered to experiments for studies with antihydrogen. The report shows the progress in the ELENA design. The choice of optics and ring layout inside of AD hall is given. The main limitations for beam parameters at extraction like intra beam scattering and tune shift due to space charge are discussed. The electron cooler plays key role in ELENA both for efficient deceleration as well as for preparing extracted beam with parameters defined by experiments. The other important systems like beam vacuum, beam instrumentations and others are reviewed as well.

WEPEA063

Upgrades and Consolidation of the CERN AD for Operation during the Next Decades

controls, target, antiproton, electron

2654

T. Eriksson, M. E. Angoletta, L. Arnaudon, J.A. Baillie, M. Calviani, F. Caspers, L.V. Joergensen, R. Kersevan, G. Le Godec, R. Louwerse, M. Ludwig, S. Maury, A. Newborough, C. Oliveira, G. Tranquille
CERN, Geneva, Switzerland

As the ELENA project is now well underway, focus is turned to the Antiproton Decelerator (AD) itself. Most of the machine’s key components are in operation since more than 25 years and a substantial consolidation program is now being launched in view of continued operation beyond 2025. Over the course of the next few years a progressive consolidation of the AD-Target area, the AD-ring and all associated systems will take place. Several investigations have recently been performed in the target area with the objective of establishing the radiation environment and the sensitivity of the antiproton production to potential misalignment of the production elements. Identification of reliability and serviceability issues of the AD-ring components and associated systems has been done and will continue during the 2013 shut-down. Planned and ongoing consolidation activities are also discussed with emphasis on stochastic and electron beam cooling, instrumentation, RF systems, vacuum, magnets, power converters and beam transfer equipment.

WEPFI014

Present Status and Progresses of RFQ of IFMIF/EVEDA

rfq, coupling, linac, quadrupole

2729

R. Dima, A. Pepato, F. Scantamburlo, E. Udup
INFN- Sez. di Padova, Padova, Italy
F. Grespan, A. Palmieri, C. Roncolato
INFN/LNL, Legnaro (PD), Italy

The RFQ of IFMIF/EVEDA is designed to accelerate a 125 mA D⁺ beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz. The production of the modules 16, 17 and 18 necessary has been completed. In this paper the progress and improvements on the production of the modules, as well the development of the brazing procedure design will be described.

WEPFI018

Comparison of High Gradient Performance in Varying Cavity Geometries

damping, coupling, acceleration, HOM

2741

T. Higo, T. Abe, Y. Arakida, Y. Higashi, S. Matsumoto, T. Shidara, T. Takatomi, M. Yamanaka
KEK, Ibaraki, Japan
A. Grudiev, G. Riddone, W. Wuensch
CERN, Geneva, Switzerland

Four types of CLIC prototype TW accelerator structures were high-gradient tested at Nextef, KEK, up to 100 MV/m level and the fifth is under test now. The ramping speed of each processing and the resultant breakdown rate were compared among them. From this comparison, it was found that the ramping speed of the structures with opening ports for HOM damping with magnetic coupling became slow and the resultant breakdown rate became high. It was also found that that with lower surface magnetic field showed faster ramping in processing and lower breakdown rate. This indicates the role of the magnetic field on vacuum breakdowns in copper structure at the region of several tens to 100 MV/m. In this paper, we review the processing stage and the high gradient performance of these structures trying to discuss the relevant parameters, surface electric field, surface magnetic field and other parameters such as Sc, “complex pointing vector”, to the performance difference.

WEPFI019

High Power Test of Kanthal-coated L-band Lossy Cavity

cavity, positron, klystron, solenoid

2744

F. Miyahara, Y. Arakida, Y. Higashi, T. Higo, K. Kakihara, S. Matsumoto
KEK, Ibaraki, Japan
K. Saito
Hitachi, Ltd., Energy and Environmental System Laboratory, Hitachi-shi, Japan
H. Sakurabata
Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken, Japan

We have been developing a Kanthal (Al-Cr-Fe)-coated collinear load as a possible candidate of the L-band acc. structure of SuperKEKB positron capture system. In order to achieve the higher capture efficiency comparing to that of KEKB, the upgrade of the e⁺ production and capture section is required. The system consists of a W target with a flux concentrator followed by acc. structures surrounded by solenoids. The increase of the e⁺ bunch charge and the reduction of satellite bunches are the main issues for this system. The frequency choice of L-band is based on the larger transverse and longitudinal acceptances than those of the S-band one. The load is preferable to compose the system with compact magnets and to minimize the dip in the solenoid field. The design of the load was reported in previous work*. We understand that the Kanthal-coated cell should be confirmed in high power to confirm the feasibility at our design field of 10 MV/m level. We are making a test cavity which consists of 3 cells and one of them is composed of Kanthal-coated disks to lower the intrinsic Q value from 20000 to the order of 1000. The cavity production and the experimental result will be reported.
*Development of L-band accelerating structure with Kanthal-coated collinear load for SuperKEKB, IPAC12, THLR04.

WEPFI021

Influence of Core Winding Tension and Ribbon Quality on the MA Core RF Characteristics

impedance, synchrotron, factory, cavity

2747

M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan
K. Hara, K. Hasegawa, C. Ohmori, M. Toda, M. Yoshii
KEK, Tokai, Ibaraki, Japan

J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) and Main Ring (MR) employ RF cavities loaded with Magnetic Alloy (MA) cores to generate a high field gradient. To achieve the high field gradient, the core shunt impedance is a key parameter. We found during the development of MA cores for RCS RF cavities that the core shunt impedance was increased by lowering a core winding tension. We lowered the core winding tension in order to improve the electrical insulation between MA ribbon layers. The lower winding tension reduced the core filling factor that is defined as the volume ratio of MA ribbons and geometrical dimensions. The core shunt impedance might be reduced according to the core filling factor reduction. We discuss the reason why the lower winding tension increased the core shunt impedance. We also report the influence of the ribbon quality variation on the MA core RF characteristics.

WEPFI055

Experience on Fabrication and Assembly of the First Clic Two-Beam Module Prototype

alignment, quadrupole, RF-structure, instrumentation

2815

D. Gudkov, S. Lebet, G. Riddone, F. Rossi
CERN, Geneva, Switzerland
A. Samoshkin
JINR, Dubna, Moscow Region, Russia

The CLIC two-beam module prototypes are intended to prove the design of all technical systems under the different operation modes. Two validation programs are currently under way and they foresee the construction of four prototype modules for mechanical tests without beam and three prototype modules for tests with RF and beam. The program without beam will show the capability of the technical solutions proposed to fulfil the stringent requirements on radio-frequency, supporting, pre-alignment, stabilization, vacuum and cooling systems. The engineering design was performed with the use of CAD/CAE software. Dedicated mock-ups of RF structures, with all mechanical interfaces and chosen technical solutions, are used for the tests and therefore reliable results are expected. The components were fabricated by applying different technologies for the part manufacturing and joining. The first full-size prototype module was assembled in 2012. This paper is focused on the production process including the comparison of several technical solutions adopted during the realization. The description of the module assembly and quality control measurements are also recalled.

WEPFI061

Petra Cavity Vacuum RF Condition with Field Balance Mechanism for TPS Storage Ring in NSRRC

cavity, coupling, controls, storage-ring

2833

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

In the first stage commissioning of TPS (Taiwan Photon source) storage ring in NSRRC, two room temperature Petra cavities will be used. At this commission stage, 100mA with 950keV beam loss is estimated to have 47.5kW beam loss for each cavity. In the meanwhile, the cavity loss at the specified 1.2MV of each cavity will be about 50kW. Therefore, coupling coefficient of 2 is required. However, the initial design specification of Petra cavity has only beta of about 1.7. Hence, the modification of the input coupler is done with the enhancement of its beta as well as advanced water cooling for some heat point. Besides, due to the two-tuner system of Petra cavity, special field-balance tuner control system is also developed. In RF condition for better vacuum up to 1.4MV, some modification of the tuner mechanical structure is also done to reach high vacuum condition (lower than 5*10^-9 Torr) for storage ring requirement.

WEPFI064

Prototype Refinement of the VELA Transverse Deflecting Cavity Design

cavity, simulation, target, emittance

2842

P. Goudket, S.R. Buckley, L.S. Cowie, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

The Versatile Linear Accelerator (VELA) at Daresbury Laboratory will deliver low energy (5/6 MeV) short bunches (~40 fs) to a number of industrial experimental stations and for scientific research. In order to measure the longitudinal profile of the bunch an S-band transverse deflecting cavity will be inserted into the beamline. A transverse kick of around 5 MV is required therefore a 9 cell design has been chosen. As part of the design iteration a three-cell prototype has been built. Frequency measurements have been performed on the prototype cavity as well as Coordinate Measuring Machine to confirm that the dimensions are to the required design tolerances. Subsequently, further modelling has been performed to improve and refine the design of the 9-cell cavity, to ensure that the frequency of the final design is within the tuning range of the water thermal control system and that the field flatness requirement can be obtained.

WEPFI065

The Commissioning of the EBTF S-band Photoinjector Gun at Daresbury Laboratory

cavity, klystron, electron, laser

2845

A.E. Wheelhouse, R.K. Buckley, S.R. Buckley, P.A. Corlett, J.W. McKenzie, B.L. Militsyn, A.J. Moss
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The first stage of the installation of the Electron Beam Test Facility (EBTF) at Daresbury Laboratory has been completed and a commissioning phase is presently underway. At the heart of the machine is a photoinjector based on a two and a half cell S-band RF gun incorporating a metallic photocathode, which is capable of delivering 4-6 MeV, low emittance, short electron pulses (10 - 250 pC). The photoinjector is driven by a UV light at 266 nm wavelength delivered by a laser system and is powered by a RF system incorporating a Low Level RF system, a high power RF modulator and a klystron. This paper describes the commissioning and conditioning of the photoinjector.

WEPFI073

A Modular Cavity for Muon Ionization Cooling R&D

cavity, simulation, coupling, solenoid

2860

D.L. Bowring, A.J. DeMello, A.R. Lambert, D. Li, S.P. Virostek, M.S. Zisman
LBNL, Berkeley, California, USA
C. Adolphsen, L. Ge, A.A. Haase, K.H. Lee, Z. Li, D.W. Martin
SLAC, Menlo Park, California, USA
D.M. Kaplan
Illinois Institute of Technology, Chicago, Illinois, USA
T.H. Luo, D.J. Summers
UMiss, University, Mississippi, USA
A. Moretti, M.A. Palmer, R.J. Pasquinelli, Y. Torun
Fermilab, Batavia, USA
R.B. Palmer
BNL, Upton, Long Island, New York, USA

The Muon Accelerator Program (MAP) collaboration is developing an ionization cooling channel for muon beams. 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 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 based on a modular pillbox cavity operating at 805 MHz. The modular cavity design allows for the evaluation of different cavity materials - such as beryllium - which may ameliorate or circumvent RF breakdown triggers. Modular cavity components may furthermore be prepared with different surface treatments, such as high-temperature baking or chemical polishing. This poster presents the design and experimental status of the modular cavity, as well as future plans for the experimental program.

WEPFI075

Design of the FRIB RFQ

rfq, linac, ion, dipole

2866

N.K. Bultman, G. Morgan, E. Pozdeyev, Y. Yamazaki, Q. Zhao
FRIB, East Lansing, Michigan, USA
J. Stovall, L.M. Young
TechSource, Santa Fe, New Mexico, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
FRIB linac driver includes a front end and a SRF linac for all stable ion beams with energy more than 200 MeV/u, and beam power on target up to 400 kW. A 80.5 MHz FRQ at the front end accelerates heavy ion beams from 12 keV/u to 0.5 MeV/u, in CW mode. Design of the RFQ is introduced and several important technical issues are discussed in this paper.

WEPFI077

LLNL X-band Test Station Status

gun, alignment, emittance, cathode

2872

R.A. Marsh, F. Albert, G.G. Anderson, S.G. Anderson, C.P.J. Barty, E.T. Dayton, S.E. Fisher, D.J. Gibson, F.V. Hartemann, S.S.Q. Wu
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344
In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test station is being developed to investigate accelerator optimization for future upgrades. This test station will enable work to explore the science and technology paths required to boost the current mono-energetic gamma-ray technology a higher effective repetition rate, potentially increasing the average gamma-ray brightness by two orders of magnitude. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. Detailed design of the test station including is complete, and will be presented with modeling simulations and future upgrade paths. The current status of the installation will also be discussed with future commissioning plans.

WEPFI078

LLNL X-band RF System

klystron, high-voltage, gun, cathode

2875

R.A. Marsh, G.G. Anderson, S.G. Anderson, C.P.J. Barty, S.E. Fisher, D.J. Gibson, F.V. Hartemann
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344
An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray technology at LLNL. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The high power RF for the test station will be provided by a SLAC XL4 11.424 GHz klystron driven by a ScandiNova solid state modulator. The high power system has been installed and results of initial testing into high power loads will be presented. Performance of the system with respect to processing and stability will be discussed as well as future plans for the low level RF system.

WEPFI082

Double-tip Magnetic Field Enhancement

simulation, cavity, electron, cathode

2887

F.Y. Wang, L. Xiao
SLAC, Menlo Park, California, USA

The local electric field enhancement factor β in an rf accelerator cavity has been studied experimentally for decades and found to be in the range from few tens up to few hundreds for various rf frequencies and materials. A large field enhancement factor is usually thought to come from sharp tips whose β is roughly the ratio of their height to their tip radius. For a β of few hundred, the corresponding tip height would need to be more than 10 microns, which should be visible in a scanning electron microscope (SEM). However, the estimated β from SEM images of cavity surfaces is around 10. Therefore, the physics of such large β values is still not clear. In this paper, we have studied differentμstructures and found that the magnetic field could be enhanced many times in the presence of two nearby tips with β of 10. The large local magnetic field enhancement could lead to large enhanced pulsed heating and thus could melt surface in a very short time and form a liquid Taylor cone.

WEPFI084

High Power S-band RF Window Optimized to Minimize Electric and Magnetic Field on the Surface

klystron, linac, simulation, positron

2893

A.D. Yeremian, V.A. Dolgashev, S.G. Tantawi
SLAC, Menlo Park, California, USA

Funding: * Work Supported by Doe Contract No. DE-AC02-76SF00515
RF windows are used to separate vacuum from atmosphere in high power microwave systems, such as klystrons. RF breakdowns in these megawatt power environments are frequent and problematic. And S-band RF window was designed to have reduced electric and magnetic field in the ceramic and waveguide joints. Specifically the normal component of the electric field on the ceramic is minimized and a traveling wave is created inside the ceramic by optimizing the shape of the window and the geometry of the joint between the circular waveguide to the rectangular waveguide. A prototype of this window in the process of being made at SLAC for high power tests.

WEPFI086

Normal Conducting Radio Frequency X-band Deflecting Cavity Fabrication, Validation and Tuning

cavity, electron, linear-collider, collider

2899

R.B. Agustsson, L. Faillace, A.Y. Murokh, E. Spranza, S. Storms
RadiaBeam, Santa Monica, USA
D. Alesini
INFN/LNF, Frascati (Roma), Italy
V.A. Dolgashev, J.R. Lewandowski
SLAC, Menlo Park, California, USA
J.B. Rosenzweig
UCLA, Los Angeles, California, USA
V. Yakimenko
BNL, Upton, Long Island, New York, USA

An X-band Traveling wave Deflector mode cavity (XTD) has been developed, fabricated, tuned and characterized by Radiabeam Technologies to perform longitudinal measurement of the sub-picosecond ultra-relativistic electron beams. The device is optimized for the 100 MeV electron beam parameters at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory, and is scalable to higher energies. The XTD is designed to operate at 11.424 GHz, and features short filling time, femtosecond resolution, and a small footprint. RF design, structure fabrication, cold testing and tuning results are presented.

WEPFI088

High-power Tests of an Ultra-high Gradient Compact S-band (HGS) Accelerating Structure

klystron, coupling, monitoring, linac

2902

L. Faillace, R.B. Agustsson, P. Frigola, A.Y. Murokh, S. Seung
RadiaBeam, Santa Monica, USA
S.G. Anderson
LLNL, Livermore, California, USA
V.A. Dolgashev
SLAC, Menlo Park, California, USA
J.B. Rosenzweig
UCLA, Los Angeles, California, USA
V. Yakimenko
BNL, Upton, Long Island, New York, USA

RadiaBeam Technologies reports on the RF design, fabrication and high-power tests of a ultra-high gradient S-Band accelerating structure (HGS) operating in the pi-mode at 2.856 GHz. The compact HGS structure offers a drop-in replacement for conventional S-Band linacs in research and industrial applications such as drivers for compact light sources, medical and security systems. The electromagnetic design (optimization of the cell shape in order to maximize RF efficiency and minimize surface fields at very high accelerating gradients) has been carried out with the codes HFSS and SuperFish while the thermal analysis has been performed by using the code ANSYS. The high-power conditioning was carried out at Lawrence Livermore National Laboratory (LLNL).

WEPFI090

An X-band Dielectric-based Wakefield Power Extractor

wakefield, simulation, damping, impedance

2908

C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
M.E. Conde, W. Gai, J.G. Power
ANL, Argonne, USA
V.A. Dolgashev, J.R. Lewandowski, S.G. Tantawi, S.P. Weathersby
SLAC, Menlo Park, California, USA
I. Syratchev
CERN, Geneva, Switzerland

Funding: US DoE SBIR Phase II project under Contract#DE-SC0004322
An X-band dielectric-based wakefield power extractor is under development to function as a high power rf source primarily for Two Beam Accelerator applications. A low surface electric field to gradient ratio and low fabrication cost are two main advantages of the dielectric-loaded accelerating/decelerating structure. We have designed a 12 GHz dielectric-based power extractor that has similar performance parameters to the CLIC PETS (23 mm beam channel, 240 ns pulse duration, 135 MW output per structure) using the CLIC drive beam. In order to study potential rf breakdown issues, as a first step we built a 11.424 GHz dielectric-based power extractor scaled from the 12 GHz design. A high power rf test will be conducted using the SLAC 11.424 GHz high power rf source in Dec. 2012. Results of the high power testing will be reported. Meanwhile, the 12 GHz fully featured dielectric power extractor is also under construction; construction progress and bench tests will be discussed.

WEPME007

Commissioning of the Upgraded Superconducting CW Linac ELBE

cavity, klystron, linac, SRF

2935

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

With the expansion of the radiation source ELBE a center for high power radiation sources is being built at the Helmholtz Zentrum Dresden-Rossendorf (HZDR). In a first step (January 2012) the available CW RF-power (1.3 GHz) per superconducting 9-cell TESLA cavity at ELBE had been increased from 8.5 kW to 20 kW (CW) using solid state amplifiers. In a second step the performance of several machine components of ELBE must be redesigned to enable full power operation without risks. The poster gives an overview how these problems have been solved at ELBE and reports on the commissioning.

WEPME058

Integrated System Modeling Analysis of a Multi-cell Deflecting-mode Cavity in Cryogenic Operation

cavity, simulation, cryomodule, coupling

3064

Y.-M. Shin, M.D. Church, J. Ruan
Fermilab, Batavia, USA

Over the past decade, multi-cell deflecting (TM110) mode cavities have been employed for experiments on six-dimensional phase-space beam manipulation *,**,***,****,****** at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently scheduled at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretic prediction. We thus fully inspected the cavity design with theoretical calculation (based on Panofsky-Wenzel theorem) combined with RF simulations. Also, we are extensively developing an integrated computational tool with comprehensive system analysis capacity to solve complex thermodynamics and mechanical stresses of a high-Q deflecting-mode cryomodule. We will benchmark simulation analysis result with experimental data from high power RF tests in Fermilab. Successfully developed modeling tool will be potentially used for prompt assessment on RF performance of vacuum-cryomodules.
* D. A. Edwards, LINAC 2002
** Y.-E Sun, PRTAB 2004
*** P. Piot, PRSTAB2006
**** J. Ruand et al., PRL 2011
***** Y.-E. Sun, et al., PRL 2010

THOAB102

A Pepper-pot Based Device for Diagnostics of the Single-shot Beam

ion, emittance, LabView, diagnostics

3093

S.X. Peng, J. Chen, J.E. Chen, Z.Y. Guo, P.N. Lu, H.T. Ren, Z.H. Wang, Y. Xu, Z.X. Yuan, T. Zhang, J. Zhao
PKU, Beijing, People's Republic of China
A.L. Zhang
Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
J. Zhao
State Key Laboratory of Nuclear Physics and Technology, Beijing, Haidian District, People's Republic of China

Generally the beam emittance can be measured by different Emittance Measurement Units (EMUs), such as the pepper-pot device, the slit-wire type facility and the Allison scanner. However, for a microsecond single-shot ion beam, the pepper-pot device is a suitable choice because of its cut-off single-shot technique without any time-consuming step. A pepper-pot based beam current & profile measurement device, which is a combination of Faraday cup technique and pepper-pot measurement facility, was developed at PKU. It consists of a main Faraday cup with a pepper-pot mask at its bottom, and a Faraday cup array locating 3 mm away from the pepper-pot mask. This device has been tested at the PKU LEBT test bench and the measurement results are consistent with the results acquired by the Allison scanner. By replacing the Faraday cup array with a fluorescent screen and a CCD camera, this device becomes a facility that not only has the ability to measure the total beam current and the beam profile, but also has the capability to measure the beam emittance for CW or pulsed ion beams. Details will be presented in this paper.

Slides THOAB102 [5.332 MB]

THPEA018

Design of an Integrated Platform based on CSS and MATLAB for SSC-LINAC System Controlling and Data Analysis

controls, EPICS, linac, power-supply

3182

M. Yue, S.Z. Gou, W. Zhang
IMP, Lanzhou, People's Republic of China

CSS is the abbreviation of Control System Studio and is widely used in particle accelerator experiments area. Based on Eclipse, it is a collection of tools which can display details of the PV, show alarm state, as well as the function of data browsers, archive engine and so on. CSS offers an integrated approach to build a control system. We have recently developed a control and monitor system for the SSC-LINAC system to control and monitor power supply, vacuum, high frequency, and other accelerator equipments. In the area of accelerator controlling, we often need to do some mathematical operations like Fourier transform of the monitored data to get some accuracy performances of interested equipments. Unfortunately, CSS cannot satisfy this requirement. It is well known that MATLAB plays very well in data process and provides many mathematical tools. If we can combine these two tools together, we can get better control strategy. In the presentation, we will discuss the design of this integrated platform to implement the display, control and data process.

THPEA034

ESS Integrated Control System Integration Support and the Agile Methodology Proposal

controls, monitoring, EPICS, target

3219

M. Reščič
Cosylab, Ljubljana, Slovenia
L. Fernandez, A. Nordt
ESS, Lund, Sweden

The stakeholders of the ESS Integrated Control System (ICS) reside in four main parts of the ESS machine: accelerator, target, neutron instruments and conventional facilities. In order to maintain and support the standardized hardware and software platforms for controls all of the stakeholders' integration requirements and efforts must be strictly harmonized. This called for a decision by the ICS to perform the majority of the work in a package titled 'Integration Support', ranging from FPGA code development to EPICS integration. This exposes a high number of interfacing systems and devices and planning of such activities for each system make the standard waterfall planning model highly inefficient and risky. In order to properly address the planning risks the agile methodology is proposed - from product owners and teams to scrums and sprints, everything to offer a better and more efficient integration support to controls stakeholders.

THPEA038

ESS Naming Convention

target, controls, linac, neutron

3222

K. Rathsman, G. Trahern
ESS, Lund, Sweden
J. Malovrh Rebec, M. Reščič, M. Vitorovic
Cosylab, Ljubljana, Slovenia

The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon thermal neutrons. The main facility will be built in Lund, Sweden. Construction is expected to start 2013 and the first neutrons will be produced in 2019. The ESS linac will deliver 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The ESS Naming Convention is based on a standard, originally developed for the Super Superconducting Collider (SSC) and later adopted by other large research facilities, e.g. the Spallation Neutron Source (SNS), Facility for Rare Isotope Beams (FRIB), International Thermonuclear Experimental Reactor (ITER), and the Continuous Electron Beam Accelerator Facility (CEBAF). The ESS Naming Convention was agreed upon and approved at a very early stage of the ESS project in order to establish a standard before names started to evolve. The main scope was to standardise meaningful, yet short and mnemonic signal and device names. The present paper describes the naming convention, the site wide implementation at ESS and associated web based tools.

THPEA041

Performance Improvements of the SPS Internal Beam Dump for the HL-LHC Beam

kicker, proton, dumping, synchrotron

3231

F.M. Velotti, O. Aberle, C. Bracco, E. Carlier, P. Chiggiato, J.A. Ferreira Somoza, B. Goddard, M. Meddahi, V. Senaj, J.A. Uythoven
CERN, Geneva, Switzerland

The SPS internal beam dump has been designed for beam specifications well below the HL-LHC ones, and for modes of operation which may not be adequate for the HL-LHC era. The present system suffers from several limitations in the allowed intensity and energy range, and its vacuum performance affects nearby high-voltage kicker systems. In this report the limitations of the internal beam dump system are reviewed, and the possible improvements compared. Preliminary upgrade proposals are presented, taking into consideration the expected operational HL-LHC parameters.

THPEA055

NESTOR Facility Control System

controls, storage-ring, power-supply, monitoring

3267

D.V. Tarasov, V.N. Boriskin, I.M. Karnaukhov, D. Korzhov, V.N. Ljashchenko, A. Mytsykov, A.A. Shcherbakov, V.L. Skirda, V.I. Trotsenko, A.Y. Zelinsky
NSC/KIPT, Kharkov, Ukraine

The general principles of the NESTOR facility control system are presented in the paper. The main features of the systems such as magnetic, vacuum, diagnostic, Rf etc. concerning the control and monitoring are discussed. The first results of the system implementation are presented.

THPFI002

Construction and Initial Tests of the Electrostatic Septa for MedAustron

septum, cathode, extraction, injection

3288

J. Borburgh, R.A. Barlow, C. Boucly, A. Prost
CERN, Geneva, Switzerland
U. Dorda, T. Kramer, T. Stadlbauer
EBG MedAustron, Wr. Neustadt, Austria

For the MedAustron facility under construction in Wiener Neustadt/Austria, two electrostatic septa are built in collaboration with CERN. These septa will be used for the multi-turn injection of protons and ions, as well as for the slow extraction from the synchrotron. The power supplies are designed to combine the required precision with the capability to cycle sufficiently fast to keep up with the machine cycle. The septa are being assembled at CERN. Initial tests have been done on the remote displacement system to validate its precision and communication protocol with the MedAustron control system. Subsequently the septa are tested for vacuum performance and then HV conditioned. The construction of the septa, the requirements of the power supplies and the high voltage circuit will be described. Results of the initial laboratory tests, prior to installation in the accelerator, will be given.

THPFI003

Vacuum Study of the Cavity String for the IFMIF - LIPAc Cryomodule

cryomodule, cavity, pick-up, linac

3291

N. Bazin, G. Devanz, F. Orsini
CEA/DSM/IRFU, France

In the framework of the International Fusion Materials Irradiation Facility (IFMIF), a superconducting option has been chosen for the 5 MeV RF Linac of the first phase of the project (EVEDA), based on a cryomodule composed of 8 HWRs, 8 RF couplers and 8 Solenoid packages. This paper will focus on the beam vacuum of the cryomodule. The cryomodule beam line is made of the pattern solenoid package / cavity-coupler, and a valve on each side of the cryomodule. During the installation of the cryomodule on the accelerator system, the cavity string has to be pumped down with the beam valves closed. Thereby a manifold is connected to the cavities during the assembly of the beam line components in the clean room. In previous conferences, the cryomodule was presented with a vacuum manifold connected to each cavity. A study realized on this complex vacuum configuration with Molflow, a test-particle Monte-Carlo simulator for ultra-high vacuum, permitted to reduce the number of cavities connected to the manifold and by consequence to reduce the risk of pollution during the clean room assembly.

THPFI004

Progress on the SRF Linac Developments for the IFMIF-LIPAC Project

cryomodule, solenoid, linac, SRF

3294

F. Orsini
CEA/DSM/IRFU, France
P. Abramian, J. Calero, J.C. Calvo, J.L. Gutiérrez, T. Martínez de Alvaro, J. Munilla, I. Podadera, F. Toral
CIEMAT, Madrid, Spain
N. Bazin, P. Brédy, P. Carbonnier, G. Devanz, G. Disset, N. Grouas, P. Hardy, V.M. Hennion, H. Jenhani, J. Migne, A. Mohamed, J. Neyret, J. Relland, B. Renard, D. Roudier
CEA/IRFU, Gif-sur-Yvette, France

In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV in CW, an accelerator prototype is presently under design and realization for the first phase of the project. This accelerator includes a SRF Linac, which is designed for the transportation and focalization of the deuteron beam up to 9 MeV. This SRF Linac is a large cryomodule of ~6 m long, working at 4.4 K and at the frequency of 175 MHz in continuous wave. It is mainly composed of 8 low-beta HWRs, 8 Solenoid Packages and 8 RF Power Couplers. This paper focuses on the recent developments and changes made on the SRF Linac design: following the abandon of the HWR frequency tuning system, initially based on a plunger located inside the central region of the resonator, a new external tuning system has been designed, implying a complete redesign of the resonator and consequently impacting the cryomodule lattice. The recent changes in the design are presented in this paper. In addition, cold tests were performed on a HWR prototype and cold tests results of the magnets prototypes are also presented.

THPFI010

High Energy RF Deflectors for the FERMI@Elettra project

electron, linac, FEL, wakefield

3309

M. Dal Forno, S. Biedron, D. Castronovo, P. Craievich, S. Di Mitri, D. La Civita, G. Penco, M. Petronio, F. Pradal, L. Rumiz, L. Sturari, D. Wang, D. Zangrando
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
P. Craievich
PSI, Villigen PSI, Switzerland
M. Dal Forno, M. Petronio, R. Vescovo
University of Trieste, Trieste, Italy
N. Faure
PMB-ALCEN, PEYNIER, France

Measuring and controlling the longitudinal phase space and the time-slice emittance of the electron bunch at 1.2 GeV entering in the undulator beam-lines, is crucial to obtain high FEL performances. In the FERMI@Elettra machine, two RF deflecting cavities have been installed at the end of the linac, in order to stretch the electron bunch horizontally and vertically, respectively. The two cavities are individually powered by the same klystron and a switch system is used to choose the deflection plane. This paper reports the RF measurements carried out during the acceptance test, the RF conditioning including the breakdown rate measurements. Finally, the commissioning with electron beam of the deflecting structure and a comparison of the measured electron bunch length evaluated by using the two deflectors are also reported.

THPFI012

Design of the cERL Vacuum System

linac, electron, diagnostics, gun

3315

Y. Tanimoto, S. Asaoka, T. Honda, T. Nogami, T. Obina, R. Takai
KEK, Ibaraki, Japan

The compact Energy Recovery Linac (cERL) is being constructed as a test accelerator for the ERL-based future light source at KEK. In the design of the cERL, electron beams with low normalized emittance (0.1 mm·mrad) and high average current (10 mA) are generated at a 500-kV gun, and accelerated up to 125 MeV at superconducting (SC) cavities that make energy recovery. The vacuum system should accommodate such high intensity, ultrashort bunch (0.1 ~ 3 ps) electron beams, and be designed so as to minimize its loss factor. Therefore, low impedance vacuum components, such as zero-gap flanges and rf-shielded screen monitors, have been developed. Extra high and clean vacuum is required in the vicinity of the SC cavities to maintain their high gradient operation, and those beam tubes are coated by Non-Evaporable Getter (NEG) films. Because of the low beam energy, photon absorbers are not necessary and the beam tubes can be made of stainless steel. However, the photon scrubbing effect is so limited that the beam tubes should be ready for in-situ bakeout and are wrapped with thin Kapton heaters, which are also useful for the NEG-coating activation.

THPFI014

Bellows with a New RF Shield Made of Metal Braid for High Intensity Proton Accelerators

impedance, background, synchrotron, coupling

3321

N. Ogiwara, J. Kamiya, M. Kinsho, Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
O. Koizumi
Sun-Tech limited, Kobe, Japan

In the 3 GeV-RCS (Rapid cycling Synchrotron) in J-PARC (Japan Accelerator Research Complex) project, large-scale hydro-formed bellows were developed to adjust the gap between the ceramic ducts and/or between the ceramic ducts and the transport ducts. They have been equipped with a newly developed RF shield, because the usual beryllium-copper spring finger contacts were found to be very hard (roughly 1000 N/mm) owing to the large size. This contact is made of Ti braid, which consists of wires with a diameter of 0.3 mm. This RF contact is a kind of basket (with two ports) made with the braids. Because of the spring effect, the contact can change shape easily. In addition, the contact can easily connect the different cross sections in a smooth fashion. Furthermore, this structure is almost free from the dust generation, which is one of the most troublesome problems for the usual spring finger contacts. This time, we have constructed reserve bellows with the RF shield made of SUS 316L wires to improve the reliability of user operation. The outline of the bellows will be presented, especially laying emphasis on the mechanical function of the RF shield.

THPFI015

In-situ Degassing of the Ferrite Cores in the Extraction Kicker Magnets of the J-PARC 3-GeV RCS

kicker, target, shielding, quadrupole

3324

J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, K. Suganuma, T. Yanagibashi
JAEA/J-PARC, Tokai-mura, Japan

Kicker magnets extract the accelerated beam to the beam transport lines in the RCS of the J-PARC. The kicker magnets mainly consist of Ni-Zn ferrite cores and Al alloy plates, and are installed in a vacuum to prevent discharge because a high voltage is applied for a short period. It is important to reduce the outgassing of water vapor from the ferrite cores. Although the kicker magnets have been working well, recently the vacuum quality became a little poor. Thus, we developed the in-situ degassing method for the ferrite cores. This is achieved by directing the heat from the heat source to the kicker magnet and not to the chamber wall. With the test stand we succeeded to flow almost all the heat toward the kicker magnet and to bake out the ferrite cores about 150°C, maintaining the temperature of the chamber wall less than 50°C. As the previous work with TDS measurements revealed that the absorbed water molecules can be easily removed by the bake-out at 100-150°C in a vacuum, the outgassing from the ferrite cores was successfully reduced. The details of the in-situ degassing method will be reported, including the practical method to reduce the outgassing of the working kickers.

THPFI016

DESIGN CONSIDERATION OF BEAM DUCTS FOR QUADRUPOLE CORRECTORS IN J-PARC RCS

quadrupole, synchrotron, injection, focusing

3327

J. Kamiya, N. Hayashi, H. Hotchi, M. Kinsho, N. Ogiwara, N. Tani, Y. Watanabe
JAEA/J-PARC, Tokai-mura, Japan

which rapidly correct the tunes, are planned to be installed during the summer shutdown in 2013. The characteristic of the excitation pattern of such quadrupoles (quadrupole corrector) is their fast change of magnetic field, which are more than 200T/s at the fastest point. In this report, we describe a deliberation flow about the design of a vacuum chamber, which is installed in the quadrupole corrector. The effect of eddy current was calculated in the case of the current titanium vacuum chamber. The results showed that the temperature rise was too much (up to ~350oC) and the magnetic field in the vacuum chamber is largely distorted by the eddy current. Therefore we decided to employ an alumina ceramics vacuum chamber, for which we have a past achievement in RCS*. We estimated the displacement and stress, which is caused by the atmospheric pressure, for the alumina ceramics vacuum chamber and vacuum component around it by making the calculation model for the finite element method. It was found that there was no large displacement and stress by installing the alumina ceramics vacuum chamber.
*M. Kinsho, et al. Vacuum 81 (2007) 808.

THPFI018

The Design and Construction of Stripping Probe System for CYCIAE-100

controls, extraction, proton, cyclotron

3333

Shizhong. An, F.P. Guan, P.Z. Li, L.P. Wen, H.D. Xie, Z.G. Yin, T.J. Zhang
CIAE, Beijing, People's Republic of China

A 100 MeV H⁻ compact cyclotron is being constructed in China Institute of Atomic Energy (CYCIAE-100). 75 MeV - 100 MeV proton beams with 200 μA beam intensity will be extracted in dual opposite directions by charge exchange stripping devices. Two stripping probes with carbon foils are inserted radially in the opposite direction from the main magnet pole and the obtained two proton beams after stripping foil are transported into the crossing point in a combination magnet center separately under the fixed main magnetic field. Because of the large energy range of the extracted beam, the stripping probe system is the most critical and complicated device in the dual extraction. In order to save the foil changing time, the structure of the foil changing system in the vacuum is adopted. The foil automatic changing machine is outside the magnetism yoke and 12 pieces foil can be changed in one time. The design and fabrication of the probe system has been finished and it is going to the progress of installation and adjusting. The experimental verification on probe rod driving and foil changing system has been finished in 2010. The whole stripping extraction system will be installed in 2013.

THPFI019

Main Magnet Installation for CYCIAE-100

target, cyclotron, tandem-accelerator, simulation

3336

Y.L. Lu, W. Jing, Z.H. Wang, T.J. Zhang
CIAE, Beijing, People's Republic of China

The CYCIAE-100 proton cyclotron being constructed in CIAE is designed to extract the proton beam of 100MeV and 200uA. The main magnet is the importantest part of the cyclotron. The diameter of the CYCIAE-100 main magnet is 6160mm. Its height is 3860mm. Its total weight is about 416 tons, and the largest part is about 170 tons. The beamline of CYCIAE-100 will be connected to the HI-13 tandem accelerator at CIAE. So, the CYCIAE-100 main magnet should be installed accurately. The vertical tolerance of the CYCIAE-100 main magnet is 0.20mm, and the horizontal tolerance is 0.50mm. The CYCIAE-100 main magnet is located in an underground building which level is -4m. There is a horizontal hole on the west wall of the accelerator building. All parts of the main magnet had been transported through this horizontal hole. The CYCIAE-100 main magnet had been installed in November 2012 at CIAE. In fact the error of installation is: the vertical 0.10mm, the horizontal 0.20mm. The installation process will be shown in this paper.

THPFI022

The M-C Application in Designing Tailored Cryopump Used in Cyciae-100 Cyclotron

cyclotron, radiation, beam-losses, ion

3342

S.P. Zhang, Z.G. Li, G.F. Pan, J.S. Xing, F. Yang, T.J. Zhang
CIAE, Beijing, People's Republic of China

A compact high intensity cyclotron CYCIAE-100 was selected as the driver for the Beijing Radioactive Ion Facility (BRIF). A pressure of 5×10-8 mbar is required to achieve acceptable beam losses in the CYCIAE-100 cyclotron. As the existing ports on the cyclotron valley are insufficient to provide enough pumping speed using commercially available pumps, two tailored cryopanels with a pumping speed of 60000 l/s for each are designed. Based on the Monte-Carlo method, a mathematical model of molecular movement and collision between the panels and their shield was developed. The ratio of molecular reflected to the baffle to molecular passing through the baffle is the sticking probability on the panels. When taking the transmission probability of the chevron baffle, capture coefficient of cryopanel can be calculated. It could provide a reference to design the cryopanel shape and its condensation area.

THPFI023

A Newly Developed High Directivity X-band Waveguide Directional Coupler

simulation, coupling, insertion, pick-up

3345

X. He, X. Wang, F. Zhao
IHEP, Beijing, People's Republic of China

A new X-band waveguide directional coupler working at 11.9924 GHZ is designed. Four holes symmetrical to the structure is drilled along the central line of the narrow-wall, which is used to couple the electromagnetic power from the main-waveguide to the sub-waveguide. The final prototype has got a measurement result of 32.2 dB Directivity (-47.0 dB Coupling Degree) together with a very low VSWR (1.067) and Insertion Loss (-0.11 dB) at 11.9924 GHz. The vacuum performance is also qualified.

THPFI026

DESIGN OF CSNS R DUMP WINDOW

neutron, target, extraction, proton

3354

L. Liu, L. Kang, X.J. Nie, H. Qu
IHEP, Beijing, People's Republic of China

The China Spallation Neutron Source (CSNS) accelerator systems will provide a 1.6 Gev proton beam to a target for neutron production. The extraction dump is used to incept the waste beam in the Ring-Target transport line. At the end of the beam pipe, we adopt a thin window to ensure the accelerator vacuum. When beam gets across the window, temperature of the window will be elevator because of the energy deposit. So, the study on structure and thermal stress analysis is necessary. This article expatiates the way on calculating the energy deposit and thermal stress analyses.

THPFI028

Anti-earthquake Structural Design for CSNS Beam Dump

acceleration, neutron

3358

X.J. Nie, L. Kang, L. Liu, H. Qu
IHEP, Beijing, People's Republic of China

To ensure the beam dump shield iron can resist the damage of earthquake and maintain the normal protective capability, anti-earthquake design was carried out in this paper. The parts for seismic resistance were designed according to the feature of foundation building. The force model was reached through the analysis of seismic load. The structure dimension was decided on the basis of the theory of strength. A pre-buried plate with hooks was achieved and the force model was simplified as fixed end. The minimal diameter of hook showed 30mm. The fixing device with plate decreases the precision requirement of foundation building and can be used to fix the shield iron to resist the earthquake.

THPFI031

Development of Beam Collimators for the 1.6 GeV Rapid Cycling Synchrotron of CSNS

collimation, synchrotron, simulation, shielding

3364

J.B. Yu, pf.He. He, L. Kang, H. Qu, Y.Q. Zou
IHEP, Beijing, People's Republic of China

In order to reduce the uncontrolled losses in the localized station, the beam collimation system has been performed for the 1.6GeV synchrotron of CSNS. The CSNS/RCS transverse collimation system is designed to be a two-stage system which consists of one primary collimator and four secondary collimators. Much work about machinery design and manufacture of the collimation system has been done till now. This paper will show the exterior frame of collimation system by considering the physical demands and spatial position. Then the progress which contains design and machining of collimators will also be introduced. Finally some problems which are mainly about the design of secondary collimators will be mentioned.

THPFI040

DEVELOPMENT OF A TARGET SYSTEM FOR RARE ISOTOPE BEAM PRODUCTION WITH HIGH-POWER HEAVY-ION BEAMS*

target, electron, radiation, ion

3373

J.-W. Kim, S. Hong, J.H. Kim, M. Kim, J. Song
IBS, Daejeon, Republic of Korea

To produce rare isotope beams, in-flight fragmentation method utilizing a thin target and heavy-ion primary beam can be used. The existing facilities provide the maximum primary beam power of a few kW, while the next generation facility is planned to use hundreds of kW of 238U beam. We are designing a rare-isotope beam facility, which can provide U beam with the maximal power of 400 kW at the energy of 200 MeV/u. The high-power target studied is made of multi-slice rotating graphite to enhance radiation cooling. The total target thickness is roughly 2 mm with more than 10 slices. The resultant power density inside the target reaches above 50 MV/cm³. Numerical simulation for thermo-mechanical analysis has been performed using PHITS and ANSYS for single and multi-slice targets. Also, empirical test was made using 70-keV electron beam for a single-slice rotation target with the thickness of 0.2 mm. The results of simulation and e-beam tests will be presented.
* Work supported by Rare Isotope Science Program (RISP) through the National Research Foundation of Korea (NRF) funded by Ministry of Science, ICT and Future Planning (MSIP) (2011-0032011)

THPFI043

The Status of the Vacuum System of the MAX IV Laboratory

storage-ring, dipole, injection, status

3382

E. Al-Dmour, J. Ahlbäck, D. Einfeld, M.J. Grabski, P.F. Tavares
MAX-lab, Lund, Sweden
Ł. Walczak
Solaris, Kraków, Poland

All the vacuum chambers of the 3 GeV storage ring of MAX IV laboratory are under production. NEG coating R&D has been done to validate technical solutions for the coating process. The standard vacuum chambers for the 1.5 GeV ring of MAX IV and Solaris are designed and they are in the procurement process. We present an update in the technical design of the vacuum chambers following the interaction with the manufacture, the implications on the production due to NEG coating and the design of the vacuum chambers of the 1.5 GeV storage ring.

THPFI044

NEG Thin Film Coating Development for the MAX IV Vacuum System

cathode, plasma, synchrotron, synchrotron-radiation

3385

M.J. Grabski, J. Ahlbäck, E. Al-Dmour, P.F. Tavares
MAX-lab, Lund, Sweden
S. Calatroni, P. Chiggiato, P. Costa Pinto, M. Taborelli
CERN, Geneva, Switzerland

The new synchrotron radiation facility of the MAX IV laboratories is under construction and expected to deliver the first light beam in 2016. To cope with the small aperture, the intense photon bombardment and the low-pressure requirement, most of the beam pipes for the 3-GeV ring are going to be coated with Ti-Zr-V non-evaporable getter (NEG) thin films. To take advantage from the experience acquired during the construction of the Large Hadron Collider (LHC), collaboration between CERN and MAX IV Laboratories has been set up. The choice of the extruded Cu tubes, the preliminary surface treatments, the coating configuration, and the performance validation of the small-diameter vacuum chambers have been addressed. In parallel, an intense development has been tackled at CERN for the coating of vacuum chambers where photon and electron beams circulate in separate pipes. The most important results of the collaboration are presented and future perspectives pointed out.

THPFI046

First Results of an Experiment on Advanced Collimator Materials at CERN HiRadMat Facility

simulation, proton, instrumentation, laser

3391

A. Bertarelli, O. Aberle, R.W. Aßmann, E. Berthomé, V. Boccone, M. Calderón Cueva, F. Carra, F. Cerutti, N. Charitonidis, C. Charrondière, A. Dallocchio, M. Donzé, P. Francon, M. Garlaschè, L. Gentini, M. Guinchard, N. Mariani, A. Masi, P. Moyret, S. Redaelli, A. Rossi, S.D.M. dos Santos
CERN, Geneva, Switzerland
M. Calderón Cueva
Universidad San Francisco de Quito, Cumbayá, Colombia
N. Charitonidis
EPFL, Lausanne, Switzerland
L. Peroni, M. Scapin
Politecnico di Torino, Torino, Italy

Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579
A comprehensive, first-of-its-kind experiment (HRMT-14) has been recently carried out at CERN HiRadMat facility on six different materials of interest for Beam Intercepting Devices (collimators, targets, dumps). Both traditional materials (Mo, W and Cu alloys) as well as advanced metal/diamond and metal/graphite composites were tested under extreme conditions as to pressure, density and temperature, leading to the development of highly dynamic phenomena as shock-waves, spallation, explosions. Experimental data were acquired, mostly in real time, relying on extensive embarked instrumentation (strain gauges, temperature and vacuum sensors) and on remote acquisition devices (laser Doppler vibrometer and high speed camera). The experiment was a success under all points of view in spite of the technological challenges and harsh environment. First measurements are in good agreement with results of complex simulations, confirming the effectiveness of the acquisition system and the reliability of advanced numerical methods when material constitutive models are completely available. Interesting information has been collected as to thermal shock robustness of tested materials.

THPFI049

Evaluation of the NEG Coating Saturation Level after 3 Years of LHC Beam Operation

proton, ion, electron, luminosity

3397

G. Bregliozzi, V. Baglin, J.M. Jimenez, G. Lanza, T. Porcelli
CERN, Geneva, Switzerland

The room temperature vacuum system of the Large Hadron Collider (LHC) at CERN system has been designed to ensure vacuum stability and beam lifetime of 100 h with nominal current of 0.56 A per beam at 7 TeV of energy. During last two years the LHC operated with proton beams at a maximum energy of 4 TeV, coasting for several hours each time, inducing high pressure due to different effects: synchrotron radiation, electron cloud and localized temperature increase. All these phenomena generated an important gas load from the vacuum chamber walls, which led in some cases to a partial or a total saturation of the NEG coating. To keep the design vacuum performances and to schedule technical interventions for NEG vacuum reactivation, it is necessary to take into account all these aspects and to regularly evaluate the saturation level of the NEG coating. This study analyses the saturation level of the NEG coated beam pipes in the LHC accelerator. Pressure reading variation without proton beams circulating are analysed and combined with laboratory studies of the NEG saturation behaviour and with Vacuum Stability Code (VASCO) simulations.

THPFI050

Some Ideas Towards Energy Optimization at CERN

proton, radiation, controls, secondary-beams

3400

H.J. Burckhart, J.-P. Burnet, F. Caspers, V. Doré, L. Gatignon, C. Martel, M. Nonis, D. Tommasini
CERN, Geneva, Switzerland

The paper presents the efforts of CERN to optimize its energy usage. Work is proceeding in 3 areas: accelerators, campus and infrastructure, and re-use of thermal “waste” energy. The accelerator chain has the potential to further reduce the energy consumption by dynamic suppression of cycles when they are temporarily not needed and by operating magnets in pulsed mode. R&D for future accelerators includes the recuperation of the RF energy, which is not used for acceleration of the beams. Concerning the CERN campus more than half of the buildings are older than 40 years. Hence there is a big need for renovation, which includes energy aspects. New buildings use renewable energy whenever possible. As an example a building is under construction, which will use a 250 m2 solar field together with an absorption refrigerator for cooling purposes. Finally, about 80% of the electric energy gets dissipated in air cooling towers. Part of this energy can be re-used for heating buildings.

THPFI051

Radio-Frequency Multipacting as Quality Control of Coatings for e-Cloud Suppression

dipole, coupling, electron, resonance

3403

P. Costa Pinto, J. Bauche, S. Calatroni, F. Caspers, P. Edwards, M. Holz, M. Taborelli
CERN, Geneva, Switzerland

To mitigate electron clouds in particle accelerators, a carbon coating with low SEY has been developed. In the case of the SPS (Super Proton Synchrotron), which belongs to the LHC injector chain, testing the performance of coated beam pipes directly in the accelerator must cope with the schedule of the regular machine operation. For this reason an alternative instrument based on RF induced multipacting in a coaxial configuration has been designed for ex-situ characterization of the main bending dipoles of the SPS. In this contribution we report the results obtained before and after coating for two 6.4 meter dipoles with different cross sections of the vacuum chambers. The multipacting is monitored by measuring the pressure rise and the RF reflected power. After coating, the power threshold to induce multipacting is strongly reduced indicating a lower propensity for electron cloud. The impact of the RF coupling on the sensitivity of the technique is discussed.

THPFI052

Application of Atmospheric Plasma-sprayed Ferrite Layers for Particle Accelerators

plasma, gun, electron, resonance

3406

F. Caspers, M. Betz, S. Federmann, M. Taborelli
CERN, Geneva, Switzerland
K. K., C.A.M. Schulz
Surface Engineering Institute, RWTH Aachen University, Aachen, Germany
J.X. Wu
IMP, Lanzhou, People's Republic of China

A common problem in all kind of cavity like structures in particle accelerators is the occurrence of RF-resonances. Typically, ferrite plates attached to the walls of such structures like diagnostic devices, kickers or collimators, are used to dampen those undesired modes. However the heat transfer rate from these plates to the walls is rather limited. Brazing ferrite plates to the walls is not possible in most cases due to the different thermal expansion coefficients. To overcome those limitations, atmospheric plasma spraying techniques have been investigated. Ferrite layers with a thickness from 50 micron to about 300 micron can be deposited on metallic surfaces like stainless steel exhibiting good thermal contact and still reasonable absorption properties. In this paper the technological aspects of plasma deposition are discussed and results of specifically developed RF loss measurement procedures for such thin magnetically lossy layers on metal are presented. This kind of layers can also be applied for the production of high temperature RF power loads and related examples will be shown.

THPFI057

Development of Vacuum Chamber in Low Z Material

radiation, impedance, background, coupling

3421

C. Garion, P. Costa Pinto, M.A. Gallilee, J. Perez Espinos
CERN, Geneva, Switzerland

Highly transparent vacuum chambers are more and more required in high energy particle physics. In particular, vacuum chambers in the experiments should be as transparent as possible to minimize the background to the detectors while reducing also the material activation. Beryllium is, so far, the most performing material for this application, but it presents some drawbacks such as brittleness, manufacturing issues, toxic hazard, high cost and low availability. A development work to obtain alternative material to the beryllium with similar performance is being carried out at CERN. Three categories have been defined and considered: raw bulk material, material and structural composites. Main requirements are the vacuum compatibility: leak tightness, low outgassing rate, temperature resistance (in the range 200-230 °C), transparency, and mechanical stiffness and strength. Carbon is the element with the lowest atomic number after beryllium and that is appropriate for this application. Therefore carbon based materials have been considered in a variety of options. In this paper, several technologies are presented and discussed. Results of preliminary tests on samples are also shown.

THPFI058

Qualification of a Glassy Carbon Blade for a LHC Fast Vacuum Valve

acceleration, accumulation, background, scattering

3424

C. Garion, P. Coly
CERN, Geneva, Switzerland

To protect sensitive LHC machine systems against an unexpected gas inrush, a fast vacuum valve system is under development at CERN. The design of the shutter has to be compatible with dynamic loads occurring during the fast closure, namely in the 20 ms range. The material has to fulfil all main requirements such as transparency, high melting temperature, dust free and adequate leak tightness. A development of a blade in vitreous carbon material has been carried out at CERN. The blade has been successfully integrated in a commercial pendulum fast valve. In this paper, the vacuum and mechanical qualification tests are presented.

THPFI067

The Mechanical Design, Fabrication, and Performance of the DCCT for TPS

shielding, storage-ring, electron, high-voltage

3451

C.-C. Chang, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, H.P. Hsueh
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

This paper describes the DC current transformers (DCCT), designed and fabricated for Taiwan Photon Source (TPS); including the mechanical structure, dissimilar material welding process for the DCCT chamber, electronically and vacuum performance testing. In the structure, a ceramic break disc is provided and jointed between to ends of the beam duct. The electrical connection path is interrupted in the beam duct adjacent to the transformer. To avoid the sensor measured the wall current and other unnecessary circulating currents. The DCCT toroid is independent installed outside of a vacuum beam duct to measure the average beam current. In order to reduce the influence of external magnetic field for the sensor, two layers of Mu metal shell are installed. The performance and progress for the DCCT are described in this paper.

THPFI071

Baking Tests and Results of A1050 Diamond Edge Gasket

target, controls, power-supply, ion

3463

Y.T. Huang, C.-C. Chang, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, H.P. Hsueh
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

A1050 is a common and soft material, widely used in everyday life. It is machinable and cheap, which makes it a candidate for a gasket material. In the case of sealing between disparate materials, treating the thermal expansion when the gasket suffers from baking is difficult. The clearance and the eccentricity between the gasket and the flange are also important; most leaks occur about 80 ~ 110 oC. The experimental apparatus comprised a vacuum chamber with six diamond-edge gaskets assembled, a turbo-molecular pump and an extractor gauge. The pre-baking torque for this gasket is 70 – 80 kg cm; the rates of both heating and cooling are less than 40 oC per hour. The gaskets are baked repeatedly under the same conditions excluding the target temperature set for baking. A1050 diamond gaskets work well after baking at 120 ~ 140 oC; at temperature 170 ~ 180 oC, leaks sometimes appear on cooling. This paper presents the baking results of A1050 diamond-edge gasket and explains the cause of leaking after baking above 150 oC.

THPFI075

Baking Test for an In-vacuum Undulator

undulator, controls, synchrotron, synchrotron-radiation

3469

L.H. Wu, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, H.P. Hsueh, J.C. Huang, C.K. Yang
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

For Taiwan Photon Source in NSRRC, the in-vacuum undulator (IU22) will be set in the straight section. The baking test took place in the NSRRC. The heating wires were welded on the outside wall of stainless chamber. The tape heaters were used for the sites without the heating wires. After acceptation test, we assemble the residual gas analysis (RGA) and extractor gauge in the IU22. The pumping down curve and RGA spectrum were recorded and investigated. It was found the slope of the pumping curve near 1 h is -0.99. When the temperature gradually increases to about 185 oC, the vacuum pressure arrives to about 8.7x10^-5 Torr. The most gas source is from water before baking process. After baking test, the major residual gas includes H2, CH4, H2O, CO, and CO2. We analyze the RGA spectrum during the baking process and discuss in the paper.

THPFI077

Construction Status of the TPS Vacuum Systems

ion, booster, storage-ring, photon

3472

G.-Y. Hsiung, C.K. Chan, C.H. Chang, C.-C. Chang, S.W. Chang, Y.P. Chang, C.L. Chen, J.-R. Chen, Z.W. Chen, C.M. Cheng, Y.T. Cheng, S-N. Hsu, H.P. Hsueh, C.S. Huang, Y.T. Huang, T.Y. Lee, L.H. Wu, Y.C. Yang
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

The vacuum systems for the 3 GeV Taiwan Photon Source (TPS) have been constructed since 2010. Most of the vacuum components and equipments have been manufactured and delivered. For the electron storage ring (SR), all the 24 cells of 14 m aluminum vacuum systems have been welded and assembled. The vacuum baking for the cells in the laboratory was undergoing to achieve the ultrahigh vacuum pressure below 1×10^-8 Pa. The vacuum systems accommodated with the insertion devices in the long straight sections have been designed and under manufacturing. For the booster (BR), all the stainless steel chambers including the 0.7 mm elliptical chambers, BPM ducts, and the pumping chambers, have been manufactured. The two transport lines: LTB for Linac to BR and BTS for BR to SR were manufactured. Vacuum chambers for BTS adopt the similar chambers for BR but will be baked to ultrahigh vacuum for connecting with SR without injection window. The beam ducts for LTB will be made of aluminum alloys. The construction works for TPS vacuum systems will be completed before April of 2013 while the installation of the systems in the TPS tunnel will be started immediately.

THPFI079

Start-up of the NESTOR Facility Vacuum System

storage-ring, electron, ion, synchrotron

3478

A.Y. Zelinsky, A.N. Gordienko, V.A. Grevtsev, I.I. Karnaukhov, I.M. Karnaukhov, N.I. Mocheshnikov, A. Mytsykov, V.L. Skirda
NSC/KIPT, Kharkov, Ukraine

The Kharkov X-ray generator NESTOR based on Compton backscattering is under commissioning. The vacuum system of the complex integrates a linear accelerator-injector, the beam transport channel and the electron storage ring with energy range from 40 to 225 MeV. Elements of vacuum chambers, pumping facilities, cleaning surfaces procedures are described. Chambers are made of stainless steel (SS). After vacuum pretesting pressure 5 × 10^-9 Torr in the storage chambers ring achieved.

THPFI085

Status of PXIE MEBT Absorber Development

electron, radiation, simulation, gun

3490

A.V. Shemyakin, C.M. Baffes, K. Carlson, A.Z. Chen, Y.I. Eidelman, B.M. Hanna, L.R. Prost, J.T. Walton
Fermilab, Batavia, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
One of the goals of the Project X Injector Experiment (PXIE) at Fermilab is to demonstrate the capability to form an arbitrary bunch pattern from an initially CW 162.5 MHz H⁻ bunch train coming out of an RFQ. The bunch-by-bunch selection will be taking place in the 2.1 MeV Medium Energy Beam Transport (MEBT) by directing the undesired bunches onto an absorber that needs to withstand a beam power of up to 21 kW, focused onto a spot with a ~2 mm rms radius. A ¼ - size prototype of the absorber is manufactured, and its thermal properties are tested with an electron beam generating a peak power density similar to the one expected during normal operation of the PXIE beam line. The paper describes the absorber concept, the prototype, the testing procedure with the electron beam, and the latest results.

THPFI087

Measurements of Secondary Electron Yield of Metal Surfaces and Films with Exposure to a Realistic Accelerator Environment

electron, photon, gun, background

3493

W. Hartung, J.V. Conway, C.A. Dennett, S. Greenwald, J.-S. Kim, Y. Li, T.P. Moore, V. Omanovic
CLASSE, Ithaca, New York, USA

One of the central goals of the CESR Test Accelerator program is to understand electron cloud (EC) effects in lepton rings and how to mitigate them. To this end, measurements of the secondary electron yield (SEY) of technical surfaces are being done in CESR. The CESR in-situ system, in operation since 2010, allows for measurements of SEY as a function of incident electron energy and angle on samples that are exposed to a realistic accelerator environment, typically 5.3 GeV electrons and positrons. The system was designed for periodic measurements to observe beam conditioning of the SEY and discrimination between exposure to direct photons from synchrotron radiation versus scattered photons and cloud electrons. Measurements so far have been done on bare metal surfaces (aluminum, copper, stainless steel) and EC-mitigatory coatings (titanium nitride, amorphous carbon, diamond-like carbon). A significant decrease in SEY with exposure to beam was observed for all cases other than the amorphous C samples; for the latter, the SEY remained near 1, independent of beam exposure. The SEY results are being used to improve predictive models for EC build-up and EC-induced beam effects.

THPFI088

Electron Cloud Diagnostic Chambers with Various EC-suppression Coatings

electron, positron, ion, pick-up

3496

Y. Li, J.V. Conway, X. Liu, M.A. Palmer
CLASSE, Ithaca, New York, USA

Funding: Work supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the U.S. Department of Energy DE-FC02-08ER41538
Suppression of electron cloud (EC) growth and density is critical for many high intensity accelerators of positively charged particles, such as positron rings for Super KEKB and ILC’s positron damping ring. Among various suppression techniques, passive coating with low secondary electron emission (SEY) coefficient is the most economic method. During CesrTA EC study program, we have created two dedicated short sections in the CESR vacuum system to study effectiveness of various SEY reduction coatings. During last 4 years, six one-meter-long EC study vacuum chambers were constructed, and rotated through these short sections. The EC chambers were not only equipped with EC diagnostics (including a RFA and RF-shield pickups), they were also installed in CESR with vacuum instrument, including a cold cathode ion gauge and a residual gas analyzer. With these EC study chambers, EC-suppression effectiveness of TiN, amorphous carbon and diamond-like carbon coatings were evaluated, relative to bare aluminum chamber. In this report, we will report vacuum properties of these coatings. In particular, the photon-induced desorption and beam conditioning histories are presented.

THPFI093

Device and Technique for In-situ Coating of the RHIC Cold Bore Vacuum Tubes with Thick OFHC

electron, cathode, cryogenics, superconducting-magnet

3508

A. Hershcovitch, M. Blaskiewicz, J.M. Brennan, W. Fischer, C.J. Liaw, W. Meng, R.J. Todd
BNL, Upton, Long Island, New York, USA
A.X. Custer, M.Y. Erickson, N.Z. Jamshidi, H.J. Poole
PVI, Oxnard, USA
J.M. Jimenez, H. Neupert, M. Taborelli, C. Yin Vallgren
CERN, Geneva, Switzerland
N. Sochugov
Institute of High Current Electronics, Tomsk, Russia

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
To mitigate electron clouds & unacceptable ohmic heating problems in RHIC, we developed a robotic plasma deposition technique & device to in-situ coat the RHIC 316LN SS cold bore tubes based on mobile mole mounted magnetrons for OFHC deposition. Scrubbed Cu has low SEY and suppress electron cloud formation. Room temperature RF resistivity measurement of Cu coated SS RHIC tube samples indicate that 10 μm of Cu coating has conductivity close to copper tubing. A 50 cm long copper cathode magnetron, mounted on a carriage with spring loaded wheels, was successfully operated, traversed magnet interconnect bellows and adjusted for variations in vacuum tube diameter, while keeping the magnetron centered. To maximize cathode lifetime, Cu cathode thickness was maximized its gap to vacuum tube minimized; movable magnet package is used. Novel cabling and vacuum-atmosphere interface system is being developed. Deposition experiments show no indentation in or damage to coating after wheels roll over coated areas; i.e. train like assembly option is a viable for in-situ RHIC coating. Details of experimental setup & coating of full-scale magnet tube sandwiched between bellows will be presented.

THPME001

Permanent Magnets in Accelerators can save Energy, Space, and Cost

permanent-magnet, dipole, quadrupole, synchrotron

3511

F. Bødker, L.O. Baandrup, A. Baurichter, N. Hauge, K.F. Laurberg, B.R. Nielsen, G. Nielsen
Danfysik A/S, Taastrup, Denmark
O. Balling
Aarhus University, Aarhus, Denmark
F.B. Bendixen, P. Kjeldsteen, P. Valler
Sintex A/S, Hobro, Denmark
S.P. Møller, H.D. Thomsen
ISA, Aarhus, Denmark
H.-A. Synal
ETH, Zurich, Switzerland

Green Magnet technology with close to zero electrical power consumption without the need for cooling water saves costs, space and hence spares natural resources. A compact dipole based on permanent magnets has been developed at Danfysik in collaboration with Sintex and Aarhus University. This first Green Magnet has been delivered to ETH Zurich for testing in a compact accelerator mass spectrometer facility. Permanent NdFeB magnets generate a fixed magnetic field of 0.43 T at a gap of 38.5 mm without using electrical power in the H-type 90° bending magnet with a bending radius of 250 mm. Thermal drift of the permanent magnets is passively compensated. Small air cooled trim coils permit fine tuning of the magnetic field. Magnetic field measurements and thermal stability tests show that the Green Magnet fully meets the magnetic requirements of the previously used electromagnet. The use of Green Magnet technology in other accelerator systems like synchrotron light sources is discussed.

THPME008

Experimental Study of Magnetic Properties for Magnet Material in CYCIAE-100

focusing, cyclotron, factory, resonance

3525

J.Q. Zhong, T. Cui, M. Li, C. Wang, Z.H. Wang, J.J. Yang, T.J. Zhang
CIAE, Beijing, People's Republic of China

The magnetic property of magnet material is one of the key factors that influence the distribution of magnetic field in large scale cyclotrons, especially embody on the vertical focusing of field and the first harmonic field error in cyclotron. According to the requirements of the physical design of CYCIAE-100, we have studied the pivotal factors, which impact on the maximum permeability, coercivity and B-H curve of material of CYCIAE-100 magnet, including the cooling rate during magnetic annealing and residual stress. The study results will be shown in this paper.

THPME011

Magnetic Field Design of the BAPS High Precision Quadrupole Magnet

quadrupole, multipole, storage-ring, photon

3531

Y.S. Zhu, F.S. Chen, W. Kang, X.J. Sun
IHEP, Beijing, People's Republic of China

The Beijing Advanced Photon Source (BAPS) is a high performance light source planned to be constructed in China. High precision small aperture quadrupole magnets are required in the BAPS storage ring, which needs extremely high mechanical accuracy. Instead of the conventional manufacture method, the coils are comprised of several U-shaped solid copper sheets. So two-piece structure of the iron core can be adopted to reduce assembly error and improve the poles symmetry. Design considerations, 2D and 3D magnetic field calculations are presented in detail, and the needed mechanical precision is estimated according to the error field analysis.

THPME019

Design of the Cold Mass Support Assembly of Test Cryomodule for IMP ADS-Injector II

solenoid, cavity, controls, cryomodule

3543

Y. Liu, S. Sun, J. Wang, L. Wang, S.Y. Wang
SINAP, Shanghai, People's Republic of China
X.L. Guo
JiangShu University, Jiangsu Province, People's Republic of China

In order to test the performance of the HWR cavities and verify the related technique for cooling of the cavities and the solenoids together, a test cryomodule (TCM1) containing one superconducting HWR cavity followed by one cold BPM and two superconducting solenoids was developed for the Injector II of the Accelerator Driven Sub-critical System (ADS). The TCM1 consists of the cryostat and the cold mass assembly. The cryostat is composed of vacuum chamber, thermal shields, cooling circuit, cold mass support assembly, and instrumentation. A set of cold mass support assembly was developed for supporting the cold mass working at 4.4 K. The support assembly mainly consists of Ti support frame, stainless steel rods, adjustable mechanisms and LHe cooling passage. It can not only support the weight of the cold mass but also stand the thermal stress during the cool down. In order not to affect the performance of the cavity, it will not impose any force on the HWR cavity. It can be adjustable for alignment of the cold mass both at room temperature and 4.4 K. This paper provides the detailed design of the TCM1 cold mass support assembly.

THPME020

Design of a Test Cryomodule for IMP ADS-Injector II

cavity, solenoid, cryomodule, radiation

3546

L. Wang, Y. Liu, S. Sun, J. Wang, S.Y. Wang, S.H. Wang
SINAP, Shanghai, People's Republic of China
X.L. Guo
JiangShu University, Jiangsu Province, People's Republic of China

Two cryomodules are to be applied for the Injector II of the Accelerator Driven Sub-critical System. Each of them will contain 8 superconducting HWR cavities and 9 superconducting solenoids. In order to test the performance of the HWR cavities and validate related technique for cooling of cavities and solenoids together, a test cryomodule (TCM1) including one HWR cavity and two solenoids was developed. The design of the TCM1 cryostat was carried out by the Shanghai Institute of Applied Physics, CAS. Both the cavity and the solenoids will work at 4.4 K by bath cooling. The fast cooling down for the cavity from 100 K to 120 K is required to avoid degrading of the cavity performance. Before energization, the solenoids can be warmed up to above 10 K and re-cooled down for degaussing. The TCM1 can not only be cooled by using the dewar-filling system, but also operated by the refrigerator system. The main components of the cryostat include vacuum chamber, thermal shields, magnet current leads, cooling circuit, and cold mass support assembly. This paper presents the detailed design of the TCM1 cryostat.

THPME025

Design of Cryomodules for RAON

cryomodule, cryogenics, cavity, linac

3558

Y. Kim, C. Choi, D. Jeon, H.J. Kim, M. Lee
IBS, Daejeon, Republic of Korea

The RAON linac utilizes four types of superconducting cavities such as QWR, HWR, SSR1, and SSR2 which are operating at 2 K in order to accelerate the various ion beams. The main role of the cryomodules is to maintain the cryogenic temperature for the superconducting cavity operation. Five types of cryomodules will be necessary since one QWR cavity, three and six HWR cavities, four SSR1 cavities, and eight SSR2 cavities will be installed in the dedicated cryomdoules. Total number of the cryomodule is 147, 48 for QWR, 60 for HWR, 22 for SSR1, 17 for SSR2. The cryomodules of RAON does not include focusing magnets but includes the cavities operating at 2 K. This paper describes the current status of the RAON cryomodule design. The issues included in the paper are the thermal load estimation, design of the components such as thermal shield and intercept of the cryomodules, and cryogenic flow circulation system according to the cryomodule operation.

THPME031

Ramped Magnetic Measurement of NSLS-II Booster Dipoles

dipole, booster, quadrupole, sextupole

3576

I.N. Okunev, G.N. Baranov, A.M. Batrakov, A.I. Erokhin, V.A. Kiselev, V.V. Kobets, A.V. Pavlenko, S.V. Sinyatkin, R.V. Vakhrushev
BINP SB RAS, Novosibirsk, Russia

13. The magnetic system of NSLS II Booster are designed, manufactured and tested in BINP, Russia. The dipoles of the Booster have quadrupole and sextupole components and should create high quality of field ± 2·10^-4 in region ± 2 cm. Magnets should provide performance of booster for energy from 170 MeV to 3.15 GeV with 2 Hz frequency. This report considers ramped magnetic measurement of NSLS-II Booster Dipoles.

THPME033

Pulsed Magnets for Injection and Extraction Sections of NSLS-II 3 GeV Booster

septum, injection, extraction, booster

3582

A.N. Zhuravlev, A.M. Batrakov, A.D. Chernyakin, V.A. Kiselev, V.M. Konstantinov, A.V. Pavlenko, V.V. Petrov, E.P. Semenov, D.V. Senkov
BINP SB RAS, Novosibirsk, Russia

Magnets for injection and extraction sections of NSLS-II 3 GeV booster are designed, manufactured and tested in BINP, Russia. This report considers the details of bump and septum magnets design, their parameters and results of inspection test in BINP. The design and electronics features of the measurement stand for these magnets are presented. Also, capabilities of specialized power supplies are listed and discussed. Finally, the first results of injection and extraction sections commissioning at BNL site are reported.

THPME039

The Control System for the Purification Station at NSRRC

cryogenics, controls, monitoring, synchrotron

3597

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

A cryogenic adsorber was used liquid nitrogen to trap the impurities from gaseous helium in the helium cryogenic system. NSRRC parallel connected five cryogenic adsorbers for the cryogenic system in the year 2011; five additional cryogenic adsorbers will be installed in the year 2013. The original design of liquid nitrogen filling was motored and controlled manually to keep the efficiency of the purifying. The regeneration of the cryogenic adsorber must be performed manually as well by using heater and vacuum pump after saturated of the cryogenic adsorber. NSRRC develop one control system that is allowed the liquid nitrogen filling and regeneration process turns into automatically. This paper is aimed to present the construction of the control system. The installation and test results will be included in this paper as well.

THPWA031

Raising the Generating Current in the VITA Neutron Source for BNCT

proton, ion, neutron, target

3693

A.S. Kuznetsov, V.I. Aleynik, A.G. Bashkirtsev, D.A. Kasatov, A.N. Makarov, I.M. Schudlo, I.N. Sorokin, S.Yu. Taskaev, M.A. Tiunov
BINP SB RAS, Novosibirsk, Russia

Funding: The work was partially supported by the Ministry of Education and Science of the Russian Federation (contract № 14.518.11.7039).
The Vacuum Insulated Tandem Accelerator (VITA) was developed in the Budker Institute of Nuclear Physics to produce epithermal neutrons for boron neutron capture therapy in the 7Li(p,n)7Be reaction. The parameters of the generated radiation allow us to carry out in vitro and in vivo investigations of BNCT. In present moment the modernization of the facility elements is carrying out to meet the parameters required for clinical usage. As the first step of the modernization the stripping target and electrode apertures were optimized. The experiments on fine beam injection were carried out as well as experiments on high current transportation. The output current in the range 1.5-2.5 mA with proton beam energy of 1 – 2 MeV was obtaned in the routine regimes of generation. In presented work the results of the experiments and possible way to rise the proton current higher then 3 mA level with energy 2 MeV are discussed.
*S. Taskaev, et al. Vacuum-insulation Tandem Accelerator for Boron Neutron Capture Therapy. Proc. 2nd International Particle Accelerator Conference (IPAC-2011),2011, San Sebastian, Spain, p.3615-3617.

THPWA032

Fields of Charged Particle Bunches in Chiral Isotropic Medium

radiation, electromagnetic-fields, polarization, factory

3696

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

Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation.
We study electromagnetic fields produced by charged particle bunches moving in a chiral isotropic medium. Such properties are typical for most of organic matters and some artificial materials (metamaterials). Therefore, this subject is of interest for chemical, biological, and medical applications as well as for study of metamaterials. First, we investigate in detail the field of a point charge. We obtain exact and approximate formulas and develop algorithm for calculation of the point charge field. Further, we use these expressions for calculation of fields produced by finite size bunches. We also present the typical energetic patterns of radiation and spectra of energy losses. Possibilities of using the obtained results for different applications are discussed.

THPWA034

Overview of CERN Technology Transfer Strategy and Accelerator-related Activities

linac, target, proton, electron

3702

E. Chesta, A. Bertarelli, F. Caspers, P. Chiggiato, S. Sgobba, T. Stora, M. Taborelli, W. Wuensch
CERN, Geneva, Switzerland

CERN, the European Organization for Nuclear Research, is actively engaged in identifying technologies developed for its accelerator complex that could be profitably used by partner research organizations or commercial companies in applications with potentially high socio-economic impact beyond pure fundamental physics research. In the first part of the paper, an overview of CERN current strategy in the field of Technology Transfer and Intellectual Property Management will be presented, with details on the most effective models, implementation tools and processes developed to achieve satisfactory dissemination and valorisation of the knowledge generated within the Organization. In the second part, CERN currently available technology portfolio will be described with focus on cases originated from the Accelerator and Technology Sector. A selection of promising on-going projects embracing a variety of technology fields and application areas will be detailed to showcase technical challenges and possible benefits of initiatives driven by (but not limited to) the needs of CERN scientific programme.

THPWA043

Production of the FETS RFQ

rfq, pick-up, alignment, simulation

3726

P. Savage, M. Aslaninejad, J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
M. Dudman, D.S. Wilsher
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
A. Garbayo
AVS, Eibar, Gipuzkoa, Spain
A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) project at RAL will use a 324 MHz 4-vane Radio Frequency Quadrupole (RFQ) to accelerate H⁻ ions from 65keV to 3 MeV. This paper will report on the current status of the production of the FETS RFQ and will detail the manufacturing strategy used to produce the major and minor vanes. In addition the inspection results will be shown and the experiences from the assembly and alignment operations will be shared. Finally, the design of the bead-pull apparatus, end flanges, tuners and pick-ups required to measure the frequency and field-flatness of the assembled RFQ will be discussed.

THPWA044

R&D into Laser Applications for Accelerators

laser, electron, cathode, acceleration

3729

C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: Work supported by the EU under Grant Agreement 289191.
Lasers can be used for the generation of high brightness electron and exotic ion beams, the acceleration of particles with the highest accelerating gradients, as well as for the characterization of many complex particle beams by means of laser-based beam diagnostics methods. In addition, (free electron) lasers can be used for achieving the highest time resolution and strongest fields for experiments in atomic physics, chemistry and biology, i.e. for studies into the dynamics of some of the most fundamental processes in nature. Without constant progress in laser technology and close collaboration between laser experts and accelerator scientists, many of today's most advanced experiments would simply be impossible. The LA3NET consortium combines developments into laser technology and sensors with their application at advanced accelerator facilities, providing complex beams ranging from highest brightness electron beams to high intensity proton beams. This contribution presents the consortium's broad, yet closely interconnected experimental program.

THPWO001

Assembling, Testing and Installing the SPIRAL2 Superconducting Linac

cryomodule, linac, cavity, alignment

3752

P.-E. Bernaudin, R. Ferdinand
GANIL, Caen, France
P. Bosland
CEA/DSM/IRFU, France
Y. Gomez Martinez
LPSC, Grenoble, France
G. Olry
IPN, Orsay, France

Assembly and tests of the SPIRAL2 superconducting linac's components are now proceeding smoothly. Cryomodules are being processed in CEA Saclay and IPN Orsay, inter-cryomodules "warm" sections in GANIL. While installation of the accelerators components is going on in the new SPIRAL2 building in Caen, installation of the cryomodules will begin during the last quarter of 2013. The latest results of the cryomodules tests as well as the installation strategy are depicted in this paper.

THPWO002

Progress of Construction and Installation of the SPIRAL2 Accelerator

ion, linac, rfq, controls

3755

R. Ferdinand, P. Bertrand, X. Hulin, M. Jacquemet, E. Petit
GANIL, Caen, France

Officially approved in May 2005, the SPIRAL2 project was launched in July 2005 at GANIL, with the active participation of French laboratories (CEA, CNRS) and international partners. This new facility is composed of a linear accelerator producing deuteron, proton and heavy ion beams in a wide range of energies and intensities, with two dedicated experimental areas in the fields of Neutron for Science (NFS) and very heavy and super heavy element production (S3). In a second step, the facility will also produce Rare elements serving a low energy RIB experimental hall, or post-accelerated by means of the existing cyclotron CIME. This paper presents the performances of the main accelerator components, and the installation process into the SPIRAL2 building.

THPWO010

Charge Stripping Tests of High Current Uranium Ion Beams with Methane and Hydrogen Gas Strippers and Carbon Foils at the GSI UNILAC

stripper, ion, heavy-ion, target

3779

B. Schlitt, W.A. Barth, G. Clemente, L. Groening, M. Kaiser, B. Lommel, M.T. Maier, S. Mickat, J. Steiner, H. Vormann
GSI, Darmstadt, Germany

At the GSI UNILAC, a nitrogen gas stripper is routinely used for stripping of heavy ion beams at 1.4 MeV/u. Different approaches to optimize the stripping efficiency as well as different options to increase the ion charge states for delivery to SIS18 are being investigated. The existing gas stripper was operated with methane and hydrogen gas for stripping of high current uranium ion beams. The results as well as the limitations of these tests will be presented and will be compared to standard nitrogen operation of the gas stripper. In addition, newest results using differently prepared carbon stripping foils for the same ion beams will be reported.

THPWO029

Beam Loss Monitoring and Mitigation at J-PARC DTL

DTL, radiation, linac, injection

3824

T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
K. Futatsukawa, M. Ikegami, T. Miyao
KEK, Ibaraki, Japan
T. Ito, A. Miura
JAEA/J-PARC, Tokai-mura, Japan

Close radiation survey at the cavity outer surface has indicated a significant beam loss in the first tank of J-PARC DTL (Drift Tube Linac) which has been localized at a certain drift tube. It has motivated us to measure the beam loss at the DTL, and we have installed beam loss monitors of scintillator type at the cavity surface. It is challenging to monitor the beam loss due to low energy of lost particles and shielding by the thick cavity wall. In this paper, we report the results of beam loss measurement and beam loss mitigation tuning using the beam loss monitors.

THPWO031

Status of J-PARC Accelerators

linac, extraction, injection, power-supply

3830

K. Hasegawa, M. Kinsho, H. Oguri
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Koseki
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

After nine-months of beam shutdown by the Great Earthquake in March 2011, the J-PARC facility resumed beam operation. In December 2011, operations were carried out at low duty such as single-shots or 1 to 2.5 Hz for beam tuning. At the beginning of January 2012, we started beam tuning at the full repetition rate of 25 Hz at the linac and the 3 GeV Rapid Cycling Synchrotron (RCS). After the tuning, user programs of the Materials and Life Science Experiment Facility (MLF), the Neutrino facility and the Hadron facility started. The beam power was increased from 100 to 300 kW to the MLF users, from 3.3 kW to 6 kW to the Hadron users, and from 140 to 200 kW to the Neutrino users. The beam availability went lower to 73 % in JFY 2011 due to the trouble of the linac klystron power supply in March, but it has got back to 90-94 % as of November in JFY2012. We have also much upgrade work during the shutdown period or in parallel to the operation. We’ve demonstrated new record power beyond 500kW from the RCS. The status and progress of the J-PARC accelerators are presented.

THPWO036

Annular-Ring Coupled Structure Linac for the J-PARC Linac Energy Upgrade

linac, ion, cavity, proton

3845

H. Ao, H. Asano, Y. Nemoto, N. Ouchi, J. Tamura
JAEA/J-PARC, Tokai-mura, Japan
F. Naito, K. Takata
KEK, Ibaraki, Japan

The linac of Japan Proton Accelerator Research Complex (J-PARC) is the injector to the 3-GeV rapid cycle synchrotron. In order to increase the beam power of the synchrotron, the task of the 400-MeV energy upgrade of the linac started from March 2009. Following the 191-MeV Separated-type DTL, the 25 modules of the Annular-ring Coupled Structure (ACS) linac will be added from August 2013. The operating frequency and the accelerating field E0 of the ACS are 972 MHz and 4.2 MV/m, respectively. The cavity fabrication of the ACS has been almost finished, and then the completed cavities are stored in the J-PARC site. Currently, pumps and vacuum components are being installed on the cavities for the test of vacuum condition. For the pulsed beam of J-PARC, the vacuum pressure have to be less than 10^-6 Pa in order not to exceed 0.1 W/m beam loss. In this paper, we present the R&D results to reduce the vacuum pressure using the stored ACS cavity and the current status of the energy upgrade.

THPWO041

The development of a high power input coupler for China ADS injector I RFQ

rfq, coupling, cavity, injection

3857

T.M. Huang, X. Chen, R. Guo, H.Y. Lin, Q. Ma, F. Meng, H.F. Ouyang, W.M. Pan, X.H. Peng, Z. Zhang, G.Y. Zhao
IHEP, Beijing, People's Republic of China

A 325 MHz RFQ is designed to accelerate a beam current of 15 mA in CW mode with injection energy of 35 keV and output energy of 3.2 MeV for China Accelerator Driven sub-critical System (ADS) injector I. Total RF power of 320 kW has to be delivered into the RFQ cavity. For reliable operation, four input couplers are adopted to share the driven power. A coaxial loop type input coupler is developed. The coupler features a Tristan type RF window, a doorknob to realize the transition from a half-height WR2300 waveguide to a coaxial line and a coaxial line with a coupling antenna loop. Two prototypes of the window and inner conductor assemblies have been fabricated and received high power test. The prototypes were tested up to 100 kW CW RF power in traveling wave mode. This paper will describe the design, fabrication and high power test of the coupler in details.

THPWO050

High Power Test and Beam Commissioning of he CPHS RFQ Accelerator

rfq, klystron, proton, ECR

3884

Q.Z. Xing, C. Cheng, L. Du, Q. Du, T. Du, C. Jiang, H.T. Lu, J. Ni, Q. Qiang, C.-X. Tang, X.W. Wang, Y.G. Yang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
J.H. Billen
Self Employment, Private address, USA
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
X. Guan
Tsinghua University, Beijing, People's Republic of China
J. Stovall
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
L.M. Young
LMY Technology, USA

Funding: Work supported by the “985 Project” of the Ministry of Education of China, National Natural Science Foundation of China (Major Research Plan Grant No. 91126003 and 11175096).
We present, in this paper, the high power test result and the beam commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The 3-meter-long RFQ is designed to deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. The RFQ has been designed, manufactured, and installed at Tsinghua University. High-vacuum test of the RFQ has been carried out carefully and the cooling system has been mounted. At the beginning of 2013, the high power RF test has been performed and the first 3 MeV proton beam is obtained.

THPWO063

The Early Stage of the Cavity Fabrication Process (ECT and furnace) for RAON

cavity, niobium, superconducting-cavity, linac

3901

M.J. Joung, H.C. Jung, H.J. Kim
IBS, Daejeon, Republic of Korea

RAON is consist of three part about the acceleration line. These are SCL1, SCL2 and SCL3. SCL1 and SCL3 will be made from QWR (Qarter Wave Resonator) and HWR (Half Wave Resonator). And SCL2 will be made from SSR1 (Single Spoke Resonator) and SSR2 (Single Spoke Resonator). Accordingly, The RAON needs 48 QWR, 276 HWR, 88 SSR1 and 136 SSR2 to get the performance that we want. To accelerate the particle using lots of cavity, we have to make a process of cavity fabrication for RAON. We will compare to each process made from the other laboratories and to make the optimal process for RAON to get the performance that we want. And that process will consider the type of cavity and the purpose of the accelerator. I will introduce the early stage of the cavity fabrication process for RAON in this paper.

THPWO094

Electromagnetic and Multi-particle Beam Dynamics Modeling of 4-Rod RFQs

rfq, simulation, quadrupole, cavity

3978

S.S. Kurennoy, R.W. Garnett, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

Detailed 3D modeling of the recently commissioned FNAL 4-rod RFQ was performed with the CST Studio Suite. The RFQ model is based on the CAD files used for its fabrication, which are imported in CST Studio. The electromagnetic (EM) analysis was done with MicroWave Studio (MWS) and the beam dynamics modeled with Particle Studio (PS) using the MWS-calculated fields. Realistic matched input CW beam distributions, generated externally with up to 10K particles per RF period and up to 70 RF periods long, are injected in the RFQ for PS simulations. The EM analysis reveals some interesting features of the RFQ fields; their origin and influence on the beam parameters is studied. In particular, the end-gap longitudinal field, which is usually not taken into account when an RFQ is designed with standard codes, can change the output beam energy. Our CST modeling results helped explain and successfully resolve some problems encountered in the FNAL RFQ commissioning. We plan to use a similar approach to evaluate a new 4-rod RFQ that will become a part of an upgraded front end of the LANSCE linac.