IPAC2011 - List of Keywords (synchrotron)

Paper	Title	Other Keywords	Page
MOXAA01	ALBA Synchrotron Light Source Commissioning	storage-ring, booster, linac, injection	1
	D. Einfeld CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3rd generation Synchrotron Light Source build in Barcelona, Spain. It is a 3 GeV Light Source with a circumference of roughly 270 m, an emittance of 4.4 nmrad and a design current of 400 mA. The storage ring has 24 straight sections from which 19 can be used for the installation of insertion devices, the rest will be used for injection, RF-cavities and diagnostic. The storage ring has been optimized for a high photon flux density for the users. The 3 GeV booster synchrotron with an emittance smaller the 10 nmrad is installed in the same tunnel. The pre injector is a 100 MeV Linac. The project started officially in 2004. The linac is operating since 2008, the booster since 2010 and the first commissioning phase for the storage ring will be finished in June 2011. This presentation gives an overview of the ALBA project with the emphasis on the results of the commissioning of the three accelerators Linac, booster synchrotron and storage ring.
	Slides MOXAA01 [8.891 MB]

MOPC001	Linac Waveguide Upgrade at the Australian Synchrotron Light Source	klystron, linac, booster, controls	62
	R.T. Dowd, G. LeBlanc, K. Zingre ASCo, Clayton, Victoria, Australia
	The Australian Synchrotron Light Source (ASLS) uses a 100 MeV linac as the start of the acceleration chain for the injector. The two main accelerating structures of linac are normally fed by independent pulsed klystrons. A recent upgrade to the waveguide system has allowed for a single klystron to power both accelerating structures. While this operation mode delivers a reduced total beam energy, the operation of only a single klystron results in less wear and enhanced robustness against klystron breakdown. Commissioning results of single klystron operation of the linac are shown and future benefits are detailed.

MOPC002	Flow Induced Vibrations of the CLIC X-band Accelerating Structures	quadrupole, alignment, linac, resonance	65
	T.K. Charles, K. Ryan Monash University, Melbourne, Australia M.J. Boland ASCo, Clayton, Victoria, Australia G. Riddone CERN, Geneva, Switzerland A. Samoshkin JINR, Dubna, Moscow Region, Russia
	Turbulent cooling water in the Compact Linear Collider (CLIC) accelerating structures will inevitably induce some vibrations. The maximum acceptable amplitude of vibrations is small, as vibrations in the accelerating structure could lead to beam jitter and alignment difficulties. A Finite Element Analysis model is needed to identify the conditions under which turbulent instabilities and significant vibrations are induced. Due to the orders of magnitude difference between the fluid motion and the structure's motion, small vibrations of the structure will not contribute to the turbulence of the cooling fluid. Therefore the resonant conditions of the cooling channels presented in this paper, directly identify the natural frequencies of the accelerating structures to be avoided under normal operating conditions. In this paper a 2D model of the cooling channel is presented finding spots of turbulence being formed from a shear layer instability. This effect is observed through direct visualisation and wavelet analysis.

MOPC019	Condition of MA Cut Cores in the RF Cavities of J-PARC Main Ring after Several Years of Operation	impedance, cavity, resonance, ion	107
	M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan E. Ezura, K. Hasegawa, K. Takata KEK, Tokai, Ibaraki, Japan K. Hara, C. Ohmori, M. Toda, M. Yoshii KEK/JAEA, Ibaraki-Ken, Japan T. Sato, M. Yamamoto JAEA, Ibaraki-ken, Japan
	J-PARC 3 GeV RCS and 50 GeV Synchrotron (MR) employ RF cavities loaded with Magnetic Alloy (MA) cores to generate a high field gradient. The RF cavities in RCS use MA un-cut cores. On the other hand, the RF cavities in MR employ MA cut cores to increase the Q-value from 0.6 to 26. We observed the impedance reductions of all MR RF cavities during several years operation. Opening the RF cavities, we found that the impedance reductions were resulting from corrosion on the cut and polished surfaces of MA cores. Before installation of the RF cavities, we had 1000 and 2000 hours long tests at a test stand. We didn't observe the impedance reduction related to the corrosion on the MA core cut surfaces at the test stand. The only difference between the test stand and MR is the quality of cooling water. The MR cooling water contains copper ions for example from copper hollow conductors of the main magnets. We report the influence of the copper ions to the corrosion on the MA core cut surface. We also show plans how to solve the issue of MA core cut surface corrosion.

MOPC054	The LHC RF System - Experience with Beam Operation	injection, klystron, emittance, damping	202
	P. Baudrenghien, M. E. Angoletta, T. Argyropoulos, L. Arnaudon, J. Bento, T. Bohl, O. Brunner, A.C. Butterworth, E. Ciapala, F. Dubouchet, J. Esteban Muller, D.C. Glenat, G. Hagmann, W. Höfle, D. Jacquet, M. Jaussi, S. Kouzue, D. Landre, J. Lollierou, P. Maesen, P. Martinez Yanez, T. Mastoridis, J.C. Molendijk, C. Nicou, J. Noirjean, G. Papotti, A.V. Pashnin, G. Pechaud, J. Pradier, J. Sanchez-Quesada, M. Schokker, E.N. Shaposhnikova, D. Stellfeld, J. Tückmantel, D. Valuch, U. Wehrle, F. Weierud CERN, Geneva, Switzerland
	The LHC RF system commissioning with beam and physics operation for 2010 and 2011 are presented. It became clear in early 2010 that RF noise was not a lifetime limiting factor: the crossing of the much feared 50 Hz line for the synchrotron frequency did not affect the beam. The broadband LHC RF noise is reduced to a level that makes its contribution to beam diffusion in physics well below that of Intra Beam Scattering. Capture losses are also under control, at well below 0.5%. Longitudinal emittance blow-up, needed for ramping of the nominal intensity single bunch, was rapidly commissioned. In 2011, 3.5 TeV/beam physics has been conducted with 1380 bunches at 50 ns spacing, corresponding to 55% of the nominal current. The intensity per bunch (1.3 ·10¹¹ p) is significantly above the nominal 1.15 ·10¹¹. By August 2011 the LHC has accumulated more than 2 fb-1 integrated luminosity, well in excess of the 1 fb-1 target for 2011.

MOPC077	Commissioning of Multibunch Feedback Systems at the Fast Ramping Stretcher Ring ELSA	kicker, cavity, feedback, booster	250
	A. Roth, F. Frommberger, N. Heurich, W. Hillert, M. Schedler, R. Zimmermann ELSA, Bonn, Germany
	Funding: Supported by German Research Foundation through SFB/TR 16 and by Helmholtz Alliance through HA-10¹. At the Electron Stretcher Facility ELSA of Bonn University, an external beam of either unpolarized or polarized electrons is supplied to hadron physics experiments. The ELSA stretcherring operates in the energy range of 1.2 to 3.5 GeV and achieves a duty cycle of up to 80% using a fast energy ramp of 4 GeV/s. Under these conditions, an increase of the internal beam current from an actual value of 20 mA up to 200 mA is planned. Such an upgrade is mainly limited by the excitation of multibunch instabilities. As one active counteraction, we have installed state-of-the-art bunch-by-bunch feedback systems for the longitudinal, as well as for both transverse planes. The detailed setup with all main components and first results of the commissioning of the systems will be presented. In particular, the performance of the longitudinal feedback with a stabilized synchrotron frequency during the fast energy ramp will be discussed.

MOPC147	Timing System for MedAustron Based on Off-The-Shelf MRF Transport Layer	controls, ion, ion-source, light-ion	424
	R. Tavcar, J. Dedič, Z. Kroflic, R. Štefanič Cosylab, Ljubljana, Slovenia J. Gutleber CERN, Geneva, Switzerland
	MedAustron is a new particle accelerator-based ion beam research and therapy centre under construction in Wiener Neustadt, Austria. The timing system for its synchrotron-based accelerator is being developed in close collaboration with Cosylab. We have usedμResearch Finland (MRF) transfer layer and designed and implemented a generic, reusable high-level logic above transport layer inside the generator and receiver FPGA to fulfill machine specific requirements which exceed MRF's original high-level logic capabilities. The new timing system is suitable for small to mid-size accelerators. Its functionalities include support for virtual accelerators and a rich selection of event response mechanisms. The timing system uses a combination of a real-time link for downstream events and a non-real-time link for upstream messaging and non time-critical communication. This article explains the benefits of building a timing system on a proven, stable timing transport layer and describes the high-level services provided by MedAustron timing system.

MOPC164	Upgrade of the ISIS Synchrotron Low Power RF System	cavity, controls, feedback, ion	466
	A. Seville, N.E. Farthing, I.S.K. Gardner, R.J. Mathieson, J.W.G. Thomason STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom D.B. Allen STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	The ISIS synchrotron at the Rutherford Appleton Laboratory in the UK now routinely uses a dual harmonic RF system to accelerate beam currents in excess of 230 uA to run two target stations simultaneously. In order to give more stable control of the phase of the RF voltage at each of the fundamental (1RF) and second harmonic (2RF) cavities, changes have been made to the low power RF (LPRF) control systems. In addition to this a new FPGA based master oscillator has been commissioned for the first time, and further changes using digital technologies to replace other components of the LPRF system are to be investigated. This paper reports on the LPRF hardware commissioning and reliability.

MOPO005	A Transverse Feedback System using Multiple Pickups for Noise Minimization	kicker, pick-up, feedback, betatron	487
	M. Alhumaidi, A.M. Zoubir TU Darmstadt, Darmstadt, Germany
	A new concept for using multiple pickups for estimating beam angle at the kicker is addressed. The estimated signal should be the driving feedback signal. The signals from the different pickups are delayed, such that they correspond to the same bunch. Consequently a weighted sum of the delayed signals is suggested as an estimator of the beam angle at the kicker. The weighting coefficients are calculated such that the estimator is unbiased, i.e. the output corresponds to the actual beam angle at the kicker for non-noisy pickup signals. Furthermore, the estimator must give the minimal noise power at the output among all linear unbiased estimators. Finally results for the heavy ions synchrotron SIS 18 at the GSI are shown.

MOPO031	Alignment of theTPS Front-End Prototype	alignment, laser, survey, synchrotron-radiation	550
	C.K. Kuan, Y.T. Cheng, W.Y. Lai, I.C. Sheng, T.C. Tseng, H.Y. Yan NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is a 3-GeV third-generation source of synchrotron radiation with beam current 500 mA stored in the storage ring. A front end allows intense synchrotron light generated in the storage ring to pass through to a beamline. Most heat load of the synchrotron light is removed in the front ends to protect the beamline components. Alignment of front-end components becomes important to prevent damage from the large heat load. Because of the many front ends and the brief period of installation, the alignment work should be easy, quick and reliable. Using a shim method, the adjustable degrees of freedom are decreased from six to two. This adjustment work becomes easier and quicker. The alignment of a front-end prototype is described here.

MOPO039	B-train Performances at CNAO	dipole, feedback, power-supply, extraction	568
	M. Pezzetta, G. Bazzano, E. Bressi, L. Falbo, C. Priano, M. Pullia CNAO Foundation, Milan, Italy O. Coiro, G. Franzini, D. Pellegrini, M. Serio, A. Stella INFN/LNF, Frascati (Roma), Italy G. Venchi University of Pavia, Pavia, Italy
	The commissioning of CNAO, the Italian Centre of Oncological Hadrontherapy, with proton beams is completed. The real-time measurement of the synchrotron dipole field with the so-called B-train, together with its electronic systems and related software and firmware are here described. An additional magnet, powered in series with the synchrotron dipoles, is equipped with a special coil that measures the field integral variation along the beam nominal path. The voltage induced in the coil is digitized with a fast ADC and numerically integrated by an FPGA. The field integral is then distributed to the users every time that the equivalent field changes by 0.1 G. The measured B field ranges from 0 to 1.6 T with maximum ramps of 3 T/s. The B-train system will be used to provide feedback in field to the dipole power supply. It will handle the limited bandwidth of the active filter, the B-field lag in the magnets and will avoid current jumps.

MOPO040	RF Reference Distribution for the Taiwan Photon Source	controls, laser, diagnostics, LLRF	571
	K.H. Hu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.Y. Hsu, C.H. Kuo, D. Lee, C.-Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a low-emittance 3-GeV synchrotron light source with circumference of 518.4 m which is being under construction at National Synchrotron Radiation Research Center (NSRRC) campus. Low noise 500 MHz master oscillator and novel fiber based CW RF reference distribution system will be employed to take advantages of advanced technology in this field and deliver better performance. The preliminary test of the prototype system is summarized in this report.

MOPO044	Bunch Length Measurements in Low-Alpha Mode at SPEAR3 with First Time-Resolved Pump/Probe Experiments*	laser, photon, single-bunch, radiation	583
	J.S. Wittenberg, A. Lindenberg, A. Miller Stanford University, Stanford, California, USA W.J. Corbett, L. Wang SLAC, Menlo Park, California, USA
	Funding: Work sponsored by U.S. Department of Energy Contract DE-AC03-76SF00515, Office of Basic Energy Sciences and SLAC Laboratory Directed Research Development funds (LDRD) The SPEAR3 synchrotron light source can be operated in low-alpha mode to generate x-ray pulse durations of order 1ps, well below streak camera resolution limits yet accessible by laser/sr cross-correlation measurements. Initial CC tests performed with a 50fs TiSa laser, frequency doubling BBO, photodiode and lock-in amplifier resolved bunch lengths down to about 6ps rms with 85uA single-bunch current. By reconfiguring the experimental setup to utilize a fiber laser, sum frequency generation and single photon counter it is now possible to measure profiles in the 1ps rms range with only 5uA single-bunch current. In this paper we report on the most recent measurements, simulations, modeling efforts and prospects for further improvement.

MOPS011	Impact of Low Transition Energy Optics to the Electron Cloud Instability of LHC Beams in the SPS	electron, optics, simulation, emittance	616
	H. Bartosik, E. Benedetto, K.S.B. Li, Y. Papaphilippou, G. Rumolo CERN, Geneva, Switzerland
	One of the main limitations for high intensity multi-bunch LHC proton beams in the SPS is imposed by electron cloud instabilities. A new optics of the SPS with lower transition energy was implemented and successfully tested in machine studies. The significant increase of the slippage factor that it provides at injection energy results in the expected increase of the single bunch instability thresholds. In this paper, the impact of this new optics on the electron cloud instability threshold is estimated by using numerical simulations, taking into account the change of the optics functions and the faster synchrotron motion due to the reduced transition energy.

MOPS048	Microbunching Instability Studies at SOLEIL	electron, radiation, storage-ring, synchrotron-radiation	709
	C. Evain, J. Barros, J.B. Brubach, L. Cassinari, M.-E. Couprie, G. Creff, M. Labat, A. Loulergue, L. Manceron, R. Nagaoka, P. Roy, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	Microbunching instability arises in storage rings when the number of electrons in a bunch exceeds a threshold value. Its signature, i.e. a strong and irregular emission of Coherent Synchrotron Radiation (CSR) in the Terahertz (THz) domain, is studied at SOLEIL on the AILES infrared beamline, with the storage ring tuned in a low-alpha configuration (used to get shorter electron bunch). The comparison of this observed THz CSR with numerical simulations of the longitudinal electron bunch dynamics, permits to put in evidence that during the instability a modulation appears and drifts in the longitudinal profile of the electron bunch. The understanding of this instability is important as it limits some operation of the storage rings. Indeed the induced fluctuations prevent the use of THz on the far IR beamline at high current per bunch. And in normal alpha operation this instability may spoil the electron/laser interaction effects used to get femtosecond and/or coherent pulse in storage rings (with slicing, Coherent Harmonic Generation or EEHG schemes on storage ring).

MOPS052	Analytical and Numerical Calculations of Beam Pipe Impedances at Low Frequencies with Application to Thin SIS100 Pipe	impedance, coupling, shielding, betatron	721
	U. Niedermayer, O. Boine-Frankenheim, L. Hänichen TEMF, TU Darmstadt, Darmstadt, Germany
	The projected fast ramped synchrotron SIS100 for FAIR uses an elliptical stainless steel beam pipe of 0.3 mm thickness. The lowest coherent betatron sidebands reach down to 100 kHz which demands accurate impedance calculations in the low frequency (LF) regime. For these frequencies, i.e. skin depth greater than wall thickness, structures behind the pipe may contribute to the impedance. Due to the extremely large wake length numerical methods in the time domain are not applicable. The longitudinal and transverse impedance of the thin SIS100 beam pipe including structures behind the pipe are obtained numerically by a method using power loss in the frequency domain. We compare different analytical models for simplified pipe structures to the numerical results. The dc and ultra-relativistic limits are investigated. The interpretation of bench measurements in the LF regime is discussed.

MOPS055	Observation of Intensity Dependent Single Bunch Effects at the Synchrotron Light Source PETRA III	impedance, emittance, single-bunch, electron	730
	R. Wanzenberg, K. Balewski DESY, Hamburg, Germany
	At DESY the PETRA ring is operated as a synchrotron radiation facility with a very low emittance of 1 nm. Regular user operation has started in summer 2010. A summary of observations and measurements of intensity dependent single bunch effects is presented in this report. The longitudinal impedance of the ring is estimated from the measured bunch length versus beam intensity. The results are compared with predictions from the impedance model. Furthermore measurements of the single bunch intensity limit due to the transverse mode coupling instability (TMCI) are reported. The tune and phase shift around the ring has been measured as a function of the beam intensity. At PETRA III tune spectra have been observed with some characteristics which have been observed at other storage rings in connection with electron cloud effects. The present status of the observations of potential electron cloud effects is also discussed.

MOPS066	Collective Effects in the MAX IV 3 GeV Ring	impedance, cavity, damping, storage-ring	754
	P.F. Tavares MAX-lab, Lund, Sweden T.F. Günzel CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	We present calculations of collective instability effects in the 3 GeV electron storage ring of the MAX IV facility currently under construction in Lund, Sweden. The storage ring is designed to deliver ultra-low emittance down to 0.24 nm rad so as to provide high brightness synchrotron radiation from undulators. This is achieved in a comparatively small machine (528 m circumference) through the use of a multi-bend achromat lattice and a compact magnet design featuring multi-purpose narrow gap magnet blocks. This design features small dispersion leading to low momentum compaction, which, together with the small circular (11 mm radius) chambers, poses a challenge to reach the design current (500 mA in 176 bunches) without exciting instabilities and degrading beam parameters due to the interaction with the machine impedance. Particularly important are multi-bunch resistive wall effects in the NEG coated copper chamber as well single-bunch instabilities driven by the broad-band impedance. A low RF frequency (100 MHz) and harmonic cavities are foreseen to lengthen the bunches and increase instability thresholds.

MOPS075	Simulation of Multibunch Motion with the HEADTAIL Code and Application to the CERN SPS and LHC	impedance, wakefield, simulation, coupling	778
	N. Mounet EPFL, Lausanne, Switzerland N. Mounet, E. Métral, G. Rumolo CERN, Geneva, Switzerland
	Multibunch instabilities due to beam-coupling impedance can be a critical limitation for synchrotrons operating with many bunches. It is particularly true for the LHC under nominal conditions, where according to theoretical predictions the 2808 bunches rely entirely on the performance of the transverse feedback system to remain stable. To study these instabilities, the HEADTAIL code has been extended to simulate the motion of many bunches under the action of wake fields. All the features already present in the single-bunch version of the code, such as synchrotron motion, chromaticity, amplitude detuning due to octupoles and the ability to load any kind of wake fields through tables, have remained available. This new code has been then parallelized in order to track thousands of bunches in a reasonable amount of time. The code was benchmarked against theory and exhibited a good agreement. We also show results for bunch trains in the LHC and compare them with beam-based measurements.

MOPS079	Simulations of Coaxial Wire Measurements of the Impedance of Asymmetric Structures	impedance, simulation, coupling, kicker	787
	H.A. Day, R.M. Jones UMAN, Manchester, United Kingdom F. Caspers, H.A. Day, E. Métral CERN, Geneva, Switzerland
	Coaxial wire measurements have provided a simple and effective way to measure the beam coupling impedance of accelerator structures for a number of years. It has been known how to measure the longitudinal and dipolar transverse impedance using one and two wires for some time. Recently the ability to measure the quadrupolar impedance of structures exhibiting top/bottom and left/right symmetry has been demonstrated. A method for measuring the beam coupling impedance of asymmetric structures using displaced single wires and two wire measurements is proposed. Simulations of the measurement system are presented with further work proposed.

MOPZ035	MICE Muon Beamline Particle Rate and Related Beam Loss in the ISIS Synchrotron	beam-losses, target, proton, solenoid	874
	A.J. Dobbs Imperial College of Science and Technology, Department of Physics, London, United Kingdom D. Adey University of Warwick, Coventry, United Kingdom L. Coney UCR, Riverside, California, USA
	The international Muon Ionization Cooling Experiment (MICE) will provide a proof of principle of ionization cooling, reduction of muon beam phase space, which will be needed at a future Neutrino Factory and Muon Collider. The MICE muon beam is generated by the decay of pions produced by dipping a cylindrical titanium target into the proton beam of the 800 MeV ISIS synchrotron at the Rutherford Appleton Laboratory, U.K. Studies of the particle rate in the MICE beamline and correlations with induced beam loss in ISIS are described, including the most recent data taken in the summer of 2010, representing some of the highest loss and rate conditions achieved to date. Ideally, a high rate of muons in the MICE beamline is desired, in order to facilitate the cooling measurement. However, impact on the host accelerator equipment must also be minimized. The implications of the observed beam loss and particle rate levels for MICE and ISIS are discussed.

TUODA02	Status of Sirius – a New Brazilian Synchrotron Light Source	dipole, emittance, permanent-magnet, lattice	931
	L. Liu, R. Basílio, J.F. Citadini, R.H.A. Farias, R.J.F. Marcondes, X.R. Resende, F. Rodrigues, A.R.D. Rodrigues, P.P. Sanchez, R.M. Seraphim, G. Tosin, F. H. de Sá LNLS, Campinas, Brazil
	We present an overview of the new synchrotron light source project Sirius, currently being designed at the Brazilian Synchrotron Light Laboratory (LNLS) in Campinas, São Paulo. Sirius will consist of a 480 m circumference, 3.0 GeV, 20 TBA cells, 1.7 nm.rad emittance storage ring. The dipoles will be based on the use of permanent magnet technology and will combine low field magnets (0.5 T) for the main beam deflection with a short slice of high field magnet (2.0 T) to generate photons of 12 keV critical energy with modest total energy loss. There will be 18 straight sections for insertion devices. In this report we describe the current status for the magnet lattice design and some of the subsystems.
	Slides TUODA02 [2.434 MB]

TUOAB02	Simultaneous Long and Short Bunch Operation in an Electron Storage Ring - a Hybrid Mode based on Nonlinear Momentum Compaction	electron, storage-ring, octupole, photon	945
	M. Ries, J. Feikes, A. Jankowiak, P.O. Schmid, G. Wüstefeld HZB, Berlin, Germany
	The generation of short pulses in electron storage rings is driven by different user groups like time resolved x-ray spectroscopy users or users of coherent synchrotron radiation. The required optics and operation conditions to generate this short bunches are worsening the experimental conditions, e.g. strongly reducing the average photon flux, for the regular user. Therefore short bunch operation is usually limited to dedicated user shifts. By controlling higher orders of the momentum compaction factor by higher multipoles it is possible to introduce a hybrid mode and simultaneously supplying long and short bunches. The Metrology Light Source (MLS) has the means to control these higher orders, therefore it is an ideal machine to investiate the feasibility of such a hybrid mode. Tracking results and first measurements will be shown. D. Robin et al., Proc. of EPAC08, p. 2100-2102, Genoa, Italy (2008). ** J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).
	Slides TUOAB02 [7.817 MB]

TUPC022	Design of the CLIC Drive Beam Recombination Complex	emittance, linac, injection, sextupole	1045
	J. Barranco, P.K. Skowroński, F. Tecker CERN, Geneva, Switzerland C. Biscari INFN/LNF, Frascati (Roma), Italy
	The CLIC Drive Beam Recombination Complex (DBRC) is designed to compress beam pulses from a current of 4.1 A to 100 A before using them to produce RF power in the deceleration lines. The beam is transported isochronously through a complex system consisting of a delay loop, two combiner rings and final turn around. The system is designed to preserve transverse and longitudinal emittances. During the optics design, chromaticity and non-linear dispersion were identified as the main single particle dynamics causes for transverse emittance increase. Different sextupole families are used to compensate these chromatic effects while keeping isochronicity. The bunch length is also adjusted to minimize coherent synchrotron radiation effects on bunch length, energy spread and transverse emittance. Finally, the injection scheme of the combiner rings was improved making the time variable bump created with help of the RF deflectors truly achromatic.

TUPC048	First Measurement Results of the LHC Longitudinal Density Monitor	photon, proton, ion, diagnostics	1105
	A. Jeff, M. Andersen, A. Boccardi, S. Bozyigit, E. Bravin, T. Lefèvre, A. Rabiller, F. Roncarolo CERN, Geneva, Switzerland A.S. Fisher SLAC, Menlo Park, California, USA C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: The primary author is funded by the E.U. under the DITANET Marie Curie network. Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, for example to check the injection quality and to characterize the development of ghost bunches before and during the physics periods. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. The LDM is able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 10⁵ to be achieved. The LDM operated during the 2010 lead ion run and during 2011 with protons. Measurements from both runs are presented in this contribution along with an analysis of the LDM performance and an outlook for future upgrades.

TUPC053	Superconducting Positron Stacking Ring for CLIC	positron, injection, damping, septum	1117
	F. Zimmermann, L. Rinolfi CERN, Geneva, Switzerland E.V. Bulyak, P. Gladkikh NSC/KIPT, Kharkov, Ukraine T. Omori, J. Urakawa, K. Yokoya KEK, Ibaraki, Japan
	The generation of polarized positrons for future colliders based on Compton storage rings is a promising method. A challenging key ingredient of this method is the necessary quasi-continuous positron injection into a stacking ring. The ordinary methods of multi-turn injection are not appropriate for this purpose, because the required number of injection-turns is a few hundred, and the emittance of the injected positron bunches is large. This paper describes a possible solution based on 5 GeV superconducting stacking ring, where a novel method of the combined longitudinal and transverse injection process is used to stack positrons. The ring dynamic aperture allows to inject the positron beam with normalized emittance up to 2000 micrometers during a few hundred turns. The injection efficiency is larger than 90% in simulation. The number of the injection turns is only limited by the synchrotron radiation power. The ring lattice and the results of injection simulations are presented.

TUPC062	Electron Beam Energy Measurement at the Australian Synchrotron Storage Ring	storage-ring, electron, resonance, scattering	1138
	M.J. Boland ASCo, Clayton, Victoria, Australia H. Panopoulos, R.P. Rassool, K.P. Wootton The University of Melbourne, Melbourne, Australia
	The technique of resonant spin depolarization was used to precisely measure the electron beam energy in the storage ring at the Australian Synchrotron. A detector and data acquisition system dedicated to the measurement were developed. Using the system, the long term energy stability of the storage ring was monitored and a mechanical realignment of the ring was clearly seen in the energy data. Details of the parameters used to optimize the measurement are also discussed.

TUPC063	Energy Verification in Ion Beam Therapy	proton, simulation, ion, closed-orbit	1141
	F. Moser ATI, Wien, Austria M. Benedikt, U. Dorda EBG MedAustron, Wr. Neustadt, Austria
	Funding: Austrian Federal Ministry for Science and Research, CERN Technology Doctoral Student Program The adoption of synchrotrons for medical applications necessitates a comprehensive on-line verification of all beam parameters, autonomous of common beam monitors. In particular for energy verification, the required precision of down to 0.1 MeV, in absolute terms, poses a special challenge regarding the betatron-core driven 3rd order extraction mechanism which is intended to be used at MedAustron. Two different energy verification options have been studied and their limiting factors were investigated: 1) A time-of-flight measurement inside the synchrotron, limited by the orbit circumference information and measurement duration as well as extraction uncertainties. 2) A calorimeter-style system in the extraction line, limited by radiation hardness and statistical fluctuations. The paper discusses in detail the benefits and specific aspects of each method.

TUPC068	SOLEIL Beam Orbit Stability Improvements	feedback, booster, photon, power-supply	1156
	N. Hubert, Y.-M. Abiven, F. Blache, F. Briquez, L. Cassinari, J.-C. Denard, J.-F. Lamarre, P. Lebasque, N. Leclercq, A. Lestrade, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	The electron beam orbit stability has been significantly improved at synchrotron SOLEIL. Low frequency noise sources have been localized and identified: the fans installed on the storage ring to cool down the ceramic chambers of the kickers, shaker and FCT, were slightly wobbling the electron beam orbit at 46, 50, 54 and 10⁸ Hz. The localization method and the solutions that will allow reducing the noise from 0.8 μm RMS down to 0.3 μm are presented. Besides, a new 160 m long beamline, NANOSCOPIUM, is being installed on a canted straight section. Its photon beam position stability requirements are very tight calling for the following improvements: addition of 2 more BPMs and fast correctors in the orbit feedback loops, new INVAR stands for BPM and XBPM integrating Hydrostatic Level System sensors. The paper is also discussing other projects that did or will contribute to improving the beam orbit stability: installation of 145 temperature sensors on the storage ring, a new analog feedforward correction system for insertion devices, and the use of the bending magnet X-BPM measurements in the slow and fast orbit feedback loops.

TUPC075	Diagnostic Devices for Beam Intensity Measurement at FAIR	ion, diagnostics, storage-ring, antiproton	1174
	M. Schwickert, T. Hoffmann, F. Kurian, H. Reeg GSI, Darmstadt, Germany R. Geithner, W. Vodel HIJ, Jena, Germany R. Neubert, P. Seidel FSU Jena, Jena, Germany
	Funding: Work supported by EU, DITANET, Project No. ITN-2008-215080. Precise determination of beam intensity is important for any accelerator facility. At FAIR, the Facility for Antiproton and Ion Research presently in the planning phase at GSI, the requirements set by beam intensities in the various accelerators, storage rings and transport lines differ significantly. A set of beam diagnostic instruments is foreseen to detect the large variety of ion beams ranging from less than 10⁴ antiprotons up to high intensity of 5·10¹¹ uranium ions. This contribution presents an overview of destined current measurement devices, both intercepting, like scintillators, ionization chambers or secondary electron monitors, and non-intercepting current-transformer type devices. Ongoing developments are discussed for non-intercepting devices, i.e. a dc current transformer with large dynamic range and a cryogenic current comparator, purpose-built for the detection of lowest beam intensities at FAIR.

TUPC084	Performance of the Scintillation Profile Monitor in the COSY Synchrotron	vacuum, proton, electron, target	1201
	V. Kamerdzhiev, J. Dietrich, K. Reimers FZJ, Jülich, Germany
	Residual gas scintillation is used for measuring profile of the proton beam circulating in the COSY synchrotron. The problem of low rate of scintillation events detected by a multichannel photomultiplier is coped with by injecting small amounts of pure nitrogen into the SPM vacuum chamber. This leads to a temporary local pressure bump of no more than an order of magnitude. A commercially available piezo-electric dosing valve allows good control over the amplitude and duration of the pressure bump. Since the average pressure in the machine is hardly changed, the method is fully compatible with experiment operation. This approach offers a robust and inexpensive way to measure the beam profile. The design of the SPM is discussed. The latest measurement results and comparison to the ionization profile monitor data is presented.

TUPC085	Observation of Microwave Radiation using Low-cost Detectors at the ANKA Storage Ring	radiation, storage-ring, vacuum, optics	1203
	V. Judin, N. Hiller, A. Hofmann, E. Huttel, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, M.J. Nasse, N.J. Smale KIT, Karlsruhe, Germany F. Caspers CERN, Geneva, Switzerland P. Peier PSI, Villigen, Switzerland
	Funding: Work supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320 Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed because the waveguide cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: The accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths above the waveguide cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually used in standard TV-SAT-receivers and are very cheap. We determined the time response of LNBs to be below 100 ns. The sensitivity of LNBs is optimized to detect very low intensity "noise-like" signals.

TUPC086	A Setup for Single Shot Electro Optical Bunch Length Measurements at the ANKA Storage Ring	laser, electron, storage-ring, radiation	1206
	N. Hiller, E. Huttel, A.-S. Müller, A. Plech KIT, Karlsruhe, Germany F. Müller, P. Peier, V. Schlott PSI, Villigen, Switzerland
	Funding: Supported by the Initiative and Networking Fund of the Helmholtz Association under VH-NG-320. Sponsored by the German Federal Ministry of Education and Research under contract number 05K10VKC Single shot electro optical bunch length measurements, in particular using spectral decoding, are foreseen for the ANKA storage ring. This will allow to resolve fast changes of bunch deformation and structure during the low alpha operation (2-15 ps rms bunch length). This technique uses a chirped laser pulse to probe the field induced birefringence in an electro optical crystal. The laser pulse is then analyzed in a single shot spectrometer. To obtain the birefringence modulation one can either use the near field of the electron bunch (placing the crystal close to the electron bunch in the UHV system of the storage ring), or the far field (coherent synchrotron radiation in the THz range at a THz-/IR-Beamline). The laser needs to supply: sufficient tunability of pulse length, a wide spectrum to allow for a sub-ps resolution. Additionally it must provide a mode-locked operation synchronized to the bunch revolution clock. For this purpose, a mode locked Ytterbium fibre laser system which operates at 10³⁰ nm has been developed at the Paul-Scherrer Institute in Switzerland. We give an overview over the experimental set up in the ANKA storage ring and the status of the project.

TUPC087	Filling Pattern Measurements at the ANKA Storage Ring	photon, electron, storage-ring, single-bunch	1209
	B. Kehrer, N. Hiller, A. Hofmann, E. Huttel, V. Judin, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale KIT, Karlsruhe, Germany
	For many accelerator physics studies, e.g. the investigation of coherent synchrotron radiation (CSR), a precise knowledge of the quantitative filling pattern (i.e. the number of electrons per bunch) is essential. This can be achieved by either using a linear detector (analog recording) or by employing the method of time-correlated single photon counting (TCSPC). At the ANKA storage ring both methods are in use. The analogue detection is based on the signal from a stripline or annular electrode, the TCSPC uses a Single Photon Avalanche Diode (SPAD). In this paper, we describe the experimental set-ups and present results of a comparison of the two techniques for single as well as for multi bunch filling patterns.

TUPC093	CSR Bunch Length Monitor for XFEL/SPring-8 - SACLA	radiation, FEL, electron, synchrotron-radiation	1224
	C. Kondo, S. Matsubara, T. Matsumoto JASRI/SPring-8, Hyogo-ken, Japan S.I. Inoue, H. Maesaka, Y. Otake RIKEN Spring-8 Harima, Hyogo, Japan
	SPring-8 Angstrom Compact Free Electron Laser (SACLA) is now under commissioning operation, aimed at the generation of a sub-angstrom free electron laser (FEL). In order to ensure the stable FEL generation, non-distractive bunch length monitors utilizing coherent synchrotron radiation (CSR) are installed. The monitors are located at the downstream of individual bunch compressor (BC1-BC3), and they measure the radiation emitted at the individual last magnets of the chicanes. At the magnets, beams with bunch lengths form 10 fs to 1000 fs generate the CSRs with a spectrum ranging the almost whole infrared region (0.03 - 3 THz). The CSRs are detected by a Schottky diode at the BC1, or pyroelectric detectors and a simple organic lens optical system at BC2 and 3. The bunch length monitor systems are used for bunch length feedback control to obtain the stable lasing by changing the rf parameter of acceleration cavities before the BCs. A preliminary system for the above mentioned system was tested at the SCSS test accelerator, and it showed sufficient performance to measure bunch length up to 300 fs. In this report, we describe the design and the results of the first operation.

TUPC112	Photon Beam Position Monitor based on Position-sensitive Detector for HLS*	photon, injection, diagnostics, feedback	1281
	Y.Y. Xiao, L.M. Gu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	In order to overcome the limitation that the existing photon beam position monitors (PBPM) cannot measure the beam position in vertical and horizontal at the same time, a new photon beam position monitor based on position-sensitive detector (PSD) has developed at HLS (Hefei Light Source). The new PBPM based on the PSD has very fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. Some results are given.

TUPC132	Imaging of the MAX III Electron Beam Profile Using Visible Synchrotron Radiation	electron, emittance, diagnostics, lattice	1332
	A. Hansson, Å. Andersson, E.J. Wallén MAX-lab, Lund, Sweden
	The recently assembled MAX III diagnostic beam line utilizes the bending magnet synchrotron radiation (SR) in the visible to ultraviolet range to form images of the transverse electron beam profile. Computer simulations model the generation and propagation of the SR through the beam line, taking into account effects such as diffraction, the longitudinally distributed source point and the curvature of the electron orbit. Using the diagnostic beam line, the electron beam size and the emittance in the MAX III synchrotron light source has been determined.

TUPC146	Beam Profiles Analysis for Beam Diagnostic Applications	background, diagnostics, synchrotron-radiation, instrumentation	1368
	C.-Y. Liao, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Beam profile and its analysis play an important role in beam diagnostics of a particle accelerator system. Use of destructive screen monitor or non-destructive synchrotron radiation monitor for beam profile measurement is a simple way and has been widely used in synchrotron light source facility. Analyze beam profiles can obtain beam parameters including beam center, σ, and tilt angle which has become a useful tool for beam diagnostic. In this report the comparison of fitting strategies affect the analysis results are studied. The computer simulated beam profiles with different background noise level and conditions are used to evaluate the computing time, and the estimated fitting errors.

TUPC155	Optimisation of the LHC Beam Current Transformers for Accurate Luminosity Determination	luminosity, instrumentation, pick-up, monitoring	1395
	J-J. Gras, D. Belohrad, M. Ludwig, P. Odier CERN, Geneva, Switzerland C. Barschel RWTH, Aachen, Germany
	During the 2010 and 2011 LHC runs a series of dedicated fills were used for luminosity calibration measurements at each of the LHC experiments. A major contribution to the final precision of these luminosity calibration campaigns originated from the absolute accuracy of the bunch current population estimation. The importance of these measurements for the LHC physics community triggered a large and fruitful collaboration between the CERN Beam Instrumentation Group and the LHC Experiments to push the LHC Beam Current Transformers performance to their limit. This paper will report on the available instruments for beam current measurements, the methodology used to improve them and the results obtained.

TUPC160	Recent Developments of Diagnostics at Diamond	photon, feedback, undulator, diagnostics	1407
	G. Rehm, C. Bloomer, A.F.D. Morgan, C.A. Thomas Diamond, Oxfordshire, United Kingdom
	This contribution summarizes some recent development of diagnostics system to improve the operation of Diamond Light Source. Firstly, we are advancing the integration of photon beam diagnostics with the orbit feedback system. Measurements have shown the correlation between recorded electron and photon beam motion on the short timescales (ms-minutes) and the potential for improvement on long timescales (minutes-days). Secondly, with the addition of more elliptically polarized undulators at Diamond, measurement of their photon beam position require a solution that reliably operates with the changing photon beam profiles emitted by these devices. To this end, we have developed an X-ray beam position monitor that analyzes the backscatter from an aperture in the front end. Thirdly, as operation in low-alpha mode with few ps bunch lengths receives increasing interest from users, we have been evaluating various techniques for the measurement of these short bunch lengths that could serve as alternatives to streak camera measurements.

TUPO007	FLUTE, a Linac Based THz Source	radiation, linac, gun, synchrotron-radiation	1458
	S. Naknaimueang, M. Schwarz Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany R. Abela, H.-H. Braun, R. Ganter, B. Patterson PSI, Villigen, Switzerland A.H. Albert, T. Baumbach, M. Hagelstein, N. Hiller, E. Huttel, V. Judin, B. Kehrer, R. Kubat, S. Marsching, W. Mexner, A.-S. Müller, M.J. Nasse, A. Plech, R. Rossmanith, M. Schuh KIT, Karlsruhe, Germany M.T. Schmelling MPI-K, Heidelberg, Germany
	We propose a versatile THz source named FLUTE (“Ferninfrarot Linac- Und Test-Experiment”) based on a 30 - 50 MeV S-band linac with bunch compressor, that shall not only provide high field THz pulses applications but shall also serve as a test facility to study important accelerator physics issues. This is also of importance in view of the planned utltra-broadband THz to mid infrared user facility TBONE. Special emphasis is put on studies of bunch compression and beam stability as a function of bunch charge (0.1-5 nC) and of different generation mechanisms of coherent radiation (CSR, CER, CTR). This paper describes the design and layout of the proposed FLUTE machine and presents results of beam dynamic calculations with the tracking programs ASTRA and CSRtrack.

TUPO009	HiSOR-II, Compact Light Source with an Innovative Lattice Design	emittance, lattice, focusing, radiation	1464
	A. Miyamoto, S. Sasaki HSRC, Higashi-Hiroshima, Japan
	Funding: This work is partially supported by Cooperative and Supporting Program for Researches and Educations in University sponsored by KEK We proposed a ring that a beam orbit is not closed with one turn and return to starting point after multiple turns around the ring. The idea of this new accumulation ring was inspired based on the torus knot theory. This ring has a long length of the total closed orbit in comparison with a conventional ring which has the orbit of one turn. Therefore this ring can have many straight sections and is advantageous to installation of insertion devices. We are designing a new ring based on the shape of a (3,11) torus knot for our future plan ‘HiSOR-II’. This ring has 11 long straight sections and can place undulators effectively by placing elements such as quadrupole magnets at the place near bending magnet, outside of the orbit crossing section. Furthermore, this ring has about 3 times longer circumference in comparison with the conventional ring, the diameter of the ring is as compact as 15 m, but its circumference is as long as 130 m. On the other hand, this ring must achieve low emittance to operate as the 3rd generation light source ring. Therefore we designed lattice of this ring in reference to MAX-III and achieved low emittance by using bending magnets with combined function.

TUPO010	An Innovative Lattice Design for a Compact Storage Ring	lattice, radiation, storage-ring, synchrotron-radiation	1467
	S. Sasaki, A. Miyamoto HSRC, Higashi-Hiroshima, Japan
	Funding: *This work is partially supported by Cooperative and Supporting Program for Researches and Educations in Universities sponsored by KEK. We propose a new concept of lattice design for a compact light source storage ring. In a ring with this new scheme, the electron beam may have extremely longer design orbit than that of a conventional ring. In this ring, a design orbit closes after completing multiple turns. The lattice for realizing this exotic beam orbit can be made by placing conventional accelerator components such as bending magnets, quadrupole magnets, RF cavity and so forth in an appropriate manner onto a projected torus knot in the horizontal orbit plane. Due to an extended closed orbit length, the ring with this type of lattice has larger maximum stored charge if operated in multiple-bunch mode, and has longer bunch-to-bunch interval if operated in a single-bunch mode. Also, essential for a storage ring as the synchrotron light source, a larger number of straight sections may accommodate with many insertion devices. In addition, this new scheme may provide advantages for designing a oscillator-type free electron laser and coherent radiation light source.

TUPS001	Upgrade of the ESRF Vacuum System	vacuum, storage-ring, controls, cathode	1515
	M. Hahn, J.C. Biasci, H.P. Marques, A. Meunier ESRF, Grenoble, France
	The upgrade program of the ESRF concerns in terms of electron storage ring vacuum chambers mainly the insertion device (ID) sectors. Here the length available for the production of intense synchrotron light is being increased from five to six or even seven meters. The presence of canted ID sectors where two independent synchrotron light beams will be produced in the same straight section requires new quadrupole chambers compatible with the new geometry. A number of long insertion device vacuum chambers for the new ID sectors has already been produced by ESRF and coated with non-evaporable getter (NEG) material, a new generation of in vacuum undulators for the extended ID sections are under preparation. This paper outlines the status of the modification of the vacuum system and informs about consequences for the ESRF NEG coating activity and some recent improvements of the vacuum measurement and control system.

TUPS002	Photodesorption Measurements at ESRF D31	vacuum, radiation, synchrotron-radiation, electron	1518
	H.P. Marques, G. Debut, M. Hahn ESRF, Grenoble, France
	Since 1998 exists at ESRF a dedicated beamline for photodesorption measurement from vacuum chambers - D31. The original goal of this installation was to study the wall pumping effect. When exposed to synchrotron radiation surfaces exhibit strong outgassing of the adsorbed gas layer despite UHV conditions. Long term outgassing leads to the depletion of the adsorbed layer and produces a very clean surface which turns the walls of the vacuum chamber into an active pumping surface. The desorption mechanisms can be described by the long standing models of Knotek-Feibelman (KF) and Menzel-Gomer-Redhead – (MGR) which are themselves encompassed under the name of Desorption Induced by Electronic Transitions (DIET). In these models the surface itself plays a fundamental role in the desorption mechanism. At D31 have been tested chambers of stainless steel, aluminum and copper, with or without coatings (e.g. NEG, copper), designed by ESRF and other institutes like ALBA, CERN, ELETTRA and Soleil. Here we review some of the results obtained and outline the future plans of D31.

TUPS009	SEY of Al Samples from the Dipole Chamber of PETRA III at DESY	electron, emittance, simulation, synchrotron-radiation	1533
	D. R. Grosso, R. Cimino, M. Commisso INFN/LNF, Frascati (Roma), Italy R. Flammini CNR-IMIP, Monterotondo Stazione RM, Italy R. Larciprete ISM-CNR, Rome, Italy R. Wanzenberg DESY, Hamburg, Germany
	At the synchrotron radiation facility PETRA III, tune spectra have been measured with some characteristics which are typically observed at other storage rings in connection with electron cloud effects. For some bunch filling patterns, an increase of the vertical emittance has been observed. To estimate such effects with the available e-cloud simulation codes, the detailed knowledge of the SEY (Secondary Electron Yield) of the Al chamber, is required. To the purpose, representative PETRA III Al samples, were studied in detail at the INFN-LNF Surface Science Laboratory. XPS (X-ray photoelectron spectroscopy) and SEY measurements were performed as a function of electron and argon ion conditioning. The SEY of the as received samples shows a maximum value of δmax ≅ 2.8. Electron conditioning at 500 eV kinetic energy, reduces the SEY to values between δmax ≅ 1.8 to 1.4 (depending on the actual sample analyzed). The XPS characterization of the sample surface, after several cycles of argon ion sputtering, shows clearly that the SEY variation is closely related to the oxidation state of the Al sample, reaching a δmax value as low as 1.3 for our cleanest surface.

TUPS010	A Novel Approach in UHV Pumping of Accelerators: the NEXTorr® Pump	ion, vacuum, insertion, insertion-device	1536
	P. Manini, A. Bonucci, L. Caruso, A. Conte, F. Siviero, L. Viale SAES Getters S.p.A., Lainate, Italy
	In spite of the large dimensions of accelerators, like synchrotrons or colliders, the space available for mounting UHV pumps is getting smaller, due to design constraints, service equipments, conductances, magnets, various instrumentations. This poses challenges to traditional UHV pump designs which are called to provide more pumping performances in smaller spaces. A radically new approach is here presented which can mitigate this issue. In this approach Non Evaporable Getter (NEG) and ion pumping technologies are properly combined and integrated in one single device, called NEXTorr®, having a unique design. In this pump, the getter cartridge acts as the main UHV pumping element, leaving to a small sputter ion pump the ancillary task of removing noble gases and methane, not pumped by the NEG. This design allows achieving large pumping speed in a very small package as well as delivering interesting pumping synergies. Main features of this new pump, including pumping tests, and example of applications will be reported, with a special focus to accelerators and high energy physics systems. Its impact in the design of vacuum systems for accelerators will also be discussed.

TUPS015	ALBA Storage Ring Vacuum System Commissioning	vacuum, storage-ring, photon, cavity	1551
	E. Al-dmour, D. Einfeld CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA booster and storage ring vacuum system installation has been done in 2009, followed by the installation of the RF cavities and the booster to storage transfer line in 2010. Early 2011, the first phase of insertion devices (ID) installation took place, with three narrow gap NEG coated vacuum chambers have been installed, for the use of two Apple-II undulators and one conventional wiggler. On 8th of March 2011, the storage ring commissioning started and it was marked with the achievement of the first turn in the storage ring on the 9th of March and on the 1st of April 2011, 100 mA of beam current has been accumulated. During this period the vacuum system conditioning took place with very good performance. The base pressure without beam was 4·10^-10 mbar and the average pressure with 100 mA was 7.7·10^-9 mbar. The results of the conditioning together with the latest developments are introduced.

TUPS016	Vacuum System Design for the MAX IV 3 GeV Ring	vacuum, storage-ring, lattice, radiation	1554
	E. Al-dmour, D. Einfeld, J. Pasquaud, M. Quispe CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain J. Ahlbäck, M.J. Grabski, P.F. Tavares MAX-lab, Lund, Sweden
	We describe the conceptual design of the vacuum system of the 3 GeV electron storage ring in the MAX IV facility currently under construction in Lund, Sweden. The standard vacuum chambers are for the most part a cylindrical copper tube with 11 mm inner radius whereas stainless steel will be used at selected locations for beam position monitors, bellows and corrector vacuum chambers. In order to cope with the low vacuum conductance, distributed pumping will be provided through NEG coating of all chambers, including those in dipole magnets making MAX IV the first storage ring to be fully NEG coated. We present the mechanical and thermal design of these chambers and discuss the challenges involved in extracting insertion device radiation as well as coping with the heat load from both IDs and bending magnets in a machine with large bending radius, narrow chambers and tight mechanical tolerance requirements.

TUPS022	MedAustron Beam Vacuum System : From sources to Patient Treatment Rooms	vacuum, instrumentation, ion, dipole	1572
	J.M. Jimenez, P. Cruikshank, L. Faisandel, W. Maan CERN, Geneva, Switzerland T. Hauser, G. Hulla, P. Landrot, J. Wallner EBG MedAustron, Wr. Neustadt, Austria
	The MedAustron beam vacuum system is a complex system integrating different technical solutions from the source to the patient treatment rooms. The specified vacuum performances combined with the challenging integration issues require technical compromise which will be presented in this poster. The status of the design of the vacuum system will be reviewed and the pending issues will be explained.

TUPS029	Development of a Feedthrough with Small Reflection for the TPS BPM	impedance, controls, vacuum	1593
	Huang, Y.T. Huang, C.-C. Chang, C.L. Chen, G.-Y. Hsiung, S-N. Hsu, H.P. Hsueh NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	The TPS BPM feedthrough is a coaxial cable with a structure of a kind for which power loss occurs readily at places at which exists an impedance mismatch. With an impedance equation for a simple coaxial cable combined with a multi-dielectric modification, a model feedthrough with small reflection has been designed. With careful setting of brazing conditions and precise control of the dimensions of devices, a TPS prototypical BPM feedthrough having a reflection coefficient less than 0.05 was manufactured. The eccentricity was constrained within 0.03 mm, and the deviation of measured capacitance of button electrodes was less than 7 %.

TUPS030	Manufacturing and Vacuum Testing of Aluminum Bending Chambers for TPS	vacuum, ion, photon, electron	1596
	Y.C. Yang, C.K. Chan, C.-C. Chang, C.L. Chen, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, T.Y. Lee NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is an aluminum alloy vacuum system with 518.4 m circumference divided into 24 sections. A6061T6 aluminum alloy material is used for TPS bending chambers. Each aluminum bending chamber is component of 2 half plates, about 3.5～4.2 m in length and～0.6 m in width, were oil-free CNC machined, ozone cleaned, and TIG welding in clean room. The deformation < 0.1 mm and leakage rate < 2x10-9mbar. L/s for each welded bending chamber has inspected and achieved. A bending chamber is inspecting the thermal outgassing rate test and ultimate pressure. The manufacturing and vacuum test will be described in this paper.

TUPS031	The Installation of One 14 Meter Cell of TPS Vacuum System	vacuum, photon, laser, site	1599
	H.P. Hsueh, C.K. Chan, C.H. Chang, C.-C. Chang, C.L. Chen, C.M. Cheng, Y.T. Cheng, G.-Y. Hsiung, S-N. Hsu, I.T. Huang, T.Y. Lee, H.Y. Yan, Y.C. Yang, C.S. huang 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. The vacuum system has been designed with off-site baking for arc section from sector gate valve to sector gate valve. There is no flange used in this arc section besides the two ends connected to sector gate valves. It is a tedious works for install such long vacuum system with aluminum chambers. In this poster, all the detailed installation procedures will be described. All the precaution inspection procedures for all vacuum components to prevent failed components to be installed will also be described. Every three weeks, one cell will be assembled and stored. Experience is being learned and could be used for the vacuum system of future new accelerator like FEL and others.

TUPS060	Designing, Integrating, and Coordinating Installation of MedAustron	survey, extraction, optics, alignment	1671
	B. Nicquevert, C. Hauviller CERN, Geneva, Switzerland M. Benedikt, B. Nicquevert EBG MedAustron, Wr. Neustadt, Austria
	Funding: CERN, Geneva, Switzerland EBG MedAustron, Wiener Neustadt, Austria "Give me a layout good enough and a building to place it, and I will install your accelerator". To paraphrase Archimedes, this is the role attributed to Integration team in MedAustron project. Starting with the optics layout and a building sketch, the integration work consists of a series of activities, interlinked in a complex manner. First the design and integration of the accelerator: list items, define geometrical envelopes with interfaces, put them in position in CAD, identify conflicts, define input for items design and infrastructure. Then the various equipment is procured: verify and validate design data, follow-up manufacturing, fiducialize equipment, build supports. Lastly global installation: check equipped building, define survey framework, install and pre-align equipment on supports, move assemblies to their final location, survey actual position and adjust to theoretical position. The whole chain of operations from a layout to a real beam in MedAustron is illustrated. The help from item-driven data management is emphasized. Grouping all activities within a single team favors interactions between stakeholders and consistency of activities.

TUPS062	The Ground Testing of TPS Ground System	site, impedance, storage-ring, background	1677
	T.-S. Ueng, J.-C. Chang, C.K. Kuan, Y.-C. Lin NSRRC, Hsinchu, Taiwan
	A ground grid of 4 rings and 62 vertical electrodes has been constructed for the TPS storage ring. The ground resistance was designed to be smaller than 0.2 ohms in order to give a good protection of the TPS electrical facility and personnel. In order to match the building construction schedule the TPS ground grid has been installed about 1/6 segment of the construction project each period. The ground impedance of each segment was measured right after the installation. The ground grid with the diameter of 200 m of outside ring and its low impedance value, also the limit testing space, challenged the measurement of ground resistance. Several different methods of ground testing have been used and the measured results are compared each other. These methods include fall-of-potential method, slope method, intersecting curves method and the test-current-reversal method. The final TPS ground impedance will be measured and compared with the calculation from combining the previous several segment measurements. The actual TPS ground resistance should have a smaller value than expected.

TUPS063	Power Saving Schemes in the NSRRC	controls, synchrotron-radiation, status, radiation	1680
	J.-C. Chang, Y.F. Chiu, J.-M. Lee, Y.-C. Lin, C.Y. Liu, Z.-D. Tsai, T.-S. Ueng NSRRC, Hsinchu, Taiwan
	National Synchrotron Radiation Research Center (NSRRC), Taiwan will complete the construction of the civil and utility system engineering of the Taiwan Photon Source (TPS) in the end of 2012. The power consumption of the TPS is estimated about 2.3 times of that of the existed Taiwan Light Source (TLS). To cope with increasing power requirement in the near future, we have been conducting several power saving schemes, which include power requirement control, optimization of chillers operation, application of heat pump, air conditioning system improvement, power factor improvement and the lighting system improvement.

TUPS067	Photon-stimulated Desorption Experiment for a TPS Crotch Absorber	photon, simulation, vacuum, radiation	1692
	Y.T. Cheng, G.-Y. Hsiung, C.K. Kuan, A. Sheng, H.Y. Yan NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	National Synchrotron Radiation Research Center (NSRRC) is constructing a large third-generation synchrotron accelerator in Taiwan, the so-called Taiwan Photon Source (TPS). This 3-GeV, 500-mA machine will generate high-density bending-magnet radiation, of which 90 % of the power is absorbed by the crotch absorber in the storage ring. To understand better the beam-cleaning and photon-desorption phenomena of a copper crotch absorber, we have performed a PSD (photon-stimulated desorption) test in Taiwan Light Source (TLS) at Beam line 19 (BL19). Some mathematical modelling, experimental designs and results are also presented here.

TUPZ010	Longitudinal Emittance Blow-up in the LHC	emittance, damping, feedback, acceleration	1819
	P. Baudrenghien, A.C. Butterworth, M. Jaussi, T. Mastoridis, G. Papotti, E.N. Shaposhnikova, J. Tückmantel CERN, Geneva, Switzerland
	The LHC relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blow-up provides the required emittance growth. The method was implemented through the summer of 2010. We inject band-limited RF phase-noise in the main accelerating cavities during the whole ramp of about 11 minutes. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are set by pre-defined constants, making the diffusion stop at the edges of the demanded distribution. The noise amplitude is controlled by feedback using the measurement of the average bunch length. This algorithm reproducibly achieves the programmed bunch length of about 1.2 ns (4 σ) at flat top with low bunch-to-bunch scatter and provides a stable beam for physics coast.

WEOAA01	The ThomX Project	laser, injection, feedback, cavity	1903
	A. Variola LAL, Orsay, France
	Funding: Work supported by the EQUIPEX program, the Ile de France region, CNRS-IN2P3 and Université Paris Sud XI ThomX is a Compton source project in the range of the hard X rays (40 / 90 keV). The machine is composed of an injector Linac and a storage ring where an electron bunch collides with a laser pulse accumulated in a Fabry-Perot resonator. The final goal is to provide an X-rays average flux of 1011/10¹³ ph/s. The emitted flux will be characterized by a dedicated X-ray line. Different users are partners in the ThomX project, especially in the area of medical science and cultural heritage. Their main goal will be the transfer of all the experimental techniques developed on big synchrotron rings to these more compact and flexible machines. The project ThomX has recently been funded and will be located on the Orsay University campus. In this article the project and its associated scientific interest are presented.
	Slides WEOAA01 [5.947 MB]

WEPC015	Tuning Methods for HIMAC Multiple-energy Operation	betatron, acceleration, resonance, beam-losses	2037
	K. Katagiri, T. Furukawa, Y. Iwata, K. Noda, S. Sato, T. Shirai NIRS, Chiba-shi, Japan K. Mizushima Chiba University, Graduate School of Science and Technology, Chiba, Japan E. Takeshita Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
	Beam stability of multiple-energy operation at HIMAC synchrotron was improved for the fast raster-scanning irradiation. In order to improve the transverse stability, the working point of the betatron tune was investigated during one operation cycle. The signals were collected from the beam position monitor using a fast data-acquisition unit. The temporal evolution of the horizontal and vertical betatron tune was evaluated by using the short time Fourier transform. Analyzed results showed that variation of the betatron tune in the acceleration interval passed through the 3rd-order coupling resonance line, and it caused undesirable emittance growth. In order to keep the working point within the desirable operating region, the current pattern of the power supplies for the quadrupole magnets was corrected by using the variation of the betatron tune. The experimental results showed that the working point could be successfully stabilized, and the undesirable beam losses could be reduced during the acceleration interval.

WEPC016	Amplitude Dependent Orbit Shift and its Effect on Beam Injection	injection, septum, betatron, sextupole	2040
	Y. Shoji LASTI, Hyogo, Japan T. Nakamura, J. Schimizu, M. Takao JASRI/SPring-8, Hyogo-ken, Japan
	The betatron oscillation amplitude dependent orbit shift was measured at the electron storage ring, NewSUBARU. The result roughly agreed with the theoretical calculation. The effect of this shift on the beam injection is discussed using parameters of NewSUBARU and SPring-8. Generally there exists a better side for the injection, the inner side or the outer side of the ring, which depends on the sign of the orbit shift at the injection septum. In case of the NewSUBARU, the beam is injected from the outer side and the shift is positive. The effective thickness of the septum is reduced by the large oscillation amplitude of the injected beam. On the other hand at SPring-8, the beam is injected from the inner side of the ring while the orbit shift is negative. This means that the two rings are using better side for the injection.

WEPC049	Operation and Storage Ring Calibration with the Transverse Bunch-by-Bunch Feedback System at the Australian Synchrotron	feedback, sextupole, damping, storage-ring	2121
	M.J. Boland, Y.E. Tan ASCo, Clayton, Victoria, Australia D.J. Peake, R.P. Rassool, K.P. Wootton The University of Melbourne, Melbourne, Australia
	The first operational experience with the transverse bunch-by-bunch feedback system for the storage ring shows a doubling of the lifetime and the ability to damp instabilities caused by IVU gap changes. The system was also used to calibrate the ring by doing simultaneous measurements on several single bunches with different bunch currents. Using the bunch-by-bunch system's capability to excite the beam to large amplitudes, the non-linear beam dynamics were also measured and compared with the model.

WEPC052	Spinor Based Calculation of Depolarizing Effects in Circular Lepton Accelerators	resonance, polarization, lepton, photon	2130
	O. Boldt, A. Dieckmann, F. Frommberger, W. Hillert ELSA, Bonn, Germany
	Funding: BMBF The emission of synchrotron radiation strongly influences the beam dynamics in case of ultra relativistic leptons. When storing or accelerating leptons in circular accelerators, the acting magnetic field shows an oscillating behavior in the rest frame of the leptons. Its properties can be determined by a spectral analysis. The stochastic emission of synchrotron light leads to a line broadening within the magnetic field spectrum. This spectrum can be used to simulate depolarizing effects in circular accelerators. Our contribution will present a tracking based calculation of the mentioned spectrum and a spinor-based determination of the resulting population of the spin-up state. These calculations base on the lattice of the electron stretcher accelerator (ELSA, Bonn) and are confirmed by measurements of the polarization.

WEPC060	Magnetic Field Description in Curved Accelerator Magnets using Local Toroidal Multipoles	multipole, dipole, antiproton, quadrupole	2154
	P. Schnizer, E.S. Fischer GSI, Darmstadt, Germany B. Schnizer TUG/ITP, Graz, Austria
	Any introduction on beam dynamics describes the field homogeneity of the accelerator magnets using local derivatives. These are then typically described as plane circular multipoles or 2D harmonics; solutions to the potential equation. The high current operation, foreseen for SIS100 accelerator of FAIR, requires an in detail understanding of the different beam effects, driven by the resonance of the magnets. Therefore different multipole sets were developed and are now finalised in the Local Elliptic Toroidal Multipoles. These are a first order approximation while the plane circular ones are a zero order one in the inverse aspect ratio.

WEPC091	Studies with a Particle Tracking Code for the SIS100 Resonant Extraction System	extraction, quadrupole, controls, feedback	2220
	M.M. Kirk, G. Franchetti, H. Klingbeil, P. Moritz, N. Pyka, H. Ramakers, P.J. Spiller, H. Welker GSI, Darmstadt, Germany
	Several issues concerning the envisaged SIS100 resonant extraction at GSI can be resolved with a simulation-lead approach for which a particle tracking code was developed. Applications to date have included: design and testing of data supply algorithms for the accelerator control system; requirements analysis for the power converter ripple in the quadrupoles forming the doublet focusing; and verification of the RF Knock-Out exciter's performance.

WEPC095	Simulations of the Microbunching Instability at ANKA using a Vlasov-Fokker-Planck Solver	radiation, electron, simulation, impedance	2232
	M. Klein, A.-S. Müller KIT, Karlsruhe, Germany K.G. Sonnad CLASSE, Ithaca, New York, USA
	In order to produce coherent synchrotron radiation the ANKA light source is operated frequently in short bunch mode. It is known that during this procedure strong self fields caused by high electron densities can enforce initial density fluctuations and thus lead to microbunching. The build-up of those substructures is accompanied by bursting radiation which provides higher radiation power for the users. Damping and diffusion due to incoherent radiation smoothens the bunch shape again and hence lead to periodic or chaotic bursting cycles. The evolution of the electron bunch density under the influence of self fields can be described by the Vlasov-Fokker-Plank (VFP) equation. We present results from a numerical solution of the VFP-equation for parameters used in standard short bunch mode at ANKA.

WEPC109	Emittance Optimization Using Particle Swarm Algorithm*	emittance, lattice, quadrupole, storage-ring	2271
	Z. Bai, W. Li, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	In this paper we use a swarm intelligence algorithm, particle swarm optimization (PSO), to optimize the emittance directly. Some constraint conditions such as beta functions, fractional tunes and dispersion function, are considered in the emittance optimization. We optimize the strengths and positions of quadrupoles to search low emittances. Here an FBA lattice studied in the design of the Hefei Advanced Light Source storage ring is used as the testing lattice. The PSO is shown to be beneficial in the optimization.

WEPO001	Design and Optimization of the MedAustron Synchrotron Main Dipoles	simulation, dipole, ion, quadrupole	2406
	M. Stockner, B. Langenbeck, C. Siedler EBG MedAustron, Wr. Neustadt, Austria Th. Zickler CERN, Geneva, Switzerland
	MedAustron, a future centre for ion-therapy and research in Austria will comprise an accelerator facility based on a synchrotron for the delivery of protons and light ions for cancer treatment and for clinical and non-clinical research. The main dipole for the synchrotron went through an extensive design process to meet the stringent requirements. The local and integrated field quality was optimized. The residual field levels in the magnet gap were calculated and the dynamic behaviour of the dipole magnet was studied, both in 2D and 3D, using OPERA. The pole profile has been optimized to reduce sextupolar components in the integrated field by adjusting the shims on the pole edge. A Rogowski-profile at the pole ends and the use of stainless-steel tension straps will enhance the dynamic behaviour and guarantee a small time constants. Appropriate pole-end shimming will be used to compensate for residual multi-pole components and to fine-tune the magnetic length. The results of this comprehensive design study are summarized in this paper.

WEPO019	Magnetic Model of the CERN Proton Synchrotron Main Magnetic Unit	focusing, multipole, proton, dipole	2439
	M. Juchno EPFL, Lausanne, Switzerland
	The CERN Proton Synchrotron (PS) will remain one of the key elements of the Large Hadron Collider (LHC) injector system for the next 20-25 years. Tuning the machine characteristics to the requirements for the LHC and its upgrades will require the establishment of an accurate magnetic model of the PS combined-function magnets, which is the subject of this paper. In the scope of this research, a detailed 2D quasi-static analysis of the PS magnets was performed, which allowed to investigate the magnetic field evolution and the contribution of separate magnet circuits at different field levels. An experimental validation of this new model was carried out through ad-hoc field measurements machine studies iterated with an optical model of the PS machine to recreate the measured optical parameters of the beam.

WEPO020	Magnetic Field Inspection and Analysis of Multipole Lattice Magnets using a Rotating-coil Measurement System*	multipole, quadrupole, storage-ring, sextupole	2442
	J.C. Jan, C.-H. Chang, Y.L. Chu, T.Y. Chung, C.-S. Hwang, C.Y. Kuo, F.-Y. Lin NSRRC, Hsinchu, Taiwan
	A precise rotating-coil measurement system (RCS) was constructed to characterize the field quality and field center of multipole lattice magnets of Taiwan Photon Source (TPS). The mechanical center of magnets is determined by the two references of the magnet-feet and the RCS system is used to characterize the field center. The location of the magnetic field center is quantitatively accurate to better than 20 micro-meter in the horizontal direction; the granite support height of the RCS system is accurate within 5 micro-meter after artificial polishing. The measurement reproducibility of the field center was better than 10 micro-meter when the magnets were reinstalled. The relative accuracy of the multipoles components is better than 2×10^-5. This paper reports the details of the bench construction and the unit composition. The field center with RCS measurement will be compared and discussed with the 3D-coordinate-measuring machine. The multipole errors obtained from RCS will be compared with a Hall-probe measurement system.

WEPS007	CNAO Synchrotron Commissioning	extraction, pick-up, proton, betatron	2496
	C. Priano, G. Balbinot, G. Bazzano, J. Bosser, E. Bressi, M. Caldara, H. Caracciolo, L. Falbo, A. Parravicini, M. Pullia, C. Viviani CNAO Foundation, Milan, Italy C. Biscari, A. Ghigo INFN/LNF, Frascati (Roma), Italy
	The CNAO (National Center for Oncological Hadrontherapy), located in Pavia, is the first Italian center for deep hadrontherapy with proton and carbon ion beams. The CNAO synchrotron initial commissioning has been carried out using proton beams in the full range of energies: 60 to 250 MeV/u. The first foreseen treatments will need energies between 120 and 170 MeV/u. The nominal proton currents have been reached. The energy scaling of the synchrotron systems and parameters leads to an extracted energy that matches the measured particle range better than 0.1 mm, fitting the treatment requirements, with repeatable beam size and beam current in the treatment room at all investigated energies. A summary of the main results of the synchrotron commissioning is presented.

WEPS010	Acceleration of High Intensity Proton Beams in the J-PARC Synchrotrons	cavity, impedance, injection, acceleration	2502
	M. Yoshii KEK/JAEA, Ibaraki-Ken, Japan E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, K. Takata, M. Toda KEK, Ibaraki, Japan T. Minamikawa University of Fukui, Fukui, Japan M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	The J-PARC accelerator complex consists of the linac, the 3GeV rapid cycling synchrotron (RCS) and the 50GeV main synchrotron (MR). These synchrotrons are the first MW-class proton accelerators which employ the high electric field gradient magnetic alloy (MA) loaded RF cavities. The beam commissioning was started in October 2007 for RCS and in May 2008 for MR. High intensity beam operation studies and user runs have been performed, while carefully controlling and minimizing the beam loss. The cycle to cycle beam operation is reproducible and quite stable, because of the stable linac beam energy and the reproducible bending field in both synchrotrons. The MA loaded RF systems and the full digital LLRF also guarantee the stable longitudinal particle motion and precise beam transfer synchronization from RCS to the MLF user facility as well as to the MR. A high intensity proton beam of 2.5·10¹³ ppp is accelerated in RCS. And in MR, a beam intensity up to ~100 Tera ppp was obtained.　We summarize the RF systems and the longitudinal parameters in both rings.

WEPS017	Plans for the Upgrade of the LHC Injectors	linac, injection, electron, booster	2517
	R. Garoby, S.S. Gilardoni, B. Goddard, K. Hanke, M. Meddahi, M. Vretenar CERN, Geneva, Switzerland
	The LHC Injectors Upgrade (LIU) project has been launched at the end of 2010 to prepare the CERN accelerator complex for reliably providing beam with the challenging characteristics required by the high luminosity LHC until at least 2030. Based on the work already started on Linac4, PS Booster, PS and SPS, the LIU project coordinates studies and implementation, and interfaces with the High Luminosity LHC (HL-LHC) project which looks after the upgrade of the LHC itself, expected by the end of the present decade. The anticipated beam characteristics are described, as well as the status of the studies and the solutions envisaged for improving the injector performances.

WEPS023	A Possible RF System for CERN RCS	cavity, injection, extraction, booster	2532
	M.M. Paoluzzi CERN, Geneva, Switzerland
	As part of the LHC Injectors Upgrade (LIU) program at CERN the possibility of replacing the PSB with a new Rapid Cycling Synchrotron (RCS) is considered. The requirements in terms of accelerating voltage (60 kV), frequency range (1.7 MHz – 9.5 MHz) and available space (4 m) make the RF system development quite challenging. The improved loss characteristics of the new FINEMET® type (FT3L) combined with a filter-like topology, allows achieving all the requirements. This paper describes the design of such a RF system.

WEPS025	First Beam Experiments at ISIS with a Low Output-impedance Second Harmonic Cavity	cavity, impedance, simulation, proton	2538
	Y. Irie, S. Fukumoto, K. Muto, H. Nakanishi, T. Oki, A. Takagi KEK, Ibaraki, Japan D. Bayley, I.S.K. Gardner, R.J. Mathieson, A. Seville, J.W.G. Thomason STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom J.C. Dooling, D. Horan, R. Kustom ANL, Argonne, USA M.E. Middendorf ORNL RAD, Oak Ridge, Tennessee, USA
	A Low Output-Impedance (LOI) rf drive, which may be suitable for future high intensity accelerator applications, has been developed jointly by ANL, ISIS and KEK for an ISIS synchrotron second harmonic cavity. The cavity is ferrite-loaded, and is driven by a high-power triode (240 kW plate dissipation) with a plate-to-grid feedback circuit. The impedance is designed to be 20~30 ohms over a 2-6 MHz frequency range. Beam induced voltage has been measured with the ISIS beam, and compared with that calculated from the designed output impedance.

WEPS028	Lattice Design of a Rapid Cycling Medical Synchrotron for Carbon/Proton Therapy	proton, extraction, ion, injection	2541
	D. Trbojevic, J.G. Alessi, M. Blaskiewicz, C. Cullen, H. Hahn, D.I. Lowenstein, I. Marneris, W. Meng, J.-L. Mi, C. Pai, D. Raparia, A. Rusek, J. Sandberg, N. Tsoupas, J.E. Tuozzolo, A. Zaltsman, W. Zhang BNL, Upton, Long Island, New York, USA N.M. Cook Stony Brook University, Stony Brook, USA J.P. Lidestri HHMI, New York, USA M. Okamura RBRC, Upton, Long Island, New York, USA S. Peggs ESS, Lund, Sweden
	Funding: Work supported by Cooperative Research and Development Agreement (CRADA), No. BNL-C-10^-03 between the Brookhaven National Laboratory and Best Medical International, Inc. We present a design of the ion Rapid Cycling Medical Synchrotron (iRCMS) for carbon/proton cancer therapy facility. The facility design, produced at Brookhaven National Accelerator (BNL) at the Collider Accelerator Division (CAD) for the BEST Medical International, Inc., will be able to treat the cancer patients with carbon, lighter ions and protons. The low energy part accelerates ions and protons to the kinetic energy of 8 MeV. It consists of two ion sources (one of fully stripped carbon ions and one for protons), a Radio-Frequency Quadrupole (RFQ) and linac. The 8 GeV beam is injected into a fast cycling synchrotron (iRCMS). The lattice design is a racetrack, with zero dispersion two parallel straight sections. There are 24 combined function magnets in the two arcs with a radius of ~5.6 meters with maximum magnetic field of less than 1.3 T. The acceleration is performed in 30 Hz up to the required energy for the cancer tumor treatment assuming the spot scanning technique. The maximum energy for carbon ions is 400 MeV. Ions are extracted in a single turn and fed to different beam lines for patient treatment.

WEPS086	Three-lens Lattices for Extending the Energy Range of Non-scaling FFAGs	lattice, closed-orbit, optics, quadrupole	2709
	S.J. Brooks STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	In this paper it is found that a three-quadrupole focussing system can be morphed continuously through FFD, FDF and DFF variants and back again while maintaining stable optics and even keeping the two transverse tunes constant. This relates to non-scaling FFAGs, where the magnet gradients define both the focussing and the variation of the field with momentum as the closed orbit sweeps across it. A two-lens focussing system cannot change the sign of either gradient without becoming unstable, meaning non-scaling FFAGs built with such a lattice eventually encounter too large a magnetic field at low energies. However, a theoretical system of magnet field variations using three lenses, with a potentially unlimited energy range and fixed tunes is presented here.

WEPS098	Combined Momentum Collimation Method in High-intensity Rapid Cycling Proton Synchrotrons	collimation, simulation, scattering, injection	2736
	J.F. Chen, J. Tang, Y. Zou IHEP Beijing, Beijing, People's Republic of China
	A new momentum collimation method – so-called combined momentum collimation method in high-intensity synchrotrons is proposed and studied here, which makes use two-stage collimation in both the longitudinal and the transverse phase planes. The primary collimator is placed at a high-dispersion location of an arc, and the longitudinal and transverse secondary collimators are in the same arc and in the down-stream dispersion-free long straight section, respectively. The particles with positive momentum deviations will be scattered and degraded by a carbon scraper and then cleaned mainly by the transverse collimators, whereas the particles with negative momentum deviations will be scattered by a tantalum scraper and mainly cleaned by the longitudinal secondary collimators in the successive turns. Numerical simulation results using TURTLE and ORBIT codes show that this method gives high collimation efficiency for medium-energy synchrotrons. The studies have also shown two interesting effects: one is that the momentum collimation is strongly dependent on the transverse beam correlation; the other is that the material for the primary collimator plays an important role in the method. This work was supported by the National Natural Science Foundation of China (10975150, 10775153), the CAS Knowledge Innovation Program-“CSNS R&D Studies”.

WEPS104	Transverse Beam Dynamics for the ISIS Synchrotron with Higher Energy Injection	resonance, space-charge, simulation, injection	2754
	B.G. Pine, C.M. Warsop STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on an 800 MeV rapid cycling synchrotron, which provides 3·10¹³ protons per pulse at 50 Hz, corresponding to a beam power of 200 kW. Studies are underway to increase the energy of the ISIS linac from 70 to 180 MeV. This would reduce space charge in the synchrotron, and enable a larger current to be accumulated, possibly up to 0.5 MW. As part of the study, transverse beam dynamics have been re-examined on ISIS, building up models from incoherent space charge tune shift, through smooth focusing models with space charge to 2D alternating gradient lattice simulations. These later simulations, using the in-house space charge code Set, include harmonic perturbations to the focusing lattice, closed orbits and images. A clearer picture of the dynamics is emerging, where there may be important constraints on the highest intensities, including half integer resonance, image induced structure resonances and transverse instabilities.

WEPS106	Status of Injection Upgrade Studies for the ISIS Synchrotron	injection, space-charge, simulation, linac	2760
	C.M. Warsop, D.J. Adams, D.J.S. Findlay, I.S.K. Gardner, S.J.S. Jago, B. Jones, R.J. Mathieson, S.J. Payne, B.G. Pine, A. Seville, H. V. Smith, J.W.G. Thomason, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom C.R. Prior, G.H. Rees STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on a high intensity proton accelerator, consisting of a 70 MeV linac and an 800 MeV rapid cycling synchrotron, which provides a beam power of 0.2 MW. Obsolescence issues are motivating plans to replace the ageing 70 MeV linac, and this paper summarises the status of studies looking at how a new, higher energy linac (~180 MeV) could be used to increase beam power in the existing synchrotron. Reduced space charge and optimized injection might allow beam powers in the 0.5 MW regime, thus providing a very cost effective upgrade. The key areas of study are: design of a practical injection straight and magnets; injection painting and dynamics; foil specifications; acceleration dynamics; transverse space charge; instabilities; RF beam loading; beam loss and activation; diagnostics and possible damping systems. Results from work on most of these topics suggest that beam powers of ~0.5 MW may well be possible, but a number of topics, particularly transverse stability, still look challenging. Conclusions so far are presented, as is progress on R&D on the main intensity limiting issues.

WEPS107	Phase Space Coating in Synchrotrons: Some Applications*	antiproton, brightness, emittance, simulation	2763
	C.M. Bhat Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy Phase-space painting to produce very high intensity beam in synchrotrons is one of the widely studied topics in accelerator physics. A remarkable example of this is multi-turn beam injection by transverse phase-space painting in spallation sources. Use of barrier buckets at synchrotron storage rings has paved way for further advancements in this field. The Fermilab Recycler, antiproton storage ring, has been augmented with multipurpose broad-band barrier rf systems. Recently we have developed a longitudinal phase-space coating technique over already e-cooled high intensity low longitudinal antiproton beam and demonstrated with beam experiments. This method is extended to map the incoherent synchrotron tune of beam particles in a barrier bucket. Here I review various phase-space painting techniques being used in particle accelerators including some new schemes developed using barrier rf systems and possible new applications.

THOAA01	Beam Diagnostics Commissioning at CNAO	proton, extraction, diagnostics, quadrupole	2848
	H. Caracciolo, G. Balbinot, G. Bazzano, J. Bosser, M. Caldara, A. Parravicini, M. Pullia, C. Viviani CNAO Foundation, Milan, Italy
	The National Centre for Oncological Hadrontherapy (CNAO) is the first Italian facility for the treatment of deep located tumors with proton and carbon ion beams using active scanning. The commissioning with proton beams is concluded and CNAO is going to start treating patients with protons; in the meantime the machine commissioning with carbon ions beam is going on. Beam diagnostics instrumentation is fundamental to measure beam properties along the lines from sources to patients. Some significant measurements performed during proton beam commissioning and the performances achieved with the CNAO beam diagnostic systems are presented in this paper.
	Slides THOAA01 [4.827 MB]

THOAA02	Implementation of an Intensity Feedback-loop for an Ion-therapy Synchrotron	feedback, controls, extraction, ion	2851
	C. Schömers, E. Feldmeier, Th. Haberer, J. Naumann, R.E. Panse, A. Peters HIT, Heidelberg, Germany
	The Heidelberg Ion Therapy-Centre (HIT) started treatment of tumour patients in 2009. Its main acceleration stage is a synchrotron, where particles are extracted slowly, in the time frame of some seconds, to support the raster-scanning method. The slow extraction is driven by the transverse "RF-nockout-exciter". So far, this device has a variable but predefined amplitude curve. As the phase-space distribution of particles is not homogeneous and varies slightly from pulse to pulse, intensity-fluctuations of the extracted beam appear. Moreover, changing accelerator-settings requires a time-consuming re-adjustment of the exciter to achieve adequate beam-properties again. To keep the intensity on a predefined level, a feedback loop will be implemented. The actual-value of the intensity is provided by an ionization chamber in front of the patient. The feedback loop controls the amplitude of the Exciter, to adapt the number of extracted particles. Beside a rectangular spill with constant intensity, a dynamic intensity-adaptation during one spill with respect to the particular treatment-plan will be investigated. First tests for flat spill and variable intensity showed promising results.
	Slides THOAA02 [2.284 MB]

THOBB02	High Gradient Magnetic Alloy Cavities for J-PARC Upgrade	cavity, impedance, proton, status	2885
	C. Ohmori, O. Araoka, E. Ezura, K. Hara, K. Hasegawa, A. Koda, Y. Makida, Y. Miyake, R. Muto, K. Nishiyama, T. Ogitsu, H. Ohhata, K. Shimomura, A. Takagi, K. Takata, K.H. Tanaka, M. Toda, M. Yoshii KEK, Tokai, Ibaraki, Japan T. Minamikawa University of Fukui, Fukui, Japan M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	Magnetic alloy cavities are used for both MR and RCS synchrotrons. Both cavity systems operate successfully and they generate a higher voltage than could be achieved by an ordinary ferrite cavity system. For the future upgrade of J-PARC, a higher RF voltage is needed. A new RF cavity system using the material, FT3L, is designed to achieve this higher field gradient. A large production system using an old cyclotron magnet was constructed to anneal 85-cm size FT3L cores in the J-PARC Hadron Experiment Hall. The muSR (Muon Spin Rotation/Relaxation/Resonance) Experiments were also carried out to study the magnetic alloy. The status of development on the J-PARC site and a new RF system design will be reported.
	Slides THOBB02 [2.729 MB]

THPC005	First Measurements with a Kicked Off Axis Bunch for Pseudo Single Bunch Mode Studies at SOLEIL	kicker, single-bunch, closed-orbit, storage-ring	2912
	L.S. Nadolski, J.-P. Lavieville, P. Lebasque, A. Nadji, J.P. Ricaud, M.G. Silly, F. Sirotti SOLEIL, Gif-sur-Yvette, France
	At SOLEIL, the time resolved French community benefits of single bunch operation few weeks a year. Meanwhile most of the multi-bunch filling pattern based experiments are not possible due to the low photon flux. Following the pioneer work performed at ALS, a new operation mode is under study at SOLEIL where the storage ring is filled up with a special hybrid mode: ¾ multibunch filling pattern and a single bunch with higher current in the last ¼. The so-called pseudo single bunch-filling pattern is obtained if the closed orbit of the single bunch is not the same as the one of the other bunches. Preliminary results are presented where the pinger magnet time impulse response has been significantly reduced while its frequency was increased from 3 Hz up to 1 kHz. This magnet is used as an additional corrector magnet to change only the single bunch closed orbit. First experimental results observed at one interested beamline are also discussed. S. Kwiatkowski et al., “'CAMSHAFT' Bunch Kicker Design for the ALS Storage Ring", Proc. of EPAC2006, THPLS114, p. 3547, (2006).

THPC006	Experiments to Measure Electron Beam Energy using Spin Depolarization Method on SOLEIL Storage Ring	polarization, storage-ring, electron, beam-losses	2915
	J.F. Zhang, L. Cassinari, M. Labat, A. Nadji, L.S. Nadolski, D. Pédeau SOLEIL, Gif-sur-Yvette, France
	The electron beam energy on SOLEIL storage ring was successfully measured using spin depolarization method after several attempts over the past few years. The experimental results demonstrate that the effective polarization was 91.3%±3% and polarization time was 17±2.3 minutes as expected from the simulation using SLIM code. The beam was depolarized using an AC shaker and the depolarization was monitored using DCCT and beam loss monitors. The beam energy was measured with accuracy up to a few 10^-5.

THPC008	Touschek Lifetime and Momentum Acceptance Measurements for ESRF	vacuum, emittance, scattering, electron	2921
	B. Nash, F. Ewald, L. Farvacque, J. Jacob, E. Plouviez, J.-L. Revol, K.B. Scheidt ESRF, Grenoble, France
	The Touschek lifetime of a synchrotron results from electrons scattering off one another within the bunch and subsequently being lost. We have measured the Touschek lifetime for the major operating modes of the ESRF as a function of RF voltages. This includes multibunch and few bunch filling patterns with correspondingly different chromaticity values. Through calibration of the RF voltage and measurement of the other beam parameters such as bunch length and vertical emittance, we may understand the momentum acceptance in the regime where this is determined by non-linear dynamics effects.

THPC010	Recent Developments at the Metrology Light Source	quadrupole, injection, feedback, vacuum	2927
	J. Feikes, T. Birke, O. Dressler, D.B. Engel, F. Falkenstern, B. Franksen, A. Heugel, H.-G. Hoberg, F. Hoffmann, J. Kuszynski, J. Rahn, M. Ries, P.O. Schmid, T. Schneegans, D. Schüler, G. Wüstefeld HZB, Berlin, Germany K.B. Bürkmann-Gehrlein, V. Dürr, H.G. Glass, G. Schindhelm BESSY GmbH, Berlin, Germany R. Klein PTB, Berlin, Germany
	The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, owns the electron storage ring Metrology Light Source (MLS) which was built and is operated by the Helmholtz-Zentrum Berlin [1, 2]. The MLS has been in regular user operation since April 2008 and supports synchrotron-radiation-based metrology and technological developments in the IR, UV, VUV and EUV spectral range. Here we report on recent progress to develop the MLS into a reliable, flexible and stable user facility.

THPC013	THz Studies at a Dedicated Beamline at the MLS	radiation, electron, synchrotron-radiation, storage-ring	2933
	R. Müller, A. Hoehl, A. Serdyukov, G. Ulm PTB, Berlin, Germany J. Feikes, M. Ries, G. Wüstefeld HZB, Berlin, Germany
	The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute is operating the low-energy electron storage ring Metrology Light Source (MLS) in Berlin-Adlershof in close cooperation with the Helmholtz-Zentrum Berlin. The MLS is designed and prepared for a special machine optics mode (low-alpha operation mode) based on a sextupole and octupole correction scheme, for the production of coherent synchrotron radiation in the THz region. At the MLS two bending magnet beamlines dedicated to the use of IR and THz synchrotron radiation are in operation: the MLS-IR beamline optimized for the NIR to FIR, and a dedicated THz beamline optimized for the FIR/THz spectral range. Low-alpha operation optic modes for different ring energies, 250 MeV, 350 MeV, 450 MeV and 630 MeV are available. We compare the THz spectra taken in the different low-alpha modes and discuss the results. J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011). ** R. Müller et al., J. Infrared Milli Terahz Waves, in press (2011), DOI: 10.10⁰⁷/s10762-011-9785-6.

THPC017	Temporal and Spatial Alignment of Electron Bunches and Ultrashort Laser Pulses for the CHG Experiment at DELTA	laser, electron, undulator, controls	2945
	M. Zeinalzadeh, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk DELTA, Dortmund, Germany
	Funding: Supported by DFG, BMBF, and the Federal State NRW The generation of ultrashort VUV pulses by CHG (Coherent Harmonic Generation) requires achieving and maintaining the longitudinal and transversal overlap of femtosecond laser pulses and electron bunches. We present the techniques and the experimental setup applied at the DELTA storage ring. For the longitudinal analysis, both a streak camera and a fast photo diode are used. Transversely, two CCD cameras acquire images of laser and synchrotron light at different positions inside of the undulator. A feedback system utilizes the intensity of a THz signal generated several meters downstream of the undulator to optimize and maintain the overlap.

THPC024	Lattice Candidates for the ILSF Storage Ring	storage-ring, lattice, emittance, dipole	2957
	H. Ghasem IPM, Tehran, Iran D. Einfeld CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain F. Saeidi ILSF, Tehran, Iran
	Iranian Light Source Facility (ILSF) is a new third generation synchrotron light source which is currently in design and will build in Iran. It will provide a high photon flux density to cover requirements of experimental science in several fields. Regarding to the proposed budget and in order to produce high quality X-ray pulses with several photon beamlines as a request of users, it is decided to design a very low emittance (ε<5nm-rad) storage ring with a typical beam intensity of 400 mA and circumference in the range of 280 m to 320 m. A number of design options with different lattice structure types, circumferences, etc., are explored and we present two designed lattice candidates of the ILSF storage ring. The associated Accelerator Physics issues are discussed.

THPC025	Booster Design for ILSF	booster, storage-ring, dipole, electron	2960
	H. Ghasem IPM, Tehran, Iran E. Ahmadi ILSF, Tehran, Iran D. Einfeld CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	A full energy 3 GeV booster synchrotron has been designed to boost electron beam to the target energy of 3 GeV for the proposed third generation synchrotron light source (ILSF) that will be constructed in Iran. The primary goal of the ILSF booster is to design a synchrotron which can deliver a small emittance (ε<30 nm-rad), while at the same time has a low cost in construction. In order to design lattice for the booster, two configurations for booster have been considered. In the first configuration, booster is designed based on locating in a separate tunnel as 3 GeV storage ring inside the ring and in the second configuration, the booster is optimized for placing inner to the ring with one shared wall as service area of ILSF storage ring. Several types of lattice with various circumferences have been explored for the booster synchrotron in each configuration and this paper presents results of linear and nonlinear optimization of the main designed lattice for booster in both configurations.

THPC031	Measurement of Longitudinal Dynamics of Injected Beam in a Storage Ring	injection, storage-ring, simulation, booster	2978
	T. Watanabe, T. Fujita, M. Masaki, K. Soutome, S. Takano, M. Takao, K. Tamura JASRI/SPring-8, Hyogo-ken, Japan
	Experimental observation of longitudinal dynamics of injected beam in a storage ring has been demonstrated. Since the injected beam undergoes synchrotron oscillation in a longitudinal phase space, two projected values, i.e., a bunch duration and an energy spread, oscillate at twice the synchrotron frequency. At SPring-8, the initial energy spread (~0.126%) at the injection goes up and down until it reaches the equilibrium energy spread (~0.11%). If the injection timing should not be optimized, an asymmetrically enhanced oscillation could distort the injection efficiency. The observation of such an oscillation helps make sure that no significant injection loss occurs. More importantly, the scheme is expected to enable us to observe non-linear longitudinal dynamics of ultra-short bunches injected from the XFEL linac; the bunches are in near future going to be transferred from the linac to the storage ring via 600-meter long transports, in which strong coherent synchrotron radiation and other high peak-current effects will not be ignorable. Experimental results obtained by a dual-scan streak camera and other devices as well as numerical simulations will be presented.

THPC037	Accelerators of the Central Japan Synchrotron Radiation Facility Project (II)	storage-ring, booster, electron, linac	2987
	N. Yamamoto, M. Hosaka, A. Mano, H. Morimoto, K. Takami, Y. Takashima Nagoya University, Nagoya, Japan Y. Hori KEK, Ibaraki, Japan M. Katoh UVSOR, Okazaki, Japan S. Koda SAGA, Tosu, Japan S. Sasaki JASRI/SPring-8, Hyogo-ken, Japan
	Central Japan Synchrotron Radiation (SR) Facility Project is making progress for the service from FY2012. The construction of SR building is almost completed in the Aichi area of Japan, and the installs of accelerators will start in a few week. The key equipments of our accelerators are an 1.2 GeV compact electron storage ring that is able to supply hard X-rays and a full energy injector for top-up operation. The beam current and natural emittance of the storage ring are 300 mA and 53 nmrad. The circumference is 72 m. The magnetic lattice consists of four triple bend cells and four straight sections. The bending magnets at the centers of the cells are 5 T superconducting magnets and the critical energy of the SR is 4.8 keV. The injector consists of a 50 MeV linac and a booster synchrotron with the circumference of 48 m. To save construction expenses, the injector is built at inside of the storage ring. More than ten hard X-ray beam-line can be constructed. One variable polarization undulator will be installed in the first phase. The top-up operation will be introduced as early as possible.

THPC054	Project Status of the Polish Synchrotron Radiation Facility Solaris	storage-ring, linac, cavity, radiation	3014
	C.J. Bocchetta, P.P. Goryl, K. Królas, M. Mlynarczyk, M.J. Stankiewicz, P.S. Tracz, Ł. Walczak, A.I. Wawrzyniak Solaris, Krakow, Poland J. Ahlbäck, Å. Andersson, M. Eriksson, M.A.G. Johansson, D. Kumbaro, S.C. Leemann, L. Malmgren, J.H. Modéer, P.F. Tavares, S. Thorin MAX-lab, Lund, Sweden E. Al-dmour, D. Einfeld CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	Funding: European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG.02.01.00-12-213/09 The Polish synchrotron radiation facility Solaris is being built at the Jagiellonian University in Krakow. The project is based on an identical copy of the 1.5 GeV storage ring being concurrently built for the MAX IV project in Lund, Sweden. A general description of the facility is given together with a status of activities. Unique features associated with Solaris are outlined, such as infra-structure, the injector and operational characteristics.

THPC055	Front Ends at ALBA	vacuum, photon, radiation, undulator	3017
	J. Marcos, J. Campmany, D. Einfeld, J. Pasquaud CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3GeV 3rd generation synchrotron radiation source built nearby Barcelona currently under commissioning phase. This paper describes the design and installation of the set of 10 Front Ends that have been manufactured and assembled for day-one operation of the facility. This initial set includes 8 Front Ends devoted to transmit the photons generated by both Insertion Device or Bending Magnet sources to experimental Beamlines, and 2 additional Front Ends for electron beam-diagnostics purposes. The design of each individual Front End has been adapted in order to meet the aperture and power load requirements posed by both the characteristics of the photon sources and the needs of the Beamline users. At the same time, an effort has been made in order to keep a suitable degree of standardization among the components of different Front Ends. With this aim a modular design approach has been adopted. The general layout of the Front Ends as well as the design and function of their main components is described. Finally, a brief summary of their performance during the commissioning period is presented.

THPC063	A 2.9 Tesla Room Temperature Superbend Magnet for the Swiss Light Source at PSI	storage-ring, power-supply, dipole, vacuum	3038
	A.L. Gabard, D. George, M. Negrazus, L. Rivkin, V. Vrankovic PSI, Villigen, Switzerland Y. Kolokolnikov, P. Vobly BINP SB RAS, Novosibirsk, Russia
	The Swiss Light Source (SLS) at the Paul Scherrer Institute (PSI) in Villigen, Switzerland, is a 3rd generation synchrotron light source. With an energy of 2.4 GeV, it provides high brightness photon beams for research in materials science, biology and chemistry. The SLS storage ring contains 36 room temperature bending magnets, all of which produce light for experimental use; at the design energy of 2.4 GeV, they have a maximum magnetic field of 1.4 Tesla. Light is produced along the entire bending arc but can only be transferred to the external experimental facilities from selected short portions of the beam path. In cooperation with the Budker Institute for Nuclear Physics (BINP) in Novosibirsk, Russia, three of these magnets were replaced with new room temperature magnets with short regions of high magnetic field up to 2.9 Tesla. This enabled the production of intense light beams at shorter wavelengths than from the existing magnets. The critical energy of the 2.9 T magnet is 11.1 keV, compared to the 5.4 keV of the normal bend. This paper describes the design, including the multiple restraints, together with the measurement and commissioning of these so-called superbends.

THPC069	Studies to Optimize the Diamond Light Source Booster Synchrotron as a 100 MeV Storage Ring	booster, quadrupole, storage-ring, linac	3053
	C. Christou, M.T. Heron, J. Rowland Diamond, Oxfordshire, United Kingdom S. Gayadeen University of Oxford, Oxford, United Kingdom
	The injection chain for the Diamond Synchrotron Light Source consists of a 100 MeV Linac and 3 GeV booster synchrotron. These were commissioned in 2005 and 2006 respectively, and have provided acceptable performance as an injector since then. To advance a programme of work in evaluating and optimizing new control algorithms for orbit stability on the Diamond Storage Ring it was decided to use the booster synchrotron as a test platform by operating it in DC mode at 100 MeV. In support of this work and to improve the operational performance of the booster a series of studies have been carried out to better understand and characterize it. This work and the results will be presented.

THPC070	An Automated Statistical Analysis Package for the Study of Synchrotron Light Source Operation	cavity, storage-ring, beam-losses, monitoring	3056
	C. Christou, C.P. Bailey, V.C. Kempson, V.J. Winter Diamond, Oxfordshire, United Kingdom
	Machine faults and interruptions to user beam at Diamond Light Source are recorded in a Fault Log Database (FLDB) running under Microsoft Access. The scope of numerical analysis in Access is limited, and so an advanced data analysis package has been written in Matlab to exploit the powerful numeric functions available in this environment to automatically analyze machine faults and summarize data for reliability reports. Figures of merit such as mean time between failure (MTBF), mean time to repair (MTTR), total up time and total number of faults over the machine as a whole and by technical group can be calculated, and more advanced Pareto and Weibull analyses can be instantly generated. Data is presented for Diamond Light Source both for the latest year of operation and since user beam began in 2007, and the impact of different technical groups, in particular the storage ring RF, is considered. Failure distributions and the underlying hazard functions are produced and compared with statistical models to highlight deviations from randomly occurring events and to quantify changes in failure probability with time.

THPC136	High Efficiency Visible Photocathode Development	cathode, vacuum, laser, diagnostics	3206
	J. Smedley, K. Mueller, T. Rao BNL, Upton, Long Island, New York, USA K. Attenkofer, S.W. Lee ANL, Argonne, USA I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Oses Stony Brook University, Stony Brook, USA H.A. Padmore, T. Vecchione LBNL, Berkeley, California, USA
	Alkali antimonide cathodes are critical both for high average current photoinjectors for energy recovery linacs and for high quantum efficiency photodetectors. These cathodes have historically been plagued by extreme vacuum sensitivity, non-reproducibility and poor lifetime. We report on ongoing efforts to improve the performance of alkali antimonides (principally K2CsSb). Cathodes have been fabricated which have a QE of 7% at 532 nm. The films are much more resistant to oxygen and water exposure than previously thought, with a 50% yield lifetime of 20 hrs at 2 pBar partial pressure of water. Several analysis techniques have been employed in this study, including in-situ x-ray diffraction during growth to measure grain size and texture, measurement of transverse momentum distribution of the emitted electrons, and measurement of the stoichiometry of the films via x-ray fluorescence. An extensive study of the growth parameters, including both transparent and metallic substrates, sputtered and evaporated films, variation of growth time and temperatures and post-growth annealing processes, is currently underway.

THPC137	Low Emittance Booster Design for CANDLE Storage Ring	booster, emittance, injection, storage-ring	3209
	G.S. Zanyan, B. Grigoryan, K. Manukyan, A. Sargsyan, V.M. Tsakanov CANDLE, Yerevan, Armenia
	The progress in synchrotron based research made the top up operation mode of storage rings as the most attractive option both from the beam lifetime and the user points of view. To provide reliable operation of the facility at top-up injection mode the full energy low emittance new booster ring for 3 GeV CANDLE storage ring is designed. The compact synchrotron magnets with integrated quadrupole and sextupole components are used. The new design provides 20 nm emittance at the top energy with sufficient dynamic aperture and optimal optical properties at straight section for effective extraction. The complete design of the new booster and beam dynamics issues during the energy ramping are presented.

THPC143	Beam-based Alignment for Injection Bump Magnets of the Storage Ring using Remote Tilt-control System	injection, alignment, controls, betatron	3221
	K. Fukami, K. Kobayashi, C. Mitsuda, T. Nakamura, K. Soutome JASRI/SPring-8, Hyogo-ken, Japan
	Stored beam is oscillated in vertical if the injection-bump magnets have alignment error in rotation around the beam-axis (tilt). In addition, even if the tilt is negligibly small, the beam out of the median plane is kicked in vertical direction. Also, there is a small long-term drift of the vertical beam positions in the bump magnets, which causes the gradual increase of the oscillation. We have already developed a remote tilt-control system to make a smooth realignment. To observe the oscillation, the beam position was measured bunch-by-bunch and turn-by-turn by using a bunch-by-bunch feedback system* with high resolution strip-line type beam position monitor. To obtain responses to the tilts of each magnet, the oscillations were measured under the condition that the magnets were tilted intentionally. Tilt errors were calculated with least-squares method using the responses. In order to confirm the source of the residual oscillation, a frequency analysis was carried out with FFT method using the position data from 1st to 128th turns. We succeeded in suppressing the vertical oscillation to sub-microns order, the value of less than one tenth of the beam size. * K. Fukami et al., Proc. of EPAC'08, p. 2172 (2008). ** T. Nakamura et al., Proc. of ICALEPCS'05, PO2.022-2 (2005).

THPC159	Factory Acceptance Test of COLDDIAG: A Cold Vacuum Chamber for Diagnostics	vacuum, electron, diagnostics, factory	3263
	S. Gerstl, T. Baumbach, S. Casalbuoni, A.W. Grau, M. Hagelstein, T. Holubek, D. Saez de Jauregui Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany V. Baglin CERN, Geneva, Switzerland C. Boffo, G. Sikler BNG, Würzburg, Germany T.W. Bradshaw STFC/RAL, Chilton, Didcot, Oxon, United Kingdom R. Cimino, M. Commisso, A. Mostacci, B. Spataro INFN/LNF, Frascati (Roma), Italy J.A. Clarke, R.M. Jones, D.J. Scott Cockcroft Institute, Warrington, Cheshire, United Kingdom M.P. Cox, J.C. Schouten Diamond, Oxfordshire, United Kingdom I.R.R. Shinton UMAN, Manchester, United Kingdom E.J. Wallén MAX-lab, Lund, Sweden R. Weigel Max-Planck Institute for Metal Research, Stuttgart, Germany
	Superconductive insertion devices (IDs) have higher fields for a given gap and period length compared with the state-of-the-art technology of permanent magnet IDs. One of the still open issues for the development of superconductive insertion devices is the understanding of the heat intake from the electron beam. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the underlying mechanisms, a cold vacuum chamber for diagnostics was built. It is equipped with the following instrumentation: retarding field analyzers to measure the electron flux, temperature sensors to measure the beam heat load, pressure gauges, and mass spectrometers to measure the gas content. The flexibility of the engineering design will allow the installation of the cryostat in different synchrotron light sources. The installation in the storage ring of the Diamond Light Source is foreseen in November 2011. Here we report about the technical design of this device, the factory acceptance test and the planned measurements with electron beam.

THPC163	Local and Integral Field Measurement Setup for 2m Long Superconducting Undulator Coils	undulator, factory, insertion, insertion-device	3275
	A.W. Grau, T. Baumbach, S. Casalbuoni, S. Gerstl, M. Hagelstein, T. Holubek, D. Saez de Jauregui Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	The performance of superconducting insertion devices depends strongly on their magnetic field quality. It is of fundamental importance to characterize the magnetic properties of insertion devices accurately before installation in synchrotron light sources. Thus a main part of the R&D program for superconducting insertion devices at the Karlsruhe Institute of Technology focuses on quality assessment. This contribution describes the instrumentation to perform magnetic measurements of the local field, of the field integrals and of the multipole components of superconducting undulator coils in a cold in vacuum (cryogen free) environment. It focuses on the outcome of the factory acceptance test together with results of first field measurements performed with mock-up coils.

THPC167	The Design of Dual Canted In-vacuum Undulators at SSRF	undulator, vacuum, radiation, ion	3287
	X. Hu, L. Yin, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	Funding: National foundation for scientific infrastructure, Development and Reform Commission of China. Five new beamlines are under design and construction at SSRF to supply the synchrotron radiation for the structural biology research in the protein project. Two in-vacuum undulators with canted angle of 6mrad are arranged in a 6.5m long straight section in order to keep the potential to accommodate more beamlines for the future. Limited by the length of the straight section and the angle between two beamlines, the layout design in the straight section is rather difficult to satisfy the required photon flux to the beamline and keep the normal design of the undulator. Many main components will be redesigned in this section on the base of existing ones, including in-vacuum undulator, correction magnet, RF bellows, photon absorbers and so on. In this paper the layout design and the modified design for some key components are described.

THPC177	Field Correction Results from NSRRC Elliptically Polarized Undulator 46	kicker, undulator, electron, multipole	3317
	J.C. Huang, C.-H. Chang, C.-S. Hwang, C. JunTune, F.-Y. Lin NSRRC, Hsinchu, Taiwan
	Elliptically polarized undulator (EPU) is a common insertion device to use in storage ring in order to provide circular polarization. The field correction is an essential step for EPU construction, and it can prevent the photon flux reduction from idea case and electron beam trajectory and exit angle from EPU. The conventional field correction method is tedious works and strongly based on experiences. An initial state of NSRRC EPU46 has phase error over 40 degrees, and many difficulties on field correction to reduce the phase error under 5 degrees. This paper will describe the detailed magnetic field correction process and practical results from in NSRRC EPU.

THPC179	Electron Beam Heating and Operation of the Cryogenic Undulator and Superconducting Wigglers at Diamond	electron, wiggler, undulator, cavity	3323
	J.C. Schouten, E.C.M. Rial Diamond, Oxfordshire, United Kingdom
	Diamond Light Source has two superconducting wigglers and one cryocooled undulator installed serving three beam lines. The cryocooled undulator (cpmu) has been operating since August 2010 while the superconducting wigglers have been operating for more than 4 years (SCW-1) and 2 years (SCW-2). We will report on the first year of operation of the cpmu including details of its spectral output and cryogenic performance. Our experience of the cooling system and measures taken to ensure reliability and to minimize the risks of a prolonged downtime are also presented. The two superconducting wigglers are exposed to a high heat load due to the beam heating of the inner liner. Until recently this resulted in a much higher helium consumption than specified and so recently a new liner has been fitted to SCW-1 and new re-condensers to SCW-2. In addition a thermal bridge has been made between the RF tapers and the outer heat shield of both SCW-1 and SCW-2. The results of these improvements will be presented.

THPO003	Rapid-cycling Power Supplies for the J-PARC RCS Sextupole Magnets	power-supply, sextupole, proton, linac	3338
	Y. Watanabe JAEA, Ibaraki-ken, Japan T. Adachi, S. Igarashi, H. Someya KEK, Ibaraki, Japan N. Tani JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The rapid-cycling synchrotron of the Japan Proton Accelerator Research Complex requires 18 sextupole magnets with three families for the chromaticity correction. One family consists of six focusing sextupole magnets, and other two families consist of six defocusing sextupole magnts. An individual power supply excited for each family and the current pattern is a DC-biased sinusoidal of a frequency of 25 Hz. This paper describes design and test results of the sextupole magnet power supplies.

THPO021	A New Control System for the ISIS Main Magnet Power Supply	controls, power-supply, status, target	3385
	J. Ranner, T.E. Carter, S. West STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory in Oxfordshire is a world-leading centre for research in the physical and life sciences. At the heart of the ISIS accelerator is a proton synchrotron which uses a ring of dipole and quadrupole magnets connected in series and configured as a White Circuit. The circuit allows the magnets to be fed with an AC current superimposed on a DC current. A recent upgrade to the main magnet power supply* involved the replacement of the original AC supply, a motor-alternator set, with a bank of four 300kVA UPS (uninterruptible power supplies) which had been modified to allow the output voltage to be varied using serial commands. However, when initially tested, this method was unable to produce the required stability in the main magnet current. This paper describes the further modifications to the UPS units to achieve the required stability and the development of a LabVIEW control system which manages the data acquisition and analysis, the communication to the UPS, interlock equipment and user interface, and provides a low latency control loop to the UPS and DC bias power supplies. * M.G. White et al., “A 3-BeV High Intensity Proton Synchrotron”, CERN Symp.1956 Proc., p525. ** S. West, J.W. Gray, W.A. Morris, “Upgrade of the ISIS Main Magnet Power Supply”, EPAC 2004 p1467.

THPO025	Longitudinal Beam Dynamics of a Laser Sliced Bunch	laser, electron, radiation, damping	3397
	P. Kuske HZB, Berlin, Germany
	Nowadays fs-laser slicing of a bunch of electrons in storage rings is quite common for creating short VUV- and soft X-ray light pulses or pulses of coherently emitted THz-radiation over a couple of revolutions. In this paper the longitudinal dynamics of the sliced bunch is studied numerically. The calculations are based on the one dimensional solution of the Vlasov-Fokker-Planck-equation assuming that the shielded CSR-wake is dominating the dynamics of the 100 fs-long slice. It is found that the density modulation survives longer and that the CSR-spectra extend to higher frequencies at later turns even below the corresponding instability threshold. This very simple model seems to support experimental observations at the Swiss Light Source.

THPO027	Novel Switching Power Supply utilizing SiC-JFET and its Potential for the Digital Accelerator	power-supply, induction, extraction, high-voltage	3400
	K. Okamura, T. Iwashita, K. Takayama, M. Wake KEK, Ibaraki, Japan K. Ise Tohoku Electric Power Co., Sendai, Japan Y. Osawa SUN-A Corporation, Miyoshi-City, Japan K. Takaki Iwate university, Morioka, Iwate, Japan
	Funding: Japan Science and Technology Agency New induction synchrotron system using an induction cell has been developed and constructed at KEK. We refer to the accelerator using the induction acceleration system combined with digitally controlled PWM power supply as "Digital Accelerator". In that system, the switching power supply is one of the key devices which realize digital acceleration. The requirements of the switching power supply are high voltage (2 kV) and high repetition frequency (1 MHz). In the present system, we used series connected MOSFETs as the switching device and obtained successful operation. However, series connection gives large complexity and less reliability. Among the various switching devices, a SiC-JFET is the promising candidates that substitute existing silicon MOSFET because it has ultrafast switching speed and voltage blocking capability. Therefore, we have started to develop new device in collaboration with device manufacturers. Switching and heat removal performance of the newly developed SiC-JFET and a future plan will be presented at the conference. T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011. ** K. Ise et al., IEEE Trans. Plasma Sci., pp. 730-736 (2011).

THPO034	Optimization of a Dual One-turn Coils Kicker Magnet System	kicker, extraction, monitoring, vacuum	3415
	K.L. Tsai, C.-T. Chen, C.-S. Fann, S.Y. Hsu, Y.D. Li, K.-K. Lin, K.-B. Liu, H.M. Shih, Y.S. Wong NSRRC, Hsinchu, Taiwan
	Optimization of a dual one-turn coils configuration for fast kicker magnet system is presented in this report. Emphasis has been made on the: 1) optimization of various possible coils arrangement restricted by the existing available hardware; and 2) synchronization between pulsed currents delivering on the respective upper and lower coils. In the consideration of coils arrangement, good field region is utilized as the guiding parameter while adjusting fixture gap between the coils. As for coil currents timing optimization, fast rise-time and pulse shape preservation are used for practical implementation purpose. Both numerical analysis and experimental data will be presented and discussed.

THPS029	Simulations of Various Driving Mechisms for the 3rd Order Resonant Extraction from the MedAustron Medical Synchrotron	extraction, betatron, lattice, resonance	3481
	G. Feldbauer, M. Benedikt CERN, Geneva, Switzerland U. Dorda EBG MedAustron, Wr. Neustadt, Austria
	The MedAustron medical synchrotron is based on the CERN-PIMMS design and its technical implementation by CNAO [1]. This document elaborates on studies performed on the baseline betatron-core driven extraction method and investigates the feasibility of alternative resonance driving mechanisms like RF-knockout, RF-noise and the lattice tune. Single particle tracking results are presented, explained and compared to analytical results. [1] M. Pullia, ‘‘Status Report on the Centro Nazionale di Adroterapia Oncologica (CNAO)'', 11th EPAC'08, Genoa, Itlay, June 2008, p. 982

THPS030	Layout and Optics of the MedAustron High Energy Beam Transfer Line	optics, proton, extraction, quadrupole	3484
	U. Dorda, P.J. Bryant CERN, Geneva, Switzerland M. Benedikt EBG MedAustron, Wr. Neustadt, Austria
	The MedAustron accelerator complex, which is currently in its final design stage at CERN, is based on the optical principles developed within the Proton Ion Medical Machine study (PIMMS) [bryantpimms]. This paper describes how these principles are practically applied in the layout and optics of the High Energy Beam Transfer line (HEBT) of the MedAustron accelerator facility. Special attention is directed to the optics of the gantry which is designed to fit into the PSI gantry-2 hardware layout, which is foreseen to be copied in collaboration with PSI.

THPS039	Diffusion of a Circulating Beam by the RF-Knockout with a Spectrum including Many Bands	resonance, extraction, simulation, controls	3508
	M. Tashiro, T. Nakanishi Nihon University, Narashino, Chiba, Japan
	The fast control of beam spill extracted from a synchrotron is a key function for the spot scanning irradiation in cancer therapy application. The authors have proposed the extraction method for the application which uses the control of a quadruple field of fast response as well as the RFKO (QAR method). The RF signal for the RFKO should cover a frequency band corresponding to a tune spread. A simulation with continuous RFKO operation, however, showed a spill intensity changes with time largely with only this band. The large change of spill is due to not uniform diffusion of circulating beam and it makes a constant spill difficult in the QAR method. A wider band gives a uniform spill, but it requires a larger Amp power. We proposed a spectrum including many bands around the resonances to reduce the power, since the bands outside around the resonances do not contribute to the diffusion. Such a spectrum has also an advantage to increase spill intensity for the QAR method, using a band so that the RFKO diffuses more inside particles of the separatrix but also it affects little them near the boundary. We can extract several times particles with a same shrink ratio of the separatrix.

THPS044	Study of Charge Exchange Injection in HITFiL	injection, ion, emittance, dipole	3520
	W.P. Chai, J. Shi, J.W. Xia, J.C. Yang IMP, Lanzhou, People's Republic of China
	A new accelerator complex dedicated to hadron cancer therapy, Heavy-Ion Therapy Facility in Lanzhou (HITFiL), is proposed and designed. Based on the operating experience and existing technology on HIRFL-CSR, a heavy-ion cyclotron is used as an injector instead of a linac. A heavy-ion synchrotron as main component is designed with special attention paid to compact structure, high reliability and low cost. HITFiL is designed to accommodate both proton and carbon-ion using the same injecting channel but different injecting points. Charge exchange injection scheme, which is more efficient compared with single-turn injection but less costly compared with multiple multi-turn injection aided by electron-cooling, is adopted. H²⁺ or C⁵⁺ beams, pre-accelerated by the cyclotron, are stripped into H⁺ or C⁶⁺ by a carbon foil at injection point, then injected and merged into synchrotron coasting orbit. The design of the injection system is presented in this paper. The whole injection process is simulated, optimization of parameters on injecting efficiency, painting scheme and emittance growth are performed. The resulting beam distribution in phase space after injection is achieved.

THPS048	Design of Electrostatic Septa and Fast Deflector for MedAustron	septum, power-supply, cathode, injection	3532
	J. Borburgh, T. Fowler, A. Prost CERN, Geneva, Switzerland T. Kramer, T. Stadlbauer EBG MedAustron, Wr. Neustadt, Austria
	For the MedAustron facility, under construction in Wiener Neustadt, three electric field deflectors are developed in collaboration with CERN. A fast deflector is used in the Low Energy Beam Transfer line to chop the beam. The chopped beam is swept onto a Faraday cup for measurement purposes and to stop beam being sent towards the synchrotron. Electrostatic septa are used for the multi turn injection of protons and ions as well as for the slow extraction from the synchrotron. Novel design features for MedAustron include an inversed cathode/anode support and high voltage feedthroughs rated at 150 kV. The possibility for a higher voltage will significantly improve the conditioning process of the septa surfaces. This paper describes the requirements of these devices as well as the mechanical design and strategies adopted for their power supplies.

THPS057	Stripping Foil Simulations for ISIS Injection Upgrades	injection, simulation, proton, scattering	3556
	H. V. Smith, D.J. Adams, B. Jones, C.M. Warsop STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	ISIS, the pulsed neutron and muon spallation source located at the Rutherford Appleton Laboratory (UK), currently delivers a mean beam power of 0.2 MW to target. A 70 MeV H⁻ linear accelerator feeds into a 50 Hz, 800 MeV proton synchrotron (through a 0.3·10^-6 m Aluminium Oxide stripping foil), accelerating up to 3·10¹³ protons per pulse. Potential injection scheme upgrades, aiming to raise average beam power towards 0.5 MW with a new 180 MeV linear accelerator, are being studied. Detailed consideration of the injection stripping foil forms a key element of this study: scattering, stripping efficiency and foil lifetime are significant factors in determining loss levels, which consequently limit operational intensity. This paper describes the identification of a suitable stripping foil specification for successful 180 MeV H⁻ charge exchange injection into the ISIS synchrotron. Simulation code was developed to investigate electron stripping, scattering events and temperature rises, in order to witness their subsequent effect on foil lifetime. ANSYS models were also used to investigate the heat transfer and temperature distribution within thin foils.

THPS066	Technical Overview of the SIEMENS Particle Therapy Accelerator	ion, proton, linac, extraction	3577
	V. Lazarev, O. Chubarov, S. Emhofer, G. Franzini, S. Göller, B. Nagorny, A. Robin, H. Rohdjess, R. Rottenbach, A.C. Sauer, R. Schedler, T. Sieber, B. Steiner, J. Tacke, D.B. Thorn, T. Uhl, P. Urschütz, O. Wilhelmi Siemens Med, Erlangen, Germany M. Budde, J.S. Gretlund, H.B. Jeppesen, C.V. Nielsen, C.G. Pedersen, Ka.T. Therkildsen, S.V. Weber Siemens DK, Jyllinge, Denmark
	Siemens has developed an accelerator system for particle therapy. It consists of an injector (7 MeV/u protons and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u. These beams are extracted slowly from the synchrotron and delivered to a number of beam ports. The first accelerator system has been built and commissioned up to the first two beam outlets. An overview of the achieved performance of the system is presented. *Particle therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.

THPS069	Particle Beam Characteristics Verification for Patient Treatment at CNAO	controls, simulation, proton, monitoring	3586
	M. Donetti, M. Ciocca, M.A. Garella, A. Mirandola, S. Molinelli, M. Pullia, G. Vilches Freixas CNAO Foundation, Milan, Italy S. Giordanengo INFN-Torino, Torino, Italy M. Lavagno DE.TEC. TOR. S.r.l., Torino, Italy R. Sacchi Torino University, ., Torino, Italy
	At Centro Nazionale di Adroterapia Oncologica (CNAO) in Pavia, Italy, a synchrotron has been designed to treat tumor with protons and ions delivered with a full active delivery system. Several pencil beams with appropriate energy are steered in sequence to the right positions inside the tumor volume covering it totally. Several beam characteristics have to be deeply known in order to be able to deliver a safe patient treatment. CNAO is now able to send beam in the treatment room and the Dose Delivery system is in the commissioning phase. Dose Delivery system, composed by beam monitoring and scanning magnets, manages the treatment with high precision in real time. The dose delivery system functions and components will be presented. Beam characteristic are studied by means of several detectors and verification systems in the treatment room to guarantee the quality of the treatment. Quality is checked in terms of pencil beam characteristics and characteristic of the overall dose in the treatment fields. The detector used and the results of the measurements will be shown.

THPS070	Status Report of the CNAO Construction and Commissioning	proton, extraction, ion, linac	3589
	M. Pullia CNAO Foundation, Milan, Italy
	The CNAO (National Center for Oncological Hadrontherapy) is the first Italian center for deep hadrontherapy. The main accelerator is a synchrotron, based on the PIMMS design, capable to accelerate carbon ions up to 400 MeV/u and protons up to 250 MeV. Four treatment lines, in three treatment rooms, are foreseen in a first stage. The CNAO facility, has been designed for a completely active beam delivery system, in which a pencil beam is scanned transversely and the extracted beam energy can be changed on a spill to spill basis. The commissioning of the synchrotron started in August 2010. At the beginning of 2011 the first Spread Out Bragg Peaks with proton beams in the energy range 120-170 MeV/u, matching the first foreseen treatments, have been measured. The commissioning of the machine with protons has now been completed and authorisation to treatment of patients has been obtained from the competent authorities. The commissioning with carbon ions is in progress.

THPS072	Commissioning of NIRS Fast Scanning System for Heavy-ion Therapy	target, controls, ion, monitoring	3595
	T. Furukawa, T. Inaniwa, K. Katagiri, K. Mizushima, K. Noda, S. Sato, T. Shirai NIRS, Chiba-shi, Japan E. Takeshita Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
	The commissioning of NIRS fast scanning system was started in September 2010, when the first beam was successfully delivered from the HIMAC synchrotron to the new treatment room. After the fine tuning of the new transport line, the commissioning of the scanning system was carried out as following steps; 1) verification of the beam size, position and intensity stability; 2) verification of beam scanning performance and calibration; 3) verification of beam monitor performance; 4) dose measurement of pencil beams for the beam parameterization in the treatment planning system; and 5) verification of 3D dose conformation. As a result of the commissioning, we verified that the new scanning delivery system can produce an accurate 3D dose distribution for the target volume in combination with the planning software. We will report the commissioning results and the performance of the scanning system.

THPS073	Dosimetric Impact of Multiple Energy Operation in Carbon-ion Radiotherapy	target, ion, simulation, scattering	3598
	T. Inaniwa, T. Furukawa, N. Kanematsu, S. Mori, K. Noda, S. Sato, T. Shirai NIRS, Chiba-shi, Japan
	In radiotherapy with a scanned carbon beam, its Bragg peak is placed within the target volume either by inserting the range shifter plates or by changing the beam energy extracted from the synchrotron. The former method (range shifter scanning: RS) is adopted in NIRS while the latter method (active energy scanning: ES) has been used in GSI and HIT. In NIRS, an intermediate method, a combination scanning (CS), is now under consideration where eleven beam energies having the ranges with 30 mm intervals are prepared and used in conjunction with the range shifter plates for slighter range shift. The disadvantages of the RS are the beam spread due to the multiple scattering within the range shifter plates and the production of fragment particles through the nuclear reactions within them. On the other hand, for the ES, severely time-consuming beam commissioning and the expensive devices are required. In this study, we compare these three methods from the viewpoint of dose distributions and the impacts for clinical cases will be discussed.

THPS075	Recent Progress of New Cancer Therapy Facility at HIMAC	ion, target, heavy-ion, controls	3604

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MOXAA01

ALBA Synchrotron Light Source Commissioning

storage-ring, booster, linac, injection

1

D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3rd generation Synchrotron Light Source build in Barcelona, Spain. It is a 3 GeV Light Source with a circumference of roughly 270 m, an emittance of 4.4 nmrad and a design current of 400 mA. The storage ring has 24 straight sections from which 19 can be used for the installation of insertion devices, the rest will be used for injection, RF-cavities and diagnostic. The storage ring has been optimized for a high photon flux density for the users. The 3 GeV booster synchrotron with an emittance smaller the 10 nmrad is installed in the same tunnel. The pre injector is a 100 MeV Linac. The project started officially in 2004. The linac is operating since 2008, the booster since 2010 and the first commissioning phase for the storage ring will be finished in June 2011. This presentation gives an overview of the ALBA project with the emphasis on the results of the commissioning of the three accelerators Linac, booster synchrotron and storage ring.

Slides MOXAA01 [8.891 MB]

MOPC001

Linac Waveguide Upgrade at the Australian Synchrotron Light Source

klystron, linac, booster, controls

62

R.T. Dowd, G. LeBlanc, K. Zingre
ASCo, Clayton, Victoria, Australia

The Australian Synchrotron Light Source (ASLS) uses a 100 MeV linac as the start of the acceleration chain for the injector. The two main accelerating structures of linac are normally fed by independent pulsed klystrons. A recent upgrade to the waveguide system has allowed for a single klystron to power both accelerating structures. While this operation mode delivers a reduced total beam energy, the operation of only a single klystron results in less wear and enhanced robustness against klystron breakdown. Commissioning results of single klystron operation of the linac are shown and future benefits are detailed.

MOPC002

Flow Induced Vibrations of the CLIC X-band Accelerating Structures

quadrupole, alignment, linac, resonance

65

T.K. Charles, K. Ryan
Monash University, Melbourne, Australia
M.J. Boland
ASCo, Clayton, Victoria, Australia
G. Riddone
CERN, Geneva, Switzerland
A. Samoshkin
JINR, Dubna, Moscow Region, Russia

Turbulent cooling water in the Compact Linear Collider (CLIC) accelerating structures will inevitably induce some vibrations. The maximum acceptable amplitude of vibrations is small, as vibrations in the accelerating structure could lead to beam jitter and alignment difficulties. A Finite Element Analysis model is needed to identify the conditions under which turbulent instabilities and significant vibrations are induced. Due to the orders of magnitude difference between the fluid motion and the structure's motion, small vibrations of the structure will not contribute to the turbulence of the cooling fluid. Therefore the resonant conditions of the cooling channels presented in this paper, directly identify the natural frequencies of the accelerating structures to be avoided under normal operating conditions. In this paper a 2D model of the cooling channel is presented finding spots of turbulence being formed from a shear layer instability. This effect is observed through direct visualisation and wavelet analysis.

MOPC019

Condition of MA Cut Cores in the RF Cavities of J-PARC Main Ring after Several Years of Operation

impedance, cavity, resonance, ion

107

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

J-PARC 3 GeV RCS and 50 GeV Synchrotron (MR) employ RF cavities loaded with Magnetic Alloy (MA) cores to generate a high field gradient. The RF cavities in RCS use MA un-cut cores. On the other hand, the RF cavities in MR employ MA cut cores to increase the Q-value from 0.6 to 26. We observed the impedance reductions of all MR RF cavities during several years operation. Opening the RF cavities, we found that the impedance reductions were resulting from corrosion on the cut and polished surfaces of MA cores. Before installation of the RF cavities, we had 1000 and 2000 hours long tests at a test stand. We didn't observe the impedance reduction related to the corrosion on the MA core cut surfaces at the test stand. The only difference between the test stand and MR is the quality of cooling water. The MR cooling water contains copper ions for example from copper hollow conductors of the main magnets. We report the influence of the copper ions to the corrosion on the MA core cut surface. We also show plans how to solve the issue of MA core cut surface corrosion.

MOPC054

The LHC RF System - Experience with Beam Operation

injection, klystron, emittance, damping

202

P. Baudrenghien, M. E. Angoletta, T. Argyropoulos, L. Arnaudon, J. Bento, T. Bohl, O. Brunner, A.C. Butterworth, E. Ciapala, F. Dubouchet, J. Esteban Muller, D.C. Glenat, G. Hagmann, W. Höfle, D. Jacquet, M. Jaussi, S. Kouzue, D. Landre, J. Lollierou, P. Maesen, P. Martinez Yanez, T. Mastoridis, J.C. Molendijk, C. Nicou, J. Noirjean, G. Papotti, A.V. Pashnin, G. Pechaud, J. Pradier, J. Sanchez-Quesada, M. Schokker, E.N. Shaposhnikova, D. Stellfeld, J. Tückmantel, D. Valuch, U. Wehrle, F. Weierud
CERN, Geneva, Switzerland

The LHC RF system commissioning with beam and physics operation for 2010 and 2011 are presented. It became clear in early 2010 that RF noise was not a lifetime limiting factor: the crossing of the much feared 50 Hz line for the synchrotron frequency did not affect the beam. The broadband LHC RF noise is reduced to a level that makes its contribution to beam diffusion in physics well below that of Intra Beam Scattering. Capture losses are also under control, at well below 0.5%. Longitudinal emittance blow-up, needed for ramping of the nominal intensity single bunch, was rapidly commissioned. In 2011, 3.5 TeV/beam physics has been conducted with 1380 bunches at 50 ns spacing, corresponding to 55% of the nominal current. The intensity per bunch (1.3 ·10¹¹ p) is significantly above the nominal 1.15 ·10¹¹. By August 2011 the LHC has accumulated more than 2 fb-1 integrated luminosity, well in excess of the 1 fb-1 target for 2011.

MOPC077

Commissioning of Multibunch Feedback Systems at the Fast Ramping Stretcher Ring ELSA

kicker, cavity, feedback, booster

250

A. Roth, F. Frommberger, N. Heurich, W. Hillert, M. Schedler, R. Zimmermann
ELSA, Bonn, Germany

Funding: Supported by German Research Foundation through SFB/TR 16 and by Helmholtz Alliance through HA-10¹.
At the Electron Stretcher Facility ELSA of Bonn University, an external beam of either unpolarized or polarized electrons is supplied to hadron physics experiments. The ELSA stretcherring operates in the energy range of 1.2 to 3.5 GeV and achieves a duty cycle of up to 80% using a fast energy ramp of 4 GeV/s. Under these conditions, an increase of the internal beam current from an actual value of 20 mA up to 200 mA is planned. Such an upgrade is mainly limited by the excitation of multibunch instabilities. As one active counteraction, we have installed state-of-the-art bunch-by-bunch feedback systems for the longitudinal, as well as for both transverse planes. The detailed setup with all main components and first results of the commissioning of the systems will be presented. In particular, the performance of the longitudinal feedback with a stabilized synchrotron frequency during the fast energy ramp will be discussed.

MOPC147

Timing System for MedAustron Based on Off-The-Shelf MRF Transport Layer

controls, ion, ion-source, light-ion

424

R. Tavcar, J. Dedič, Z. Kroflic, R. Štefanič
Cosylab, Ljubljana, Slovenia
J. Gutleber
CERN, Geneva, Switzerland

MedAustron is a new particle accelerator-based ion beam research and therapy centre under construction in Wiener Neustadt, Austria. The timing system for its synchrotron-based accelerator is being developed in close collaboration with Cosylab. We have usedμResearch Finland (MRF) transfer layer and designed and implemented a generic, reusable high-level logic above transport layer inside the generator and receiver FPGA to fulfill machine specific requirements which exceed MRF's original high-level logic capabilities. The new timing system is suitable for small to mid-size accelerators. Its functionalities include support for virtual accelerators and a rich selection of event response mechanisms. The timing system uses a combination of a real-time link for downstream events and a non-real-time link for upstream messaging and non time-critical communication. This article explains the benefits of building a timing system on a proven, stable timing transport layer and describes the high-level services provided by MedAustron timing system.

MOPC164

Upgrade of the ISIS Synchrotron Low Power RF System

cavity, controls, feedback, ion

466

A. Seville, N.E. Farthing, I.S.K. Gardner, R.J. Mathieson, J.W.G. Thomason
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
D.B. Allen
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The ISIS synchrotron at the Rutherford Appleton Laboratory in the UK now routinely uses a dual harmonic RF system to accelerate beam currents in excess of 230 uA to run two target stations simultaneously. In order to give more stable control of the phase of the RF voltage at each of the fundamental (1RF) and second harmonic (2RF) cavities, changes have been made to the low power RF (LPRF) control systems. In addition to this a new FPGA based master oscillator has been commissioned for the first time, and further changes using digital technologies to replace other components of the LPRF system are to be investigated. This paper reports on the LPRF hardware commissioning and reliability.

MOPO005

A Transverse Feedback System using Multiple Pickups for Noise Minimization

kicker, pick-up, feedback, betatron

487

M. Alhumaidi, A.M. Zoubir
TU Darmstadt, Darmstadt, Germany

A new concept for using multiple pickups for estimating beam angle at the kicker is addressed. The estimated signal should be the driving feedback signal. The signals from the different pickups are delayed, such that they correspond to the same bunch. Consequently a weighted sum of the delayed signals is suggested as an estimator of the beam angle at the kicker. The weighting coefficients are calculated such that the estimator is unbiased, i.e. the output corresponds to the actual beam angle at the kicker for non-noisy pickup signals. Furthermore, the estimator must give the minimal noise power at the output among all linear unbiased estimators. Finally results for the heavy ions synchrotron SIS 18 at the GSI are shown.

MOPO031

Alignment of theTPS Front-End Prototype

alignment, laser, survey, synchrotron-radiation

550

C.K. Kuan, Y.T. Cheng, W.Y. Lai, I.C. Sheng, T.C. Tseng, H.Y. Yan
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is a 3-GeV third-generation source of synchrotron radiation with beam current 500 mA stored in the storage ring. A front end allows intense synchrotron light generated in the storage ring to pass through to a beamline. Most heat load of the synchrotron light is removed in the front ends to protect the beamline components. Alignment of front-end components becomes important to prevent damage from the large heat load. Because of the many front ends and the brief period of installation, the alignment work should be easy, quick and reliable. Using a shim method, the adjustable degrees of freedom are decreased from six to two. This adjustment work becomes easier and quicker. The alignment of a front-end prototype is described here.

MOPO039

B-train Performances at CNAO

dipole, feedback, power-supply, extraction

568

M. Pezzetta, G. Bazzano, E. Bressi, L. Falbo, C. Priano, M. Pullia
CNAO Foundation, Milan, Italy
O. Coiro, G. Franzini, D. Pellegrini, M. Serio, A. Stella
INFN/LNF, Frascati (Roma), Italy
G. Venchi
University of Pavia, Pavia, Italy

The commissioning of CNAO, the Italian Centre of Oncological Hadrontherapy, with proton beams is completed. The real-time measurement of the synchrotron dipole field with the so-called B-train, together with its electronic systems and related software and firmware are here described. An additional magnet, powered in series with the synchrotron dipoles, is equipped with a special coil that measures the field integral variation along the beam nominal path. The voltage induced in the coil is digitized with a fast ADC and numerically integrated by an FPGA. The field integral is then distributed to the users every time that the equivalent field changes by 0.1 G. The measured B field ranges from 0 to 1.6 T with maximum ramps of 3 T/s. The B-train system will be used to provide feedback in field to the dipole power supply. It will handle the limited bandwidth of the active filter, the B-field lag in the magnets and will avoid current jumps.

MOPO040

RF Reference Distribution for the Taiwan Photon Source

controls, laser, diagnostics, LLRF

571

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

Taiwan Photon Source (TPS) is a low-emittance 3-GeV synchrotron light source with circumference of 518.4 m which is being under construction at National Synchrotron Radiation Research Center (NSRRC) campus. Low noise 500 MHz master oscillator and novel fiber based CW RF reference distribution system will be employed to take advantages of advanced technology in this field and deliver better performance. The preliminary test of the prototype system is summarized in this report.

MOPO044

Bunch Length Measurements in Low-Alpha Mode at SPEAR3 with First Time-Resolved Pump/Probe Experiments*

laser, photon, single-bunch, radiation

583

J.S. Wittenberg, A. Lindenberg, A. Miller
Stanford University, Stanford, California, USA
W.J. Corbett, L. Wang
SLAC, Menlo Park, California, USA

Funding: Work sponsored by U.S. Department of Energy Contract DE-AC03-76SF00515, Office of Basic Energy Sciences and SLAC Laboratory Directed Research Development funds (LDRD)
The SPEAR3 synchrotron light source can be operated in low-alpha mode to generate x-ray pulse durations of order 1ps, well below streak camera resolution limits yet accessible by laser/sr cross-correlation measurements. Initial CC tests performed with a 50fs TiSa laser, frequency doubling BBO, photodiode and lock-in amplifier resolved bunch lengths down to about 6ps rms with 85uA single-bunch current. By reconfiguring the experimental setup to utilize a fiber laser, sum frequency generation and single photon counter it is now possible to measure profiles in the 1ps rms range with only 5uA single-bunch current. In this paper we report on the most recent measurements, simulations, modeling efforts and prospects for further improvement.

MOPS011

Impact of Low Transition Energy Optics to the Electron Cloud Instability of LHC Beams in the SPS

electron, optics, simulation, emittance

616

H. Bartosik, E. Benedetto, K.S.B. Li, Y. Papaphilippou, G. Rumolo
CERN, Geneva, Switzerland

One of the main limitations for high intensity multi-bunch LHC proton beams in the SPS is imposed by electron cloud instabilities. A new optics of the SPS with lower transition energy was implemented and successfully tested in machine studies. The significant increase of the slippage factor that it provides at injection energy results in the expected increase of the single bunch instability thresholds. In this paper, the impact of this new optics on the electron cloud instability threshold is estimated by using numerical simulations, taking into account the change of the optics functions and the faster synchrotron motion due to the reduced transition energy.

MOPS048

Microbunching Instability Studies at SOLEIL

electron, radiation, storage-ring, synchrotron-radiation

709

C. Evain, J. Barros, J.B. Brubach, L. Cassinari, M.-E. Couprie, G. Creff, M. Labat, A. Loulergue, L. Manceron, R. Nagaoka, P. Roy, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

Microbunching instability arises in storage rings when the number of electrons in a bunch exceeds a threshold value. Its signature, i.e. a strong and irregular emission of Coherent Synchrotron Radiation (CSR) in the Terahertz (THz) domain, is studied at SOLEIL on the AILES infrared beamline, with the storage ring tuned in a low-alpha configuration (used to get shorter electron bunch). The comparison of this observed THz CSR with numerical simulations of the longitudinal electron bunch dynamics, permits to put in evidence that during the instability a modulation appears and drifts in the longitudinal profile of the electron bunch. The understanding of this instability is important as it limits some operation of the storage rings. Indeed the induced fluctuations prevent the use of THz on the far IR beamline at high current per bunch. And in normal alpha operation this instability may spoil the electron/laser interaction effects used to get femtosecond and/or coherent pulse in storage rings (with slicing, Coherent Harmonic Generation or EEHG schemes on storage ring).

MOPS052

Analytical and Numerical Calculations of Beam Pipe Impedances at Low Frequencies with Application to Thin SIS100 Pipe

impedance, coupling, shielding, betatron

721

U. Niedermayer, O. Boine-Frankenheim, L. Hänichen
TEMF, TU Darmstadt, Darmstadt, Germany

The projected fast ramped synchrotron SIS100 for FAIR uses an elliptical stainless steel beam pipe of 0.3 mm thickness. The lowest coherent betatron sidebands reach down to 100 kHz which demands accurate impedance calculations in the low frequency (LF) regime. For these frequencies, i.e. skin depth greater than wall thickness, structures behind the pipe may contribute to the impedance. Due to the extremely large wake length numerical methods in the time domain are not applicable. The longitudinal and transverse impedance of the thin SIS100 beam pipe including structures behind the pipe are obtained numerically by a method using power loss in the frequency domain. We compare different analytical models for simplified pipe structures to the numerical results. The dc and ultra-relativistic limits are investigated. The interpretation of bench measurements in the LF regime is discussed.

MOPS055

Observation of Intensity Dependent Single Bunch Effects at the Synchrotron Light Source PETRA III

impedance, emittance, single-bunch, electron

730

R. Wanzenberg, K. Balewski
DESY, Hamburg, Germany

At DESY the PETRA ring is operated as a synchrotron radiation facility with a very low emittance of 1 nm. Regular user operation has started in summer 2010. A summary of observations and measurements of intensity dependent single bunch effects is presented in this report. The longitudinal impedance of the ring is estimated from the measured bunch length versus beam intensity. The results are compared with predictions from the impedance model. Furthermore measurements of the single bunch intensity limit due to the transverse mode coupling instability (TMCI) are reported. The tune and phase shift around the ring has been measured as a function of the beam intensity. At PETRA III tune spectra have been observed with some characteristics which have been observed at other storage rings in connection with electron cloud effects. The present status of the observations of potential electron cloud effects is also discussed.

MOPS066

Collective Effects in the MAX IV 3 GeV Ring

impedance, cavity, damping, storage-ring

754

P.F. Tavares
MAX-lab, Lund, Sweden
T.F. Günzel
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
R. Nagaoka
SOLEIL, Gif-sur-Yvette, France

We present calculations of collective instability effects in the 3 GeV electron storage ring of the MAX IV facility currently under construction in Lund, Sweden. The storage ring is designed to deliver ultra-low emittance down to 0.24 nm rad so as to provide high brightness synchrotron radiation from undulators. This is achieved in a comparatively small machine (528 m circumference) through the use of a multi-bend achromat lattice and a compact magnet design featuring multi-purpose narrow gap magnet blocks. This design features small dispersion leading to low momentum compaction, which, together with the small circular (11 mm radius) chambers, poses a challenge to reach the design current (500 mA in 176 bunches) without exciting instabilities and degrading beam parameters due to the interaction with the machine impedance. Particularly important are multi-bunch resistive wall effects in the NEG coated copper chamber as well single-bunch instabilities driven by the broad-band impedance. A low RF frequency (100 MHz) and harmonic cavities are foreseen to lengthen the bunches and increase instability thresholds.

MOPS075

Simulation of Multibunch Motion with the HEADTAIL Code and Application to the CERN SPS and LHC

impedance, wakefield, simulation, coupling

778

N. Mounet
EPFL, Lausanne, Switzerland
N. Mounet, E. Métral, G. Rumolo
CERN, Geneva, Switzerland

Multibunch instabilities due to beam-coupling impedance can be a critical limitation for synchrotrons operating with many bunches. It is particularly true for the LHC under nominal conditions, where according to theoretical predictions the 2808 bunches rely entirely on the performance of the transverse feedback system to remain stable. To study these instabilities, the HEADTAIL code has been extended to simulate the motion of many bunches under the action of wake fields. All the features already present in the single-bunch version of the code, such as synchrotron motion, chromaticity, amplitude detuning due to octupoles and the ability to load any kind of wake fields through tables, have remained available. This new code has been then parallelized in order to track thousands of bunches in a reasonable amount of time. The code was benchmarked against theory and exhibited a good agreement. We also show results for bunch trains in the LHC and compare them with beam-based measurements.

MOPS079

Simulations of Coaxial Wire Measurements of the Impedance of Asymmetric Structures

impedance, simulation, coupling, kicker

787

H.A. Day, R.M. Jones
UMAN, Manchester, United Kingdom
F. Caspers, H.A. Day, E. Métral
CERN, Geneva, Switzerland

Coaxial wire measurements have provided a simple and effective way to measure the beam coupling impedance of accelerator structures for a number of years. It has been known how to measure the longitudinal and dipolar transverse impedance using one and two wires for some time. Recently the ability to measure the quadrupolar impedance of structures exhibiting top/bottom and left/right symmetry has been demonstrated. A method for measuring the beam coupling impedance of asymmetric structures using displaced single wires and two wire measurements is proposed. Simulations of the measurement system are presented with further work proposed.

MOPZ035

MICE Muon Beamline Particle Rate and Related Beam Loss in the ISIS Synchrotron

beam-losses, target, proton, solenoid

874

A.J. Dobbs
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
D. Adey
University of Warwick, Coventry, United Kingdom
L. Coney
UCR, Riverside, California, USA

The international Muon Ionization Cooling Experiment (MICE) will provide a proof of principle of ionization cooling, reduction of muon beam phase space, which will be needed at a future Neutrino Factory and Muon Collider. The MICE muon beam is generated by the decay of pions produced by dipping a cylindrical titanium target into the proton beam of the 800 MeV ISIS synchrotron at the Rutherford Appleton Laboratory, U.K. Studies of the particle rate in the MICE beamline and correlations with induced beam loss in ISIS are described, including the most recent data taken in the summer of 2010, representing some of the highest loss and rate conditions achieved to date. Ideally, a high rate of muons in the MICE beamline is desired, in order to facilitate the cooling measurement. However, impact on the host accelerator equipment must also be minimized. The implications of the observed beam loss and particle rate levels for MICE and ISIS are discussed.

TUODA02

Status of Sirius – a New Brazilian Synchrotron Light Source

dipole, emittance, permanent-magnet, lattice

931

L. Liu, R. Basílio, J.F. Citadini, R.H.A. Farias, R.J.F. Marcondes, X.R. Resende, F. Rodrigues, A.R.D. Rodrigues, P.P. Sanchez, R.M. Seraphim, G. Tosin, F. H. de Sá
LNLS, Campinas, Brazil

We present an overview of the new synchrotron light source project Sirius, currently being designed at the Brazilian Synchrotron Light Laboratory (LNLS) in Campinas, São Paulo. Sirius will consist of a 480 m circumference, 3.0 GeV, 20 TBA cells, 1.7 nm.rad emittance storage ring. The dipoles will be based on the use of permanent magnet technology and will combine low field magnets (0.5 T) for the main beam deflection with a short slice of high field magnet (2.0 T) to generate photons of 12 keV critical energy with modest total energy loss. There will be 18 straight sections for insertion devices. In this report we describe the current status for the magnet lattice design and some of the subsystems.

Slides TUODA02 [2.434 MB]

TUOAB02

Simultaneous Long and Short Bunch Operation in an Electron Storage Ring - a Hybrid Mode based on Nonlinear Momentum Compaction

electron, storage-ring, octupole, photon

945

M. Ries, J. Feikes, A. Jankowiak, P.O. Schmid, G. Wüstefeld
HZB, Berlin, Germany

The generation of short pulses in electron storage rings is driven by different user groups like time resolved x-ray spectroscopy users or users of coherent synchrotron radiation. The required optics and operation conditions to generate this short bunches are worsening the experimental conditions, e.g. strongly reducing the average photon flux, for the regular user. Therefore short bunch operation is usually limited to dedicated user shifts. By controlling higher orders of the momentum compaction factor by higher multipoles it is possible to introduce a hybrid mode and simultaneously supplying long and short bunches*. The Metrology Light Source (MLS) has the means to control these higher orders**, therefore it is an ideal machine to investiate the feasibility of such a hybrid mode. Tracking results and first measurements will be shown.
* D. Robin et al., Proc. of EPAC08, p. 2100-2102, Genoa, Italy (2008).
** J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).

Slides TUOAB02 [7.817 MB]

TUPC022

Design of the CLIC Drive Beam Recombination Complex

emittance, linac, injection, sextupole

1045

J. Barranco, P.K. Skowroński, F. Tecker
CERN, Geneva, Switzerland
C. Biscari
INFN/LNF, Frascati (Roma), Italy

The CLIC Drive Beam Recombination Complex (DBRC) is designed to compress beam pulses from a current of 4.1 A to 100 A before using them to produce RF power in the deceleration lines. The beam is transported isochronously through a complex system consisting of a delay loop, two combiner rings and final turn around. The system is designed to preserve transverse and longitudinal emittances. During the optics design, chromaticity and non-linear dispersion were identified as the main single particle dynamics causes for transverse emittance increase. Different sextupole families are used to compensate these chromatic effects while keeping isochronicity. The bunch length is also adjusted to minimize coherent synchrotron radiation effects on bunch length, energy spread and transverse emittance. Finally, the injection scheme of the combiner rings was improved making the time variable bump created with help of the RF deflectors truly achromatic.

TUPC048

First Measurement Results of the LHC Longitudinal Density Monitor

photon, proton, ion, diagnostics

1105

A. Jeff, M. Andersen, A. Boccardi, S. Bozyigit, E. Bravin, T. Lefèvre, A. Rabiller, F. Roncarolo
CERN, Geneva, Switzerland
A.S. Fisher
SLAC, Menlo Park, California, USA
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: The primary author is funded by the E.U. under the DITANET Marie Curie network.
Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, for example to check the injection quality and to characterize the development of ghost bunches before and during the physics periods. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. The LDM is able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 10⁵ to be achieved. The LDM operated during the 2010 lead ion run and during 2011 with protons. Measurements from both runs are presented in this contribution along with an analysis of the LDM performance and an outlook for future upgrades.

TUPC053

Superconducting Positron Stacking Ring for CLIC

positron, injection, damping, septum

1117

F. Zimmermann, L. Rinolfi
CERN, Geneva, Switzerland
E.V. Bulyak, P. Gladkikh
NSC/KIPT, Kharkov, Ukraine
T. Omori, J. Urakawa, K. Yokoya
KEK, Ibaraki, Japan

The generation of polarized positrons for future colliders based on Compton storage rings is a promising method. A challenging key ingredient of this method is the necessary quasi-continuous positron injection into a stacking ring. The ordinary methods of multi-turn injection are not appropriate for this purpose, because the required number of injection-turns is a few hundred, and the emittance of the injected positron bunches is large. This paper describes a possible solution based on 5 GeV superconducting stacking ring, where a novel method of the combined longitudinal and transverse injection process is used to stack positrons. The ring dynamic aperture allows to inject the positron beam with normalized emittance up to 2000 micrometers during a few hundred turns. The injection efficiency is larger than 90% in simulation. The number of the injection turns is only limited by the synchrotron radiation power. The ring lattice and the results of injection simulations are presented.

TUPC062

Electron Beam Energy Measurement at the Australian Synchrotron Storage Ring

storage-ring, electron, resonance, scattering

1138

M.J. Boland
ASCo, Clayton, Victoria, Australia
H. Panopoulos, R.P. Rassool, K.P. Wootton
The University of Melbourne, Melbourne, Australia

The technique of resonant spin depolarization was used to precisely measure the electron beam energy in the storage ring at the Australian Synchrotron. A detector and data acquisition system dedicated to the measurement were developed. Using the system, the long term energy stability of the storage ring was monitored and a mechanical realignment of the ring was clearly seen in the energy data. Details of the parameters used to optimize the measurement are also discussed.

TUPC063

Energy Verification in Ion Beam Therapy

proton, simulation, ion, closed-orbit

1141

F. Moser
ATI, Wien, Austria
M. Benedikt, U. Dorda
EBG MedAustron, Wr. Neustadt, Austria

Funding: Austrian Federal Ministry for Science and Research, CERN Technology Doctoral Student Program
The adoption of synchrotrons for medical applications necessitates a comprehensive on-line verification of all beam parameters, autonomous of common beam monitors. In particular for energy verification, the required precision of down to 0.1 MeV, in absolute terms, poses a special challenge regarding the betatron-core driven 3rd order extraction mechanism which is intended to be used at MedAustron. Two different energy verification options have been studied and their limiting factors were investigated: 1) A time-of-flight measurement inside the synchrotron, limited by the orbit circumference information and measurement duration as well as extraction uncertainties. 2) A calorimeter-style system in the extraction line, limited by radiation hardness and statistical fluctuations. The paper discusses in detail the benefits and specific aspects of each method.

TUPC068

SOLEIL Beam Orbit Stability Improvements

feedback, booster, photon, power-supply

1156

N. Hubert, Y.-M. Abiven, F. Blache, F. Briquez, L. Cassinari, J.-C. Denard, J.-F. Lamarre, P. Lebasque, N. Leclercq, A. Lestrade, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

The electron beam orbit stability has been significantly improved at synchrotron SOLEIL. Low frequency noise sources have been localized and identified: the fans installed on the storage ring to cool down the ceramic chambers of the kickers, shaker and FCT, were slightly wobbling the electron beam orbit at 46, 50, 54 and 10⁸ Hz. The localization method and the solutions that will allow reducing the noise from 0.8 μm RMS down to 0.3 μm are presented. Besides, a new 160 m long beamline, NANOSCOPIUM, is being installed on a canted straight section. Its photon beam position stability requirements are very tight calling for the following improvements: addition of 2 more BPMs and fast correctors in the orbit feedback loops, new INVAR stands for BPM and XBPM integrating Hydrostatic Level System sensors. The paper is also discussing other projects that did or will contribute to improving the beam orbit stability: installation of 145 temperature sensors on the storage ring, a new analog feedforward correction system for insertion devices, and the use of the bending magnet X-BPM measurements in the slow and fast orbit feedback loops.

TUPC075

Diagnostic Devices for Beam Intensity Measurement at FAIR

ion, diagnostics, storage-ring, antiproton

1174

M. Schwickert, T. Hoffmann, F. Kurian, H. Reeg
GSI, Darmstadt, Germany
R. Geithner, W. Vodel
HIJ, Jena, Germany
R. Neubert, P. Seidel
FSU Jena, Jena, Germany

Funding: Work supported by EU, DITANET, Project No. ITN-2008-215080.
Precise determination of beam intensity is important for any accelerator facility. At FAIR, the Facility for Antiproton and Ion Research presently in the planning phase at GSI, the requirements set by beam intensities in the various accelerators, storage rings and transport lines differ significantly. A set of beam diagnostic instruments is foreseen to detect the large variety of ion beams ranging from less than 10⁴ antiprotons up to high intensity of 5·10¹¹ uranium ions. This contribution presents an overview of destined current measurement devices, both intercepting, like scintillators, ionization chambers or secondary electron monitors, and non-intercepting current-transformer type devices. Ongoing developments are discussed for non-intercepting devices, i.e. a dc current transformer with large dynamic range and a cryogenic current comparator, purpose-built for the detection of lowest beam intensities at FAIR.

TUPC084

Performance of the Scintillation Profile Monitor in the COSY Synchrotron

vacuum, proton, electron, target

1201

V. Kamerdzhiev, J. Dietrich, K. Reimers
FZJ, Jülich, Germany

Residual gas scintillation is used for measuring profile of the proton beam circulating in the COSY synchrotron. The problem of low rate of scintillation events detected by a multichannel photomultiplier is coped with by injecting small amounts of pure nitrogen into the SPM vacuum chamber. This leads to a temporary local pressure bump of no more than an order of magnitude. A commercially available piezo-electric dosing valve allows good control over the amplitude and duration of the pressure bump. Since the average pressure in the machine is hardly changed, the method is fully compatible with experiment operation. This approach offers a robust and inexpensive way to measure the beam profile. The design of the SPM is discussed. The latest measurement results and comparison to the ionization profile monitor data is presented.

TUPC085

Observation of Microwave Radiation using Low-cost Detectors at the ANKA Storage Ring

radiation, storage-ring, vacuum, optics

1203

V. Judin, N. Hiller, A. Hofmann, E. Huttel, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, M.J. Nasse, N.J. Smale
KIT, Karlsruhe, Germany
F. Caspers
CERN, Geneva, Switzerland
P. Peier
PSI, Villigen, Switzerland

Funding: Work supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320
Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed because the waveguide cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: The accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths above the waveguide cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually used in standard TV-SAT-receivers and are very cheap. We determined the time response of LNBs to be below 100 ns. The sensitivity of LNBs is optimized to detect very low intensity "noise-like" signals.

TUPC086

A Setup for Single Shot Electro Optical Bunch Length Measurements at the ANKA Storage Ring

laser, electron, storage-ring, radiation

1206

N. Hiller, E. Huttel, A.-S. Müller, A. Plech
KIT, Karlsruhe, Germany
F. Müller, P. Peier, V. Schlott
PSI, Villigen, Switzerland

Funding: Supported by the Initiative and Networking Fund of the Helmholtz Association under VH-NG-320. Sponsored by the German Federal Ministry of Education and Research under contract number 05K10VKC
Single shot electro optical bunch length measurements, in particular using spectral decoding, are foreseen for the ANKA storage ring. This will allow to resolve fast changes of bunch deformation and structure during the low alpha operation (2-15 ps rms bunch length). This technique uses a chirped laser pulse to probe the field induced birefringence in an electro optical crystal. The laser pulse is then analyzed in a single shot spectrometer. To obtain the birefringence modulation one can either use the near field of the electron bunch (placing the crystal close to the electron bunch in the UHV system of the storage ring), or the far field (coherent synchrotron radiation in the THz range at a THz-/IR-Beamline). The laser needs to supply: sufficient tunability of pulse length, a wide spectrum to allow for a sub-ps resolution. Additionally it must provide a mode-locked operation synchronized to the bunch revolution clock. For this purpose, a mode locked Ytterbium fibre laser system which operates at 10³⁰ nm has been developed at the Paul-Scherrer Institute in Switzerland. We give an overview over the experimental set up in the ANKA storage ring and the status of the project.

TUPC087

Filling Pattern Measurements at the ANKA Storage Ring

photon, electron, storage-ring, single-bunch

1209

B. Kehrer, N. Hiller, A. Hofmann, E. Huttel, V. Judin, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale
KIT, Karlsruhe, Germany

For many accelerator physics studies, e.g. the investigation of coherent synchrotron radiation (CSR), a precise knowledge of the quantitative filling pattern (i.e. the number of electrons per bunch) is essential. This can be achieved by either using a linear detector (analog recording) or by employing the method of time-correlated single photon counting (TCSPC). At the ANKA storage ring both methods are in use. The analogue detection is based on the signal from a stripline or annular electrode, the TCSPC uses a Single Photon Avalanche Diode (SPAD). In this paper, we describe the experimental set-ups and present results of a comparison of the two techniques for single as well as for multi bunch filling patterns.

TUPC093

CSR Bunch Length Monitor for XFEL/SPring-8 - SACLA

radiation, FEL, electron, synchrotron-radiation

1224

C. Kondo, S. Matsubara, T. Matsumoto
JASRI/SPring-8, Hyogo-ken, Japan
S.I. Inoue, H. Maesaka, Y. Otake
RIKEN Spring-8 Harima, Hyogo, Japan

SPring-8 Angstrom Compact Free Electron Laser (SACLA) is now under commissioning operation, aimed at the generation of a sub-angstrom free electron laser (FEL). In order to ensure the stable FEL generation, non-distractive bunch length monitors utilizing coherent synchrotron radiation (CSR) are installed. The monitors are located at the downstream of individual bunch compressor (BC1-BC3), and they measure the radiation emitted at the individual last magnets of the chicanes. At the magnets, beams with bunch lengths form 10 fs to 1000 fs generate the CSRs with a spectrum ranging the almost whole infrared region (0.03 - 3 THz). The CSRs are detected by a Schottky diode at the BC1, or pyroelectric detectors and a simple organic lens optical system at BC2 and 3. The bunch length monitor systems are used for bunch length feedback control to obtain the stable lasing by changing the rf parameter of acceleration cavities before the BCs. A preliminary system for the above mentioned system was tested at the SCSS test accelerator, and it showed sufficient performance to measure bunch length up to 300 fs. In this report, we describe the design and the results of the first operation.

TUPC112

Photon Beam Position Monitor based on Position-sensitive Detector for HLS*

photon, injection, diagnostics, feedback

1281

Y.Y. Xiao, L.M. Gu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

In order to overcome the limitation that the existing photon beam position monitors (PBPM) cannot measure the beam position in vertical and horizontal at the same time, a new photon beam position monitor based on position-sensitive detector (PSD) has developed at HLS (Hefei Light Source). The new PBPM based on the PSD has very fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. Some results are given.

TUPC132

Imaging of the MAX III Electron Beam Profile Using Visible Synchrotron Radiation

electron, emittance, diagnostics, lattice

1332

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

The recently assembled MAX III diagnostic beam line utilizes the bending magnet synchrotron radiation (SR) in the visible to ultraviolet range to form images of the transverse electron beam profile. Computer simulations model the generation and propagation of the SR through the beam line, taking into account effects such as diffraction, the longitudinally distributed source point and the curvature of the electron orbit. Using the diagnostic beam line, the electron beam size and the emittance in the MAX III synchrotron light source has been determined.

TUPC146

Beam Profiles Analysis for Beam Diagnostic Applications

background, diagnostics, synchrotron-radiation, instrumentation

1368

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

Beam profile and its analysis play an important role in beam diagnostics of a particle accelerator system. Use of destructive screen monitor or non-destructive synchrotron radiation monitor for beam profile measurement is a simple way and has been widely used in synchrotron light source facility. Analyze beam profiles can obtain beam parameters including beam center, σ, and tilt angle which has become a useful tool for beam diagnostic. In this report the comparison of fitting strategies affect the analysis results are studied. The computer simulated beam profiles with different background noise level and conditions are used to evaluate the computing time, and the estimated fitting errors.

TUPC155

Optimisation of the LHC Beam Current Transformers for Accurate Luminosity Determination

luminosity, instrumentation, pick-up, monitoring

1395

J-J. Gras, D. Belohrad, M. Ludwig, P. Odier
CERN, Geneva, Switzerland
C. Barschel
RWTH, Aachen, Germany

During the 2010 and 2011 LHC runs a series of dedicated fills were used for luminosity calibration measurements at each of the LHC experiments. A major contribution to the final precision of these luminosity calibration campaigns originated from the absolute accuracy of the bunch current population estimation. The importance of these measurements for the LHC physics community triggered a large and fruitful collaboration between the CERN Beam Instrumentation Group and the LHC Experiments to push the LHC Beam Current Transformers performance to their limit. This paper will report on the available instruments for beam current measurements, the methodology used to improve them and the results obtained.

TUPC160

Recent Developments of Diagnostics at Diamond

photon, feedback, undulator, diagnostics

1407

G. Rehm, C. Bloomer, A.F.D. Morgan, C.A. Thomas
Diamond, Oxfordshire, United Kingdom

This contribution summarizes some recent development of diagnostics system to improve the operation of Diamond Light Source. Firstly, we are advancing the integration of photon beam diagnostics with the orbit feedback system. Measurements have shown the correlation between recorded electron and photon beam motion on the short timescales (ms-minutes) and the potential for improvement on long timescales (minutes-days). Secondly, with the addition of more elliptically polarized undulators at Diamond, measurement of their photon beam position require a solution that reliably operates with the changing photon beam profiles emitted by these devices. To this end, we have developed an X-ray beam position monitor that analyzes the backscatter from an aperture in the front end. Thirdly, as operation in low-alpha mode with few ps bunch lengths receives increasing interest from users, we have been evaluating various techniques for the measurement of these short bunch lengths that could serve as alternatives to streak camera measurements.

TUPO007

FLUTE, a Linac Based THz Source

radiation, linac, gun, synchrotron-radiation

1458

S. Naknaimueang, M. Schwarz
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
R. Abela, H.-H. Braun, R. Ganter, B. Patterson
PSI, Villigen, Switzerland
A.H. Albert, T. Baumbach, M. Hagelstein, N. Hiller, E. Huttel, V. Judin, B. Kehrer, R. Kubat, S. Marsching, W. Mexner, A.-S. Müller, M.J. Nasse, A. Plech, R. Rossmanith, M. Schuh
KIT, Karlsruhe, Germany
M.T. Schmelling
MPI-K, Heidelberg, Germany

We propose a versatile THz source named FLUTE (“Ferninfrarot Linac- Und Test-Experiment”) based on a 30 - 50 MeV S-band linac with bunch compressor, that shall not only provide high field THz pulses applications but shall also serve as a test facility to study important accelerator physics issues. This is also of importance in view of the planned utltra-broadband THz to mid infrared user facility TBONE. Special emphasis is put on studies of bunch compression and beam stability as a function of bunch charge (0.1-5 nC) and of different generation mechanisms of coherent radiation (CSR, CER, CTR). This paper describes the design and layout of the proposed FLUTE machine and presents results of beam dynamic calculations with the tracking programs ASTRA and CSRtrack.

TUPO009

HiSOR-II, Compact Light Source with an Innovative Lattice Design

emittance, lattice, focusing, radiation

1464

A. Miyamoto, S. Sasaki
HSRC, Higashi-Hiroshima, Japan

Funding: This work is partially supported by Cooperative and Supporting Program for Researches and Educations in University sponsored by KEK
We proposed a ring that a beam orbit is not closed with one turn and return to starting point after multiple turns around the ring. The idea of this new accumulation ring was inspired based on the torus knot theory. This ring has a long length of the total closed orbit in comparison with a conventional ring which has the orbit of one turn. Therefore this ring can have many straight sections and is advantageous to installation of insertion devices. We are designing a new ring based on the shape of a (3,11) torus knot for our future plan ‘HiSOR-II’. This ring has 11 long straight sections and can place undulators effectively by placing elements such as quadrupole magnets at the place near bending magnet, outside of the orbit crossing section. Furthermore, this ring has about 3 times longer circumference in comparison with the conventional ring, the diameter of the ring is as compact as 15 m, but its circumference is as long as 130 m. On the other hand, this ring must achieve low emittance to operate as the 3rd generation light source ring. Therefore we designed lattice of this ring in reference to MAX-III and achieved low emittance by using bending magnets with combined function.

TUPO010

An Innovative Lattice Design for a Compact Storage Ring

lattice, radiation, storage-ring, synchrotron-radiation

1467

S. Sasaki, A. Miyamoto
HSRC, Higashi-Hiroshima, Japan

Funding: *This work is partially supported by Cooperative and Supporting Program for Researches and Educations in Universities sponsored by KEK.
We propose a new concept of lattice design for a compact light source storage ring. In a ring with this new scheme, the electron beam may have extremely longer design orbit than that of a conventional ring. In this ring, a design orbit closes after completing multiple turns. The lattice for realizing this exotic beam orbit can be made by placing conventional accelerator components such as bending magnets, quadrupole magnets, RF cavity and so forth in an appropriate manner onto a projected torus knot in the horizontal orbit plane. Due to an extended closed orbit length, the ring with this type of lattice has larger maximum stored charge if operated in multiple-bunch mode, and has longer bunch-to-bunch interval if operated in a single-bunch mode. Also, essential for a storage ring as the synchrotron light source, a larger number of straight sections may accommodate with many insertion devices. In addition, this new scheme may provide advantages for designing a oscillator-type free electron laser and coherent radiation light source.

TUPS001

Upgrade of the ESRF Vacuum System

vacuum, storage-ring, controls, cathode

1515

M. Hahn, J.C. Biasci, H.P. Marques, A. Meunier
ESRF, Grenoble, France

The upgrade program of the ESRF concerns in terms of electron storage ring vacuum chambers mainly the insertion device (ID) sectors. Here the length available for the production of intense synchrotron light is being increased from five to six or even seven meters. The presence of canted ID sectors where two independent synchrotron light beams will be produced in the same straight section requires new quadrupole chambers compatible with the new geometry. A number of long insertion device vacuum chambers for the new ID sectors has already been produced by ESRF and coated with non-evaporable getter (NEG) material, a new generation of in vacuum undulators for the extended ID sections are under preparation. This paper outlines the status of the modification of the vacuum system and informs about consequences for the ESRF NEG coating activity and some recent improvements of the vacuum measurement and control system.

TUPS002

Photodesorption Measurements at ESRF D31

vacuum, radiation, synchrotron-radiation, electron

1518

H.P. Marques, G. Debut, M. Hahn
ESRF, Grenoble, France

Since 1998 exists at ESRF a dedicated beamline for photodesorption measurement from vacuum chambers - D31. The original goal of this installation was to study the wall pumping effect. When exposed to synchrotron radiation surfaces exhibit strong outgassing of the adsorbed gas layer despite UHV conditions. Long term outgassing leads to the depletion of the adsorbed layer and produces a very clean surface which turns the walls of the vacuum chamber into an active pumping surface. The desorption mechanisms can be described by the long standing models of Knotek-Feibelman (KF) and Menzel-Gomer-Redhead – (MGR) which are themselves encompassed under the name of Desorption Induced by Electronic Transitions (DIET). In these models the surface itself plays a fundamental role in the desorption mechanism. At D31 have been tested chambers of stainless steel, aluminum and copper, with or without coatings (e.g. NEG, copper), designed by ESRF and other institutes like ALBA, CERN, ELETTRA and Soleil. Here we review some of the results obtained and outline the future plans of D31.

TUPS009

SEY of Al Samples from the Dipole Chamber of PETRA III at DESY

electron, emittance, simulation, synchrotron-radiation

1533

D. R. Grosso, R. Cimino, M. Commisso
INFN/LNF, Frascati (Roma), Italy
R. Flammini
CNR-IMIP, Monterotondo Stazione RM, Italy
R. Larciprete
ISM-CNR, Rome, Italy
R. Wanzenberg
DESY, Hamburg, Germany

At the synchrotron radiation facility PETRA III, tune spectra have been measured with some characteristics which are typically observed at other storage rings in connection with electron cloud effects. For some bunch filling patterns, an increase of the vertical emittance has been observed. To estimate such effects with the available e-cloud simulation codes, the detailed knowledge of the SEY (Secondary Electron Yield) of the Al chamber, is required. To the purpose, representative PETRA III Al samples, were studied in detail at the INFN-LNF Surface Science Laboratory. XPS (X-ray photoelectron spectroscopy) and SEY measurements were performed as a function of electron and argon ion conditioning. The SEY of the as received samples shows a maximum value of δmax ≅ 2.8. Electron conditioning at 500 eV kinetic energy, reduces the SEY to values between δmax ≅ 1.8 to 1.4 (depending on the actual sample analyzed). The XPS characterization of the sample surface, after several cycles of argon ion sputtering, shows clearly that the SEY variation is closely related to the oxidation state of the Al sample, reaching a δmax value as low as 1.3 for our cleanest surface.

TUPS010

A Novel Approach in UHV Pumping of Accelerators: the NEXTorr® Pump

ion, vacuum, insertion, insertion-device

1536

P. Manini, A. Bonucci, L. Caruso, A. Conte, F. Siviero, L. Viale
SAES Getters S.p.A., Lainate, Italy

In spite of the large dimensions of accelerators, like synchrotrons or colliders, the space available for mounting UHV pumps is getting smaller, due to design constraints, service equipments, conductances, magnets, various instrumentations. This poses challenges to traditional UHV pump designs which are called to provide more pumping performances in smaller spaces. A radically new approach is here presented which can mitigate this issue. In this approach Non Evaporable Getter (NEG) and ion pumping technologies are properly combined and integrated in one single device, called NEXTorr®, having a unique design. In this pump, the getter cartridge acts as the main UHV pumping element, leaving to a small sputter ion pump the ancillary task of removing noble gases and methane, not pumped by the NEG. This design allows achieving large pumping speed in a very small package as well as delivering interesting pumping synergies. Main features of this new pump, including pumping tests, and example of applications will be reported, with a special focus to accelerators and high energy physics systems. Its impact in the design of vacuum systems for accelerators will also be discussed.

TUPS015

ALBA Storage Ring Vacuum System Commissioning

vacuum, storage-ring, photon, cavity

1551

E. Al-dmour, D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA booster and storage ring vacuum system installation has been done in 2009, followed by the installation of the RF cavities and the booster to storage transfer line in 2010. Early 2011, the first phase of insertion devices (ID) installation took place, with three narrow gap NEG coated vacuum chambers have been installed, for the use of two Apple-II undulators and one conventional wiggler. On 8th of March 2011, the storage ring commissioning started and it was marked with the achievement of the first turn in the storage ring on the 9th of March and on the 1st of April 2011, 100 mA of beam current has been accumulated. During this period the vacuum system conditioning took place with very good performance. The base pressure without beam was 4·10^-10 mbar and the average pressure with 100 mA was 7.7·10^-9 mbar. The results of the conditioning together with the latest developments are introduced.

TUPS016

Vacuum System Design for the MAX IV 3 GeV Ring

vacuum, storage-ring, lattice, radiation

1554

E. Al-dmour, D. Einfeld, J. Pasquaud, M. Quispe
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
J. Ahlbäck, M.J. Grabski, P.F. Tavares
MAX-lab, Lund, Sweden

We describe the conceptual design of the vacuum system of the 3 GeV electron storage ring in the MAX IV facility currently under construction in Lund, Sweden. The standard vacuum chambers are for the most part a cylindrical copper tube with 11 mm inner radius whereas stainless steel will be used at selected locations for beam position monitors, bellows and corrector vacuum chambers. In order to cope with the low vacuum conductance, distributed pumping will be provided through NEG coating of all chambers, including those in dipole magnets making MAX IV the first storage ring to be fully NEG coated. We present the mechanical and thermal design of these chambers and discuss the challenges involved in extracting insertion device radiation as well as coping with the heat load from both IDs and bending magnets in a machine with large bending radius, narrow chambers and tight mechanical tolerance requirements.

TUPS022

MedAustron Beam Vacuum System : From sources to Patient Treatment Rooms

vacuum, instrumentation, ion, dipole

1572

J.M. Jimenez, P. Cruikshank, L. Faisandel, W. Maan
CERN, Geneva, Switzerland
T. Hauser, G. Hulla, P. Landrot, J. Wallner
EBG MedAustron, Wr. Neustadt, Austria

The MedAustron beam vacuum system is a complex system integrating different technical solutions from the source to the patient treatment rooms. The specified vacuum performances combined with the challenging integration issues require technical compromise which will be presented in this poster. The status of the design of the vacuum system will be reviewed and the pending issues will be explained.

TUPS029

Development of a Feedthrough with Small Reflection for the TPS BPM

impedance, controls, vacuum

1593

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

The TPS BPM feedthrough is a coaxial cable with a structure of a kind for which power loss occurs readily at places at which exists an impedance mismatch. With an impedance equation for a simple coaxial cable combined with a multi-dielectric modification, a model feedthrough with small reflection has been designed. With careful setting of brazing conditions and precise control of the dimensions of devices, a TPS prototypical BPM feedthrough having a reflection coefficient less than 0.05 was manufactured. The eccentricity was constrained within 0.03 mm, and the deviation of measured capacitance of button electrodes was less than 7 %.

TUPS030

Manufacturing and Vacuum Testing of Aluminum Bending Chambers for TPS

vacuum, ion, photon, electron

1596

Y.C. Yang, C.K. Chan, C.-C. Chang, C.L. Chen, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, T.Y. Lee
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is an aluminum alloy vacuum system with 518.4 m circumference divided into 24 sections. A6061T6 aluminum alloy material is used for TPS bending chambers. Each aluminum bending chamber is component of 2 half plates, about 3.5～4.2 m in length and～0.6 m in width, were oil-free CNC machined, ozone cleaned, and TIG welding in clean room. The deformation < 0.1 mm and leakage rate < 2x10-9mbar. L/s for each welded bending chamber has inspected and achieved. A bending chamber is inspecting the thermal outgassing rate test and ultimate pressure. The manufacturing and vacuum test will be described in this paper.

TUPS031

The Installation of One 14 Meter Cell of TPS Vacuum System

vacuum, photon, laser, site

1599

H.P. Hsueh, C.K. Chan, C.H. Chang, C.-C. Chang, C.L. Chen, C.M. Cheng, Y.T. Cheng, G.-Y. Hsiung, S-N. Hsu, I.T. Huang, T.Y. Lee, H.Y. Yan, Y.C. Yang, C.S. huang
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. The vacuum system has been designed with off-site baking for arc section from sector gate valve to sector gate valve. There is no flange used in this arc section besides the two ends connected to sector gate valves. It is a tedious works for install such long vacuum system with aluminum chambers. In this poster, all the detailed installation procedures will be described. All the precaution inspection procedures for all vacuum components to prevent failed components to be installed will also be described. Every three weeks, one cell will be assembled and stored. Experience is being learned and could be used for the vacuum system of future new accelerator like FEL and others.

TUPS060

Designing, Integrating, and Coordinating Installation of MedAustron

survey, extraction, optics, alignment

1671

B. Nicquevert, C. Hauviller
CERN, Geneva, Switzerland
M. Benedikt, B. Nicquevert
EBG MedAustron, Wr. Neustadt, Austria

Funding: CERN, Geneva, Switzerland EBG MedAustron, Wiener Neustadt, Austria
"Give me a layout good enough and a building to place it, and I will install your accelerator". To paraphrase Archimedes, this is the role attributed to Integration team in MedAustron project. Starting with the optics layout and a building sketch, the integration work consists of a series of activities, interlinked in a complex manner. First the design and integration of the accelerator: list items, define geometrical envelopes with interfaces, put them in position in CAD, identify conflicts, define input for items design and infrastructure. Then the various equipment is procured: verify and validate design data, follow-up manufacturing, fiducialize equipment, build supports. Lastly global installation: check equipped building, define survey framework, install and pre-align equipment on supports, move assemblies to their final location, survey actual position and adjust to theoretical position. The whole chain of operations from a layout to a real beam in MedAustron is illustrated. The help from item-driven data management is emphasized. Grouping all activities within a single team favors interactions between stakeholders and consistency of activities.

TUPS062

The Ground Testing of TPS Ground System

site, impedance, storage-ring, background

1677

T.-S. Ueng, J.-C. Chang, C.K. Kuan, Y.-C. Lin
NSRRC, Hsinchu, Taiwan

A ground grid of 4 rings and 62 vertical electrodes has been constructed for the TPS storage ring. The ground resistance was designed to be smaller than 0.2 ohms in order to give a good protection of the TPS electrical facility and personnel. In order to match the building construction schedule the TPS ground grid has been installed about 1/6 segment of the construction project each period. The ground impedance of each segment was measured right after the installation. The ground grid with the diameter of 200 m of outside ring and its low impedance value, also the limit testing space, challenged the measurement of ground resistance. Several different methods of ground testing have been used and the measured results are compared each other. These methods include fall-of-potential method, slope method, intersecting curves method and the test-current-reversal method. The final TPS ground impedance will be measured and compared with the calculation from combining the previous several segment measurements. The actual TPS ground resistance should have a smaller value than expected.

TUPS063

Power Saving Schemes in the NSRRC

controls, synchrotron-radiation, status, radiation

1680

J.-C. Chang, Y.F. Chiu, J.-M. Lee, Y.-C. Lin, C.Y. Liu, Z.-D. Tsai, T.-S. Ueng
NSRRC, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC), Taiwan will complete the construction of the civil and utility system engineering of the Taiwan Photon Source (TPS) in the end of 2012. The power consumption of the TPS is estimated about 2.3 times of that of the existed Taiwan Light Source (TLS). To cope with increasing power requirement in the near future, we have been conducting several power saving schemes, which include power requirement control, optimization of chillers operation, application of heat pump, air conditioning system improvement, power factor improvement and the lighting system improvement.

TUPS067

Photon-stimulated Desorption Experiment for a TPS Crotch Absorber

photon, simulation, vacuum, radiation

1692

Y.T. Cheng, G.-Y. Hsiung, C.K. Kuan, A. Sheng, H.Y. Yan
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC) is constructing a large third-generation synchrotron accelerator in Taiwan, the so-called Taiwan Photon Source (TPS). This 3-GeV, 500-mA machine will generate high-density bending-magnet radiation, of which 90 % of the power is absorbed by the crotch absorber in the storage ring. To understand better the beam-cleaning and photon-desorption phenomena of a copper crotch absorber, we have performed a PSD (photon-stimulated desorption) test in Taiwan Light Source (TLS) at Beam line 19 (BL19). Some mathematical modelling, experimental designs and results are also presented here.

TUPZ010

Longitudinal Emittance Blow-up in the LHC

emittance, damping, feedback, acceleration

1819

P. Baudrenghien, A.C. Butterworth, M. Jaussi, T. Mastoridis, G. Papotti, E.N. Shaposhnikova, J. Tückmantel
CERN, Geneva, Switzerland

The LHC relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blow-up provides the required emittance growth. The method was implemented through the summer of 2010. We inject band-limited RF phase-noise in the main accelerating cavities during the whole ramp of about 11 minutes. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are set by pre-defined constants, making the diffusion stop at the edges of the demanded distribution. The noise amplitude is controlled by feedback using the measurement of the average bunch length. This algorithm reproducibly achieves the programmed bunch length of about 1.2 ns (4 σ) at flat top with low bunch-to-bunch scatter and provides a stable beam for physics coast.

WEOAA01

The ThomX Project

laser, injection, feedback, cavity

1903

A. Variola
LAL, Orsay, France

Funding: Work supported by the EQUIPEX program, the Ile de France region, CNRS-IN2P3 and Université Paris Sud XI
ThomX is a Compton source project in the range of the hard X rays (40 / 90 keV). The machine is composed of an injector Linac and a storage ring where an electron bunch collides with a laser pulse accumulated in a Fabry-Perot resonator. The final goal is to provide an X-rays average flux of 1011/10¹³ ph/s. The emitted flux will be characterized by a dedicated X-ray line. Different users are partners in the ThomX project, especially in the area of medical science and cultural heritage. Their main goal will be the transfer of all the experimental techniques developed on big synchrotron rings to these more compact and flexible machines. The project ThomX has recently been funded and will be located on the Orsay University campus. In this article the project and its associated scientific interest are presented.

Slides WEOAA01 [5.947 MB]

WEPC015

Tuning Methods for HIMAC Multiple-energy Operation

betatron, acceleration, resonance, beam-losses

2037

K. Katagiri, T. Furukawa, Y. Iwata, K. Noda, S. Sato, T. Shirai
NIRS, Chiba-shi, Japan
K. Mizushima
Chiba University, Graduate School of Science and Technology, Chiba, Japan
E. Takeshita
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan

Beam stability of multiple-energy operation at HIMAC synchrotron was improved for the fast raster-scanning irradiation. In order to improve the transverse stability, the working point of the betatron tune was investigated during one operation cycle. The signals were collected from the beam position monitor using a fast data-acquisition unit. The temporal evolution of the horizontal and vertical betatron tune was evaluated by using the short time Fourier transform. Analyzed results showed that variation of the betatron tune in the acceleration interval passed through the 3rd-order coupling resonance line, and it caused undesirable emittance growth. In order to keep the working point within the desirable operating region, the current pattern of the power supplies for the quadrupole magnets was corrected by using the variation of the betatron tune. The experimental results showed that the working point could be successfully stabilized, and the undesirable beam losses could be reduced during the acceleration interval.

WEPC016

Amplitude Dependent Orbit Shift and its Effect on Beam Injection

injection, septum, betatron, sextupole

2040

Y. Shoji
LASTI, Hyogo, Japan
T. Nakamura, J. Schimizu, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan

The betatron oscillation amplitude dependent orbit shift was measured at the electron storage ring, NewSUBARU. The result roughly agreed with the theoretical calculation. The effect of this shift on the beam injection is discussed using parameters of NewSUBARU and SPring-8. Generally there exists a better side for the injection, the inner side or the outer side of the ring, which depends on the sign of the orbit shift at the injection septum. In case of the NewSUBARU, the beam is injected from the outer side and the shift is positive. The effective thickness of the septum is reduced by the large oscillation amplitude of the injected beam. On the other hand at SPring-8, the beam is injected from the inner side of the ring while the orbit shift is negative. This means that the two rings are using better side for the injection.

WEPC049

Operation and Storage Ring Calibration with the Transverse Bunch-by-Bunch Feedback System at the Australian Synchrotron

feedback, sextupole, damping, storage-ring

2121

M.J. Boland, Y.E. Tan
ASCo, Clayton, Victoria, Australia
D.J. Peake, R.P. Rassool, K.P. Wootton
The University of Melbourne, Melbourne, Australia

The first operational experience with the transverse bunch-by-bunch feedback system for the storage ring shows a doubling of the lifetime and the ability to damp instabilities caused by IVU gap changes. The system was also used to calibrate the ring by doing simultaneous measurements on several single bunches with different bunch currents. Using the bunch-by-bunch system's capability to excite the beam to large amplitudes, the non-linear beam dynamics were also measured and compared with the model.

WEPC052

Spinor Based Calculation of Depolarizing Effects in Circular Lepton Accelerators

resonance, polarization, lepton, photon

2130

O. Boldt, A. Dieckmann, F. Frommberger, W. Hillert
ELSA, Bonn, Germany

Funding: BMBF
The emission of synchrotron radiation strongly influences the beam dynamics in case of ultra relativistic leptons. When storing or accelerating leptons in circular accelerators, the acting magnetic field shows an oscillating behavior in the rest frame of the leptons. Its properties can be determined by a spectral analysis. The stochastic emission of synchrotron light leads to a line broadening within the magnetic field spectrum. This spectrum can be used to simulate depolarizing effects in circular accelerators. Our contribution will present a tracking based calculation of the mentioned spectrum and a spinor-based determination of the resulting population of the spin-up state. These calculations base on the lattice of the electron stretcher accelerator (ELSA, Bonn) and are confirmed by measurements of the polarization.

WEPC060

Magnetic Field Description in Curved Accelerator Magnets using Local Toroidal Multipoles

multipole, dipole, antiproton, quadrupole

2154

P. Schnizer, E.S. Fischer
GSI, Darmstadt, Germany
B. Schnizer
TUG/ITP, Graz, Austria

Any introduction on beam dynamics describes the field homogeneity of the accelerator magnets using local derivatives. These are then typically described as plane circular multipoles or 2D harmonics; solutions to the potential equation. The high current operation, foreseen for SIS100 accelerator of FAIR, requires an in detail understanding of the different beam effects, driven by the resonance of the magnets. Therefore different multipole sets were developed and are now finalised in the Local Elliptic Toroidal Multipoles. These are a first order approximation while the plane circular ones are a zero order one in the inverse aspect ratio.

WEPC091

Studies with a Particle Tracking Code for the SIS100 Resonant Extraction System

extraction, quadrupole, controls, feedback

2220

M.M. Kirk, G. Franchetti, H. Klingbeil, P. Moritz, N. Pyka, H. Ramakers, P.J. Spiller, H. Welker
GSI, Darmstadt, Germany

Several issues concerning the envisaged SIS100 resonant extraction at GSI can be resolved with a simulation-lead approach for which a particle tracking code was developed. Applications to date have included: design and testing of data supply algorithms for the accelerator control system; requirements analysis for the power converter ripple in the quadrupoles forming the doublet focusing; and verification of the RF Knock-Out exciter's performance.

WEPC095

Simulations of the Microbunching Instability at ANKA using a Vlasov-Fokker-Planck Solver

radiation, electron, simulation, impedance

2232

M. Klein, A.-S. Müller
KIT, Karlsruhe, Germany
K.G. Sonnad
CLASSE, Ithaca, New York, USA

In order to produce coherent synchrotron radiation the ANKA light source is operated frequently in short bunch mode. It is known that during this procedure strong self fields caused by high electron densities can enforce initial density fluctuations and thus lead to microbunching. The build-up of those substructures is accompanied by bursting radiation which provides higher radiation power for the users. Damping and diffusion due to incoherent radiation smoothens the bunch shape again and hence lead to periodic or chaotic bursting cycles. The evolution of the electron bunch density under the influence of self fields can be described by the Vlasov-Fokker-Plank (VFP) equation. We present results from a numerical solution of the VFP-equation for parameters used in standard short bunch mode at ANKA.

WEPC109

Emittance Optimization Using Particle Swarm Algorithm*

emittance, lattice, quadrupole, storage-ring

2271

Z. Bai, W. Li, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

In this paper we use a swarm intelligence algorithm, particle swarm optimization (PSO), to optimize the emittance directly. Some constraint conditions such as beta functions, fractional tunes and dispersion function, are considered in the emittance optimization. We optimize the strengths and positions of quadrupoles to search low emittances. Here an FBA lattice studied in the design of the Hefei Advanced Light Source storage ring is used as the testing lattice. The PSO is shown to be beneficial in the optimization.

WEPO001

Design and Optimization of the MedAustron Synchrotron Main Dipoles

simulation, dipole, ion, quadrupole

2406

M. Stockner, B. Langenbeck, C. Siedler
EBG MedAustron, Wr. Neustadt, Austria
Th. Zickler
CERN, Geneva, Switzerland

MedAustron, a future centre for ion-therapy and research in Austria will comprise an accelerator facility based on a synchrotron for the delivery of protons and light ions for cancer treatment and for clinical and non-clinical research. The main dipole for the synchrotron went through an extensive design process to meet the stringent requirements. The local and integrated field quality was optimized. The residual field levels in the magnet gap were calculated and the dynamic behaviour of the dipole magnet was studied, both in 2D and 3D, using OPERA. The pole profile has been optimized to reduce sextupolar components in the integrated field by adjusting the shims on the pole edge. A Rogowski-profile at the pole ends and the use of stainless-steel tension straps will enhance the dynamic behaviour and guarantee a small time constants. Appropriate pole-end shimming will be used to compensate for residual multi-pole components and to fine-tune the magnetic length. The results of this comprehensive design study are summarized in this paper.

WEPO019

Magnetic Model of the CERN Proton Synchrotron Main Magnetic Unit

focusing, multipole, proton, dipole

2439

M. Juchno
EPFL, Lausanne, Switzerland

The CERN Proton Synchrotron (PS) will remain one of the key elements of the Large Hadron Collider (LHC) injector system for the next 20-25 years. Tuning the machine characteristics to the requirements for the LHC and its upgrades will require the establishment of an accurate magnetic model of the PS combined-function magnets, which is the subject of this paper. In the scope of this research, a detailed 2D quasi-static analysis of the PS magnets was performed, which allowed to investigate the magnetic field evolution and the contribution of separate magnet circuits at different field levels. An experimental validation of this new model was carried out through ad-hoc field measurements machine studies iterated with an optical model of the PS machine to recreate the measured optical parameters of the beam.

WEPO020

Magnetic Field Inspection and Analysis of Multipole Lattice Magnets using a Rotating-coil Measurement System*

multipole, quadrupole, storage-ring, sextupole

2442

J.C. Jan, C.-H. Chang, Y.L. Chu, T.Y. Chung, C.-S. Hwang, C.Y. Kuo, F.-Y. Lin
NSRRC, Hsinchu, Taiwan

A precise rotating-coil measurement system (RCS) was constructed to characterize the field quality and field center of multipole lattice magnets of Taiwan Photon Source (TPS). The mechanical center of magnets is determined by the two references of the magnet-feet and the RCS system is used to characterize the field center. The location of the magnetic field center is quantitatively accurate to better than 20 micro-meter in the horizontal direction; the granite support height of the RCS system is accurate within 5 micro-meter after artificial polishing. The measurement reproducibility of the field center was better than 10 micro-meter when the magnets were reinstalled. The relative accuracy of the multipoles components is better than 2×10^-5. This paper reports the details of the bench construction and the unit composition. The field center with RCS measurement will be compared and discussed with the 3D-coordinate-measuring machine. The multipole errors obtained from RCS will be compared with a Hall-probe measurement system.

WEPS007

CNAO Synchrotron Commissioning

extraction, pick-up, proton, betatron

2496

C. Priano, G. Balbinot, G. Bazzano, J. Bosser, E. Bressi, M. Caldara, H. Caracciolo, L. Falbo, A. Parravicini, M. Pullia, C. Viviani
CNAO Foundation, Milan, Italy
C. Biscari, A. Ghigo
INFN/LNF, Frascati (Roma), Italy

The CNAO (National Center for Oncological Hadrontherapy), located in Pavia, is the first Italian center for deep hadrontherapy with proton and carbon ion beams. The CNAO synchrotron initial commissioning has been carried out using proton beams in the full range of energies: 60 to 250 MeV/u. The first foreseen treatments will need energies between 120 and 170 MeV/u. The nominal proton currents have been reached. The energy scaling of the synchrotron systems and parameters leads to an extracted energy that matches the measured particle range better than 0.1 mm, fitting the treatment requirements, with repeatable beam size and beam current in the treatment room at all investigated energies. A summary of the main results of the synchrotron commissioning is presented.

WEPS010

Acceleration of High Intensity Proton Beams in the J-PARC Synchrotrons

cavity, impedance, injection, acceleration

2502

M. Yoshii
KEK/JAEA, Ibaraki-Ken, Japan
E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, K. Takata, M. Toda
KEK, Ibaraki, Japan
T. Minamikawa
University of Fukui, Fukui, Japan
M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

The J-PARC accelerator complex consists of the linac, the 3GeV rapid cycling synchrotron (RCS) and the 50GeV main synchrotron (MR). These synchrotrons are the first MW-class proton accelerators which employ the high electric field gradient magnetic alloy (MA) loaded RF cavities. The beam commissioning was started in October 2007 for RCS and in May 2008 for MR. High intensity beam operation studies and user runs have been performed, while carefully controlling and minimizing the beam loss. The cycle to cycle beam operation is reproducible and quite stable, because of the stable linac beam energy and the reproducible bending field in both synchrotrons. The MA loaded RF systems and the full digital LLRF also guarantee the stable longitudinal particle motion and precise beam transfer synchronization from RCS to the MLF user facility as well as to the MR. A high intensity proton beam of 2.5·10¹³ ppp is accelerated in RCS. And in MR, a beam intensity up to ~100 Tera ppp was obtained.　We summarize the RF systems and the longitudinal parameters in both rings.

WEPS017

Plans for the Upgrade of the LHC Injectors

linac, injection, electron, booster

2517

R. Garoby, S.S. Gilardoni, B. Goddard, K. Hanke, M. Meddahi, M. Vretenar
CERN, Geneva, Switzerland

The LHC Injectors Upgrade (LIU) project has been launched at the end of 2010 to prepare the CERN accelerator complex for reliably providing beam with the challenging characteristics required by the high luminosity LHC until at least 2030. Based on the work already started on Linac4, PS Booster, PS and SPS, the LIU project coordinates studies and implementation, and interfaces with the High Luminosity LHC (HL-LHC) project which looks after the upgrade of the LHC itself, expected by the end of the present decade. The anticipated beam characteristics are described, as well as the status of the studies and the solutions envisaged for improving the injector performances.

WEPS023

A Possible RF System for CERN RCS

cavity, injection, extraction, booster

2532

M.M. Paoluzzi
CERN, Geneva, Switzerland

As part of the LHC Injectors Upgrade (LIU) program at CERN the possibility of replacing the PSB with a new Rapid Cycling Synchrotron (RCS) is considered. The requirements in terms of accelerating voltage (60 kV), frequency range (1.7 MHz – 9.5 MHz) and available space (4 m) make the RF system development quite challenging. The improved loss characteristics of the new FINEMET® type (FT3L) combined with a filter-like topology, allows achieving all the requirements. This paper describes the design of such a RF system.

WEPS025

First Beam Experiments at ISIS with a Low Output-impedance Second Harmonic Cavity

cavity, impedance, simulation, proton

2538

Y. Irie, S. Fukumoto, K. Muto, H. Nakanishi, T. Oki, A. Takagi
KEK, Ibaraki, Japan
D. Bayley, I.S.K. Gardner, R.J. Mathieson, A. Seville, J.W.G. Thomason
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.C. Dooling, D. Horan, R. Kustom
ANL, Argonne, USA
M.E. Middendorf
ORNL RAD, Oak Ridge, Tennessee, USA

A Low Output-Impedance (LOI) rf drive, which may be suitable for future high intensity accelerator applications, has been developed jointly by ANL, ISIS and KEK for an ISIS synchrotron second harmonic cavity. The cavity is ferrite-loaded, and is driven by a high-power triode (240 kW plate dissipation) with a plate-to-grid feedback circuit. The impedance is designed to be 20~30 ohms over a 2-6 MHz frequency range. Beam induced voltage has been measured with the ISIS beam, and compared with that calculated from the designed output impedance.

WEPS028

Lattice Design of a Rapid Cycling Medical Synchrotron for Carbon/Proton Therapy

proton, extraction, ion, injection

2541

D. Trbojevic, J.G. Alessi, M. Blaskiewicz, C. Cullen, H. Hahn, D.I. Lowenstein, I. Marneris, W. Meng, J.-L. Mi, C. Pai, D. Raparia, A. Rusek, J. Sandberg, N. Tsoupas, J.E. Tuozzolo, A. Zaltsman, W. Zhang
BNL, Upton, Long Island, New York, USA
N.M. Cook
Stony Brook University, Stony Brook, USA
J.P. Lidestri
HHMI, New York, USA
M. Okamura
RBRC, Upton, Long Island, New York, USA
S. Peggs
ESS, Lund, Sweden

Funding: Work supported by Cooperative Research and Development Agreement (CRADA), No. BNL-C-10^-03 between the Brookhaven National Laboratory and Best Medical International, Inc.
We present a design of the ion Rapid Cycling Medical Synchrotron (iRCMS) for carbon/proton cancer therapy facility. The facility design, produced at Brookhaven National Accelerator (BNL) at the Collider Accelerator Division (CAD) for the BEST Medical International, Inc., will be able to treat the cancer patients with carbon, lighter ions and protons. The low energy part accelerates ions and protons to the kinetic energy of 8 MeV. It consists of two ion sources (one of fully stripped carbon ions and one for protons), a Radio-Frequency Quadrupole (RFQ) and linac. The 8 GeV beam is injected into a fast cycling synchrotron (iRCMS). The lattice design is a racetrack, with zero dispersion two parallel straight sections. There are 24 combined function magnets in the two arcs with a radius of ~5.6 meters with maximum magnetic field of less than 1.3 T. The acceleration is performed in 30 Hz up to the required energy for the cancer tumor treatment assuming the spot scanning technique. The maximum energy for carbon ions is 400 MeV. Ions are extracted in a single turn and fed to different beam lines for patient treatment.

WEPS086

Three-lens Lattices for Extending the Energy Range of Non-scaling FFAGs

lattice, closed-orbit, optics, quadrupole

2709

S.J. Brooks
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

In this paper it is found that a three-quadrupole focussing system can be morphed continuously through FFD, FDF and DFF variants and back again while maintaining stable optics and even keeping the two transverse tunes constant. This relates to non-scaling FFAGs, where the magnet gradients define both the focussing and the variation of the field with momentum as the closed orbit sweeps across it. A two-lens focussing system cannot change the sign of either gradient without becoming unstable, meaning non-scaling FFAGs built with such a lattice eventually encounter too large a magnetic field at low energies. However, a theoretical system of magnet field variations using three lenses, with a potentially unlimited energy range and fixed tunes is presented here.

WEPS098

Combined Momentum Collimation Method in High-intensity Rapid Cycling Proton Synchrotrons

collimation, simulation, scattering, injection

2736

J.F. Chen, J. Tang, Y. Zou
IHEP Beijing, Beijing, People's Republic of China

A new momentum collimation method – so-called combined momentum collimation method in high-intensity synchrotrons is proposed and studied here, which makes use two-stage collimation in both the longitudinal and the transverse phase planes. The primary collimator is placed at a high-dispersion location of an arc, and the longitudinal and transverse secondary collimators are in the same arc and in the down-stream dispersion-free long straight section, respectively. The particles with positive momentum deviations will be scattered and degraded by a carbon scraper and then cleaned mainly by the transverse collimators, whereas the particles with negative momentum deviations will be scattered by a tantalum scraper and mainly cleaned by the longitudinal secondary collimators in the successive turns. Numerical simulation results using TURTLE and ORBIT codes show that this method gives high collimation efficiency for medium-energy synchrotrons. The studies have also shown two interesting effects: one is that the momentum collimation is strongly dependent on the transverse beam correlation; the other is that the material for the primary collimator plays an important role in the method.
This work was supported by the National Natural Science Foundation of China (10975150, 10775153), the CAS Knowledge Innovation Program-“CSNS R&D Studies”.

WEPS104

Transverse Beam Dynamics for the ISIS Synchrotron with Higher Energy Injection

resonance, space-charge, simulation, injection

2754

B.G. Pine, C.M. Warsop
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on an 800 MeV rapid cycling synchrotron, which provides 3·10¹³ protons per pulse at 50 Hz, corresponding to a beam power of 200 kW. Studies are underway to increase the energy of the ISIS linac from 70 to 180 MeV. This would reduce space charge in the synchrotron, and enable a larger current to be accumulated, possibly up to 0.5 MW. As part of the study, transverse beam dynamics have been re-examined on ISIS, building up models from incoherent space charge tune shift, through smooth focusing models with space charge to 2D alternating gradient lattice simulations. These later simulations, using the in-house space charge code Set, include harmonic perturbations to the focusing lattice, closed orbits and images. A clearer picture of the dynamics is emerging, where there may be important constraints on the highest intensities, including half integer resonance, image induced structure resonances and transverse instabilities.

WEPS106

Status of Injection Upgrade Studies for the ISIS Synchrotron

injection, space-charge, simulation, linac

2760

C.M. Warsop, D.J. Adams, D.J.S. Findlay, I.S.K. Gardner, S.J.S. Jago, B. Jones, R.J. Mathieson, S.J. Payne, B.G. Pine, A. Seville, H. V. Smith, J.W.G. Thomason, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
C.R. Prior, G.H. Rees
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on a high intensity proton accelerator, consisting of a 70 MeV linac and an 800 MeV rapid cycling synchrotron, which provides a beam power of 0.2 MW. Obsolescence issues are motivating plans to replace the ageing 70 MeV linac, and this paper summarises the status of studies looking at how a new, higher energy linac (~180 MeV) could be used to increase beam power in the existing synchrotron. Reduced space charge and optimized injection might allow beam powers in the 0.5 MW regime, thus providing a very cost effective upgrade. The key areas of study are: design of a practical injection straight and magnets; injection painting and dynamics; foil specifications; acceleration dynamics; transverse space charge; instabilities; RF beam loading; beam loss and activation; diagnostics and possible damping systems. Results from work on most of these topics suggest that beam powers of ~0.5 MW may well be possible, but a number of topics, particularly transverse stability, still look challenging. Conclusions so far are presented, as is progress on R&D on the main intensity limiting issues.

WEPS107

Phase Space Coating in Synchrotrons: Some Applications*

antiproton, brightness, emittance, simulation

2763

C.M. Bhat
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
Phase-space painting to produce very high intensity beam in synchrotrons is one of the widely studied topics in accelerator physics. A remarkable example of this is multi-turn beam injection by transverse phase-space painting in spallation sources. Use of barrier buckets at synchrotron storage rings has paved way for further advancements in this field. The Fermilab Recycler, antiproton storage ring, has been augmented with multipurpose broad-band barrier rf systems. Recently we have developed a longitudinal phase-space coating technique over already e-cooled high intensity low longitudinal antiproton beam and demonstrated with beam experiments. This method is extended to map the incoherent synchrotron tune of beam particles in a barrier bucket. Here I review various phase-space painting techniques being used in particle accelerators including some new schemes developed using barrier rf systems and possible new applications.

THOAA01

Beam Diagnostics Commissioning at CNAO

proton, extraction, diagnostics, quadrupole

2848

H. Caracciolo, G. Balbinot, G. Bazzano, J. Bosser, M. Caldara, A. Parravicini, M. Pullia, C. Viviani
CNAO Foundation, Milan, Italy

The National Centre for Oncological Hadrontherapy (CNAO) is the first Italian facility for the treatment of deep located tumors with proton and carbon ion beams using active scanning. The commissioning with proton beams is concluded and CNAO is going to start treating patients with protons; in the meantime the machine commissioning with carbon ions beam is going on. Beam diagnostics instrumentation is fundamental to measure beam properties along the lines from sources to patients. Some significant measurements performed during proton beam commissioning and the performances achieved with the CNAO beam diagnostic systems are presented in this paper.

Slides THOAA01 [4.827 MB]

THOAA02

Implementation of an Intensity Feedback-loop for an Ion-therapy Synchrotron

feedback, controls, extraction, ion

2851

C. Schömers, E. Feldmeier, Th. Haberer, J. Naumann, R.E. Panse, A. Peters
HIT, Heidelberg, Germany

The Heidelberg Ion Therapy-Centre (HIT) started treatment of tumour patients in 2009. Its main acceleration stage is a synchrotron, where particles are extracted slowly, in the time frame of some seconds, to support the raster-scanning method. The slow extraction is driven by the transverse "RF-nockout-exciter". So far, this device has a variable but predefined amplitude curve. As the phase-space distribution of particles is not homogeneous and varies slightly from pulse to pulse, intensity-fluctuations of the extracted beam appear. Moreover, changing accelerator-settings requires a time-consuming re-adjustment of the exciter to achieve adequate beam-properties again. To keep the intensity on a predefined level, a feedback loop will be implemented. The actual-value of the intensity is provided by an ionization chamber in front of the patient. The feedback loop controls the amplitude of the Exciter, to adapt the number of extracted particles. Beside a rectangular spill with constant intensity, a dynamic intensity-adaptation during one spill with respect to the particular treatment-plan will be investigated. First tests for flat spill and variable intensity showed promising results.

Slides THOAA02 [2.284 MB]

THOBB02

High Gradient Magnetic Alloy Cavities for J-PARC Upgrade

cavity, impedance, proton, status

2885

C. Ohmori, O. Araoka, E. Ezura, K. Hara, K. Hasegawa, A. Koda, Y. Makida, Y. Miyake, R. Muto, K. Nishiyama, T. Ogitsu, H. Ohhata, K. Shimomura, A. Takagi, K. Takata, K.H. Tanaka, M. Toda, M. Yoshii
KEK, Tokai, Ibaraki, Japan
T. Minamikawa
University of Fukui, Fukui, Japan
M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

Magnetic alloy cavities are used for both MR and RCS synchrotrons. Both cavity systems operate successfully and they generate a higher voltage than could be achieved by an ordinary ferrite cavity system. For the future upgrade of J-PARC, a higher RF voltage is needed. A new RF cavity system using the material, FT3L, is designed to achieve this higher field gradient. A large production system using an old cyclotron magnet was constructed to anneal 85-cm size FT3L cores in the J-PARC Hadron Experiment Hall. The muSR (Muon Spin Rotation/Relaxation/Resonance) Experiments were also carried out to study the magnetic alloy. The status of development on the J-PARC site and a new RF system design will be reported.

Slides THOBB02 [2.729 MB]

THPC005

First Measurements with a Kicked Off Axis Bunch for Pseudo Single Bunch Mode Studies at SOLEIL

kicker, single-bunch, closed-orbit, storage-ring

2912

L.S. Nadolski, J.-P. Lavieville, P. Lebasque, A. Nadji, J.P. Ricaud, M.G. Silly, F. Sirotti
SOLEIL, Gif-sur-Yvette, France

At SOLEIL, the time resolved French community benefits of single bunch operation few weeks a year. Meanwhile most of the multi-bunch filling pattern based experiments are not possible due to the low photon flux. Following the pioneer work performed at ALS*, a new operation mode is under study at SOLEIL where the storage ring is filled up with a special hybrid mode: ¾ multibunch filling pattern and a single bunch with higher current in the last ¼. The so-called pseudo single bunch-filling pattern is obtained if the closed orbit of the single bunch is not the same as the one of the other bunches. Preliminary results are presented where the pinger magnet time impulse response has been significantly reduced while its frequency was increased from 3 Hz up to 1 kHz. This magnet is used as an additional corrector magnet to change only the single bunch closed orbit. First experimental results observed at one interested beamline are also discussed.
* S. Kwiatkowski et al., “'CAMSHAFT' Bunch Kicker Design for the ALS Storage Ring", Proc. of EPAC2006, THPLS114, p. 3547, (2006).

THPC006

Experiments to Measure Electron Beam Energy using Spin Depolarization Method on SOLEIL Storage Ring

polarization, storage-ring, electron, beam-losses

2915

J.F. Zhang, L. Cassinari, M. Labat, A. Nadji, L.S. Nadolski, D. Pédeau
SOLEIL, Gif-sur-Yvette, France

The electron beam energy on SOLEIL storage ring was successfully measured using spin depolarization method after several attempts over the past few years. The experimental results demonstrate that the effective polarization was 91.3%±3% and polarization time was 17±2.3 minutes as expected from the simulation using SLIM code. The beam was depolarized using an AC shaker and the depolarization was monitored using DCCT and beam loss monitors. The beam energy was measured with accuracy up to a few 10^-5.

THPC008

Touschek Lifetime and Momentum Acceptance Measurements for ESRF

vacuum, emittance, scattering, electron

2921

B. Nash, F. Ewald, L. Farvacque, J. Jacob, E. Plouviez, J.-L. Revol, K.B. Scheidt
ESRF, Grenoble, France

The Touschek lifetime of a synchrotron results from electrons scattering off one another within the bunch and subsequently being lost. We have measured the Touschek lifetime for the major operating modes of the ESRF as a function of RF voltages. This includes multibunch and few bunch filling patterns with correspondingly different chromaticity values. Through calibration of the RF voltage and measurement of the other beam parameters such as bunch length and vertical emittance, we may understand the momentum acceptance in the regime where this is determined by non-linear dynamics effects.

THPC010

Recent Developments at the Metrology Light Source

quadrupole, injection, feedback, vacuum

2927

J. Feikes, T. Birke, O. Dressler, D.B. Engel, F. Falkenstern, B. Franksen, A. Heugel, H.-G. Hoberg, F. Hoffmann, J. Kuszynski, J. Rahn, M. Ries, P.O. Schmid, T. Schneegans, D. Schüler, G. Wüstefeld
HZB, Berlin, Germany
K.B. Bürkmann-Gehrlein, V. Dürr, H.G. Glass, G. Schindhelm
BESSY GmbH, Berlin, Germany
R. Klein
PTB, Berlin, Germany

The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, owns the electron storage ring Metrology Light Source (MLS) which was built and is operated by the Helmholtz-Zentrum Berlin [1, 2]. The MLS has been in regular user operation since April 2008 and supports synchrotron-radiation-based metrology and technological developments in the IR, UV, VUV and EUV spectral range. Here we report on recent progress to develop the MLS into a reliable, flexible and stable user facility.

THPC013

THz Studies at a Dedicated Beamline at the MLS

radiation, electron, synchrotron-radiation, storage-ring

2933

R. Müller, A. Hoehl, A. Serdyukov, G. Ulm
PTB, Berlin, Germany
J. Feikes, M. Ries, G. Wüstefeld
HZB, Berlin, Germany

The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute is operating the low-energy electron storage ring Metrology Light Source (MLS) in Berlin-Adlershof in close cooperation with the Helmholtz-Zentrum Berlin. The MLS is designed and prepared for a special machine optics mode (low-alpha operation mode) based on a sextupole and octupole correction scheme, for the production of coherent synchrotron radiation in the THz region*. At the MLS two bending magnet beamlines dedicated to the use of IR and THz synchrotron radiation are in operation: the MLS-IR beamline optimized for the NIR to FIR, and a dedicated THz beamline optimized for the FIR/THz spectral range**. Low-alpha operation optic modes for different ring energies, 250 MeV, 350 MeV, 450 MeV and 630 MeV are available. We compare the THz spectra taken in the different low-alpha modes and discuss the results.
* J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).
** R. Müller et al., J. Infrared Milli Terahz Waves, in press (2011), DOI: 10.10⁰⁷/s10762-011-9785-6.

THPC017

Temporal and Spatial Alignment of Electron Bunches and Ultrashort Laser Pulses for the CHG Experiment at DELTA

laser, electron, undulator, controls

2945

M. Zeinalzadeh, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk
DELTA, Dortmund, Germany

Funding: Supported by DFG, BMBF, and the Federal State NRW
The generation of ultrashort VUV pulses by CHG (Coherent Harmonic Generation) requires achieving and maintaining the longitudinal and transversal overlap of femtosecond laser pulses and electron bunches. We present the techniques and the experimental setup applied at the DELTA storage ring. For the longitudinal analysis, both a streak camera and a fast photo diode are used. Transversely, two CCD cameras acquire images of laser and synchrotron light at different positions inside of the undulator. A feedback system utilizes the intensity of a THz signal generated several meters downstream of the undulator to optimize and maintain the overlap.

THPC024

Lattice Candidates for the ILSF Storage Ring

storage-ring, lattice, emittance, dipole

2957

H. Ghasem
IPM, Tehran, Iran
D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
F. Saeidi
ILSF, Tehran, Iran

Iranian Light Source Facility (ILSF) is a new third generation synchrotron light source which is currently in design and will build in Iran. It will provide a high photon flux density to cover requirements of experimental science in several fields. Regarding to the proposed budget and in order to produce high quality X-ray pulses with several photon beamlines as a request of users, it is decided to design a very low emittance (ε<5nm-rad) storage ring with a typical beam intensity of 400 mA and circumference in the range of 280 m to 320 m. A number of design options with different lattice structure types, circumferences, etc., are explored and we present two designed lattice candidates of the ILSF storage ring. The associated Accelerator Physics issues are discussed.

THPC025

Booster Design for ILSF

booster, storage-ring, dipole, electron

2960

H. Ghasem
IPM, Tehran, Iran
E. Ahmadi
ILSF, Tehran, Iran
D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

A full energy 3 GeV booster synchrotron has been designed to boost electron beam to the target energy of 3 GeV for the proposed third generation synchrotron light source (ILSF) that will be constructed in Iran. The primary goal of the ILSF booster is to design a synchrotron which can deliver a small emittance (ε<30 nm-rad), while at the same time has a low cost in construction. In order to design lattice for the booster, two configurations for booster have been considered. In the first configuration, booster is designed based on locating in a separate tunnel as 3 GeV storage ring inside the ring and in the second configuration, the booster is optimized for placing inner to the ring with one shared wall as service area of ILSF storage ring. Several types of lattice with various circumferences have been explored for the booster synchrotron in each configuration and this paper presents results of linear and nonlinear optimization of the main designed lattice for booster in both configurations.

THPC031

Measurement of Longitudinal Dynamics of Injected Beam in a Storage Ring

injection, storage-ring, simulation, booster

2978

T. Watanabe, T. Fujita, M. Masaki, K. Soutome, S. Takano, M. Takao, K. Tamura
JASRI/SPring-8, Hyogo-ken, Japan

Experimental observation of longitudinal dynamics of injected beam in a storage ring has been demonstrated. Since the injected beam undergoes synchrotron oscillation in a longitudinal phase space, two projected values, i.e., a bunch duration and an energy spread, oscillate at twice the synchrotron frequency. At SPring-8, the initial energy spread (~0.126%) at the injection goes up and down until it reaches the equilibrium energy spread (~0.11%). If the injection timing should not be optimized, an asymmetrically enhanced oscillation could distort the injection efficiency. The observation of such an oscillation helps make sure that no significant injection loss occurs. More importantly, the scheme is expected to enable us to observe non-linear longitudinal dynamics of ultra-short bunches injected from the XFEL linac; the bunches are in near future going to be transferred from the linac to the storage ring via 600-meter long transports, in which strong coherent synchrotron radiation and other high peak-current effects will not be ignorable. Experimental results obtained by a dual-scan streak camera and other devices as well as numerical simulations will be presented.

THPC037

Accelerators of the Central Japan Synchrotron Radiation Facility Project (II)

storage-ring, booster, electron, linac

2987

N. Yamamoto, M. Hosaka, A. Mano, H. Morimoto, K. Takami, Y. Takashima
Nagoya University, Nagoya, Japan
Y. Hori
KEK, Ibaraki, Japan
M. Katoh
UVSOR, Okazaki, Japan
S. Koda
SAGA, Tosu, Japan
S. Sasaki
JASRI/SPring-8, Hyogo-ken, Japan

Central Japan Synchrotron Radiation (SR) Facility Project is making progress for the service from FY2012. The construction of SR building is almost completed in the Aichi area of Japan, and the installs of accelerators will start in a few week. The key equipments of our accelerators are an 1.2 GeV compact electron storage ring that is able to supply hard X-rays and a full energy injector for top-up operation. The beam current and natural emittance of the storage ring are 300 mA and 53 nmrad. The circumference is 72 m. The magnetic lattice consists of four triple bend cells and four straight sections. The bending magnets at the centers of the cells are 5 T superconducting magnets and the critical energy of the SR is 4.8 keV. The injector consists of a 50 MeV linac and a booster synchrotron with the circumference of 48 m. To save construction expenses, the injector is built at inside of the storage ring. More than ten hard X-ray beam-line can be constructed. One variable polarization undulator will be installed in the first phase. The top-up operation will be introduced as early as possible.

THPC054

Project Status of the Polish Synchrotron Radiation Facility Solaris

storage-ring, linac, cavity, radiation

3014

C.J. Bocchetta, P.P. Goryl, K. Królas, M. Mlynarczyk, M.J. Stankiewicz, P.S. Tracz, Ł. Walczak, A.I. Wawrzyniak
Solaris, Krakow, Poland
J. Ahlbäck, Å. Andersson, M. Eriksson, M.A.G. Johansson, D. Kumbaro, S.C. Leemann, L. Malmgren, J.H. Modéer, P.F. Tavares, S. Thorin
MAX-lab, Lund, Sweden
E. Al-dmour, D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

Funding: European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG.02.01.00-12-213/09
The Polish synchrotron radiation facility Solaris is being built at the Jagiellonian University in Krakow. The project is based on an identical copy of the 1.5 GeV storage ring being concurrently built for the MAX IV project in Lund, Sweden. A general description of the facility is given together with a status of activities. Unique features associated with Solaris are outlined, such as infra-structure, the injector and operational characteristics.

THPC055

Front Ends at ALBA

vacuum, photon, radiation, undulator

3017

J. Marcos, J. Campmany, D. Einfeld, J. Pasquaud
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3GeV 3rd generation synchrotron radiation source built nearby Barcelona currently under commissioning phase. This paper describes the design and installation of the set of 10 Front Ends that have been manufactured and assembled for day-one operation of the facility. This initial set includes 8 Front Ends devoted to transmit the photons generated by both Insertion Device or Bending Magnet sources to experimental Beamlines, and 2 additional Front Ends for electron beam-diagnostics purposes. The design of each individual Front End has been adapted in order to meet the aperture and power load requirements posed by both the characteristics of the photon sources and the needs of the Beamline users. At the same time, an effort has been made in order to keep a suitable degree of standardization among the components of different Front Ends. With this aim a modular design approach has been adopted. The general layout of the Front Ends as well as the design and function of their main components is described. Finally, a brief summary of their performance during the commissioning period is presented.

THPC063

A 2.9 Tesla Room Temperature Superbend Magnet for the Swiss Light Source at PSI

storage-ring, power-supply, dipole, vacuum

3038

A.L. Gabard, D. George, M. Negrazus, L. Rivkin, V. Vrankovic
PSI, Villigen, Switzerland
Y. Kolokolnikov, P. Vobly
BINP SB RAS, Novosibirsk, Russia

The Swiss Light Source (SLS) at the Paul Scherrer Institute (PSI) in Villigen, Switzerland, is a 3rd generation synchrotron light source. With an energy of 2.4 GeV, it provides high brightness photon beams for research in materials science, biology and chemistry. The SLS storage ring contains 36 room temperature bending magnets, all of which produce light for experimental use; at the design energy of 2.4 GeV, they have a maximum magnetic field of 1.4 Tesla. Light is produced along the entire bending arc but can only be transferred to the external experimental facilities from selected short portions of the beam path. In cooperation with the Budker Institute for Nuclear Physics (BINP) in Novosibirsk, Russia, three of these magnets were replaced with new room temperature magnets with short regions of high magnetic field up to 2.9 Tesla. This enabled the production of intense light beams at shorter wavelengths than from the existing magnets. The critical energy of the 2.9 T magnet is 11.1 keV, compared to the 5.4 keV of the normal bend. This paper describes the design, including the multiple restraints, together with the measurement and commissioning of these so-called superbends.

THPC069

Studies to Optimize the Diamond Light Source Booster Synchrotron as a 100 MeV Storage Ring

booster, quadrupole, storage-ring, linac

3053

C. Christou, M.T. Heron, J. Rowland
Diamond, Oxfordshire, United Kingdom
S. Gayadeen
University of Oxford, Oxford, United Kingdom

The injection chain for the Diamond Synchrotron Light Source consists of a 100 MeV Linac and 3 GeV booster synchrotron. These were commissioned in 2005 and 2006 respectively, and have provided acceptable performance as an injector since then. To advance a programme of work in evaluating and optimizing new control algorithms for orbit stability on the Diamond Storage Ring it was decided to use the booster synchrotron as a test platform by operating it in DC mode at 100 MeV. In support of this work and to improve the operational performance of the booster a series of studies have been carried out to better understand and characterize it. This work and the results will be presented.

THPC070

An Automated Statistical Analysis Package for the Study of Synchrotron Light Source Operation

cavity, storage-ring, beam-losses, monitoring

3056

C. Christou, C.P. Bailey, V.C. Kempson, V.J. Winter
Diamond, Oxfordshire, United Kingdom

Machine faults and interruptions to user beam at Diamond Light Source are recorded in a Fault Log Database (FLDB) running under Microsoft Access. The scope of numerical analysis in Access is limited, and so an advanced data analysis package has been written in Matlab to exploit the powerful numeric functions available in this environment to automatically analyze machine faults and summarize data for reliability reports. Figures of merit such as mean time between failure (MTBF), mean time to repair (MTTR), total up time and total number of faults over the machine as a whole and by technical group can be calculated, and more advanced Pareto and Weibull analyses can be instantly generated. Data is presented for Diamond Light Source both for the latest year of operation and since user beam began in 2007, and the impact of different technical groups, in particular the storage ring RF, is considered. Failure distributions and the underlying hazard functions are produced and compared with statistical models to highlight deviations from randomly occurring events and to quantify changes in failure probability with time.

THPC136

High Efficiency Visible Photocathode Development

cathode, vacuum, laser, diagnostics

3206

J. Smedley, K. Mueller, T. Rao
BNL, Upton, Long Island, New York, USA
K. Attenkofer, S.W. Lee
ANL, Argonne, USA
I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Oses
Stony Brook University, Stony Brook, USA
H.A. Padmore, T. Vecchione
LBNL, Berkeley, California, USA

Alkali antimonide cathodes are critical both for high average current photoinjectors for energy recovery linacs and for high quantum efficiency photodetectors. These cathodes have historically been plagued by extreme vacuum sensitivity, non-reproducibility and poor lifetime. We report on ongoing efforts to improve the performance of alkali antimonides (principally K2CsSb). Cathodes have been fabricated which have a QE of 7% at 532 nm. The films are much more resistant to oxygen and water exposure than previously thought, with a 50% yield lifetime of 20 hrs at 2 pBar partial pressure of water. Several analysis techniques have been employed in this study, including in-situ x-ray diffraction during growth to measure grain size and texture, measurement of transverse momentum distribution of the emitted electrons, and measurement of the stoichiometry of the films via x-ray fluorescence. An extensive study of the growth parameters, including both transparent and metallic substrates, sputtered and evaporated films, variation of growth time and temperatures and post-growth annealing processes, is currently underway.

THPC137

Low Emittance Booster Design for CANDLE Storage Ring

booster, emittance, injection, storage-ring

3209

G.S. Zanyan, B. Grigoryan, K. Manukyan, A. Sargsyan, V.M. Tsakanov
CANDLE, Yerevan, Armenia

The progress in synchrotron based research made the top up operation mode of storage rings as the most attractive option both from the beam lifetime and the user points of view. To provide reliable operation of the facility at top-up injection mode the full energy low emittance new booster ring for 3 GeV CANDLE storage ring is designed. The compact synchrotron magnets with integrated quadrupole and sextupole components are used. The new design provides 20 nm emittance at the top energy with sufficient dynamic aperture and optimal optical properties at straight section for effective extraction. The complete design of the new booster and beam dynamics issues during the energy ramping are presented.

THPC143

Beam-based Alignment for Injection Bump Magnets of the Storage Ring using Remote Tilt-control System

injection, alignment, controls, betatron

3221

K. Fukami, K. Kobayashi, C. Mitsuda, T. Nakamura, K. Soutome
JASRI/SPring-8, Hyogo-ken, Japan

Stored beam is oscillated in vertical if the injection-bump magnets have alignment error in rotation around the beam-axis (tilt). In addition, even if the tilt is negligibly small, the beam out of the median plane is kicked in vertical direction. Also, there is a small long-term drift of the vertical beam positions in the bump magnets, which causes the gradual increase of the oscillation. We have already developed a remote tilt-control system to make a smooth realignment*. To observe the oscillation, the beam position was measured bunch-by-bunch and turn-by-turn by using a bunch-by-bunch feedback system** with high resolution strip-line type beam position monitor. To obtain responses to the tilts of each magnet, the oscillations were measured under the condition that the magnets were tilted intentionally. Tilt errors were calculated with least-squares method using the responses. In order to confirm the source of the residual oscillation, a frequency analysis was carried out with FFT method using the position data from 1st to 128th turns. We succeeded in suppressing the vertical oscillation to sub-microns order, the value of less than one tenth of the beam size.
* K. Fukami et al., Proc. of EPAC'08, p. 2172 (2008).
** T. Nakamura et al., Proc. of ICALEPCS'05, PO2.022-2 (2005).

THPC159

Factory Acceptance Test of COLDDIAG: A Cold Vacuum Chamber for Diagnostics

vacuum, electron, diagnostics, factory

3263

S. Gerstl, T. Baumbach, S. Casalbuoni, A.W. Grau, M. Hagelstein, T. Holubek, D. Saez de Jauregui
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
V. Baglin
CERN, Geneva, Switzerland
C. Boffo, G. Sikler
BNG, Würzburg, Germany
T.W. Bradshaw
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
R. Cimino, M. Commisso, A. Mostacci, B. Spataro
INFN/LNF, Frascati (Roma), Italy
J.A. Clarke, R.M. Jones, D.J. Scott
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M.P. Cox, J.C. Schouten
Diamond, Oxfordshire, United Kingdom
I.R.R. Shinton
UMAN, Manchester, United Kingdom
E.J. Wallén
MAX-lab, Lund, Sweden
R. Weigel
Max-Planck Institute for Metal Research, Stuttgart, Germany

Superconductive insertion devices (IDs) have higher fields for a given gap and period length compared with the state-of-the-art technology of permanent magnet IDs. One of the still open issues for the development of superconductive insertion devices is the understanding of the heat intake from the electron beam. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the underlying mechanisms, a cold vacuum chamber for diagnostics was built. It is equipped with the following instrumentation: retarding field analyzers to measure the electron flux, temperature sensors to measure the beam heat load, pressure gauges, and mass spectrometers to measure the gas content. The flexibility of the engineering design will allow the installation of the cryostat in different synchrotron light sources. The installation in the storage ring of the Diamond Light Source is foreseen in November 2011. Here we report about the technical design of this device, the factory acceptance test and the planned measurements with electron beam.

THPC163

Local and Integral Field Measurement Setup for 2m Long Superconducting Undulator Coils

undulator, factory, insertion, insertion-device

3275

A.W. Grau, T. Baumbach, S. Casalbuoni, S. Gerstl, M. Hagelstein, T. Holubek, D. Saez de Jauregui
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

The performance of superconducting insertion devices depends strongly on their magnetic field quality. It is of fundamental importance to characterize the magnetic properties of insertion devices accurately before installation in synchrotron light sources. Thus a main part of the R&D program for superconducting insertion devices at the Karlsruhe Institute of Technology focuses on quality assessment. This contribution describes the instrumentation to perform magnetic measurements of the local field, of the field integrals and of the multipole components of superconducting undulator coils in a cold in vacuum (cryogen free) environment. It focuses on the outcome of the factory acceptance test together with results of first field measurements performed with mock-up coils.

THPC167

The Design of Dual Canted In-vacuum Undulators at SSRF

undulator, vacuum, radiation, ion

3287

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

Funding: National foundation for scientific infrastructure, Development and Reform Commission of China.
Five new beamlines are under design and construction at SSRF to supply the synchrotron radiation for the structural biology research in the protein project. Two in-vacuum undulators with canted angle of 6mrad are arranged in a 6.5m long straight section in order to keep the potential to accommodate more beamlines for the future. Limited by the length of the straight section and the angle between two beamlines, the layout design in the straight section is rather difficult to satisfy the required photon flux to the beamline and keep the normal design of the undulator. Many main components will be redesigned in this section on the base of existing ones, including in-vacuum undulator, correction magnet, RF bellows, photon absorbers and so on. In this paper the layout design and the modified design for some key components are described.

THPC177

Field Correction Results from NSRRC Elliptically Polarized Undulator 46

kicker, undulator, electron, multipole

3317

J.C. Huang, C.-H. Chang, C.-S. Hwang, C. JunTune, F.-Y. Lin
NSRRC, Hsinchu, Taiwan

Elliptically polarized undulator (EPU) is a common insertion device to use in storage ring in order to provide circular polarization. The field correction is an essential step for EPU construction, and it can prevent the photon flux reduction from idea case and electron beam trajectory and exit angle from EPU. The conventional field correction method is tedious works and strongly based on experiences. An initial state of NSRRC EPU46 has phase error over 40 degrees, and many difficulties on field correction to reduce the phase error under 5 degrees. This paper will describe the detailed magnetic field correction process and practical results from in NSRRC EPU.

THPC179

Electron Beam Heating and Operation of the Cryogenic Undulator and Superconducting Wigglers at Diamond

electron, wiggler, undulator, cavity

3323

J.C. Schouten, E.C.M. Rial
Diamond, Oxfordshire, United Kingdom

Diamond Light Source has two superconducting wigglers and one cryocooled undulator installed serving three beam lines. The cryocooled undulator (cpmu) has been operating since August 2010 while the superconducting wigglers have been operating for more than 4 years (SCW-1) and 2 years (SCW-2). We will report on the first year of operation of the cpmu including details of its spectral output and cryogenic performance. Our experience of the cooling system and measures taken to ensure reliability and to minimize the risks of a prolonged downtime are also presented. The two superconducting wigglers are exposed to a high heat load due to the beam heating of the inner liner. Until recently this resulted in a much higher helium consumption than specified and so recently a new liner has been fitted to SCW-1 and new re-condensers to SCW-2. In addition a thermal bridge has been made between the RF tapers and the outer heat shield of both SCW-1 and SCW-2. The results of these improvements will be presented.

THPO003

Rapid-cycling Power Supplies for the J-PARC RCS Sextupole Magnets

power-supply, sextupole, proton, linac

3338

Y. Watanabe
JAEA, Ibaraki-ken, Japan
T. Adachi, S. Igarashi, H. Someya
KEK, Ibaraki, Japan
N. Tani
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The rapid-cycling synchrotron of the Japan Proton Accelerator Research Complex requires 18 sextupole magnets with three families for the chromaticity correction. One family consists of six focusing sextupole magnets, and other two families consist of six defocusing sextupole magnts. An individual power supply excited for each family and the current pattern is a DC-biased sinusoidal of a frequency of 25 Hz. This paper describes design and test results of the sextupole magnet power supplies.

THPO021

A New Control System for the ISIS Main Magnet Power Supply

controls, power-supply, status, target

3385

J. Ranner, T.E. Carter, S. West
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory in Oxfordshire is a world-leading centre for research in the physical and life sciences. At the heart of the ISIS accelerator is a proton synchrotron which uses a ring of dipole and quadrupole magnets connected in series and configured as a White Circuit*. The circuit allows the magnets to be fed with an AC current superimposed on a DC current. A recent upgrade to the main magnet power supply** involved the replacement of the original AC supply, a motor-alternator set, with a bank of four 300kVA UPS (uninterruptible power supplies) which had been modified to allow the output voltage to be varied using serial commands. However, when initially tested, this method was unable to produce the required stability in the main magnet current. This paper describes the further modifications to the UPS units to achieve the required stability and the development of a LabVIEW control system which manages the data acquisition and analysis, the communication to the UPS, interlock equipment and user interface, and provides a low latency control loop to the UPS and DC bias power supplies.
* M.G. White et al., “A 3-BeV High Intensity Proton Synchrotron”, CERN Symp.1956 Proc., p525.
** S. West, J.W. Gray, W.A. Morris, “Upgrade of the ISIS Main Magnet Power Supply”, EPAC 2004 p1467.

THPO025

Longitudinal Beam Dynamics of a Laser Sliced Bunch

laser, electron, radiation, damping

3397

P. Kuske
HZB, Berlin, Germany

Nowadays fs-laser slicing of a bunch of electrons in storage rings is quite common for creating short VUV- and soft X-ray light pulses or pulses of coherently emitted THz-radiation over a couple of revolutions. In this paper the longitudinal dynamics of the sliced bunch is studied numerically. The calculations are based on the one dimensional solution of the Vlasov-Fokker-Planck-equation assuming that the shielded CSR-wake is dominating the dynamics of the 100 fs-long slice. It is found that the density modulation survives longer and that the CSR-spectra extend to higher frequencies at later turns even below the corresponding instability threshold. This very simple model seems to support experimental observations at the Swiss Light Source.

THPO027

Novel Switching Power Supply utilizing SiC-JFET and its Potential for the Digital Accelerator

power-supply, induction, extraction, high-voltage

3400

K. Okamura, T. Iwashita, K. Takayama, M. Wake
KEK, Ibaraki, Japan
K. Ise
Tohoku Electric Power Co., Sendai, Japan
Y. Osawa
SUN-A Corporation, Miyoshi-City, Japan
K. Takaki
Iwate university, Morioka, Iwate, Japan

Funding: Japan Science and Technology Agency
New induction synchrotron system using an induction cell has been developed and constructed at KEK*. We refer to the accelerator using the induction acceleration system combined with digitally controlled PWM power supply as "Digital Accelerator". In that system, the switching power supply is one of the key devices which realize digital acceleration. The requirements of the switching power supply are high voltage (2 kV) and high repetition frequency (1 MHz). In the present system, we used series connected MOSFETs as the switching device and obtained successful operation. However, series connection gives large complexity and less reliability. Among the various switching devices, a SiC-JFET is the promising candidates that substitute existing silicon MOSFET because it has ultrafast switching speed and voltage blocking capability**. Therefore, we have started to develop new device in collaboration with device manufacturers. Switching and heat removal performance of the newly developed SiC-JFET and a future plan will be presented at the conference.
* T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.
** K. Ise et al., IEEE Trans. Plasma Sci., pp. 730-736 (2011).

THPO034

Optimization of a Dual One-turn Coils Kicker Magnet System

kicker, extraction, monitoring, vacuum

3415

K.L. Tsai, C.-T. Chen, C.-S. Fann, S.Y. Hsu, Y.D. Li, K.-K. Lin, K.-B. Liu, H.M. Shih, Y.S. Wong
NSRRC, Hsinchu, Taiwan

Optimization of a dual one-turn coils configuration for fast kicker magnet system is presented in this report. Emphasis has been made on the: 1) optimization of various possible coils arrangement restricted by the existing available hardware; and 2) synchronization between pulsed currents delivering on the respective upper and lower coils. In the consideration of coils arrangement, good field region is utilized as the guiding parameter while adjusting fixture gap between the coils. As for coil currents timing optimization, fast rise-time and pulse shape preservation are used for practical implementation purpose. Both numerical analysis and experimental data will be presented and discussed.

THPS029

Simulations of Various Driving Mechisms for the 3rd Order Resonant Extraction from the MedAustron Medical Synchrotron

extraction, betatron, lattice, resonance

3481

G. Feldbauer, M. Benedikt
CERN, Geneva, Switzerland
U. Dorda
EBG MedAustron, Wr. Neustadt, Austria

The MedAustron medical synchrotron is based on the CERN-PIMMS design and its technical implementation by CNAO [1]. This document elaborates on studies performed on the baseline betatron-core driven extraction method and investigates the feasibility of alternative resonance driving mechanisms like RF-knockout, RF-noise and the lattice tune. Single particle tracking results are presented, explained and compared to analytical results.
[1] M. Pullia, ‘‘Status Report on the Centro Nazionale di Adroterapia Oncologica (CNAO)'', 11th EPAC'08, Genoa, Itlay, June 2008, p. 982

THPS030

Layout and Optics of the MedAustron High Energy Beam Transfer Line

optics, proton, extraction, quadrupole

3484

U. Dorda, P.J. Bryant
CERN, Geneva, Switzerland
M. Benedikt
EBG MedAustron, Wr. Neustadt, Austria

The MedAustron accelerator complex, which is currently in its final design stage at CERN, is based on the optical principles developed within the Proton Ion Medical Machine study (PIMMS) [bryantpimms]. This paper describes how these principles are practically applied in the layout and optics of the High Energy Beam Transfer line (HEBT) of the MedAustron accelerator facility. Special attention is directed to the optics of the gantry which is designed to fit into the PSI gantry-2 hardware layout, which is foreseen to be copied in collaboration with PSI.

THPS039

Diffusion of a Circulating Beam by the RF-Knockout with a Spectrum including Many Bands

resonance, extraction, simulation, controls

3508

M. Tashiro, T. Nakanishi
Nihon University, Narashino, Chiba, Japan

The fast control of beam spill extracted from a synchrotron is a key function for the spot scanning irradiation in cancer therapy application. The authors have proposed the extraction method for the application which uses the control of a quadruple field of fast response as well as the RFKO (QAR method). The RF signal for the RFKO should cover a frequency band corresponding to a tune spread. A simulation with continuous RFKO operation, however, showed a spill intensity changes with time largely with only this band. The large change of spill is due to not uniform diffusion of circulating beam and it makes a constant spill difficult in the QAR method. A wider band gives a uniform spill, but it requires a larger Amp power. We proposed a spectrum including many bands around the resonances to reduce the power, since the bands outside around the resonances do not contribute to the diffusion. Such a spectrum has also an advantage to increase spill intensity for the QAR method, using a band so that the RFKO diffuses more inside particles of the separatrix but also it affects little them near the boundary. We can extract several times particles with a same shrink ratio of the separatrix.

THPS044

Study of Charge Exchange Injection in HITFiL

injection, ion, emittance, dipole

3520

W.P. Chai, J. Shi, J.W. Xia, J.C. Yang
IMP, Lanzhou, People's Republic of China

A new accelerator complex dedicated to hadron cancer therapy, Heavy-Ion Therapy Facility in Lanzhou (HITFiL), is proposed and designed. Based on the operating experience and existing technology on HIRFL-CSR, a heavy-ion cyclotron is used as an injector instead of a linac. A heavy-ion synchrotron as main component is designed with special attention paid to compact structure, high reliability and low cost. HITFiL is designed to accommodate both proton and carbon-ion using the same injecting channel but different injecting points. Charge exchange injection scheme, which is more efficient compared with single-turn injection but less costly compared with multiple multi-turn injection aided by electron-cooling, is adopted. H²⁺ or C⁵⁺ beams, pre-accelerated by the cyclotron, are stripped into H⁺ or C⁶⁺ by a carbon foil at injection point, then injected and merged into synchrotron coasting orbit. The design of the injection system is presented in this paper. The whole injection process is simulated, optimization of parameters on injecting efficiency, painting scheme and emittance growth are performed. The resulting beam distribution in phase space after injection is achieved.

THPS048

Design of Electrostatic Septa and Fast Deflector for MedAustron

septum, power-supply, cathode, injection

3532

J. Borburgh, T. Fowler, A. Prost
CERN, Geneva, Switzerland
T. Kramer, T. Stadlbauer
EBG MedAustron, Wr. Neustadt, Austria

For the MedAustron facility, under construction in Wiener Neustadt, three electric field deflectors are developed in collaboration with CERN. A fast deflector is used in the Low Energy Beam Transfer line to chop the beam. The chopped beam is swept onto a Faraday cup for measurement purposes and to stop beam being sent towards the synchrotron. Electrostatic septa are used for the multi turn injection of protons and ions as well as for the slow extraction from the synchrotron. Novel design features for MedAustron include an inversed cathode/anode support and high voltage feedthroughs rated at 150 kV. The possibility for a higher voltage will significantly improve the conditioning process of the septa surfaces. This paper describes the requirements of these devices as well as the mechanical design and strategies adopted for their power supplies.

THPS057

Stripping Foil Simulations for ISIS Injection Upgrades

injection, simulation, proton, scattering

3556

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

ISIS, the pulsed neutron and muon spallation source located at the Rutherford Appleton Laboratory (UK), currently delivers a mean beam power of 0.2 MW to target. A 70 MeV H⁻ linear accelerator feeds into a 50 Hz, 800 MeV proton synchrotron (through a 0.3·10^-6 m Aluminium Oxide stripping foil), accelerating up to 3·10¹³ protons per pulse. Potential injection scheme upgrades, aiming to raise average beam power towards 0.5 MW with a new 180 MeV linear accelerator, are being studied. Detailed consideration of the injection stripping foil forms a key element of this study: scattering, stripping efficiency and foil lifetime are significant factors in determining loss levels, which consequently limit operational intensity. This paper describes the identification of a suitable stripping foil specification for successful 180 MeV H⁻ charge exchange injection into the ISIS synchrotron. Simulation code was developed to investigate electron stripping, scattering events and temperature rises, in order to witness their subsequent effect on foil lifetime. ANSYS models were also used to investigate the heat transfer and temperature distribution within thin foils.

THPS066

Technical Overview of the SIEMENS Particle Therapy Accelerator

ion, proton, linac, extraction

3577

V. Lazarev, O. Chubarov, S. Emhofer, G. Franzini, S. Göller, B. Nagorny, A. Robin, H. Rohdjess, R. Rottenbach, A.C. Sauer, R. Schedler, T. Sieber, B. Steiner, J. Tacke, D.B. Thorn, T. Uhl, P. Urschütz, O. Wilhelmi
Siemens Med, Erlangen, Germany
M. Budde, J.S. Gretlund, H.B. Jeppesen, C.V. Nielsen, C.G. Pedersen, Ka.T. Therkildsen, S.V. Weber
Siemens DK, Jyllinge, Denmark

Siemens has developed an accelerator system for particle therapy. It consists of an injector (7 MeV/u protons and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u. These beams are extracted slowly from the synchrotron and delivered to a number of beam ports. The first accelerator system has been built and commissioned up to the first two beam outlets. An overview of the achieved performance of the system is presented.
*Particle therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.

THPS069

Particle Beam Characteristics Verification for Patient Treatment at CNAO

controls, simulation, proton, monitoring

3586

M. Donetti, M. Ciocca, M.A. Garella, A. Mirandola, S. Molinelli, M. Pullia, G. Vilches Freixas
CNAO Foundation, Milan, Italy
S. Giordanengo
INFN-Torino, Torino, Italy
M. Lavagno
DE.TEC. TOR. S.r.l., Torino, Italy
R. Sacchi
Torino University, ., Torino, Italy

At Centro Nazionale di Adroterapia Oncologica (CNAO) in Pavia, Italy, a synchrotron has been designed to treat tumor with protons and ions delivered with a full active delivery system. Several pencil beams with appropriate energy are steered in sequence to the right positions inside the tumor volume covering it totally. Several beam characteristics have to be deeply known in order to be able to deliver a safe patient treatment. CNAO is now able to send beam in the treatment room and the Dose Delivery system is in the commissioning phase. Dose Delivery system, composed by beam monitoring and scanning magnets, manages the treatment with high precision in real time. The dose delivery system functions and components will be presented. Beam characteristic are studied by means of several detectors and verification systems in the treatment room to guarantee the quality of the treatment. Quality is checked in terms of pencil beam characteristics and characteristic of the overall dose in the treatment fields. The detector used and the results of the measurements will be shown.

THPS070

Status Report of the CNAO Construction and Commissioning

proton, extraction, ion, linac

3589

M. Pullia
CNAO Foundation, Milan, Italy

The CNAO (National Center for Oncological Hadrontherapy) is the first Italian center for deep hadrontherapy. The main accelerator is a synchrotron, based on the PIMMS design, capable to accelerate carbon ions up to 400 MeV/u and protons up to 250 MeV. Four treatment lines, in three treatment rooms, are foreseen in a first stage. The CNAO facility, has been designed for a completely active beam delivery system, in which a pencil beam is scanned transversely and the extracted beam energy can be changed on a spill to spill basis. The commissioning of the synchrotron started in August 2010. At the beginning of 2011 the first Spread Out Bragg Peaks with proton beams in the energy range 120-170 MeV/u, matching the first foreseen treatments, have been measured. The commissioning of the machine with protons has now been completed and authorisation to treatment of patients has been obtained from the competent authorities. The commissioning with carbon ions is in progress.

THPS072

Commissioning of NIRS Fast Scanning System for Heavy-ion Therapy

target, controls, ion, monitoring

3595

T. Furukawa, T. Inaniwa, K. Katagiri, K. Mizushima, K. Noda, S. Sato, T. Shirai
NIRS, Chiba-shi, Japan
E. Takeshita
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan

The commissioning of NIRS fast scanning system was started in September 2010, when the first beam was successfully delivered from the HIMAC synchrotron to the new treatment room. After the fine tuning of the new transport line, the commissioning of the scanning system was carried out as following steps; 1) verification of the beam size, position and intensity stability; 2) verification of beam scanning performance and calibration; 3) verification of beam monitor performance; 4) dose measurement of pencil beams for the beam parameterization in the treatment planning system; and 5) verification of 3D dose conformation. As a result of the commissioning, we verified that the new scanning delivery system can produce an accurate 3D dose distribution for the target volume in combination with the planning software. We will report the commissioning results and the performance of the scanning system.

THPS073

Dosimetric Impact of Multiple Energy Operation in Carbon-ion Radiotherapy

target, ion, simulation, scattering

3598

T. Inaniwa, T. Furukawa, N. Kanematsu, S. Mori, K. Noda, S. Sato, T. Shirai
NIRS, Chiba-shi, Japan

In radiotherapy with a scanned carbon beam, its Bragg peak is placed within the target volume either by inserting the range shifter plates or by changing the beam energy extracted from the synchrotron. The former method (range shifter scanning: RS) is adopted in NIRS while the latter method (active energy scanning: ES) has been used in GSI and HIT. In NIRS, an intermediate method, a combination scanning (CS), is now under consideration where eleven beam energies having the ranges with 30 mm intervals are prepared and used in conjunction with the range shifter plates for slighter range shift. The disadvantages of the RS are the beam spread due to the multiple scattering within the range shifter plates and the production of fragment particles through the nuclear reactions within them. On the other hand, for the ES, severely time-consuming beam commissioning and the expensive devices are required. In this study, we compare these three methods from the viewpoint of dose distributions and the impacts for clinical cases will be discussed.

THPS075

Recent Progress of New Cancer Therapy Facility at HIMAC

ion, target, heavy-ion, controls

3604

T. Shirai, T. Furukawa, T. Inaniwa, Y. Iwata, K. Katagiri, K. Mizushima, S. Sato, E. Takada, Y. Takei, E. Takeshita
NIRS, Chiba-shi, Japan
T. Fujimoto, T. Kadowaki, T. Miyoshi, Y. Sano
AEC, Chiba, Japan

Since 1994, the carbon beam treatment has been continued at Heavy Ion Medical Accelerator in Chiba (HIMAC). The total number of patients treated is more than 5,000 in 2010. Based on more than ten years of experience with HIMAC, we have developed new treatment equipments toward adaptive cancer therapy with heavy ion at New Particle Therapy Research Facility in NIRS.

THPS076

Sub-mm Therapeutic Carbon-Ion Irradiation Port in Gunma University

ion, betatron, lattice, linac

3607

K. Torikai, T. Kanai, N.T. Nakano, H. Shimada, E. Takeshita, M. Tashiro, S. Yamada, K. Yusa
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
K. Hanakawa, T. Honda, K. Yoshida
Mitsubishi Electric Corporation, Kobe, Japan

Funding: This Study was done by Grant-in-Aid for Scientific Research (KAKENHI).
One of advantage of particle therapy is concentration of irradiation dose. In April 2011, we developed "in-body-focusing type" irradiation port for "Proof-of-Principle" . This sub-mm port produces 1mm(1σ) beam. we will explain this irradion port at the conference.

FRXAA01

Theory of Microwave Instability and Coherent Synchrotron Radiation in Electron Storage Rings

impedance, electron, shielding, storage-ring

3774

Y. Cai
SLAC, Menlo Park, California, USA

Funding: This work was supported by Department of Energy Contract No. DE-AC02-76SF00515.
Bursting of coherent synchrotron radiation has been observed and in fact used to generate THz radiation in many electron storage rings. In order to understand and control the bursting, we return to the study of the microwave instability. In this talk, we will report on the theoretical understanding, including recent developments, of the microwave instability in electron storage rings. The historical progress of the theories will be surveyed, starting from the dispersion relation of coasting beams, to the work of Sacherer on a bunched beam, and ending with the Oide and Yokoya method of discretization. This theoretical survey will be supplemented with key experimental results over the years. Finally, we will describe the recent theoretical development of utilizing the Laguerre polynomials in the presence of potential-well distortion. This self-consistent method will be applied to study the microwave instability driven by commonly known impedances, including that of coherent synchrotron radiation.

Slides FRXAA01 [0.948 MB]

FRYAA01

Review of Hadron Therapy Accelerators Worldwide and Future Trends

ion, proton, hadron, target

3784

K. Noda
NIRS, Chiba-shi, Japan

Hadron beams have attractive growing interest for cancer treatment owing to their high dose localization at the Bragg peak and owing to high biological effect there, especially for heavy-ion beams. Recently, therefore, hadron cancer radiotherapy has been successfully carried out at various facilities and several facility construction projects have also been progressing in the world, based on the development of the accelerator and beam-delivery technologies. This report will review the development of the accelerator and beam-delivery technologies in the hadron beam radiotherapy facilities in the world.