IPAC2011 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOXAA01	ALBA Synchrotron Light Source Commissioning	storage-ring, booster, linac, synchrotron	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]

MOXBA01	J-PARC Beam Commissioning Progress	beam-losses, linac, extraction, vacuum	6
	H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The J-PARC is a multi-purpose proton accelerator facility amiming at MW-class output beam power, consisting of a 400 MeV H⁻ linac, a 3-GeV RCS, a 50-GeV MR (Main Ring) and three experimental facilities, the MLF (materials and life science experimental facility), the HD (hadron experimental hall) and the NU (neutrino beam line). The J-PARC beam commissioning started in November 2006 from the linac to the downstream facilities. The current output beam power from the RCS to the MLF users is 210 kW, and the MR delivers 145 kW beam to the NU by fast extraction and a few kW beam to the HD by slow extraction. In this talk, we present a current status of the J-PARC beam commissioning, in which a recent progress in the course of the RCS beam power ramp-up scenario will be described in more detail. This talk will focus on the issues (including beam dynamics), challenges, solutions, and lessons learned during the commissioning and user operation of J-PARC and future plans.
	Slides MOXBA01 [2.615 MB]

MOYAA01	The LHC from Commissioning to Operation	luminosity, controls, optics, ion	11
	M. Lamont CERN, Geneva, Switzerland
	In 2011 the LHC moves from commissioning into the physics production phase with the aim of accumulating 1fb-1 by the end of 2011. The progress from commissioning to operation is described. Emphasis is put on the beam performance, but also on the performance of the different hardware systems. The role of collimation and machine protection is discussed, in view of the very high stored beam and magnet energy. Comment: Other invited presentations in this conference will cover the experience with beam instrumentation and the upgrade programmes.
	Slides MOYAA01 [7.410 MB]

MOPC015	S-band Vacuum Isolator and Circulator for Injector System of SPring-8 Linac	vacuum, linac, cavity, insertion	95
	T. Taniuchi, H. Hanaki, S. Suzuki JASRI/SPring-8, Hyogo-ken, Japan A. Miura, K. Shinohara, S. Tsuruoka Nihon Koshuha Co. Ltd, Yokohama, Japan
	A pressurized sulfur hexafluoride (SF6) waveguide system at an injector section of SPring-8 linac, will be replaced with a vacuum waveguide system in order to renew aged equipments and improve a phase stability. For this renewal, RF isolator and a circulator operated in vacuum, are newly developed. High power RF test for these components were performed and a good result for RF and vacuum characteristics were obtained.

MOPC022	Development of a Compact C-band Photocathode RF Gun	gun, electron, cathode, emittance	116
	X.H. Liu, H. Chen, W.-H. Huang, H.J. Qian, C.-X. Tang, Z. Zhang TUB, Beijing, People's Republic of China
	Funding: This work is supported by National Natural Science Foundation of China and National Basic Research Program of China (973 Program). A C-band photocathode RF gun for a compact electron diffraction facility is developed in Tsinghua University, which is designed to work at the frequency of 5.712GHz. This paper presents the physics and structure design of this C-band RF gun, and the comparison on beam dynamics of S-band and C-band photoinjector has been done. Some new structure design will be adopted in this gun, including the optimized cavity length and elliptical iris, which is helpful to achieve lower emittance and larger mode separation.

MOPC054	The LHC RF System - Experience with Beam Operation	synchrotron, 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.

MOPC057	Loss of Landau Damping in the LHC	emittance, damping, acceleration, impedance	211
	E.N. Shaposhnikova, T. Argyropoulos, P. Baudrenghien, T. Bohl, A.C. Butterworth, J. Esteban Muller, T. Mastoridis, G. Papotti, J. Tückmantel, W. Venturini Delsolaro, U. Wehrle CERN, Geneva, Switzerland C.M. Bhat Fermilab, Batavia, USA
	Loss of Landau damping leading to a single bunch longitudinal quadrupole instability has been observed in the LHC during the ramp and on the 3.5 TeV flat top for small injected longitudinal emittances. The first measurements are in good agreement with the threshold calculated for the expected longitudinal reactive impedance budget of the LHC as well as with the threshold dependence on beam energy. The cure is a controlled longitudinal emittance blow-up during the ramp which for constant threshold through the cycle should provide an emittance proportional to the square root of energy.

MOPC158	RF Capture of a Beam with Charge-exchanging Multi-turn Injection	simulation, acceleration, closed-orbit, linac	454
	T. Uesugi, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, B. Qin, E. Yamakawa KURRI, Osaka, Japan Y. Niwa, K. Okabe, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan
	Funding: This work was supported by MEXT of Japan in the framework of a task entitled ”Research and Development for an Accelerator-Driven Sub-critical System Using an FFAG Accelerator”. In the fixed field alternating gradient (FFAG) synchrotron in Kyoto university research reactor Institute (KURRI), charge exchange injection was adopted since 2011. The charge stripping foil is located on the closed orbit of the injection energy, and no bump orbit system is used. Instead, the injected beam escapes from the stripping foil according to the closed-orbit shift due to acceleration. In this scheme, it is important to minimize the number of foil hitting, which causes emittance growth and foil heating. In this paper, the rf capture is studied by means of simulation.

MOPO012	LHC Damper Beam Commissioning in 2010	damping, feedback, kicker, ion	505
	W. Höfle, G. Kotzian, M. Schokker, D. Valuch CERN, Geneva, Switzerland
	The LHC transverse dampers were commissioned in 2010 with beam and their use at injection energy of 450 GeV, during the ramp and in collisions at 3.5 TeV for Physics have become part of the standard operations procedure. The system proved important to limit emittance blow-up at injection and maintain smaller than nominal emittances throughout the accelerating cycle. We describe the commissioning of the system step-by-step as done in 2010 and summarize its performance as achieved for proton as well as ion beams in 2010. Although its principle function is to keep transverse oscillations under control, the system has also been used as an exciter for abort gap cleaning and tune measurement. The dedicated beam position measurement system with its low noise properties provides additional possibilities for diagnostics.

MOPO015	Operation Status of Bunch-by-bunch Feedback System in the TLS	feedback, controls, diagnostics, kicker	514
	C.H. Kuo, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.-Y. Liao NSRRC, Hsinchu, Taiwan
	There are several FPGA based bunch-by-bunch feedback systems that were deployed in the Taiwan Light Source now. They play various roles to suppress beam instability. By using SPring-8 designed feedback processors is pioneer to apply in the storage ring of TLS successfully and help Dimtel system to be quick commission. The Dimtel feedback system provide a life spare unit and explore to control system integration especially to the EPICS toolkit system. Rich functionality includes of excitation of individual bunch or specifies bunches, averaged spectrum, tune measurement by the feedback dip in the averaged spectrum. Operation status of the system will be summary in this report.

MOPO023	Laser-based Alignment System at the KEKB Injector Linac	laser, alignment, linac, vacuum	529
	M. Satoh, N. Iida, T. Suwada KEK, Ibaraki, Japan K. Minoshima, S. Telada AIST, Tsukuba, Japan
	A laser-based alignment system is under development at the 500-m-long KEKB injector linac. The original system was designed and constructed more than thirty-years ago, and thus, we are revisiting our alignment system because the previous alignment system has become too obsolete. The new alignment system is again strongly required for the next generation SuperKEKB project. The new laser alignment system is similar to the previous one, which comprises a helium-neon laser and quadrant photodetectors installed in vacuum light pipes. A girder displacement of the accelerating structure can be precisely measured in the direction of the laser-ray trace, where the laser light must stably propagate up to 500-m downstream without any orbital and beam-size fluctuation. We tested the laser-ray propagation and the stability along a 100-m-long beam line under a vacuum condition of 0.1-1 Torr. In this paper, we will report the system description and test results in detail.

MOPS004	Mitigation of Beam Instability due to Space Charge Effects at 3 GeV RCS in J-PARC	impedance, space-charge, kicker, bunching	595
	Y. Shobuda, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y.H. Chin KEK, Ibaraki, Japan F. Tamura KEK/JAEA, Ibaraki-Ken, Japan
	In order to accomplish high intensity proton beams, it is important to identify the impedance source in accelerators. At 3 GeV rapid cycling synchrotron (RCS) in Japan Proton Research Complex (J-PARC), the kicker impedance is the most dominant among such impedance sources. Beam instability can be observed by correcting chromaticity during the acceleration. Growth rate due to the beam instability can be reduced by making peak current larger (bunching factor smaller). In other words, it is experimentally found that space charge effects mitigate the beam instability.

MOPS005	Beam Dynamics Simulations of J-PARC Main Ring for Upgrade Plan of Fast Extraction Operation	simulation, beam-losses, proton, power-supply	598
	Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori, M. Tomizawa KEK, Ibaraki, Japan H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Beam loss simulations under space charge effects are necessary to seek higher intensity proton beams. This paper presents simulations for fast extraction operation of Japan Proton Accelerator Research Complex (J-PARC) Main Ring. For upgrade plan, increasing protons per bunch and making higher repetition pattern are considered. Their optimal balance is discussed to minimize beam losses for aimed beam power considering space charge effects. We found that to optimize RF voltage pattern is a strong key to reduce beam losses for higher repetition. As benchmark works, we compare our simulations with the measured beam loss in our past operation.

MOPS008	Simulation of Longitudinal Emittance Control in J-PARC RCS for 400 MeV Injection	extraction, emittance, simulation, bunching	607
	M. Yamamoto, M. Nomura, A. Schnase, T. Shimada, F. Tamura JAEA/J-PARC, Tokai-mura, Japan E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, A. Takagi, K. Takata, M. Toda, M. Yoshii KEK, Ibaraki, Japan
	The injection energy upgrade of the J-PARC RCS from 181 MeV to 400 MeV is scheduled, this is necessary to achieve the design beam intensity. The high intensity beam is delivered to the MR, and the space charge effect at the MR injection should be alleviated by optimizing the longitudinal beam emittance at RCS extraction. This is realized by matching the shape of the beam emittance between the RCS and the MR. We describe the results of particle tracking simulation with the longitudinal emittance control during the whole acceleration period of the RCS.

MOPS009	Probing Intensity Limits of LHC-type Bunches in the CERN SPS with Nominal Optics	emittance, single-bunch, optics, extraction	610
	B. Salvant, G. Adrian, D.J. Allen, O. Andujar, T. Argyropoulos, J. Axensalva, J. Baldy, H. Bartosik, S. Cettour Cave, F. Chapuis, J.F. Comblin, K. Cornelis, D.G. Cotte, K. Cunnington, H. Damerau, M. Delrieux, J.L. Duran-Lopez, A. Findlay, J. Fleuret, F. Follin, P. Freyermuth, H. Genoud, S.S. Gilardoni, A. Guerrero, S. Hancock, K. Hanke, O. Hans, R. Hazelaar, W. Höfle, L.K. Jensen, J. Kuczerowski, Y. Le Borgne, R. Maillet, D. Manglunki, S. Massot, E. Matli, G. Metral, B. Mikulec, E. Métral, J.-M. Nonglaton, E. Ovalle, L. Pereira, F.C. Peters, A. Rey, J.P. Ridewood, G. Rumolo, J.L. Sanchez Alvarez, E.N. Shaposhnikova, R.R. Steerenberg, R.J. Steinhagen, J. Tan, B. Vandorpe, E. Veyrunes CERN, Geneva, Switzerland
	Some of the upgrade scenarios of the high-luminosity LHC require large intensity per bunch from the injector chain. Single bunch beams with intensities of up to 3.5 to 4·10¹¹ p/b and nominal emittances were successfully produced in the PS Complex and delivered to the SPS in 2010. This contribution presents results of studies with this new intense beam in the SPS to probe single bunch intensity limitations with nominal gamma transition. In particular, the vertical Transverse Mode Coupling Instability (TMCI) threshold with low chromaticity was observed at 1.6·10¹¹ p/b for single nominal LHC bunches in the SPS. With increased vertical chromaticity, larger intensities could be injected, stored along the flat bottom and accelerated up to 450 GeV/c. However, significant losses and/or transverse emittance blow up were then observed. Longitudinal and transverse optimization efforts in the PSB, PS and SPS were put in place to minimize this beam degradation and succeeded to obtain single 2.3·10¹¹ p/b LHC type bunches with satisfying parameters at extraction of the SPS.

MOPS010	Experimental Studies with Low Transition Energy Optics in the SPS	optics, emittance, single-bunch, damping	613
	H. Bartosik, T. Argyropoulos, T. Bohl, S. Cettour Cave, K. Cornelis, J. Esteban Muller, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova, J. Wenninger CERN, Geneva, Switzerland
	The optics of the SPS can be tuned to lower transition energy such that the slippage factor at injection is raised by a factor of almost 3. From theory, an increase of the intensity thresholds for transverse mode coupling, longitudinal coupled bunch and longitudinal instabilities due to the loss of Landau damping can be expected. In this paper, experimental studies in the SPS with single bunches of protons with intensities of up to 3.5·10¹¹ p/b on the flat bottom and at 450 GeV/c are presented. Longitudinal instabilities were studied with LHC-type beams with 50~ns spacing and injected intensities up to 1.8·10¹¹ p/b. The measurements address the increase of intensity thresholds and the achievable transverse emittances in the new low gamma transition optics with respect to the nominal SPS optics. The obtained results are compared with numerical simulations.

MOPS012	Optics Considerations for Lowering Transition Energy in the SPS	optics, resonance, emittance, lattice	619
	H. Bartosik, G. Arduini, Y. Papaphilippou CERN, Geneva, Switzerland
	Beam stability for high intensity LHC beams in the SPS can be improved by increasing the slippage factor, i.e. reducing the transition energy. In this paper, possible ways of modifying the optics of the SPS for lower transition energy are reviewed. In particular, a threefold increase of the slippage factor at injection can be achieved by decreasing the integer part of the tunes by 6 units. The properties of this new low-transition optics are compared with the nominal SPS optics, including working point and resonance behavior. Possible limitations are discussed.

MOPS013	Transverse Low Frequency Broad-band Impedance Measurements in the CERN PS	impedance, proton, space-charge, extraction	622
	S. Aumon EPFL, Lausanne, Switzerland P. Freyermuth, S.S. Gilardoni, O. Hans, E. Métral, G. Rumolo CERN, Geneva, Switzerland
	The base-line scenario for the High-Luminosity LHC upgrade foresees an intensity increase delivered by the injectors. With its 53 years, the CERN PS would have to operate beyond the limit of its performances to match the future requirements. Beam instabilities driven by transverse impedance are an important issue for the operation of high intensity beams as for the high-brightness LHC beams. Measurements of transverse tune dependence with beam intensity were performed at injection kinetic energy 1.4~GeV and at LHC beam extraction momentum 26~GeV/c. This allows deducing the low frequency inductive broad-band impedance of the machine. Then an estimation of the real part of the impedance is made by the rise time measurement of a fast transverse instability believed to be a TMCI type. Those are the first step towards a global machine impedance characterization in order to push forward the performances of the accelerator.

MOPS014	Tune and Space Charge Studies for High-brightness and High-intensity Beams at CERN PS	resonance, emittance, space-charge, beam-losses	625
	S.S. Gilardoni, S. Aumon, J. Brenas, P. Freyermuth, A. Huschauer, R. Maillet, E. Matli, R.R. Steerenberg, B. Vandorpe CERN, Geneva, Switzerland E. Benedetto National Technical University of Athens, Zografou, Greece
	The current 1.4 GeV CERN PS injection energy limits the maximum intensity required by the future High-Luminosity LHC. The bare-machine large chromaticity combined with the non-linear space charge forces make high-brightness and high-intensity beams crossing betatron resonances along the injection flat bottom, inducing transverse emittance blow-up and beam losses. A scan of the working point plane {Qx,Qy} was done in order to identify beam destructive resonances, in the framework of a possible 2 GeV injection energy upgrade which would reduce the space charge effect on the tune. Experiments were carried out in order to review the maximum space charge tune shift for which no transverse emittance blow-up is observed. The results of measurements and simulations will be presented in this paper.

MOPS017	Simulation Studies of Macro-particles Falling into the LHC Proton Beam	proton, beam-losses, simulation, vacuum	634
	F. Zimmermann, T. Baer, M. Giovannozzi, E.B. Holzer, E. Nebot Del Busto, A. Nordt, M. Sapinski CERN, Geneva, Switzerland N. Fuster Valencia University, Atomic Molecular and Nuclear Physics Department, Valencia, Spain Z. Yang EPFL, Lausanne, Switzerland
	We report updated simulations on the interaction of macro-particles falling from the top of the vacuum chamber into the circulating LHC proton beam. The path and charge state of micron size micro-particles are computed together with the resulting beam losses, which – if high enough - can lead to the local quench of SC magnets. The simulated time evolution of the beam loss is compared with observations in order to constrain some macro-particle parameters. We also discuss the possibility of a "multiple crossing" by the same macro-particle, the effect of a strong dipole field, and the dependence of peak loss rate and loss duration on beam current and on beam size.

MOPS018	Simulation and Measurement of Half Integer Resonance in Coasting Beams on the ISIS Ring	resonance, emittance, simulation, space-charge	637
	C.M. Warsop STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom D.J. Adams, B. Jones, B.G. Pine, H. V. Smith, R.E. Williamson 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 (RCS), which provides 3·10¹³ protons per pulse at 50 Hz, corresponding to a beam power of 0.2 MW. In common with many lower energy, high intensity proton rings, a key loss mechanism on ISIS is half integer resonance under space charge. This paper summarises experimental and simulation work studying half integer resonance in a “2D” coasting beam in the ISIS ring: understanding this is an essential prerequisite for explaining the more complicated case of RCS operation. For coasting beam experiments, the ring is reconfigured to storage ring mode with RF off and main magnets powered on DC current only. A 70 MeV beam is injected, painted appropriately, and manipulated so as to approach resonance. Understanding how the resonant condition develops is central to explaining observations, so realistic simulations of resonance, including injection, ramping of intensity and tunes are being developed. Results from the ORBIT code are presented and compared with experimental and theoretical results. Finally, future plans are summarized.

MOPS019	High Intensity Longitudinal Dynamics Studies for Higher Energy Injection into the ISIS Synchrotron	simulation, bunching, space-charge, linac	640
	R.E. Williamson, D.J. Adams, C.M. Warsop STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	ISIS is the world’s most productive pulsed neutron and muon source, at the Rutherford Appleton Laboratory in the UK. Operation is centred on a loss-limited 50 Hz proton synchrotron which accelerates 3·10¹³ protons per pulse from 70 MeV to 800 MeV, delivering a mean beam power of 0.2 MW. Present studies on ISIS upgrades are focussed on a new linac for higher energy injection into the existing ring, potentially increasing beam current through reduction in space charge and optimized injection. Studies assume injection of a chopped beam at 180 MeV and offer the possibility of beam powers in the 0.5 MW regime. A critical aspect of such an upgrade is the longitudinal dynamics, associated RF parameters, space charge levels and stringent requirements on beam loss. This paper outlines studies optimizing longitudinal parameters including key design requirements such as bunching factor and satisfying the Keil-Schnell-Boussard stability criterion throughout acceleration. Work developing and benchmarking the in-house longitudinal dynamics code used for these studies is also summarized.

MOPS034	Progress on Space Charge Compensation Study in Low Energy High Intense H⁺ Beam*	emittance, electron, ion, space-charge	676
	P.N. Lu, Z.Y. Guo, S.X. Peng, Z.X. Yuan, J. Zhao PKU/IHIP, Beijing, People's Republic of China H.T. Ren Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
	This article lays emphasis on the relationship between the Space Charge Compensation (SCC) and the beam quality in different conditions. Ar and Kr are used to compensate a 35keV/90mA H⁺ beam with the gas pressure from 3.7×10^-4 Pa to 6×10^-3 Pa. Experiments are conducted in different compensation states with three approaches. With an energy spectrometer, we have got the energy spectra of Extra Compensation Gas Ions (ECGI). By a beam profile meter, the beam profiles are obtained when the injection of compensation gas is gradually rising. In the meantime, the beam emittance is measured under different compensation conditions. After measurements of the above data, the potential and the rest charge distributions in the beam are calculated by analyzing the ECGI energy spectra and beam profiles. All experiments performed aimed to seek out the best circumstance for SCC dominated low energy high intensity ion beams.together to calculate the potential distribution are calculated by analyzing the energy spectra and beam profiles. All experiments performed aimed to seeking for the best circumstances in SCC dominated low energy high intensity ion beams.

MOPS039	High Power Proton Linac Front-End: Beam Dynamics Investigation and Plans for the ESS	rfq, solenoid, emittance, proton	688
	A. Ponton ESS, Lund, Sweden
	Beam availibility is one of the major concerns for the designer of high power proton linacs. Since the Radio-Frequency Quadrupole (RFQ) will shape and accelerate the beam in the early stage of its propagation it will have a significant impact on the particle dynamics throughout the rest of the linac. The key role of the RFQ is consequently to deliver high quality beams with optimal transmission. Furthermore understanding the space charge compensation mechanism in the Low Energy Beam Transport line (LEBT) is mandatory if one wants to perform calculations with realistic beams. The European Spallation Source (ESS) has put important R&D efforts in designing the linac front-end and deep beam dynamics studies have been undertaken. Results of the investigation work will be presented. We will then deal with the future plans for the ESS and we will finally give a full description of the RFQ and LEBT scheme.

MOPS058	KEKB Linac Wakefield Studies of Comparing Theoretical Calculation, Simulation and Experimental Measurement*	emittance, wakefield, linac, simulation	739
	L. Zang, N. Iida, Y. Ogawa, M. Satoh, M. Yoshida, D.M. Zhou KEK, Ibaraki, Japan
	For superKEKB, in order to achieve aiming luminosity machine need to run with a nano-beam scheme so that a small beam emittance is critical important. During the beam propagation, the short-range wake field in the accelerating structure will cause the beam instability and emittance growth. In practical, injecting beam with certain offset could compensate wakfield. And beam emittance could be measured by tuning the quadruple known as quadscan method. In this paper, wakefield theoretical calculation, simulation results will be presented. And then the wakefield impact to beam emittance and wakefield compensation will be discussed. Finally, we will show the comparison of the results getting from theoretical calculation and experimental measurement.

MOPS060	Study on Resistive Wall Instability in CSNS/RCS	simulation, impedance, wakefield, extraction	745
	L. Huang, Y.D. Liu, S. Wang IHEP Beijing, Bejing, People's Republic of China
	Rapid Cycling Synchrotron of the China Spallation Neutron Source is a high intensity proton accelerator, with average beam power of 100kW. The collective effects caused by the coupling impedance may be the limit to beam power. The impedance estimation for components on beam line shows that the resistive wall impedance and its instability are more serious than any others. Based on the impedance budget, the instability is theoretically estimated. And a simple resistive wall wake field model is used to simulate the bunch oscillation and the growth rate instability. In this model, the continuous resistive wall wake field is equivalent to a point wake field and long bunch is sliced into many micro-bunches. By tracking the dynamics of the macro-bunches, the transverse growth rate are obtained and the result are analyzed.

MOPS064	Longitudinal Beam Stability and Related Effects at the ALBA Storage Ring	kicker, impedance, resonance, vacuum	748
	T.F. Günzel CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The risk of longitudinal instabilities excited by narrowband and broadband resonator impedance was studied. A campaign for the search of modes trapped in vacuum chamber elements of the ALBA storage ring via electromagnetic simulation was initiated. Several critical vacuum elements in the ring like the vertical scraper, the injection and feedback kickers were identified. The outlets of the injection kicker had to be protected with RF-fingers whereas the scraper only produces dangerous modes in the withdrawn state, both do not pose a real problem. However, the calculated power distribution generated in the feedback kickers could be an obstacle for reaching the nominal current of 400mA. Furthermore, the budget of Z(n)/n of the storage ring was computed and checked on the risk of microwave instability using the Boussard criterion.

MOPS069	Review of Beam Instabilities in the Presence of Electron Clouds in the LHC	emittance, electron, simulation, luminosity	760
	K.S.B. Li, G. Rumolo CERN, Geneva, Switzerland
	Recent observations at the LHC indicate the build-up of electron clouds when 50 ns spaced beams are injected into the machine at nominal intensity. These electron clouds are a source of coherent beam instabilities and incoherent emittance growth and limit the achievable luminosity. To better understand the influence of electron clouds on the beam dynamics, simulations have been carried out to study both the coherent and the incoherent effects on the beam. The simulations are performed with the HeadTail tracking code; the usage of new post-processing software allows determining not only the beam intensity thresholds in terms of the central electron cloud density but also the footprint of the beam in tune space. In this paper we review instability thresholds and tune footprints for beams with different emittances and interacting with an electron cloud in field-free or dipole regions.

MOPS078	Coaxial Wire Measurements of Ferrite Kicker Magnets	impedance, kicker, simulation, extraction	784
	H.A. Day, R.M. Jones UMAN, Manchester, United Kingdom M.J. Barnes, F. Caspers, H.A. Day, E. Métral, B. Salvant, C. Zannini CERN, Geneva, Switzerland
	Fast kicker magnets are used to inject beam into and eject beam out of the CERN accelerator rings. These kickers are generally transmission line type magnets with a rectangular shaped aperture through which the beam passes. Unless special precautions are taken the impedance of the yoke can provoke significant beam induced heating, especially for high intensities. In addition the impedance may contribute to beam instabilities. The results of longitudinal and transverse impedance measurements, for various kicker magnets, are presented and compared with analytical calculations: in addition predictions from a numerical analysis are discussed.

MOPS085	Wakefield Calculations for the LCLS in Multibunch Operation*	linac, dipole, HOM, FEL	802
	K.L.F. Bane SLAC, Menlo Park, California, USA
	Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515. Normally the Linac Coherent Light Source (LCLS) operates in single-bunch mode, sending a bunch of up to 250 pC charge at 120 Hz through the linac and the undulator, and the resulting FEL radiation into one of the experimental hutches. With two bunches per rf pulse, each pulse could feed either two experiments or one experiment in a pump-probe type configuration. Two-bunch FEL operation has already been briefly tested at the LCLS, and works reasonably well, although not yet routinely. In this report we study the longitudinal and transverse long-range (bunch-to-bunch) wakefields of the linacs and their effects on LCLS performance in two-bunch mode. The longitudinal wake changes the average energy and chirp at the second bunch, and the transverse wake misaligns the second bunch (in transverse phase space) in the presence of e.g. transverse injection jitter or quad misalignments. Finally, we extend the study to consider the LCLS with trains of up to 20 bunches per rf pulse. F.-J. Decker et al, "A demonstration of multi-bunch operation in the LCLS," Proceedings of FEL2010, Malmoe, Sweden, p. 467.

MOPZ004	Studies for the PRISM FFAG Ring for the Next Generation Muon to Electron Conversion Experiment	kicker, electron, extraction, septum	826
	J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom M. Aslaninejad, L.J. Jenner, A. Kurup, J. Pasternak, Y. Shi, Y. Uchida Imperial College of Science and Technology, Department of Physics, London, United Kingdom R.J. Barlow UMAN, Manchester, United Kingdom K.M. Hock, B.D. Muratori Cockcroft Institute, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida, C.R. Prior STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom Y. Kuno, A. Sato Osaka University, Osaka, Japan J.-B. Lagrange, Y. Mori KURRI, Osaka, Japan M. Lancaster UCL, London, United Kingdom C. Ohmori KEK, Tokai, Ibaraki, Japan T. Planche TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada S.L. Smith STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom H. Witte, T. Yokoi JAI, Oxford, United Kingdom
	High intensity and high quality muon beams are needed for the next generation lepton flavour violation experiments. Such beams can be produced by sending a short proton pulse to a pion production target, capturing the pions and performing RF phase rotation on the resulting muon beam in an FFAG ring. Such a solution was proposed for the PRISM project and this paper summarizes its current status. In particular the PRISM task force was created to address the accelerator and detector issues that need to be solved in order to realise the PRISM experiment. Alternative designs for the PRISM FFAG ring are discussed and their performance compared. The injection/extraction systems and matching to the solenoid channels upstream and downstream of the FFAG ring are presented. The future direction for the study will be outlined.

MOPZ007	A Non-scaling Fixed Field Alternating Gradient Accelerator for the Final Acceleration Stage of the International Design Study of the Neutrino Factory	kicker, extraction, cavity, lattice	832
	J.S. Berg BNL, Upton, Long Island, New York, USA M. Aslaninejad, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom N. Bliss, M.A. Cordwell, T.J. Jones STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom A.A. Muir STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom H. Witte JAI, Oxford, United Kingdom
	Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The International Design Study of the Neutrino Factory (IDS-NF) has recently completed its Interim Design Report (IDR), which presents our current baseline design of the neutrino factory. To increase the efficiency and reduce the cost of acceleration, the IDR design uses a linear non-scaling fixed field alternating gradient accelerator (FFAG) for its final acceleration stage. We present the current lattice design of that FFAG, including the main ring plus its injection and extraction systems. We describe parameters for the main ring magnets, kickers, and septa, as well as the power supplies for the kickers. We present a first pass at an engineering layout for the ring and its subsystems.

MOPZ030	Status of Studies of Achromat-based 6D Ionization Cooling Rings for Muons	lattice, solenoid, kicker, extraction	865
	X.P. Ding, D.B. Cline UCLA, Los Angeles, California, USA J.S. Berg, H.G. Kirk BNL, Upton, Long Island, New York, USA A.A. Garren Particle Beam Lasers, Inc., Northridge, California, USA
	Funding: This work was supported by the U.S. Department of Energy in part under award numbers DE-FG02-92ER40695 (UCLA), DE-AC02-98CH10886 (BNL) and DE-FG02-07ER84855 (Particle Beam Lasers, Inc.)” Six dimensional ionization cooling of muons is needed to achieve the necessary luminosity for a muon collider. If that cooling could occur over multiple turns in a closed ring, there would be significant cost savings over a single-pass cooling channel. We report on the status of a cooling ring with achromatic arcs. The achromatic design permits the design to easily switch between a closed ring and a snaking geometry on injection or extraction from the ring. The ring is designed with sufficient space in each superperiod for injection and extraction magnets. We describe the ring's lattice design, performance, and injection/extraction requirements.

MOPZ038	EMMA Injection and Extraction	extraction, dipole, septum, kicker	883
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom Y. Giboudot Brunel University, Middlesex, United Kingdom D.J. Holder The University of Liverpool, Liverpool, United Kingdom
	EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. NS-FFAGs related to EMMA have an unprecedented potential for medical accelerators for carbon and proton hadron therapy. They could also be used as the accelerator for a sub-critical reactor. We summarize the design and commissioning of both the injection and extraction lines for this machine. In particular, we look at the commissioning challenges of injection and extraction.

MOPZ039	Dispersion-free Regions and Insertions for EMMA	lattice, sextupole, extraction, quadrupole	886
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. Several upgrade possibilities for EMMA are explored, from creating a dispersion-free region in the ring to facilitate injection and extraction to making an insertion in EMMA by turning it into a racetrack-style machine. A dispersion-free region may be created in two separate ways. The first is by using a layout of EMMA which is naturally dispersion-free at the start and end of each cell. This means that we can arrange for periodic dispersion-free sections in every cell or in-between cells. The second is achieved through the use of sextupoles, by going off-axis in them, one has essentially a quadrupolar force which can be used to match the dispersion to zero in a particular place and for a particular energy. The benefits and drawbacks of both methods are discussed from the point of view of practicality and space in general, and applicability to EMMA in particular.

TUYB01	First Results from the EMMA Experiment	acceleration, electron, cavity, septum	951
	S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Report on first commissioning results and operational experience with EMMA, the world's first nonscaling FFAG. In particular review the effect of resonance crossing, and the efficiency of serpentine acceleration.
	Slides TUYB01 [9.201 MB]

TUPC022	Design of the CLIC Drive Beam Recombination Complex	emittance, linac, sextupole, synchrotron	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.

TUPC053	Superconducting Positron Stacking Ring for CLIC	positron, damping, synchrotron, 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.

TUPC060	A Multi-mode RF Photocathode Gun	gun, cathode, cavity, electron	1135
	S.V. Kuzikov, A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia J.L. Hirshfield Yale University, Physics Department, New Haven, CT, USA Y. Jiang Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA V. Vogel DESY, Hamburg, Germany
	A photocathode injection gun based on standard emittance compensating techniques and driven by several (N ≥ 2) harmonically related RF sources is considered. Multi-harmonic excitation can provide high-quality flatness in time of the field at the cathode when a bunch is being injected. This allows one to obtain ≥1 nC, 20-40 ps electron bunches with preservation of low emittance. Another advantage is a reduction of Ohmic losses and the required input RF power (for a given cathode field). Preliminary calculations show that input power in a three-mode cavity (0.65 GHz, 1.3 GHz, 2.6 GHz) is nearly half the power needed to feed a single mode with the same cathode field. A further appealing property is the predicted increase of breakdown threshold due to a reduction of surface exposure time to high fields in a symmetric cavity, and due to the so-called anode-cathode effect in a longitudinally asymmetric cavity. These properties may help one to reach bunch energies as high as 3-5 MeV after the first half cell.

TUPC064	Transverse Phase Space Tomography in TRIUMF Injection Beamline	emittance, space-charge, TRIUMF, quadrupole	1144
	Y.-N. Rao, R.A. Baartman TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Funding: TRIUMF receives funding via a contribution agreement through the National Research Council of Canada. By tomography is meant the reconstruction of a 2-dimensional distribution from a number of 1-dimensional projections. In the case of transverse phase space, one records many profiles while varying a focusing device such as a quadrupole. Our aim was to investigate the two transverse phase space distributions in our 300keV H-minus beamline. We performed a series of measurements of beam profiles as a function of the voltage of an electrostatic quadrupole and used these along with the corresponding calculated transfer matrices in an iterative program based upon the Maximum Entropy algorithm, to find the phase space distributions. As well, we made measurements using an Allison-type emittance scanner to scan both planes. In this paper we present the details of these measurements, calculations, and we compare the two techniques.

TUPC095	Bucket-by-bucket On/Off-axis Injection with Variable Field Fast Kicker	kicker, dipole, quadrupole, emittance	1230
	T. Nakamura JASRI/SPring-8, Hyogo-ken, Japan
	Dynamic aperture of ultra-low emittance storage rings is expected to be as small as a few mm; one order smaller than that of current rings, because of their high nonlinearity. The conventional injection scheme with bump formation may not be applied for such small aperture. On-axis injection with fast magnet is one of the solutions, however, it requires the injection beam of long trains of bunches, which impose serious limitation on the injector and the filling pattern. We propose a bucket-by-bucket on-axis/off-axis injection scheme, which manipulates the injection and stored beams bucket-by-bucket with a variable field fast kicker. For on-axis injection, this scheme eliminates the limitation on injectors and filling pattern, and also it can reject the contaminated electrons from the injector to keep the bunch purity. Those advantages allow the SPring-8 XFEL low emittance linac to be an injector matched with ultra-low emittance rings like the SPring-8 II: upgrade plan of SPring-8. By changing the drive power to the kicker, it can also produce position dependent kick required for the off-axis injection, with minimal perturbation on the stored beam achieved by bucket-by-bucket scheme.

TUPC098	Beam Profile Measurement using Flying Wire Monitors at the J-PARC Main Ring*	simulation, space-charge, proton, emittance	1239
	S. Igarashi, K. Ohmi, Y. Sato, M.J. Shirakata, M. Tejima, T. Toyama KEK, Ibaraki, Japan Y. Hashimoto, K. Satou J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Transverse beam profiles have been measured using flying wire monitors at the main ring of the Japan Proton Accelerator Research Complex (J-PARC). The flying wire is a beam profile monitor using a thin carbon fiber as a target. The beam is scanned with the wire target at the maximum speed of 5 m/s. The secondary particles from the beam-wire scattering are detected using a scintillation counter as a function of the wire position. The measurement has revealed a characteristic temporal change of the beam profile during the injection period of 120 ms. A multiparticle tracking simulation program, SCTR, taking account of space charge effects has successfully reproduced the beam profiles.

TUPC099	New Measurements of Proton Beam Extinction at J-PARC	proton, secondary-beams, linac, vacuum	1242
	K. Yoshimura, Y. Hori, Y. Igarashi, S. Mihara, H. Nishiguchi, Y. Sato, M. Shimamoto, Y. Takeda, M. Uota KEK, Ibaraki, Japan M. Aoki, S. Hikida, H. Nakai Osaka University, Osaka, Japan Y. Hashimoto J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Proton beam extinction, defined as a residual to primary ratio of beam intensity, is one of the most important parameters to realize the future muon electron conversion experiment (COMET) proposed at J-PARC. To achieve the required extinction level of 10^-9, we started measuring extinction at main ring (MR) as its first step. According to the various measurements done at the different positions, empty RF buckets of RCS, which were considered to be swept away by the RF chopper, contained about 10^-7 ~ 10^-5 of the main beam pulse due to chopper inefficiency. We have developed a new beam monitor with improved performance for further studies at the abort line. In addition, we have started new measurements at the Hadron experimental hall by using slow-extracted beam. In this paper, we present recent results and future prospect of beam extinction measurements.

TUPC100	Longitudinal Beam Profile Measurement at J-PARC Separated Drift Tube Linac	beam-losses, cavity, linac, simulation	1245
	T. Maruta KEK/JAEA, Ibaraki-Ken, Japan M. Ikegami KEK, Ibaraki, Japan A. Miura, G.H. Wei JAEA/J-PARC, Tokai-mura, Japan H. Sako JAEA, Ibaraki-ken, Japan
	We measured longitudinal beam profile at Separated Drift Tube Linac (SDTL) injection part by scanning beam transmission and beamloss at the downstream of SDTL section by changing SDTL injection phase. As the beam goes to acceptance edge, part of the beam which is out of acceptance isn't accelerate and finally it is lost by hitting to beam duct. Thus beam transmission shows sliced bunch shape by acceptance edge, it is possible to reconstruct the beam bunch shape. The result shows about 60% wider profile in both phi and E direction against to design.

TUPC103	Monitoring of the Betatron Tune and Amplitude at Multi-batch Injection of J-PARC MR	kicker, betatron, feedback, quadrupole	1254
	S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan M. Takagi Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan M. Tejima, T. Toyama KEK, Ibaraki, Japan
	The beam power of J-PARC Main Ring Synchrotron (MR) increased gradually from 2008, and came to be able regularly to supply the beam of 145kW February, 2011. Many of current beam losses are localized to the collimator located on the injection section. One of the problems of the beam injection is that the orbit of the beam transportation line is unstable. It causes sometimes large transverse injection error. Because the transverse injection error is essentially proportional to the amplitude of the betatron oscillation, it is possible to observe by measuring the turn-by-turn position for every bunch of injected beam by using BPMs located on the injection section. In this report, it is described the method how to measure injection error from beam position. It is also discussed about the effect of reflection wave of injection kicker magnets.

TUPC107	Some Preliminary Experiments using LIBERA BPMs in BEPCII*	coupling, resonance, kicker, feedback	1266
	Y. Zhang, H.Z. Ma, J. Yue IHEP Beijing, Beijing, People's Republic of China
	Funding: Supported by the National Natural Science Foundation of China (10805051) There are total 16 LIBERA BPMs in BEPCII, which is a double ring e⁺e⁻ collider. The turn-by-turn BPMs serve as only tune measurement system in most cases during normal operation. We tried to do some more machine study using them: the local coupling parameter at the BPM, the resonance driving term, the decoherence parameter which could be used to calibrate the strength of octupole in the ring. We also compare the difference from the different exciting method: single time kick with injection kicker or sinusoidal kick with feedback system.

TUPC112	Photon Beam Position Monitor based on Position-sensitive Detector for HLS*	photon, synchrotron, 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.

TUPC115	Application of Libera Brilliance Single Pass at NSRL Linac BPM System	brilliance, linac, controls, pick-up	1284
	J.Y. Zou, J. Fang, P. Lu, T.J. Ma, B.G. Sun, Y.L. Yang, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Libera Brilliance Single Pass is a digital beam position processor with capabilities of single pass position measurement. This device can be used on the stripline beam position monitor (BPM) of the linac and transfer lines on light sources as well as injector system for the FELs. The linac of Hefei light source (HLS) was equipped with 2 stripline beam position monitors, which will be increased to 20 BPMs after upgrading. The existing BPM electronics were the homemade electronics with logarithm detector. To enhance the functionality of the BPM system, the Libera Brilliance Single Pass is employed to replace the existing BPM electronics. The newly buying devices have made test of characterization. The mapping of stripline BPM is made on a workbench with Libera Brilliance Single Pass. The beam position is tested at linac using Libera Brilliance Single Pass. And the results of these measurement performed on Libera are reported to compared to measurements with the linac’s existing BPM electronics.

TUPC135	Beam Loss Monitors Comparison at the CERN Proton Synchrotron	beam-losses, radiation, electron, proton	1341
	S.S. Gilardoni, S. Aumon, E. Effinger, J. Gil Flores CERN, Geneva, Switzerland U. Wienands SLAC, Menlo Park, California, USA
	CERN is planning the renovation and upgrade of the beam loss detection system for the Proton Synchrotron (PS). Improved performance in speed–to be able to monitor beam loss on a bunch-by-bunch basis–and in long-term stability–to reduce or avoid the need for periodic calibration–are aimed for. To select the most suitable technology, different detectors were benchmarked in the machine with respect to the same beam loss. The characteristics of the different detectors, the results of the measurement campaign and their suitability as future monitors for the PS are presented.

TUPC136	Analysis of Fast Losses in the LHC with the BLM System	beam-losses, quadrupole, superconducting-magnet, proton	1344
	E. Nebot Del Busto, T. Baer, B. Dehning, E. Effinger, J. Emery, E.B. Holzer, A. Marsili, A. Nordt, M. Sapinski, R. Schmidt, B. Velghe, J. Wenninger, C. Zamantzas, F. Zimmermann CERN, Geneva, Switzerland N. Fuster Valencia University, Atomic Molecular and Nuclear Physics Department, Valencia, Spain Z. Yang EPFL, Lausanne, Switzerland
	About 3600 Ionization Chambers are located around the LHC ring to detect beam losses that could damage the equipment or quench superconducting magnets. The BLMs integrate the losses in 12 different time intervals (from 40 us to 83.8 s) allowing for different abort thresholds depending on the duration of the loss and the beam energy. The signals are also recorded in a database at 1 Hz for offline analysis. During the 2010 run, a limiting factor in the machine availability were sudden losses appearing around the ring on the ms time scale and detected exclusively by the BLM system. It is believed that such losses originate from dust particles falling into the beam, or being attracted by its strong electromagnetic field. This document describes some of the properties of these "Unidentified Falling Objects" (UFOs) putting special emphasis on their dependence on beam parameters (energy, intensity, etc). The subsequent modification of the BLM beam abort thresholds for the 2011 run that were made to avoid unnecessary beam dumps caused by these UFO losses are also discussed.

TUPC137	UFOs in the LHC	beam-losses, kicker, simulation, acceleration	1347
	T. Baer, M.J. Barnes, B. Goddard, E.B. Holzer, J.M. Jimenez, A. Lechner, V. Mertens, E. Nebot Del Busto, A. Nordt, J.A. Uythoven, B. Velghe, J. Wenninger, F. Zimmermann CERN, Geneva, Switzerland
	One of the major known limitations for the performance of the Large Hadron Collider are so called UFOs (”Unidentified Falling Objects”). UFOs were first observed in July 2010 and have since caused numerous protection beam dumps. UFOs are thought to be micrometer sized dust particles which lead to fast beam losses with a duration of about 10 turns when they interact with the beam. In 2011, the diagnostics for such events was significantly improved which allows estimates of the properties, dynamics and production mechanisms of the dust particles. The state of knowledge and mitigation strategies are presented.

TUPC144	Preliminary BPM Electrics Testing for the Taiwan Photon Source Project	brilliance, controls, electron, feedback	1362
	C.H. Kuo, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.-Y. Liao NSRRC, Hsinchu, Taiwan
	The preliminary BPM electrics are developing and testing for Taiwan Photon Source (TPS), is a 3 GeV synchrotron light source which being in construction at NSRRC. This new BPM electronics with integrated FPGA based hardware, and will be testing in the TLS (Taiwan Light Source) with real beam at first. The enhance functionality of current generation will be adopted in the TPS. The electronic prototype testing and relative property will be reported in this report.

TUPC149	Measurements at the ALICE Tomography Section	quadrupole, emittance, simulation, background	1377
	M.G. Ibison, K.M. Hock, D.J. Holder, B.D. Muratori, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Korostelev The University of Liverpool, Liverpool, United Kingdom
	Funding: STFC This paper reports the results of tomography measurements of the electron beam transverse phase space distribution in the ALICE accelerator at Daresbury Laboratory. These measurements have two main aims. The first is to give a detailed picture of the phase space distribution of the electron beam injected from ALICE into the EMMA prototype non-scaling FFAG accelerator. The second is to provide data for the development and testing of a variety of techniques for tomographic reconstruction. We summarize the measurement results which we have obtained and discuss the advantages and disadvantages of some different tomography methods.

TUPC150	The Effect of Space-Charge on the Tomographic Measurement of Transverse Phase-Space in the EMMA Injection Line	space-charge, quadrupole, emittance, simulation	1380
	M.G. Ibison, M. Korostelev The University of Liverpool, Liverpool, United Kingdom K.M. Hock, D.J. Holder, B.D. Muratori, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: STFC Phase-space tomography for particle beams depends upon detailed knowledge of the particle transport through specified sections of a beam line. In the simplest case, only the effects of magnets (such as quadrupoles) and drift spaces need to be taken into account; however, in certain parameter regimes (high charge density and low energy) space charge forces may play a significant role. The ALICE accelerator is the electron source for EMMA, a prototype ns-FFAG machine. Results are presented of investigations into these effects on phase-space tomography in the injection line between ALICE and EMMA. The application of suitable correction techniques* to the EMMA injection line tomography measurements in the presence of space-charge is also discussed. * D. Stratakis et al., Phys. Rev. ST Accel. Beams 9, 112801 (2006).

TUPC157	Design and Initial Results of a Turn-by-Turn Beam Position Monitoring System for Multiple Bunch Operation of the ATF Damping Ring	damping, single-bunch, feedback, extraction	1398
	G.B. Christian, D.R. Bett, M.R. Davis, C. Perry JAI, Oxford, United Kingdom R. Apsimon, P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom B. Constance, A. Gerbershagen CERN, Geneva, Switzerland J. Resta-López IFIC, Valencia, Spain
	An FPGA-based monitoring system has been developed to study multi-bunch beam instabilities in the damping ring (DR) of the KEK Accelerator Test Facility (ATF), utilising a stripline beam position monitor (BPM) and existing BPM processor hardware. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR in single-bunch multi-train mode or the head bunch of up to three trains in multi-bunch mode, with a bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software were modified to record turn-by-turn data for up to six channels and 1–3 bunches in the DR. An overview of the system and initial results will be presented.

TUPC168	Results from the LHC BRAN Luminosity Monitor at Increased Luminosities	luminosity, emittance, radiation, simulation	1428
	R. Miyamoto BNL, Upton, Long Island, New York, USA E. Bravin CERN, Geneva, Switzerland H.S. Matis, A. Ratti, W.C. Turner, H. Yaver, T. stezelberger LBNL, Berkeley, California, USA
	Funding: This work supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP). The LHC BRAN luminosity monitors are used to monitor and optimize the luminosity at the LHC high luminosity interaction points IP1 and IP5. The Argon gas ionization chambers detect showers produced in the TAN absorbers by neutral particles emerging from pp collisions. The detectors have been operated during the 2010 run by counting the shower rate. As the current 2011 run has the multiplicity of proton-proton collisions per bunch crossing near ten, the detector sees more than one collision per bunch crossing. Therefore, the operation of the detector has been switched to pulse height mode to detect the average shower flux. This paper presents results from recent pulse height mode measurements, including the total and bunch-by-bunch luminosity as well as a determination of the crossing angle at these IPs. Comparisons with luminosity measurements from ATLAS and CMS are also presented.

TUPO012	Stable Planner Type Four-mirror Cavity Development for X-ray Production as Basic Development of Quantum Beam Technology Program	laser, cavity, superconducting-RF, target	1470
	H. Shimizu, Y. Higashi, Y. Honda, J. Urakawa KEK, Ibaraki, Japan
	As the development of quantum beam technology program, a facility to produce a semi-monochromatic X-ray via inverse Compton scattering with an electron beam accelerated by a superconducting RF cavity and a fiber amplified high power laser stacked in an external optical cavity system are now under construction. To achieve high brightness of Compton X-ray, we introduced a chicane with about a 1m-long zero dispersion straight section that includes IP. Head on collision scheme improves the yield of X-ray, but to do so, a huge and stout external optical cavity system must be needed. According to this demand, we develop a quite tolerable planner type four-mirror cavity with movable mirror mount system. In this paper, results obtained by the cavity construction and also laser development activities are described.

TUPS017	The LHC Experimental Beam Pipe Neon Venting, Pumping and Conditioning	vacuum, ion, monitoring, shielding	1557
	V. Baglin, G. Bregliozzi, D. Calegari, J.M. Jimenez, G. Lanza, G. Schneider CERN, Geneva, Switzerland
	The experimental vacuum chambers of the four LHC experiments (ATLAS, CMS, LHCb and ALICE) are mechanically optimized in order to be transparent to particles. In order to grant their mechanical stability and to avoid any overstress, every time there was a request for detector opening or closing and for working in the vicinity of the vacuum chamber, the experimental beam vacuum chambers have been vented to atmospheric pressure. Since the LHC start up a safety procedure has been applied to mechanically secure the four experimental beam pipes during each long technical stop. Ultra-pure neon was used to preserve at best the NEG pumping efficiency. Up to now more than 15 neon injections and pump down have been performed without detecting any reduction of the NEG efficiency. This paper describes the Gas Injection System performances and the main points of the venting and pumping procedure. Details of the experimental beam pipe vacuum recovery and conditioning are presented for each of the four LHC experiments (ATLAS, CMS, LHCb and ALICE).

TUPS026	Specification of New Vacuum Chambers for the LHC Experimental Interactions	vacuum, alignment, impedance, optics	1584
	R. Veness, R.W. Assmann, A. Ball, A. Behrens, C. Bracco, G. Bregliozzi, R. Bruce, H. Burkhardt, G. Corti, M.A. Gallilee, M. Giovannozzi, B. Goddard, D. Mergelkuhl, E. Métral, M. Nessi, W. Riegler, J. Wenninger CERN, Geneva, Switzerland N. Mounet, B. Salvant EPFL, Lausanne, Switzerland
	The apertures for the vacuum chambers at the interaction points inside the LHC experiments are key both to the safe operation of the LHC machine and to obtaining the best physics performance from the experiments. Following the successful startup of the LHC physics programme the ALICE, ATLAS and CMS experiments have launched projects to improve physics performance by adding detector layers closer to the beam. To achieve this they have requested smaller aperture vacuum chambers to be installed. The first periods of LHC operation have yielded much information both on the performance of the LHC and the stability and alignment of the experiments. In this paper, the new information relating to the aperture of these chambers is presented and a summary is made of analysis of parameters required to safely reduce the vacuum chambers apertures for the high-luminosity experiments ATLAS and CMS.

TUPS033	Foil Scattering Loss Mitigation by the Additional Collimation System of J-PARC RCS	collimation, vacuum, septum, scattering	1605
	K. Yamamoto, H. Harada, J. Kamiya, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the RCS, the significant losses were observed at the branch of H0 dump line and the Beam Position Monitor which was put at the downstream of the H0 dump branch duct. From the beam study, we were certain that these losses were caused by the scattering of the injection and circulating beam at the charge exchange injection foil. In order to mitigate these losses, we started to develop a new collimation system in the H0 branch duct. We presents a overview of this new collimation system.

TUPS052	An FPGA Based Controller for the MICE Target	target, controls, extraction, EPICS	1647
	P.J. Smith, C.N. Booth, P. Hodgson, E. Overton, M. Robinson Sheffield University, Sheffield, United Kingdom J. Leaver, K.R. Long Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Funding: UK Science and Technology Facilities Council The MICE experiment uses a beam of low energy muons to test the feasibility of ionization cooling. This beam is derived parasitically from the ISIS accelerator at the Rutherford Appleton Laboratory. A target mechanism has been developed that rapidly inserts a small titanium target into the circulating proton beam immediately prior to extraction without unduly disturbing the primary ISIS beam. The original control electronics for the MICE target was based upon an 8-bit PIC. Although this system was fully functional it did not provide the necessary IO to permit full integration of the target electronics onto the MICE EPICS system. A three phase program was established to migrate both the target control and DAQ electronics from the original prototype onto a fully integrated FPGA system that is capable of interfacing with EPICS through a local PC. This paper discusses this upgrade program, the motivation behind it and the performance of the upgraded target controller.

TUPS077	Shaping of Ion Pulses from an Electron Beam Ion Source for Particle Injection into Accelerators	ion, electron, ion-source, proton	1716
	F. Ullmann, A. Schwan DREEBIT GmbH, Dresden, Germany U. Hagen, O. Heid, H. von Jagwitz Siemens AG, Healthcare Technology and Concepts, Erlangen, Germany G. Zschornack Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany
	Electron Beam Ion Sources (EBISs) provide highly charged ions for many applications, amongst others for particle injection into accelerators. Although EBISs are limited in ion output they feature a lot of advantages which qualify them for accelerator injection. The ion pulses extracted from the ion sources can be directly injected into an accelerator sequence which however requires ion pulses with distinct shape and length. We present the production of ion pulses matching the requirements of particle injection. The ions are produced by trapping in a high density electron beam for a certain time with electrostatic potentials providing for their axial trapping. The ions are extracted by lowering the trapping potential, i.e. opening the trap. Due to the ion energy distribution within the trapping region ion extraction can be controlled by controlling the trapping potential. A specific time dependent control mode of the trapping potential thus allows to produce ion pulses with designated shape and length. Source parameters such as working gas pressure, electron beam current and energy are influencing the energy distribution of the ions which in turn is influencing pulse shaping.

TUPS078	Electron Beam Ion Sources – A New Access for Particle Acceleration	ion, electron, ion-source, emittance	1719
	F. Ullmann, F. Grossmann, V.P. Ovsyannikov, A. Schwan DREEBIT GmbH, Dresden, Germany G. Zschornack Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany
	Electron Beam Ion Sources (EBISs) produce highly charged ions in a high density electron beam. Due to their operational principle EBISs have a lot of advantages although limited in ion output. Since the radial source region is given by a narrow electron beam the extracted ion beam features a very low transversal emittance. Moreover, the ions are ionized by a monoenergetic electron beam resulting in a small variation of the ion energy distribution, and thus in a very low longitudinal emittance. Together with a low basis pressure of less than 10^-9 mbar this result in a high quality ion beam. The ions can be extracted as continuous beam as well as ion pulses with distinct pulse shapes. Providing almost any element with any charge state of up to completely ionized ions gives a large number of different projectiles and kinetic energies. The use of EBISs whether based on permanent magnets or on cryogen-free superconducting magnets has been proven in a variety of fields and applications. In addition, their compact design makes them transportable, low in operational costs, and guarantee easy handling.

TUPS080	Low Energy Bunching with a Double Gap RF Buncher	bunching, ion, ion-source, proton	1725
	H. von Jagwitz, U. Hagen, O. Heid, S. Setzer Siemens AG, Erlangen, Germany
	A compact double gap bunching system for low energy proton beams is presented. The system is designed for the bunching of a low current proton beam (less than 50μA) with an energy of 10 keV. The buncher operates at 150 MHz and bunches without significantly changing the beam energy. The beam is generated by an Electron Beam Ion Source and has to be bunched for the subsequent acceleration in a 150 MHz linear accelerator. The buncher contains two short gaps and an RF electrode inbetween. Thus the full length of the buncher in the beamline is in the range of 2 cm. The location of the bunch focus depends on the buncher power. The bunched beam was analysed at a distance of 550 mm with a fast faraday cup. The bunching effectivity was determined as 50%, which means that 50% of the protons of the beam were located in bunches with a width of 60°, which is a reasonable value of acceptance for a conventional accelerator cavity. Some theory and detailed results will be presented.

TUPZ001	90 m Optics Commissioning	optics, proton, coupling, scattering	1795
	S. Cavalier LAL, Orsay, France H. Burkhardt, M. Fitterer, G.J. Müller, S. Redaelli, R. Tomás, G. Vanbavinckhove, J. Wenninger CERN, Geneva, Switzerland
	Special β* = 90 m optics have been developed for the two very high luminosity insertions of the LHC, as a first step towards to allow for very low angle precision measurements of the proton-proton collisions in the LHC. These optics were developed to be compatible with the standard LHC injection and ramp optics. The target value of β* = 90 m is reached by an un-squeeze from the injection β* = 11 m. We describe the implementation of this optics in the LHC and the first experience in the commissioning of these optics.

TUPZ003	Simulation of Electron-cloud Build-Up for the Cold Arcs of the LHC and Comparison with Measured Data	electron, simulation, dipole, vacuum	1801
	G.H.I. Maury Cuna CINVESTAV, Mérida, Mexico G. Arduini, G. Rumolo, L.J. Tavian, F. Zimmermann CERN, Geneva, Switzerland
	The electron cloud generated by synchrotron radiation or residual gas ionization is a concern for LHC operation and performance. We report the results of simulations studies which examine the electron cloud build-up, at injection energy, 3.5 TeV for various operation parameters In particular we determine the value of the secondary emission yield corresponding to the multipacting threshold, and investigate the electron density, and heat as a function of bunch intensity for dipoles and field-free regions. We also include a comparison between simulations results and measured heat-load data from the LHC scrubbing runs in 2011

TUPZ004	The NICA Facility in Polarized Proton Operation Mode	collider, proton, ion, booster	1804
	A.D. Kovalenko, N.N. Agapov, Y. Filatov, V.D. Kekelidze, R.I. Lednicky, I.N. Meshkov, V.A. Mikhaylov, A.O. Sidorin, A. Sorin, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia
	Basic goal of the planned NICA facility at JINR is focused on the studying of heavy ion collisions over the energy range √s ~ 411 GeV/u. Capabilities of the proposed scheme were carefully analyzed in this case and reaching of the desired average luminosity, L = 1·10²⁷ cm^-2 s⁻¹ for gold-gold collisions at √s = 9 GeV/u, have been confirmed. The other important NICA research domain is the experiments with polarized proton beams at the highest possible energy, the highest luminosity and polarization degree as well. The main aim is to provide √s ~ 25 GeV and L ~ 1·10³¹ cm^-2 s⁻¹. The unsolved aspects of the problem are discussed, possible solutions are analyzed and necessary modifications of the NICA scheme are considered as well.

TUPZ006	Aperture Determination in the LHC Based on an Emittance Blowup Technique with Collimator Position Scan	beam-losses, emittance, optics, storage-ring	1810
	R.W. Assmann, R. Bruce, M. Giovannozzi, G.J. Müller, S. Redaelli, F. Schmidt, R. Tomás, J. Wenninger, D. Wollmann CERN, Geneva, Switzerland M. Alabau IFIC, Valencia, Spain
	A new method to determine the LHC aperture was proposed. The new component is a collimator scan technique that refers the globally measured aperture limit to the shadow of the primary collimator, expressed in σs of rms beam size. As a by-product the BLM response to beam loss is quantified. The method is described and LHC measurement results are presented.

TUPZ013	Calculation Method for Safe Beta* in the LHC	luminosity, emittance, optics, collimation	1828
	R. Bruce, R.W. Assmann, W. Herr, D. Wollmann CERN, Geneva, Switzerland
	One way of increasing the peak luminosity in the LHC is to decrease the beam size at the interaction points by squeezing to smaller values of beta. The LHC is now in a regime where safety and stability determines the limit in beta, as opposed to traditional optics limits. In this paper, we derive a calculation model to determine the safe beta-values based on collimator settings and operational stability of the LHC. This model was used to calculate the settings for the LHC run in 2011. It was found that beta could be decreased from 3.5 m to 1.5 m, which has now successfully been put into operation.

TUPZ016	First Run of the LHC as a Heavy-ion Collider	ion, luminosity, proton, heavy-ion	1837
	J.M. Jowett, G. Arduini, R.W. Assmann, P. Baudrenghien, C. Carli, M. Lamont, M. Solfaroli Camillocci, J.A. Uythoven, W. Venturini Delsolaro, J. Wenninger CERN, Geneva, Switzerland
	A year of LHC operation typically consists of an extended run with colliding protons, ending with a month in which the LHC has to switch to its second role as a heavy ion collider and provide a useful integrated luminosity to three experiments. The first such run in November 2010 demonstrated that this is feasible. Commissioning was extremely rapid, with collisions of Pb nuclei achieved within 55 h of first injection. Stable beams for physics data-taking were declared a little over one day later and the final integrated luminosity substantially exceeded expectations.

TUPZ019	Transverse Emittance Preservation through the LHC Cycle	emittance, luminosity, extraction, controls	1843
	V. Kain, B. Goddard, B.J. Holzer, J.M. Jowett, M. Meddahi, T. Mertens, F. Roncarolo CERN, Geneva, Switzerland
	The preservation of the transverse emittance is crucial for luminosity performance. At the LHC design stage the total allowed emittance increase was set to 7% throughout the LHC cycle. The proton run in 2010 showed that the injectors can provide beams with smaller emittances than nominal and higher bunch intensities. The LHC parameters are well under control and the emittances are kept below nominal until physics. The LHC luminosity goals for the first year of running could therefore be achieved with fewer bunches than initially foreseen. This paper will report on the measured emittance growth at injection from the SPS and the evolution of the emittance through the entire LHC cycle. Sources and possible cures for the observed emittance growth will be discussed.

TUPZ021	The SPS Beam Quality Monitor, from Design to Operation	extraction, dipole, quadrupole, luminosity	1849
	G. Papotti, T. Bohl, F. Follin, E.N. Shaposhnikova CERN, Geneva, Switzerland
	The SPS Beam Quality Monitor is a system that monitors longitudinal beam parameters on a cycle-by-cycle basis and prevents extraction to the LHC in case the specifications are not met. This avoids losses, unnecessary stress of machine protection components and luminosity degradation, additionally helping efficiency during the filling process. The system has been operational since the 2009 LHC run, checking the beam pattern, its correct position with respect to the LHC references, individual bunch lengths and stability. In this paper the algorithms used, the hardware implementation and the operational aspects are presented.

TUPZ022	Longitudinal Beam Measurements at the LHC: The LHC Beam Quality Monitor	pick-up, controls, emittance, damping	1852
	G. Papotti, T. Bohl, F. Follin, U. Wehrle CERN, Geneva, Switzerland
	The LHC Beam Quality Monitor is a system that measures individual bunch lengths and positions, similarly to the twin system SPS Beam Quality Monitor, from which it was derived. The pattern verification that the system provides is vital during the injection process to verify the correctness of the injected pattern, while the bunch length measurement is fedback to control the longitudinal emittance blow up performed during the energy ramp. In 2010 the system could for example clearly detect instances of longitudinal instabilities and beam excitation due to excess RF noise. The algorithms used, the hardware implementation and the system integration in the LHC control infrastructure are presented in this paper, along with possible improvements.

TUPZ023	Observation of Bunch to Bunch Differences due to Beam-beam Effects	luminosity, emittance, kicker, dynamic-aperture	1855
	G. Papotti, R. Alemany-Fernandez, R. Giachino, W. Herr, T. Pieloni, M. Schaumann, G. Trad CERN, Geneva, Switzerland
	Due to the bunch filling schemes in the LHC the bunches experience a very different collision schedule and therefore different beam-beam effects. These differences and the effect on the performance have been observed and compared with the expectations. Possible limitations due to these effects are discussed.

TUPZ026	Alternative Working Point(s) at Injection for the LHC	coupling, optics, quadrupole, emittance	1861
	R. Calaga, R. Miyamoto BNL, Upton, Long Island, New York, USA R. Tomás CERN, Geneva, Switzerland G. Vanbavinckhove NIKHEF, Amsterdam, The Netherlands
	Funding: This work partially supported by the US Department of Energy through the LHC Accelerator Research Program (LARP). At present, the LHC operates with a different fractional tunes at injection and at collision energy due to improved dynamic aperture indicated by tracking studies. Therefore, a tune swing crossing the 10th order resonance is needed during the beta-squeeze. A new proposal to alter the working point to collision tunes already at injection and during an energy ramp is foreseen to avoid the tune jump. Simulations and measurements of the optics along with the beam emittances and lifetime are compared to the nominal injection tunes. Feasibility for a working point close to the 1/2 integer is also attempted.

TUPZ034	Impact of Arc Phase Advance on Chromatic Optics in RHIC	optics, quadrupole, ion, proton	1885
	R. Calaga, R. Miyamoto, G. Robert-Demolaize, S.M. White BNL, Upton, Long Island, New York, USA R. De Maria, R. Tomás CERN, Geneva, Switzerland G. Vanbavinckhove NIKHEF, Amsterdam, The Netherlands
	Funding: This work is partially supported by the US Department of Energy through the LHC Accelerator Research program (LARP). The phase advance between the two interaction points in RHIC is optimized for dynamic aperture for a initial design beta-star. This may not hold true as RHIC presently operates with a considerably reduced beta-star. Additionally the reduction of the available beam aperture due to an enlarged chromatic beta-beating is evident. Results from phase advance scans between the two IPs to reduce the chromatic beta-beating in model and measurements are presented. Impact on the single beam lifetime and momentum aperture is compared to the nominal optics.

TUPZ041	Site Studies for the SuperB Collider and Synchrotron Radiation Facility Project	site, ground-motion, collider, linac	1900
	S. Tomassini, M.E. Biagini, P. Raimondi, C. Sanelli INFN/LNF, Frascati (Roma), Italy B. Bolzon CERN, Geneva, Switzerland G. Deleglise, A. Jeremie IN2P3-LAPP, Annecy-le-Vieux, France J.T. Seeman SLAC, Menlo Park, California, USA
	The SuperB project aims at the construction of a very high luminosity (10³⁶ cm^-2 s⁻¹) asymmetric electron-positron collider. Due to its large beam current (~2 A) high energy (~7 GeV) and low vertical emittance (less than 10^-11 m) the facility looks very attractive as an x-ray synchrotron radiation source, and therefore few beam lines are also foreseen. Possible locations are the campus of the University of Rome Tor Vergata or near another Italian INFN laboratory site. This paper presents and describes the status of the preliminary design of the civil infrastructure layout and related site issues.

WEOAA01	The ThomX Project	laser, feedback, cavity, synchrotron	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]

WEOBA02	KEK Digital Accelerator and its Beam Commissioning	ion, acceleration, induction, kicker	1920
	K. Takayama, T. Arai, Y. Arakida, M. Hasimoto, T. Iwashita, E. Kadokura, T. Kawakubo, T. Kubo, H. Nakanishi, K. Okamura, H. Someya, A. Takagi, M. Wake KEK, Ibaraki, Japan T. Adachi, K.W. Leo Sokendai, Ibaraki, Japan K. Okazaki Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
	The digital accelerator (DA), which is a small-scale induction synchrotron no requiring a high-energy injector accelerator and capable of providing a wide variety of ions, has been constructed at KEK. Since the last winter beam commissioning has been carried out. Preliminary results of the beam commissioning experiment as well as the accelerator itself will be presented at the conference. The KEK-DA consists of a 200 kV high voltage terminal, in which an ECRIS is embedded, 15 m long LEBT, electro-static injection kicker, and a 10 Hz rapid cycle synchrotron, which is the recycle use of the former 500 MeV Booster synchrotron. An ion pulse, which is chopped in 5 μs by the newly developed Marx generator driven chopper, is guided through the LEBT and injected by the electrostatic kicker, which is turned off before the injected ion pulse completes the first turn. Then the ion pulse is captured with a pair of barrier voltages and accelerated with the induction acceleration voltage through a full acceleration period. Beam commissioning has been started with a He¹⁺ ion beam of 50 micro-ampere. Beam commissioning of other ions such as C, N, O, Ne, and Ar will be expected. T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011. ** T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, these proceedings.
	Slides WEOBA02 [4.268 MB]

WEPC009	Design of an Antiproton Injection and Matching Beam Line for the AD Recycler Ring	antiproton, acceleration, quadrupole, ion	2019
	O. Karamyshev, G.A. Karamysheva MPI-K, Heidelberg, Germany O. Karamyshev, A.I. Papash JINR, Dubna, Moscow Region, Russia M.R.F. Siggel-King, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by STFC, the Helmholtz Association and GSI under contract VH-NG.328. A small antiproton recycler ring (AD-Rec) for use in the MUSASHI beamline at the CERN AD has been designed by the QUASAR Group for operation at energies between 3 and 30 keV. A highly efficient beam line for capturing the beam after extraction from the trap, transporting and injecting it into the AD Rec is very important to minimize losses and full the ring up to its space charge limit. In this contribution, the beam optical and mechanical design of the injector is presented.

WEPC010	Investigations into Efficient Extraction and Acceleration of Beams from Ion Traps	antiproton, extraction, emittance, ion	2022
	O. Karamyshev, G.A. Karamysheva MPI-K, Heidelberg, Germany O. Karamyshev, A.I. Papash JINR, Dubna, Moscow Region, Russia M.R.F. Siggel-King, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by STFC, the Helmholtz Association and GSI under contract VH-NG.328 A number of exotic ion species, such as for example radioactive isotopes or antiprotons, are highly desirable at very low energies of some tens of keV for fundamental studies. In order to obtain cooled beams with low emittance and low momentum spread, these particles are often first captured in an ion trap, cooled and then extracted and accelerated before being used in experiments. The extraction mechanism and subsequent beam handling impacts critically on the final beam quality. In this contribnution, an optimized scheme for efficient beam extraction and acceleration from ion traps is presented. Field maps from different existing ion trap setups, such as for example the Musashi trap at CERN, are used as a basis for simulation studies into the beam dynamics. Input and final beam emittances are analyzed as a function of the extraction and acceleration field geometries and the performance of different possible scenarios is directly compared.

WEPC016	Amplitude Dependent Orbit Shift and its Effect on Beam Injection	septum, betatron, sextupole, synchrotron	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.

WEPC025	Modeling Results of the ALBA Booster	booster, emittance, dipole, quadrupole	2058
	G. Benedetti, D. Einfeld, U. Iriso, J. Marcos, Z. Martí, M. Muñoz, M. Pont CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The 3rd generation light source ALBA is in the process of being commissioned. The full energy 3 GeV booster synchrotron was commissioned in the during 2010, ramping the beam from extracted from the LINAC from an energy of 110 MeV to the 3 GeV required for injection in the storage ring. The lattice is based in combined function bending magnets, providing a small emittance beam (< 12 nmrad) at extraction. This paper reviews the agreement between the optics modeling and the measures performed during the commissioning, with special regard to the optics measurement during the ramping process. The results from the magnetic measurement for the combined magnets while ramping are included in the model to explain the movement of the tunes during the ramp.

WEPC028	Record Low Beta-beat of 10% in the LHC	optics, hadron, quadrupole, collider	2061
	G. Vanbavinckhove NIKHEF, Amsterdam, The Netherlands M. Aiba PSI, Villigen, Switzerland R. Calaga, R. Miyamoto BNL, Upton, Long Island, New York, USA R. Tomás CERN, Geneva, Switzerland
	During the 2011 LHC run several measurements and correction campaigns were conducted. As a result a peak beta-beat of 10% level was achieved. This level, well below the specified tolerances of the LHC, improves the aperture margins and helps minimize the luminosity imbalance between the different experiments. A combination of local corrections at the insertion regions and an overall global correction were used to achieve this record low beta-beat. The sequence of the optics corrections and stability along the 2011 run are reported.

WEPC032	First Measurements of Higher Order Optics Parameters in the LHC	simulation, optics, resonance, kicker	2073
	G. Vanbavinckhove NIKHEF, Amsterdam, The Netherlands M. Aiba PSI, Villigen, Switzerland R. Bartolini Diamond, Oxfordshire, United Kingdom R. Calaga, R. Miyamoto BNL, Upton, Long Island, New York, USA M. Giovannozzi, F. Schmidt, R. Tomás CERN, Geneva, Switzerland E.H. Maclean JAI, Oxford, United Kingdom
	Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these parameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed simulations are compared to the measurements together with discussions on the measurement limitations.

WEPC042	Implementation of Double Mini-beta Optics at the Diamond Light Source	optics, quadrupole, single-bunch, insertion	2103
	B. Singh, R.T. Fielder, I.P.S. Martin, G. Rehm Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Funding: Diamond Light Source Ltd. We report the results of the implementation of two vertical mini-beta and horizontally focusing optics at the Diamond light source, the first in August 2010 and the second in March 2011. Commissioning results of the two optics changes and experimental characterization of the optics are compared with the expected performance and theoretical modeling. The implications of a possible third customized optics are also investigated.

WEPC044	Minimizing Beam Motion in a Long-pulse Linear Induction Accelerator	induction, target, kicker, focusing	2109
	C. Ekdahl, E.O. Abeyta, J.B. Johnson, K. Nielsen, M.E. Schulze LANL, Los Alamos, New Mexico, USA T.P. Hughes, C.H. Thoma Voss Scientific, Albuquerque, New Mexico, USA C.-Y. Tom NSTec, Los Alamos, New Mexico, USA
	Funding: This work was supported by the US National Nuclear Security Agency and the US Department of Energy under contract DE-AC52-06NA25396. The Dual Axis Radiography for Hydrodynamic Testing (DARHT) Facility at Los Alamos uses two linear induction accelerators (LIAs) for flash radiography of explosively driven experiments from orthogonal viewpoints. The DARHT Axis-II long-pulse 1.8-kA, 16.5-MeV LIA is unique. It has a beam pulse with a 1600-ns flattop during which the kinetic energy varies < 2%. During this flattop, a kicker cleaves out four short micro-pulses, which are focused onto a high-Z target and converted to bremsstrahlung for multi-pulse flash radiography of the experiments. Asymmetric injection of the beam into the solenoidal focusing field, small temporal variations in accelerating potentials, and slight cell misalignments cause the beam position to wander during the flattop. This is undesirable for radiography, because it causes a displacement of the four radiographic source spots. Since the specific energy deposition from each micro-pulse can vaporize target material, succeeding pulses impact an asymmetric object causing a distortion of the source spot. This presentation will review the physics of the beam motion and the tuning procedures we have optimized to minimize the number of shots required.

WEPC050	New Optics for the SOLEIL Storage Ring	optics, coupling, undulator, vacuum	2124
	P. Brunelle, F. Briquez, A. Loulergue, O. Marcouillé, A. Nadji, L.S. Nadolski, M.-A. Tordeux, J.F. Zhang SOLEIL, Gif-sur-Yvette, France
	SOLEIL, the French 2.75GeV synchrotron light source is delivering photons to 24 beam lines and is presently equipped with 22 insertion devices (ID) including a high field and small gap in-vacuum wiggler. This paper presents the continuous work performed to reduce the strong non linear effects of several IDs. On one side, the ID defaults have been precisely identified using on-beam measurements, and magnetic correction developments are going on, especially for the in-vacuum wiggler and for the 10m long HU640 undulator. On the other side, a new optics has been optimised in terms of beta-functions (at the ID location) and non linear dynamics in order to improve the injection efficiency and the beam lifetime in the presence of IDs. The modified optics has been used daily in operation since November 2010 and ensures a beam lifetime greater than 10h for a 400mA stored beam with the users ID configuration. In parallel, an extensive experimental optimization has been performed to prepare the operation with an additional quadrupole triplet that provides double low vertical beta functions in one long straight section that will accommodate two canted in-vacuum insertion devices. O. Marcouillé et al., IPAC10, p. 3102 (2010). ** A. Loulergue et al., IPAC10, p. 2496 (2010).

WEPC065	Design of a Low Energy Ion Beam Facility*	ion, antiproton, vacuum, quadrupole	2169
	M.R.F. Siggel-King, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom O. Karamyshev JINR/DLNP, Dubna, Moscow region, Russia G.A. Karamysheva MPI-K, Heidelberg, Germany A.I. Papash JINR, Dubna, Moscow Region, Russia M.R.F. Siggel-King The University of Liverpool, Liverpool, United Kingdom
	Funding: Work supported by STFC, the EU under GA-PITN-215080, the Helmholtz Association and GSI under VH-NG-328. A small electrostatic ring, and associated electrostatic injection beamlines, are being designed and developed. The ring will make possible a variety of experiments using a choice of many types of recirculating ions (e.g., from protons, H-, and antiprotons up to and including large charged biomolecules). A reaction microscope will be incorporated into the ring to enable differential ionization experiments between the recirculating ion beam and gas jet targets. Two injection sections have been designed to cover a variety of ion sources. The facility will be portable to enable it to be moved between facilities and beamlines and it will be unique due to its combination of design elements, flexible beam properties, energy (ca 3-30 keV) and type of circulating particles. In this paper, we give an update on this project.

WEPC069	Impact of Nonlinear Resonances on Beam Dynamics at the SPring-8 Storage Ring	resonance, storage-ring, coupling, betatron	2181
	M. Takao, J. Schimizu, Y. Shimosaki, K. Soutome JASRI/SPring-8, Hyogo-ken, Japan
	For a low emittance storage ring like high brilliant light sources, the improvement of nonlinear beam dynamics is necessary for the stable operation, or for providing large dynamic aperture and momentum acceptance for efficient injection and long Touschek lifetime. At the SPring-8 storage ring it is observed that injection efficiency is affected by the gap heights of the magnet arrays of the in-vacuum insertion devices. The fact that the injected beam of fundamentally oscillating in horizontal direction is limited by the vertical aperture means that coupling resonances influence the beam dynamics. To clarify the phenomena, we studied the nonlinear beam dynamics of transverse betatron motion by means of turn-by-turn method. Then, we found some nonlinear coupling resonances, such as the one by skew sextupole field, are excited to enhance vertical oscillation and to deteriorate the injection efficiency. By analyzing these results, we developed measures to suppress the effect of the nonlinear coupling resonances and to improve the injection efficiency.

WEPC075	ITEP-TWAC Progress Report	ion, proton, laser, target	2193
	N.N. Alexeev, P.N. Alekseev, V. Andreev, A. Balabaev, V.I. Nikolaev, A.S. Ryabtsev, Yu.A. Satov, V.A. Schegolev, B.Y. Sharkov, A. Shumshurov, V.P. Zavodov ITEP, Moscow, Russia
	The program of the ITEP-TWAC Facility upgrade for next three years has been approved last year in the frame of National Research Center Kurchatov Institute taking up ITEP in accordance with government decision. It includes expanding of multimode using proton and heavy ion beams in different applications on a base of new accelerator technologies development. The laser ion source advantage of high temperature plasma generation has to be transformed to high current and high charge state ion beam of Z/A up to 0.4 for elements with A ~ 60 to be effectively stacked in the accumulator ring with multiple charge exchange injection technique. The new high current heavy ion RFQ section is in progress for the beam test. Accelerating system of accumulator ring U-10 is modified to increase compression voltage for stacked beam by factor of four. Design of proton injection and beam slow extraction for UK ring is performed for its utilizing as self-depending synchrotron in medical application and for imitation of cosmic radiation. The machine status analysis and current results of activities aiming at both subsequent improvement of beam parameters and expanding beam applications are presented.

WEPC078	Non-linear Chromaticity Studies of the LHC at Injection	octupole, dipole, optics, emittance	2199
	E.H. Maclean, M. Giovannozzi, F. Schmidt, R.J. Steinhagen, E. Todesco, R. Tomás, G. Vanbavinckhove CERN, Geneva, Switzerland R. Bartolini JAI, Oxford, United Kingdom
	The non-linear chromaticity of the LHC has been studied. Measurements of variation in tune with dp/p on both beams at injection optics are being compared with Q'' and Q''' as calculated with the LHC effective model. This model uses the best currently available measurements of magnetic field harmonics. An attempt is being made to optimize the b4 and b5 pool-pieces corrections in view of the corresponding chromaticity terms.

WEPC079	Beta-beating in the Effective Model of the LHC Using PTC	optics, alignment, closed-orbit, quadrupole	2202
	M.C. Alabau Pons, F. Schmidt, R. Tomás CERN, Geneva, Switzerland E.H. Maclean JAI, Oxford, United Kingdom
	An effective model of the LHC optics has been developed based on measurements of magnetic field, alignment errors and closed orbit. This model utilizes the Polymorphic Tracking Code with MAD-X as front-end to allow the inclusion of harmonics to an arbitrary order in thick lattice elements. Beta-beating calculations have been performed with this model at injection optics and at 3.5 TeV squeezed optics to 3.5 m beta-function at the interaction point. The model predictions are in remarkable agreement with the measurements performed in the 2010 LHC commissioning run.

WEPC102	Recent Developments for Efficient 3D Space Charge Computations Based on Adaptive Multigrid Discretizations	space-charge, simulation, brightness, optics	2253
	G. Pöplau, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany M.J. de Loos TUE, Eindhoven, The Netherlands S.B. van der Geer Pulsar Physics, Eindhoven, The Netherlands
	Funding: Partly supported by BMBF under contract number 05K10HRC Efficient and accurate space-charge computations are essential for the design of high-brightness charged particle sources. Recently a new adaptive meshing strategy based on multigrid was implemented in GPT and the capabilities were demonstrated. This new meshing scheme uses the solution of an intermediate step in the multigrid algorithm itself to define optimal mesh line positions. In this paper we discuss further developments of this adaptive meshing strategy. We compare the new algorithm with the current meshing scheme of GPT, where the mesh line positions are based upon the projected charge density.

WEPC111	Single Particle Tracking Simulation for Compact Cyclotron*	simulation, cyclotron, cavity, positron	2274
	H.W. Kim, J.-S. Chai, B.N. Lee, Y.S. Lee, K.R. Nam, H.S. Song SKKU, Suwon, Republic of Korea
	Funding: Ministry of Education, Science and Technology, Republic of Korea. Department of Energy Science and School of Information and Communication Engineering of SungKyunKwan University. Low energy compact cyclotrons for Positron emission tomography (PET) are needed for the production of radio-isotope. In the magnet design for those cyclotrons, single particle tracking simulation after the design is important to check the quality of designed magnetic field of the magnet. The study of single particle tracking simulation for cyclotron magnet is shown in this paper. Maximum beam energy of example cyclotron is 9 MeV for proton and pseudo accelerating gap is adapted for the simulation. 3D CAD program CATIA P3 V5 R18 is used for design the magnet and pseudo accelerating gap. All magnetic and electric field calculations had been performed by OPERA-3D TOSCA and the own-made program OPTICY is used for other calculations - phase slip, radial and axial tune.

WEPC158	The EMMA Accelerator, A Diagnostic Systems Overview	extraction, diagnostics, pick-up, EPICS	2355
	R.J. Smith, M. Dufau, C. Hill, J.K. Jones, A. Kalinin, L. Ma, P.A. McIntosh, B.D. Muratori, B.J.A. Shepherd STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom J.S. Berg BNL, Upton, Long Island, New York, USA N. Bliss, G. Cox, A. Gallagher, A. Oates STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom R.G. Borrell WareWorks Ltd, Manchester, United Kingdom J.L. Crisp FRIB, East Lansing, Michigan, USA K.M. Hock, D.J. Holder Cockcroft Institute, Warrington, Cheshire, United Kingdom M.G. Ibison, I. Kirkman The University of Liverpool, Liverpool, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	The ‘EMMA’ Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) international project is currently being commissioned at Daresbury Laboratory, UK. This accelerator has been equipped with a number of diagnostic systems to facilitate this. These systems include a novel time-domain-multiplexing BPM system, moveable screen systems, a time-of-flight instrument, Faraday cups, and injection/extraction tomography sections to analyse the single bunch beams. An upgrade still to implement includes the installation of a fast wall current monitor. This paper gives an overview of these systems and shows some data and results that have contributed to the successful demonstration of a serpentine acceleration by this novel accelerator.

WEPC170	Handling of BLM Abort Thresholds in the LHC	beam-losses, monitoring, quadrupole, proton	2382
	E. Nebot Del Busto, B. Dehning, E.B. Holzer, S. Jackson, G. Kruk, M. Nemcic, A. Nordt, A. Orecka, C. Roderick, M. Sapinski, A. Skaugen, C. Zamantzas CERN, Geneva, Switzerland
	The Beam Loss Monitoring system (BLM) for the LHC consists of about 3600 Ionization Chambers located around the ring. Its main purpose is to request a beam abort when the measured losses exceed a certain threshold. The BLM detectors integrate the measured signals in 12 different time intervals (running from 40 us to 83.8 s) enabling for a different set of abort thresholds depending on the duration of the beam loss. Furthermore, 32 energy levels running from 0 to 7 TeV account for the fact that the energy density of a particle shower increases with the energy of the primary particle, i.e. the beam energy. Thus, about 1.3·10⁶ thresholds must be handled and send to the appropriate processing modules for the system to function. These thresholds are highly critical for the safety of the machine and depend to a large part on human judgment, which cannot be replaced by automatic test procedures. The BLM team has defined well established procedures to compute, set and check new BLM thresholds, in order to avoid and/or find non-conformities due to manipulation. These procedures, as well as the tools developed to automate this process are described in detail in this document.

WEPC174	A Failure Catalogue for the LHC	monitoring, extraction, vacuum, beam-losses	2394
	S. Wagner, R. Schmidt, B. Todd, J.A. Uythoven, M. Zerlauth CERN, Geneva, Switzerland
	The LHC, with a stored energy of more than 360 MJ per beam, requires a complex machine protection system to prevent equipment damage. The system was designed based on a large number of possible failures in the subsystems and operational phases of the LHC. This led to a mixed system with active and passive protection. The active part monitors many thousand parameters (such as beam losses, temperatures in superconducting magnets, power converter currents, etc.) and triggers a beam dump in case a failure is detected. The passive part includes protection elements like collimators and beam absorbers to ensure the prevention of damage in case of single turn beam losses (e.g. during beam transfer and injection). So far, the knowledge of the possible failures is distributed over the different teams involved in the design, construction and operation of the LHC. A newly started project aims at bringing together this knowledge in a common failure catalogue. The chosen approach in addition is expected to allow for the identification of failures that might not have been considered yet or that require further measures. This paper introduces the approach and presents the first experience.

WEPO013	Septum and Kicker Magnets for the ALBA Booster and Storage Ring	kicker, booster, vacuum, storage-ring	2421
	M. Pont, R. Nunez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain E. Huttel KIT, Karlsruhe, Germany
	At the ALBA Synchrotron light source 6 kicker and 3 septa magnets are installed for beam injection and extraction. A 100 MeV beam coming from the linac is injected on axis into the Booster. The full energy (3 GeV) beam is extracted from the booster and injected into the Storage Ring, where 4 kicker magnets bring the stored beam close to the septa. All septa are direct driven out-of-vacuum magnets with C shape iron laminated yoke. The magnets are excited by a full sine approx. 300 μs pulse length; the nominal field is 0.15/0.84/0.9 T (booster injection/extraction/storage-ring-injection). The stray field seen by the stored beam is less than 1 μT. The booster kicker magnets are in-vacuum magnets with C-ferrite yoke. The magnets are excited by a 0.4 μs flat top pulse; the nominal field is 0.03/0.04 T (booster injection/extraction). The storage ring kickers have a C-ferrite yoke and a 0.4 μm Ti coated ceramic vacuum chamber. The excitation is done by 6 μs half sine; the nominal field is 0.13 T. The paper will present the design of the elements and their magnetic characteristics. First results of their behaviour during commissioning will also be discussed.

WEPO028	Design of HTS Sector Magnets for the RCNP New Injector Cyclotron	cyclotron, dipole, neutron, cavity	2460
	K. Hatanaka, M. Fukuda, N. Izumi, M. Kibayashi, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, H. Ueda, Y. Yasuda, T. Yorita RCNP, Osaka, Japan T. Kawaguchi KT Science Ltd., Akashi, Japan
	The RCNP cyclotron cascade system consists of K140 AVF cyclotron and K400 ring cyclotron and is providing high quality beams for various experiments. There are increasing demands for high intensity beams and even to improve the quality. In order to increase the physics research opportunities, a new injector cyclotron is recently proposed, which has four separated sector magnets and two accelerating cavities. Sector magnets are designed to use High Temperature Superconducting (HTS) wire. At RCNP we have been developing magnets with HTS wires for a decade. In this paper, we will report recent results of developed HTS magnets and the design of sector magnets for the new injector SSC.

WEPO031	The Magnetic Model of the LHC during Commissioning to Higher Beam Intensities in 2010-2011	quadrupole, dipole, optics, sextupole	2466
	L. Deniau, N. Aquilina, L. Fiscarelli, M. Giovannozzi, P. Hagen, M. Lamont, G. Montenero, R.J. Steinhagen, M. Strzelczyk, E. Todesco, R. Tomás, W. Venturini Delsolaro, J. Wenninger CERN, Geneva, Switzerland
	The Field Description of the Large Hadron Collider (FiDeL) model is a set of semi-empirical equations linking the magnets behaviours established from magnetic measurements to the magnetic properties of the machine observed through beam measurements. The FiDeL model includes the parameterization of static components such as magnets residual magnetization, persistent currents, hysteresis and saturation as well as the decay and snap-back dynamic components. In the present paper, we outline the relationship between the beam observables (orbit, tune, chromaticity) and the model components during the commissioning to higher beam intensities in 2010-2011, with an energy of 3.5 TeV per beam. The main relevant issues are (i) the operation at 2 A/s and 10 A/s ramp rate and their influence on chromatic correction, (ii) the beta beating and its relation to the knowledge of the resistive quadrupoles transfer functions and (iii) the observed tune decay at injection energy and its possibles origins.

WEPS001	A New Lattice for the Beta-beam Decay Ring to Reduce the Head Tail Effects	lattice, dipole, ion, dynamic-aperture	2478
	A. Chancé, J. Payet CEA/DSM/IRFU, France C. Hansen CERN, Geneva, Switzerland
	Funding: I acknowledge the financial support of the European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372. The beta-beam concept relies on the production, by beta decay of radioactive ions of a very high flux, of an electron neutrino and anti-neutrino beam towards a distant detector. In this aim, the radioactive isotopes are stored in a long racetrack-shaped ring, called the decay ring, where they orbit until they decay or are lost. The intensities to store in the decay ring to obtain the required neutrino fluxes are very high (several amperes in average). Therefore, collective effects occur. Among them, the head tail effect, caused by transversal resonance impedance, is one of the main issues: the beam was shown to be unstable with the previous decay ring lattice. The transition gamma was reduced to mitigate this problem. For this purpose the lattice was changed by removing the injection from the arc to put it in a chicane which is added in one of the long straight sections. After presenting the limitation due to head tail effects, we will present the modification in the lattice and their impact on the dynamic aperture in the decay ring. Then the improvement on the beta-beam performance with respect to the lower transition gamma will be shown.

WEPS002	Limitations in Mitigating Collective Effects in the Beta-Beam Decay Ring by the Use of Octupoles	octupole, ion, damping, impedance	2481
	C. Hansen CERN, Geneva, Switzerland E. Benedetto National Technical University of Athens, Zografou, Greece A. Chancé, J. Payet CEA/DSM/IRFU, France
	Funding: I acknowledge the financial support of the European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372. The beta-beam concept relies on the production, by beta decay of radioactive ions of a very high flux, of an electron neutrino and anti-neutrino beam towards a distant detector. After production and acceleration in an accelerator complex consisting of a rapid cycling synchrotron, the CERN PS and the CERN SPS, the radioactive isotopes are injected into a long racetrack-shaped ring, called the decay ring, where they orbit until they decay or are lost. The required intensities to store in the decay ring to reach the aimed neutrino fluxes are very high. Among the collective effects, the head tail effect, caused by transversal resonance impedance, is one of the main issues: the beam was shown to be unstable with the previous decay ring lattice. The lattice was changed to handle this problem; e.g. octupoles were included to increase the stability limit with an amplitude detuning. We here report on the improvement on the beta-beam performance with respect to amplitude detuning in the decay ring and discuss other mitigation attempts.

WEPS003	SIS18 – Intensity Record with Intermediate Charge State Heavy Ions	ion, heavy-ion, beam-losses, acceleration	2484
	P.J. Spiller GSI, Darmstadt, Germany L.H.J. Bozyk FIAS, Frankfurt am Main, Germany P. Puppel HIC for FAIR, Frankfurt am Main, Germany
	Funding: Project partly funded by the European Community DIRAC-PHASE-1 / Contract number: 515876 In order to reach the desired intensities of heavy ion beams for the experiments at FAIR, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 10¹¹ ions per cycle has never been demonstrated elsewhere and requires a dedicated upgrade program for SIS18 and a dedicated machine design for SIS100. The specific problems coming along with the intermediate charge state operation in terms of charge exchange processes at collisions with residual gas atoms, pressure bumps by ion induced desorption and corresponding beam loss appears far below the typical space charge limits. Thus, new design concepts and new technical equipment addressing these issues are developed and realized with highest priority. The upgrade program of SIS18 addressing the goal of minimum ionization beam loss and stable residual gas pressure conditions has been defined in 2005. A major part of this upgrade program has been successfully realized, with the result of a world record in accelerated number of intermediate charge state heavy ions.

WEPS004	Confinement, Accumulation and Diagnostic of Low Energy Ion Beams in Toroidal Fields	ion, diagnostics, electron, beam-transport	2487
	M. Droba, A. Ates, O. Meusel, H. Niebuhr, U. Ratzinger, J.F. Wagner IAP, Frankfurt am Main, Germany
	An optimized design of a stellarator-type storage ring for low energy ion beams was numerically investigated. The magnetic field variation along the circumference and therefore magnetic heating is suppressed by using simple circular correction coils. Particle-in-Cell (PIC) simulations in a magnetic flux coordinate system show the ability of high current ion beam accumulation in such a configuration with unique features for clockwise and anticlockwise moving beams. Additionally scaled down experiments with two 30 degree room temperature toroidal segments were performed to demonstrate toroidal transport and to develop optical beam diagnostics. Properties of multi-component beams, redistribution of transversal momenta in the non-adiabatic part of the experimental configuration and investigation of strongly confined beam induced electron clouds will be addressed.

WEPS010	Acceleration of High Intensity Proton Beams in the J-PARC Synchrotrons	cavity, impedance, acceleration, synchrotron	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.

WEPS014	RF Systems and Bunch Formation at NICA	collider, ion, booster, cavity	2511
	A.V. Eliseev, I.N. Meshkov, A.O. Sidorin, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia O.I. Brovko JINR/VBLHEP, Moscow, Russia G.Y. Kurkin, V.M. Petrov BINP SB RAS, Novosibirsk, Russia
	The NICA facility being constructed at JINR will consists of two synchrotrons (Booster and Nuclotron) and collider working at constant magnetic field. To reach required luminosity level the collider rings will be operated with short ion bunches. The bunch formation in the collider as well as longitudinal dynamics in all the rings is described. The parameters and preliminary design of RF systems are presented.

WEPS017	Plans for the Upgrade of the LHC Injectors	linac, synchrotron, 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.

WEPS018	The Proposed CERN Proton-Synchrotron Upgrade Program	emittance, cavity, space-charge, electron	2520
	S.S. Gilardoni, S. Bart Pedersen, W. Bartmann, S. Bartolome, O.E. Berrig, C. Bertone, A. Blas, D. Bodart, J. Borburgh, R.J. Brown, A.C. Butterworth, M.C.L. Buzio, C. Carli, P. Chiggiato, H. Damerau, T. Dobers, R. Folch, R. Garoby, B. Goddard, M. Gourber-Pace, S. Hancock, M. Hourican, P. Le Roux, L.A. Lopez Hernandez, A. Masi, G. Metral, Y. Muttoni, E. Métral, M. Nonis, J. Pierlot, S. Pittet, C. Rossi, I. Ruehl, G. Rumolo, L. Sermeus, R.R. Steerenberg, M. Widorski CERN, Geneva, Switzerland
	In the framework of the High-Luminosity LHC project, the CERN Proton Synchrotron would require a major upgrade to match the future beam parameters requested as pre-injector of the collider. The different beam dynamics issues, from space-charge limitations to longitudinal instabilities are discussed, as well as the proposed technical solutions to overcome them, covering the increase of the injection energy to RF related improvements.

WEPS019	Study of a Rapid Cycling Synchrotron to Replace the CERN PS Booster	extraction, booster, linac, lattice	2523
	K. Hanke, O. Aberle, M. E. Angoletta, B. Balhan, W. Bartmann, M. Benedikt, J. Borburgh, D. Bozzini, C. Carli, P. Dahlen, T. Dobers, M. Fitterer, R. Garoby, S.S. Gilardoni, B. Goddard, J. Hansen, T. Hermanns, M. Hourican, S. Jensen, A. Kosmicki, L.A. Lopez Hernandez, M. Meddahi, B. Mikulec, A. Newborough, M. Nonis, S. Olek, M.M. Paoluzzi, S. Pittet, B. Puccio, V. Raginel, I. Ruehl, H.O. Schönauer, L. Sermeus, R.R. Steerenberg, J. Tan, J. Tückmantel, M. Vretenar, M. Widorski CERN, Geneva, Switzerland
	CERN’s proton injector chain is undergoing a massive consolidation and upgrade program in order to deliver beams meeting the needs of the LHC Luminosity Upgrade. As an alternative to the upgrade of the existing Proton Synchrotron Booster (PSB), the construction of a Rapid Cycling Synchrotron (RCS) has been studied. This machine would replace the PSB and deliver beams to the LHC as well as to CERN’s rich fixed-target physics program. This paper summarizes the outcome of the feasibility study along with a tentative RCS design.

WEPS020	Study of an Energy Upgrade of the CERN PS Booster	booster, power-supply, extraction, emittance	2526
	K. Hanke, O. Aberle, M. E. Angoletta, W. Bartmann, S. Bartolome, C. Bertone, A. Blas, J. Borburgh, D. Bozzini, A.C. Butterworth, C. Carli, P. Dahlen, T. Dobers, A. Findlay, R. Folch, N. Gilbert, J. Hansen, T. Hermanns, S. Jensen, P. Le Roux, L.A. Lopez Hernandez, E. Mahner, A. Masi, B. Mikulec, Y. Muttoni, A. Newborough, D. Nisbet, M. Nonis, S. Olek, M.M. Paoluzzi, S. Pittet, B. Puccio, V. Raginel, I. Ruehl, J. Tan, B. Todd, W.J.M. Weterings, M. Widorski CERN, Geneva, Switzerland
	CERN’s LHC injector chain will have to deliver beams with ultimate brilliance as the LHC is heading for increased luminosity in the coming years. In order to overcome bottlenecks in the injector chain, an increase of the beam transfer energy from the CERN Proton Synchrotron Booster (PSB) to the Proton Synchrotron (PS) has been investigated as a possible upgrade scenario. This paper gives an overview of the technical solutions and summarizes the conclusions of the feasibility study.

WEPS022	Ions for LHC: Performance of the Injector Chain	ion, luminosity, linac, proton	2529
	D. Manglunki, M. E. Angoletta, P. Baudrenghien, G. Bellodi, A. Blas, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, M. Chanel, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, S. Maury, E. Métral, S. Pasinelli, M. Schokker, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger CERN, Geneva, Switzerland
	The first LHC Pb ion run took place at 1.38 A TeV/c per beam in autumn 2010. After a short period of running-in, the injector chain was able to fill the collider with up to 137 bunches per ring, with an intensity of 10⁸ Pb ions/bunch, about 50% higher than the design value. This yielded a luminosity of 3E25 Hz/cm², allowing the experiments to accumulate just under 10 inverse microbarn each during the four week run. We review the performance of the individual links of the injector chain, and address the main issues limiting the LHC luminosity, in view of reaching 10²6 Hz/cm² in 2011, and substantially beyond when the LHC energy increases after the long shutdown in 2013-14.

WEPS023	A Possible RF System for CERN RCS	cavity, synchrotron, 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.

WEPS028	Lattice Design of a Rapid Cycling Medical Synchrotron for Carbon/Proton Therapy	synchrotron, proton, extraction, ion	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.

WEPS032	Conceptual Study for the New HE-Linac at GSI	cavity, linac, DTL, acceleration	2553
	G. Clemente, W.A. Barth, B. Schlitt GSI, Darmstadt, Germany
	The commissioning of the first three modules of the FAIR accelerator facility is planned to be completed in 2016. At that time the DTL section of the UNILAC will be more than 40 years old. Different proposals for a new high intensity, heavy ion linac which will replace the ALVAREZ DTL as synchrotron injector are under discussion. This new High Energy-UNILAC will be design accordingly to the advanced FAIR requirements and will allow for complete and reliable multi-ion-operation for at least the next 30 years. In a first step it is foreseen to replace the first two DTL cavity, up to 4.7 AMeV. 4 IH cavities will be used to accelerate U⁴⁺ to 3 AMeV and, after gas stripping, another cavity will provide the second step of acceleration for U³⁸⁺ to 4.77 AMeV. For the next upgrade different options concerning the injection energy are under investigation. The main target is to provide a higher charge state and a higher injection energy to increase the life time of the heavy ion beam inside the synchrotron. The paper presents the beam dynamics and RF investigation for the first upgrade together with a conceptual study design for the complete replacement of the GSI ALVAREZ DTL.

WEPS049	Floor Deformation of J-PARC Linac after the Tohoku Earthquake in Japan	linac, alignment, cavity, DTL	2601
	T. Morishita, H. Asano JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan M. Ikegami KEK, Ibaraki, Japan
	J-PARC linac has finalized its precise alignment at the end of summer 2006, and the beam provision to the Rapid Cycling Synchrotron has been started at Sept. 2007. Since then, the deformation of the accelerator tunnel is small enough to keep the soundness of the alignment accuracy. Therefore, the linac has been operated without realignment of the accelerator components for these four years. However, the alignment has seriously been damaged due to the large earthquake at Mar. 11th, 2011 in eastern Japan. Now, work for restoration is being continued. In this paper, the deformation of the linac tunnel floor due to the earthquake is reported. Since then, aftershock happens frequently. We also report the stability of the tunnel floor.

WEPS070	Commissioning Status of Kolkata Superconducting Cyclotron	cyclotron, extraction, acceleration, ion	2664
	C. Mallik, R.K. Bhandari DAE/VECC, Calcutta, India
	After completing the construction of the K~500 superconducting cyclotron at Kolkata, the internal beam acceleration was accomplished in August 2009 and several tests were conducted to confirm the acceleration. Earlier the superconducting magnet using Nb-Ti superconductor with 300 litre liquid helium cryostat and 80 tonne iron was commissioned and field mapped. The radiofrequency system spanning 9-27 MHz and with three independent resonators were integrated into the machine. Some difficulties were experienced with achieving the voltage related to ceramic failures. Finally, ~50 kV on the dees have been achieved with reasonable phase stability between the three dees. The cyclotron uses a 14 GHz external ECR ion source and the beam is injected through 28 metre long injection line. Till date several beams like neon, argon, nitrogen, oxygen etc. have been accelerated mostly in analogous mode and at around 14 MHz frequency and ~32 kG field. Valuable experience has been obtained with various systems. The paper would describe the experience with different subsystems and beam acceleration experience. Presently, beam extraction is being tried and will be achieved shortly.

WEPS072	A Superconducting Ring Cyclotron to Search for CP Violation in the Neutrino Sector	cavity, cyclotron, extraction, focusing	2670
	L.A.C. Piazza, M.M. Maggiore INFN/LNL, Legnaro (PD), Italy L. Calabretta, D. Campo, D. Rifuggiato INFN/LNS, Catania, Italy A. Calanna CSFNSM, Catania, Italy
	Multi Megawatt accelerators are today requested for different use. In particular the experiment DAEdALUS, recently proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector* and of a booster ring cyclotron has been proposed**. The booster Superconducting Ring Cyclotron, able to accelerate a H²⁺ molecule beam up to 800 MeV/n and average power higher than 1.6 MW, will be described. Although the average power is 1.6 MW, due to the low duty cycle, the peak power will be 8 MW. The main advantages to accelerate H²⁺ are a reduction of space charge effects, a simple extraction process, extraction of two beams at the same time from each booster cyclotron to simplify the beam dump. The features of the magnetic sector, of the superconducting coils and the magnetic forces evaluated by the code TOSCA are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too. J.Alonso etal., Novel Search for CP Violation in the Neutrino Sector: DAEdALUS, June2010;e-Print arXiv:10⁰⁶.0260. L.Calabretta, IPAC 2011,this conference. *L.Calabretta, Cyclotrons 2010, Lanzhou.

WEPS074	H⁻ Injection Studies of FFAG Accelerator at KURRI	linac, beam-transport, proton, neutron	2676
	K. Okabe, Y. Niwa, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, B. Qin, T. Uesugi, E. Yamakawa KURRI, Osaka, Japan
	Aiming to demonstrate the basic feasibility of the accelerator driven sub-critical reactor (ADSR), proton Fixed Field Alternating Gradient (FFAG) accelerator complex as a neutron production driver has been constructed in Kyoto University Research Reactor Institute (KURRI). In order to upgrade beam power of the FFAG neutron source, a project about a new H⁻ linac injector for FFAG main ring instead of present injector has been started. A charge exchange multi-turn beam injection has been performed for the first time at FFAG main ring in KURRI. In this paper, the detail of injection system and beam study of low energy H⁻ injection at FFAG is described.

WEPS078	Compact FFAG Accelerators for Medium Energy Hadron Applications	proton, hadron, extraction, linac	2688
	B. Qin, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, K. Okabe, T. Uesugi, E. Yamakawa KURRI, Osaka, Japan
	Funding: This work was supported by Japan Science and Technology Agency under Strategic Promotion of Innovative Research and Development Program. Medium energy hadron beams are widely applied in accelerator driven subcritical systems (ADSR), high intensity neutron sources and carbon therapy. Compactness feature is important for this energy region, especially in the case of medical use purposes. This paper introduces a novel superferric scheme with scaling fixed-field alternating gradient (FFAG) accelerators, which can deliver 400MeV/u carbon ions or 1.2GeV protons. By using high permeability materials, 5T magnetic field with high field index can be achieved to reduce accelerator circumference significantly. The lattice configuration and design of superferric magnet are described in details.

WEPS079	Serpentine Acceleration in Scaling FFAG	acceleration, proton, electron, closed-orbit	2691
	E. Yamakawa, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, B. Qin, T. Uesugi KURRI, Osaka, Japan K. Okabe, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan
	A serpentine acceleration in scaling FFAG accelerator has been examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is also derived analytically.

WEPS082	Development of FLNR JINR Heavy Ion Accelerator Complex in the Next Seven Years: New DC-280 Cyclotron Project	ion, cyclotron, target, extraction	2700
	G.G. Gulbekyan, S.L. Bogomolov, O.N. Borisov, S.N. Dmitriev, J. Franko, B. Gikal, I.A. Ivanenko, I.V. Kalagin, V.I. Kazacha, N.Yu. Kazarinov, N.F. Osipov, A. Tikhomirov JINR, Dubna, Moscow Region, Russia
	At present time four isochronous cyclotrons: U-400, U-400M, U-200 and IC-100 are in operation at the JINR FLNR. Total operation time is about 10000 hours per year. The U400M is a primary beam generator and U400 is as postaccelerator in RIB (DRIBs) experiments to produce and accelerate exotic nuclides such as 6He, 8He etc. One of the basic scientific programs which are carried out in FLNR - synthesis of new elements which demands intensive beams of heavy ions. Now U-400 is capable to provide long term experiments on Ca 48 beams with intensity of 1 pμA.In order to improve efficiency of the experiments for the next 7 years it is necessary to obtain the accelerated ion beams with the following parameters. Ion energy 4/8 MeV/n Masses 10/238 Beam intensity (up to A=50) 10 pμA Beam emittance less 30 π mm·mrad These parameters have underlain the project of new cyclotron DC-280.

WEPS083	DC280 Cyclotron Central Region with Independent Flat-Top System	cyclotron, acceleration, ion, heavy-ion	2703
	I.A. Ivanenko, B. Gikal, G.G. Gulbekyan, N.Yu. Kazarinov JINR, Dubna, Moscow Region, Russia
	At the present time, the activities on creation of the new isochronous cyclotron DC280 are carried out at the FLNR, JINR. The cyclotron DC280 is intended for accelerating the wide range of ion beams with A/Z= 4 - 7 to energy W= 4 - 8MeV/u and intensity up to 10pmcA. To achieve high-intensity ion beams the cyclotron is equipped with Flat-Top system. At the cyclotron DC280 the Flat-Top system is physically separated from main resonators. The investigation of the cyclotron centre region with independent Flat-Top is presented. The simulation of the beams acceleration is carried out by means of the computer code CENTR.

WEPS096	Injection Energy Recovery of J-PARC RCS	power-supply, beam-losses, impedance, septum	2730
	N. Hayashi, H. Hotchi, J. Kamiya, P.K. Saha, T. Takayanagi, K. Yamamoto, M. Yamamoto, Y. Yamazaki JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

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MOXAA01

ALBA Synchrotron Light Source Commissioning

storage-ring, booster, linac, synchrotron

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]

MOXBA01

J-PARC Beam Commissioning Progress

beam-losses, linac, extraction, vacuum

6

H. Hotchi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC is a multi-purpose proton accelerator facility amiming at MW-class output beam power, consisting of a 400 MeV H⁻ linac, a 3-GeV RCS, a 50-GeV MR (Main Ring) and three experimental facilities, the MLF (materials and life science experimental facility), the HD (hadron experimental hall) and the NU (neutrino beam line). The J-PARC beam commissioning started in November 2006 from the linac to the downstream facilities. The current output beam power from the RCS to the MLF users is 210 kW, and the MR delivers 145 kW beam to the NU by fast extraction and a few kW beam to the HD by slow extraction. In this talk, we present a current status of the J-PARC beam commissioning, in which a recent progress in the course of the RCS beam power ramp-up scenario will be described in more detail. This talk will focus on the issues (including beam dynamics), challenges, solutions, and lessons learned during the commissioning and user operation of J-PARC and future plans.

Slides MOXBA01 [2.615 MB]

MOYAA01

The LHC from Commissioning to Operation

luminosity, controls, optics, ion

11

M. Lamont
CERN, Geneva, Switzerland

In 2011 the LHC moves from commissioning into the physics production phase with the aim of accumulating 1fb-1 by the end of 2011. The progress from commissioning to operation is described. Emphasis is put on the beam performance, but also on the performance of the different hardware systems. The role of collimation and machine protection is discussed, in view of the very high stored beam and magnet energy. Comment: Other invited presentations in this conference will cover the experience with beam instrumentation and the upgrade programmes.

Slides MOYAA01 [7.410 MB]

MOPC015

S-band Vacuum Isolator and Circulator for Injector System of SPring-8 Linac

vacuum, linac, cavity, insertion

95

T. Taniuchi, H. Hanaki, S. Suzuki
JASRI/SPring-8, Hyogo-ken, Japan
A. Miura, K. Shinohara, S. Tsuruoka
Nihon Koshuha Co. Ltd, Yokohama, Japan

A pressurized sulfur hexafluoride (SF6) waveguide system at an injector section of SPring-8 linac, will be replaced with a vacuum waveguide system in order to renew aged equipments and improve a phase stability. For this renewal, RF isolator and a circulator operated in vacuum, are newly developed. High power RF test for these components were performed and a good result for RF and vacuum characteristics were obtained.

MOPC022

Development of a Compact C-band Photocathode RF Gun

gun, electron, cathode, emittance

116

X.H. Liu, H. Chen, W.-H. Huang, H.J. Qian, C.-X. Tang, Z. Zhang
TUB, Beijing, People's Republic of China

Funding: This work is supported by National Natural Science Foundation of China and National Basic Research Program of China (973 Program).
A C-band photocathode RF gun for a compact electron diffraction facility is developed in Tsinghua University, which is designed to work at the frequency of 5.712GHz. This paper presents the physics and structure design of this C-band RF gun, and the comparison on beam dynamics of S-band and C-band photoinjector has been done. Some new structure design will be adopted in this gun, including the optimized cavity length and elliptical iris, which is helpful to achieve lower emittance and larger mode separation.

MOPC054

The LHC RF System - Experience with Beam Operation

synchrotron, 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.

MOPC057

Loss of Landau Damping in the LHC

emittance, damping, acceleration, impedance

211

E.N. Shaposhnikova, T. Argyropoulos, P. Baudrenghien, T. Bohl, A.C. Butterworth, J. Esteban Muller, T. Mastoridis, G. Papotti, J. Tückmantel, W. Venturini Delsolaro, U. Wehrle
CERN, Geneva, Switzerland
C.M. Bhat
Fermilab, Batavia, USA

Loss of Landau damping leading to a single bunch longitudinal quadrupole instability has been observed in the LHC during the ramp and on the 3.5 TeV flat top for small injected longitudinal emittances. The first measurements are in good agreement with the threshold calculated for the expected longitudinal reactive impedance budget of the LHC as well as with the threshold dependence on beam energy. The cure is a controlled longitudinal emittance blow-up during the ramp which for constant threshold through the cycle should provide an emittance proportional to the square root of energy.

MOPC158

RF Capture of a Beam with Charge-exchanging Multi-turn Injection

simulation, acceleration, closed-orbit, linac

454

T. Uesugi, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, B. Qin, E. Yamakawa
KURRI, Osaka, Japan
Y. Niwa, K. Okabe, I. Sakai
University of Fukui, Faculty of Engineering, Fukui, Japan

Funding: This work was supported by MEXT of Japan in the framework of a task entitled ”Research and Development for an Accelerator-Driven Sub-critical System Using an FFAG Accelerator”.
In the fixed field alternating gradient (FFAG) synchrotron in Kyoto university research reactor Institute (KURRI), charge exchange injection was adopted since 2011. The charge stripping foil is located on the closed orbit of the injection energy, and no bump orbit system is used. Instead, the injected beam escapes from the stripping foil according to the closed-orbit shift due to acceleration. In this scheme, it is important to minimize the number of foil hitting, which causes emittance growth and foil heating. In this paper, the rf capture is studied by means of simulation.

MOPO012

LHC Damper Beam Commissioning in 2010

damping, feedback, kicker, ion

505

W. Höfle, G. Kotzian, M. Schokker, D. Valuch
CERN, Geneva, Switzerland

The LHC transverse dampers were commissioned in 2010 with beam and their use at injection energy of 450 GeV, during the ramp and in collisions at 3.5 TeV for Physics have become part of the standard operations procedure. The system proved important to limit emittance blow-up at injection and maintain smaller than nominal emittances throughout the accelerating cycle. We describe the commissioning of the system step-by-step as done in 2010 and summarize its performance as achieved for proton as well as ion beams in 2010. Although its principle function is to keep transverse oscillations under control, the system has also been used as an exciter for abort gap cleaning and tune measurement. The dedicated beam position measurement system with its low noise properties provides additional possibilities for diagnostics.

MOPO015

Operation Status of Bunch-by-bunch Feedback System in the TLS

feedback, controls, diagnostics, kicker

514

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

There are several FPGA based bunch-by-bunch feedback systems that were deployed in the Taiwan Light Source now. They play various roles to suppress beam instability. By using SPring-8 designed feedback processors is pioneer to apply in the storage ring of TLS successfully and help Dimtel system to be quick commission. The Dimtel feedback system provide a life spare unit and explore to control system integration especially to the EPICS toolkit system. Rich functionality includes of excitation of individual bunch or specifies bunches, averaged spectrum, tune measurement by the feedback dip in the averaged spectrum. Operation status of the system will be summary in this report.

MOPO023

Laser-based Alignment System at the KEKB Injector Linac

laser, alignment, linac, vacuum

529

M. Satoh, N. Iida, T. Suwada
KEK, Ibaraki, Japan
K. Minoshima, S. Telada
AIST, Tsukuba, Japan

A laser-based alignment system is under development at the 500-m-long KEKB injector linac. The original system was designed and constructed more than thirty-years ago, and thus, we are revisiting our alignment system because the previous alignment system has become too obsolete. The new alignment system is again strongly required for the next generation SuperKEKB project. The new laser alignment system is similar to the previous one, which comprises a helium-neon laser and quadrant photodetectors installed in vacuum light pipes. A girder displacement of the accelerating structure can be precisely measured in the direction of the laser-ray trace, where the laser light must stably propagate up to 500-m downstream without any orbital and beam-size fluctuation. We tested the laser-ray propagation and the stability along a 100-m-long beam line under a vacuum condition of 0.1-1 Torr. In this paper, we will report the system description and test results in detail.

MOPS004

Mitigation of Beam Instability due to Space Charge Effects at 3 GeV RCS in J-PARC

impedance, space-charge, kicker, bunching

595

Y. Shobuda, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y.H. Chin
KEK, Ibaraki, Japan
F. Tamura
KEK/JAEA, Ibaraki-Ken, Japan

In order to accomplish high intensity proton beams, it is important to identify the impedance source in accelerators. At 3 GeV rapid cycling synchrotron (RCS) in Japan Proton Research Complex (J-PARC), the kicker impedance is the most dominant among such impedance sources. Beam instability can be observed by correcting chromaticity during the acceleration. Growth rate due to the beam instability can be reduced by making peak current larger (bunching factor smaller). In other words, it is experimentally found that space charge effects mitigate the beam instability.

MOPS005

Beam Dynamics Simulations of J-PARC Main Ring for Upgrade Plan of Fast Extraction Operation

simulation, beam-losses, proton, power-supply

598

Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori, M. Tomizawa
KEK, Ibaraki, Japan
H. Hotchi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Beam loss simulations under space charge effects are necessary to seek higher intensity proton beams. This paper presents simulations for fast extraction operation of Japan Proton Accelerator Research Complex (J-PARC) Main Ring. For upgrade plan, increasing protons per bunch and making higher repetition pattern are considered. Their optimal balance is discussed to minimize beam losses for aimed beam power considering space charge effects. We found that to optimize RF voltage pattern is a strong key to reduce beam losses for higher repetition. As benchmark works, we compare our simulations with the measured beam loss in our past operation.

MOPS008

Simulation of Longitudinal Emittance Control in J-PARC RCS for 400 MeV Injection

extraction, emittance, simulation, bunching

607

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

The injection energy upgrade of the J-PARC RCS from 181 MeV to 400 MeV is scheduled, this is necessary to achieve the design beam intensity. The high intensity beam is delivered to the MR, and the space charge effect at the MR injection should be alleviated by optimizing the longitudinal beam emittance at RCS extraction. This is realized by matching the shape of the beam emittance between the RCS and the MR. We describe the results of particle tracking simulation with the longitudinal emittance control during the whole acceleration period of the RCS.

MOPS009

Probing Intensity Limits of LHC-type Bunches in the CERN SPS with Nominal Optics

emittance, single-bunch, optics, extraction

610

B. Salvant, G. Adrian, D.J. Allen, O. Andujar, T. Argyropoulos, J. Axensalva, J. Baldy, H. Bartosik, S. Cettour Cave, F. Chapuis, J.F. Comblin, K. Cornelis, D.G. Cotte, K. Cunnington, H. Damerau, M. Delrieux, J.L. Duran-Lopez, A. Findlay, J. Fleuret, F. Follin, P. Freyermuth, H. Genoud, S.S. Gilardoni, A. Guerrero, S. Hancock, K. Hanke, O. Hans, R. Hazelaar, W. Höfle, L.K. Jensen, J. Kuczerowski, Y. Le Borgne, R. Maillet, D. Manglunki, S. Massot, E. Matli, G. Metral, B. Mikulec, E. Métral, J.-M. Nonglaton, E. Ovalle, L. Pereira, F.C. Peters, A. Rey, J.P. Ridewood, G. Rumolo, J.L. Sanchez Alvarez, E.N. Shaposhnikova, R.R. Steerenberg, R.J. Steinhagen, J. Tan, B. Vandorpe, E. Veyrunes
CERN, Geneva, Switzerland

Some of the upgrade scenarios of the high-luminosity LHC require large intensity per bunch from the injector chain. Single bunch beams with intensities of up to 3.5 to 4·10¹¹ p/b and nominal emittances were successfully produced in the PS Complex and delivered to the SPS in 2010. This contribution presents results of studies with this new intense beam in the SPS to probe single bunch intensity limitations with nominal gamma transition. In particular, the vertical Transverse Mode Coupling Instability (TMCI) threshold with low chromaticity was observed at 1.6·10¹¹ p/b for single nominal LHC bunches in the SPS. With increased vertical chromaticity, larger intensities could be injected, stored along the flat bottom and accelerated up to 450 GeV/c. However, significant losses and/or transverse emittance blow up were then observed. Longitudinal and transverse optimization efforts in the PSB, PS and SPS were put in place to minimize this beam degradation and succeeded to obtain single 2.3·10¹¹ p/b LHC type bunches with satisfying parameters at extraction of the SPS.

MOPS010

Experimental Studies with Low Transition Energy Optics in the SPS

optics, emittance, single-bunch, damping

613

H. Bartosik, T. Argyropoulos, T. Bohl, S. Cettour Cave, K. Cornelis, J. Esteban Muller, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova, J. Wenninger
CERN, Geneva, Switzerland

The optics of the SPS can be tuned to lower transition energy such that the slippage factor at injection is raised by a factor of almost 3. From theory, an increase of the intensity thresholds for transverse mode coupling, longitudinal coupled bunch and longitudinal instabilities due to the loss of Landau damping can be expected. In this paper, experimental studies in the SPS with single bunches of protons with intensities of up to 3.5·10¹¹ p/b on the flat bottom and at 450 GeV/c are presented. Longitudinal instabilities were studied with LHC-type beams with 50~ns spacing and injected intensities up to 1.8·10¹¹ p/b. The measurements address the increase of intensity thresholds and the achievable transverse emittances in the new low gamma transition optics with respect to the nominal SPS optics. The obtained results are compared with numerical simulations.

MOPS012

Optics Considerations for Lowering Transition Energy in the SPS

optics, resonance, emittance, lattice

619

H. Bartosik, G. Arduini, Y. Papaphilippou
CERN, Geneva, Switzerland

Beam stability for high intensity LHC beams in the SPS can be improved by increasing the slippage factor, i.e. reducing the transition energy. In this paper, possible ways of modifying the optics of the SPS for lower transition energy are reviewed. In particular, a threefold increase of the slippage factor at injection can be achieved by decreasing the integer part of the tunes by 6 units. The properties of this new low-transition optics are compared with the nominal SPS optics, including working point and resonance behavior. Possible limitations are discussed.

MOPS013

Transverse Low Frequency Broad-band Impedance Measurements in the CERN PS

impedance, proton, space-charge, extraction

622

S. Aumon
EPFL, Lausanne, Switzerland
P. Freyermuth, S.S. Gilardoni, O. Hans, E. Métral, G. Rumolo
CERN, Geneva, Switzerland

The base-line scenario for the High-Luminosity LHC upgrade foresees an intensity increase delivered by the injectors. With its 53 years, the CERN PS would have to operate beyond the limit of its performances to match the future requirements. Beam instabilities driven by transverse impedance are an important issue for the operation of high intensity beams as for the high-brightness LHC beams. Measurements of transverse tune dependence with beam intensity were performed at injection kinetic energy 1.4~GeV and at LHC beam extraction momentum 26~GeV/c. This allows deducing the low frequency inductive broad-band impedance of the machine. Then an estimation of the real part of the impedance is made by the rise time measurement of a fast transverse instability believed to be a TMCI type. Those are the first step towards a global machine impedance characterization in order to push forward the performances of the accelerator.

MOPS014

Tune and Space Charge Studies for High-brightness and High-intensity Beams at CERN PS

resonance, emittance, space-charge, beam-losses

625

S.S. Gilardoni, S. Aumon, J. Brenas, P. Freyermuth, A. Huschauer, R. Maillet, E. Matli, R.R. Steerenberg, B. Vandorpe
CERN, Geneva, Switzerland
E. Benedetto
National Technical University of Athens, Zografou, Greece

The current 1.4 GeV CERN PS injection energy limits the maximum intensity required by the future High-Luminosity LHC. The bare-machine large chromaticity combined with the non-linear space charge forces make high-brightness and high-intensity beams crossing betatron resonances along the injection flat bottom, inducing transverse emittance blow-up and beam losses. A scan of the working point plane {Qx,Qy} was done in order to identify beam destructive resonances, in the framework of a possible 2 GeV injection energy upgrade which would reduce the space charge effect on the tune. Experiments were carried out in order to review the maximum space charge tune shift for which no transverse emittance blow-up is observed. The results of measurements and simulations will be presented in this paper.

MOPS017

Simulation Studies of Macro-particles Falling into the LHC Proton Beam

proton, beam-losses, simulation, vacuum

634

F. Zimmermann, T. Baer, M. Giovannozzi, E.B. Holzer, E. Nebot Del Busto, A. Nordt, M. Sapinski
CERN, Geneva, Switzerland
N. Fuster
Valencia University, Atomic Molecular and Nuclear Physics Department, Valencia, Spain
Z. Yang
EPFL, Lausanne, Switzerland

We report updated simulations on the interaction of macro-particles falling from the top of the vacuum chamber into the circulating LHC proton beam. The path and charge state of micron size micro-particles are computed together with the resulting beam losses, which – if high enough - can lead to the local quench of SC magnets. The simulated time evolution of the beam loss is compared with observations in order to constrain some macro-particle parameters. We also discuss the possibility of a "multiple crossing" by the same macro-particle, the effect of a strong dipole field, and the dependence of peak loss rate and loss duration on beam current and on beam size.

MOPS018

Simulation and Measurement of Half Integer Resonance in Coasting Beams on the ISIS Ring

resonance, emittance, simulation, space-charge

637

C.M. Warsop
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
D.J. Adams, B. Jones, B.G. Pine, H. V. Smith, R.E. Williamson
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 (RCS), which provides 3·10¹³ protons per pulse at 50 Hz, corresponding to a beam power of 0.2 MW. In common with many lower energy, high intensity proton rings, a key loss mechanism on ISIS is half integer resonance under space charge. This paper summarises experimental and simulation work studying half integer resonance in a “2D” coasting beam in the ISIS ring: understanding this is an essential prerequisite for explaining the more complicated case of RCS operation. For coasting beam experiments, the ring is reconfigured to storage ring mode with RF off and main magnets powered on DC current only. A 70 MeV beam is injected, painted appropriately, and manipulated so as to approach resonance. Understanding how the resonant condition develops is central to explaining observations, so realistic simulations of resonance, including injection, ramping of intensity and tunes are being developed. Results from the ORBIT code are presented and compared with experimental and theoretical results. Finally, future plans are summarized.

MOPS019

High Intensity Longitudinal Dynamics Studies for Higher Energy Injection into the ISIS Synchrotron

simulation, bunching, space-charge, linac

640

R.E. Williamson, D.J. Adams, C.M. Warsop
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

ISIS is the world’s most productive pulsed neutron and muon source, at the Rutherford Appleton Laboratory in the UK. Operation is centred on a loss-limited 50 Hz proton synchrotron which accelerates 3·10¹³ protons per pulse from 70 MeV to 800 MeV, delivering a mean beam power of 0.2 MW. Present studies on ISIS upgrades are focussed on a new linac for higher energy injection into the existing ring, potentially increasing beam current through reduction in space charge and optimized injection. Studies assume injection of a chopped beam at 180 MeV and offer the possibility of beam powers in the 0.5 MW regime. A critical aspect of such an upgrade is the longitudinal dynamics, associated RF parameters, space charge levels and stringent requirements on beam loss. This paper outlines studies optimizing longitudinal parameters including key design requirements such as bunching factor and satisfying the Keil-Schnell-Boussard stability criterion throughout acceleration. Work developing and benchmarking the in-house longitudinal dynamics code used for these studies is also summarized.

MOPS034

Progress on Space Charge Compensation Study in Low Energy High Intense H⁺ Beam*

emittance, electron, ion, space-charge

676

P.N. Lu, Z.Y. Guo, S.X. Peng, Z.X. Yuan, J. Zhao
PKU/IHIP, Beijing, People's Republic of China
H.T. Ren
Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China

This article lays emphasis on the relationship between the Space Charge Compensation (SCC) and the beam quality in different conditions. Ar and Kr are used to compensate a 35keV/90mA H⁺ beam with the gas pressure from 3.7×10^-4 Pa to 6×10^-3 Pa. Experiments are conducted in different compensation states with three approaches. With an energy spectrometer, we have got the energy spectra of Extra Compensation Gas Ions (ECGI). By a beam profile meter, the beam profiles are obtained when the injection of compensation gas is gradually rising. In the meantime, the beam emittance is measured under different compensation conditions. After measurements of the above data, the potential and the rest charge distributions in the beam are calculated by analyzing the ECGI energy spectra and beam profiles. All experiments performed aimed to seek out the best circumstance for SCC dominated low energy high intensity ion beams.together to calculate the potential distribution are calculated by analyzing the energy spectra and beam profiles. All experiments performed aimed to seeking for the best circumstances in SCC dominated low energy high intensity ion beams.

MOPS039

High Power Proton Linac Front-End: Beam Dynamics Investigation and Plans for the ESS

rfq, solenoid, emittance, proton

688

A. Ponton
ESS, Lund, Sweden

Beam availibility is one of the major concerns for the designer of high power proton linacs. Since the Radio-Frequency Quadrupole (RFQ) will shape and accelerate the beam in the early stage of its propagation it will have a significant impact on the particle dynamics throughout the rest of the linac. The key role of the RFQ is consequently to deliver high quality beams with optimal transmission. Furthermore understanding the space charge compensation mechanism in the Low Energy Beam Transport line (LEBT) is mandatory if one wants to perform calculations with realistic beams. The European Spallation Source (ESS) has put important R&D efforts in designing the linac front-end and deep beam dynamics studies have been undertaken. Results of the investigation work will be presented. We will then deal with the future plans for the ESS and we will finally give a full description of the RFQ and LEBT scheme.

MOPS058

KEKB Linac Wakefield Studies of Comparing Theoretical Calculation, Simulation and Experimental Measurement*

emittance, wakefield, linac, simulation

739

L. Zang, N. Iida, Y. Ogawa, M. Satoh, M. Yoshida, D.M. Zhou
KEK, Ibaraki, Japan

For superKEKB, in order to achieve aiming luminosity machine need to run with a nano-beam scheme so that a small beam emittance is critical important. During the beam propagation, the short-range wake field in the accelerating structure will cause the beam instability and emittance growth. In practical, injecting beam with certain offset could compensate wakfield. And beam emittance could be measured by tuning the quadruple known as quadscan method. In this paper, wakefield theoretical calculation, simulation results will be presented. And then the wakefield impact to beam emittance and wakefield compensation will be discussed. Finally, we will show the comparison of the results getting from theoretical calculation and experimental measurement.

MOPS060

Study on Resistive Wall Instability in CSNS/RCS

simulation, impedance, wakefield, extraction

745

L. Huang, Y.D. Liu, S. Wang
IHEP Beijing, Bejing, People's Republic of China

Rapid Cycling Synchrotron of the China Spallation Neutron Source is a high intensity proton accelerator, with average beam power of 100kW. The collective effects caused by the coupling impedance may be the limit to beam power. The impedance estimation for components on beam line shows that the resistive wall impedance and its instability are more serious than any others. Based on the impedance budget, the instability is theoretically estimated. And a simple resistive wall wake field model is used to simulate the bunch oscillation and the growth rate instability. In this model, the continuous resistive wall wake field is equivalent to a point wake field and long bunch is sliced into many micro-bunches. By tracking the dynamics of the macro-bunches, the transverse growth rate are obtained and the result are analyzed.

MOPS064

Longitudinal Beam Stability and Related Effects at the ALBA Storage Ring

kicker, impedance, resonance, vacuum

748

T.F. Günzel
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The risk of longitudinal instabilities excited by narrowband and broadband resonator impedance was studied. A campaign for the search of modes trapped in vacuum chamber elements of the ALBA storage ring via electromagnetic simulation was initiated. Several critical vacuum elements in the ring like the vertical scraper, the injection and feedback kickers were identified. The outlets of the injection kicker had to be protected with RF-fingers whereas the scraper only produces dangerous modes in the withdrawn state, both do not pose a real problem. However, the calculated power distribution generated in the feedback kickers could be an obstacle for reaching the nominal current of 400mA. Furthermore, the budget of Z(n)/n of the storage ring was computed and checked on the risk of microwave instability using the Boussard criterion.

MOPS069

Review of Beam Instabilities in the Presence of Electron Clouds in the LHC

emittance, electron, simulation, luminosity

760

K.S.B. Li, G. Rumolo
CERN, Geneva, Switzerland

Recent observations at the LHC indicate the build-up of electron clouds when 50 ns spaced beams are injected into the machine at nominal intensity. These electron clouds are a source of coherent beam instabilities and incoherent emittance growth and limit the achievable luminosity. To better understand the influence of electron clouds on the beam dynamics, simulations have been carried out to study both the coherent and the incoherent effects on the beam. The simulations are performed with the HeadTail tracking code; the usage of new post-processing software allows determining not only the beam intensity thresholds in terms of the central electron cloud density but also the footprint of the beam in tune space. In this paper we review instability thresholds and tune footprints for beams with different emittances and interacting with an electron cloud in field-free or dipole regions.

MOPS078

Coaxial Wire Measurements of Ferrite Kicker Magnets

impedance, kicker, simulation, extraction

784

H.A. Day, R.M. Jones
UMAN, Manchester, United Kingdom
M.J. Barnes, F. Caspers, H.A. Day, E. Métral, B. Salvant, C. Zannini
CERN, Geneva, Switzerland

Fast kicker magnets are used to inject beam into and eject beam out of the CERN accelerator rings. These kickers are generally transmission line type magnets with a rectangular shaped aperture through which the beam passes. Unless special precautions are taken the impedance of the yoke can provoke significant beam induced heating, especially for high intensities. In addition the impedance may contribute to beam instabilities. The results of longitudinal and transverse impedance measurements, for various kicker magnets, are presented and compared with analytical calculations: in addition predictions from a numerical analysis are discussed.

MOPS085

Wakefield Calculations for the LCLS in Multibunch Operation*

linac, dipole, HOM, FEL

802

K.L.F. Bane
SLAC, Menlo Park, California, USA

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515.
Normally the Linac Coherent Light Source (LCLS) operates in single-bunch mode, sending a bunch of up to 250 pC charge at 120 Hz through the linac and the undulator, and the resulting FEL radiation into one of the experimental hutches. With two bunches per rf pulse, each pulse could feed either two experiments or one experiment in a pump-probe type configuration. Two-bunch FEL operation has already been briefly tested at the LCLS, and works reasonably well*, although not yet routinely. In this report we study the longitudinal and transverse long-range (bunch-to-bunch) wakefields of the linacs and their effects on LCLS performance in two-bunch mode. The longitudinal wake changes the average energy and chirp at the second bunch, and the transverse wake misaligns the second bunch (in transverse phase space) in the presence of e.g. transverse injection jitter or quad misalignments. Finally, we extend the study to consider the LCLS with trains of up to 20 bunches per rf pulse.
* F.-J. Decker et al, "A demonstration of multi-bunch operation in the LCLS," Proceedings of FEL2010, Malmoe, Sweden, p. 467.

MOPZ004

Studies for the PRISM FFAG Ring for the Next Generation Muon to Electron Conversion Experiment

kicker, electron, extraction, septum

826

J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
M. Aslaninejad, L.J. Jenner, A. Kurup, J. Pasternak, Y. Shi, Y. Uchida
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
R.J. Barlow
UMAN, Manchester, United Kingdom
K.M. Hock, B.D. Muratori
Cockcroft Institute, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
Y. Kuno, A. Sato
Osaka University, Osaka, Japan
J.-B. Lagrange, Y. Mori
KURRI, Osaka, Japan
M. Lancaster
UCL, London, United Kingdom
C. Ohmori
KEK, Tokai, Ibaraki, Japan
T. Planche
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
S.L. Smith
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
H. Witte, T. Yokoi
JAI, Oxford, United Kingdom

High intensity and high quality muon beams are needed for the next generation lepton flavour violation experiments. Such beams can be produced by sending a short proton pulse to a pion production target, capturing the pions and performing RF phase rotation on the resulting muon beam in an FFAG ring. Such a solution was proposed for the PRISM project and this paper summarizes its current status. In particular the PRISM task force was created to address the accelerator and detector issues that need to be solved in order to realise the PRISM experiment. Alternative designs for the PRISM FFAG ring are discussed and their performance compared. The injection/extraction systems and matching to the solenoid channels upstream and downstream of the FFAG ring are presented. The future direction for the study will be outlined.

MOPZ007

A Non-scaling Fixed Field Alternating Gradient Accelerator for the Final Acceleration Stage of the International Design Study of the Neutrino Factory

kicker, extraction, cavity, lattice

832

J.S. Berg
BNL, Upton, Long Island, New York, USA
M. Aslaninejad, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
N. Bliss, M.A. Cordwell, T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
A.A. Muir
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
H. Witte
JAI, Oxford, United Kingdom

Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The International Design Study of the Neutrino Factory (IDS-NF) has recently completed its Interim Design Report (IDR), which presents our current baseline design of the neutrino factory. To increase the efficiency and reduce the cost of acceleration, the IDR design uses a linear non-scaling fixed field alternating gradient accelerator (FFAG) for its final acceleration stage. We present the current lattice design of that FFAG, including the main ring plus its injection and extraction systems. We describe parameters for the main ring magnets, kickers, and septa, as well as the power supplies for the kickers. We present a first pass at an engineering layout for the ring and its subsystems.

MOPZ030

Status of Studies of Achromat-based 6D Ionization Cooling Rings for Muons

lattice, solenoid, kicker, extraction

865

X.P. Ding, D.B. Cline
UCLA, Los Angeles, California, USA
J.S. Berg, H.G. Kirk
BNL, Upton, Long Island, New York, USA
A.A. Garren
Particle Beam Lasers, Inc., Northridge, California, USA

Funding: This work was supported by the U.S. Department of Energy in part under award numbers DE-FG02-92ER40695 (UCLA), DE-AC02-98CH10886 (BNL) and DE-FG02-07ER84855 (Particle Beam Lasers, Inc.)”
Six dimensional ionization cooling of muons is needed to achieve the necessary luminosity for a muon collider. If that cooling could occur over multiple turns in a closed ring, there would be significant cost savings over a single-pass cooling channel. We report on the status of a cooling ring with achromatic arcs. The achromatic design permits the design to easily switch between a closed ring and a snaking geometry on injection or extraction from the ring. The ring is designed with sufficient space in each superperiod for injection and extraction magnets. We describe the ring's lattice design, performance, and injection/extraction requirements.

MOPZ038

EMMA Injection and Extraction

extraction, dipole, septum, kicker

883

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
Y. Giboudot
Brunel University, Middlesex, United Kingdom
D.J. Holder
The University of Liverpool, Liverpool, United Kingdom

EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. NS-FFAGs related to EMMA have an unprecedented potential for medical accelerators for carbon and proton hadron therapy. They could also be used as the accelerator for a sub-critical reactor. We summarize the design and commissioning of both the injection and extraction lines for this machine. In particular, we look at the commissioning challenges of injection and extraction.

MOPZ039

Dispersion-free Regions and Insertions for EMMA

lattice, sextupole, extraction, quadrupole

886

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. Several upgrade possibilities for EMMA are explored, from creating a dispersion-free region in the ring to facilitate injection and extraction to making an insertion in EMMA by turning it into a racetrack-style machine. A dispersion-free region may be created in two separate ways. The first is by using a layout of EMMA which is naturally dispersion-free at the start and end of each cell. This means that we can arrange for periodic dispersion-free sections in every cell or in-between cells. The second is achieved through the use of sextupoles, by going off-axis in them, one has essentially a quadrupolar force which can be used to match the dispersion to zero in a particular place and for a particular energy. The benefits and drawbacks of both methods are discussed from the point of view of practicality and space in general, and applicability to EMMA in particular.

TUYB01

First Results from the EMMA Experiment

acceleration, electron, cavity, septum

951

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

Report on first commissioning results and operational experience with EMMA, the world's first nonscaling FFAG. In particular review the effect of resonance crossing, and the efficiency of serpentine acceleration.

Slides TUYB01 [9.201 MB]

TUPC022

Design of the CLIC Drive Beam Recombination Complex

emittance, linac, sextupole, synchrotron

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.

TUPC053

Superconducting Positron Stacking Ring for CLIC

positron, damping, synchrotron, 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.

TUPC060

A Multi-mode RF Photocathode Gun

gun, cathode, cavity, electron

1135

S.V. Kuzikov, A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
Y. Jiang
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
V. Vogel
DESY, Hamburg, Germany

A photocathode injection gun based on standard emittance compensating techniques and driven by several (N ≥ 2) harmonically related RF sources is considered. Multi-harmonic excitation can provide high-quality flatness in time of the field at the cathode when a bunch is being injected. This allows one to obtain ≥1 nC, 20-40 ps electron bunches with preservation of low emittance. Another advantage is a reduction of Ohmic losses and the required input RF power (for a given cathode field). Preliminary calculations show that input power in a three-mode cavity (0.65 GHz, 1.3 GHz, 2.6 GHz) is nearly half the power needed to feed a single mode with the same cathode field. A further appealing property is the predicted increase of breakdown threshold due to a reduction of surface exposure time to high fields in a symmetric cavity, and due to the so-called anode-cathode effect in a longitudinally asymmetric cavity. These properties may help one to reach bunch energies as high as 3-5 MeV after the first half cell.

TUPC064

Transverse Phase Space Tomography in TRIUMF Injection Beamline

emittance, space-charge, TRIUMF, quadrupole

1144

Y.-N. Rao, R.A. Baartman
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Funding: TRIUMF receives funding via a contribution agreement through the National Research Council of Canada.
By tomography is meant the reconstruction of a 2-dimensional distribution from a number of 1-dimensional projections. In the case of transverse phase space, one records many profiles while varying a focusing device such as a quadrupole. Our aim was to investigate the two transverse phase space distributions in our 300keV H-minus beamline. We performed a series of measurements of beam profiles as a function of the voltage of an electrostatic quadrupole and used these along with the corresponding calculated transfer matrices in an iterative program based upon the Maximum Entropy algorithm, to find the phase space distributions. As well, we made measurements using an Allison-type emittance scanner to scan both planes. In this paper we present the details of these measurements, calculations, and we compare the two techniques.

TUPC095

Bucket-by-bucket On/Off-axis Injection with Variable Field Fast Kicker

kicker, dipole, quadrupole, emittance

1230

T. Nakamura
JASRI/SPring-8, Hyogo-ken, Japan

Dynamic aperture of ultra-low emittance storage rings is expected to be as small as a few mm; one order smaller than that of current rings, because of their high nonlinearity. The conventional injection scheme with bump formation may not be applied for such small aperture. On-axis injection with fast magnet is one of the solutions, however, it requires the injection beam of long trains of bunches, which impose serious limitation on the injector and the filling pattern. We propose a bucket-by-bucket on-axis/off-axis injection scheme, which manipulates the injection and stored beams bucket-by-bucket with a variable field fast kicker. For on-axis injection, this scheme eliminates the limitation on injectors and filling pattern, and also it can reject the contaminated electrons from the injector to keep the bunch purity. Those advantages allow the SPring-8 XFEL low emittance linac to be an injector matched with ultra-low emittance rings like the SPring-8 II: upgrade plan of SPring-8. By changing the drive power to the kicker, it can also produce position dependent kick required for the off-axis injection, with minimal perturbation on the stored beam achieved by bucket-by-bucket scheme.

TUPC098

Beam Profile Measurement using Flying Wire Monitors at the J-PARC Main Ring*

simulation, space-charge, proton, emittance

1239

S. Igarashi, K. Ohmi, Y. Sato, M.J. Shirakata, M. Tejima, T. Toyama
KEK, Ibaraki, Japan
Y. Hashimoto, K. Satou
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Transverse beam profiles have been measured using flying wire monitors at the main ring of the Japan Proton Accelerator Research Complex (J-PARC). The flying wire is a beam profile monitor using a thin carbon fiber as a target. The beam is scanned with the wire target at the maximum speed of 5 m/s. The secondary particles from the beam-wire scattering are detected using a scintillation counter as a function of the wire position. The measurement has revealed a characteristic temporal change of the beam profile during the injection period of 120 ms. A multiparticle tracking simulation program, SCTR, taking account of space charge effects has successfully reproduced the beam profiles.

TUPC099

New Measurements of Proton Beam Extinction at J-PARC

proton, secondary-beams, linac, vacuum

1242

K. Yoshimura, Y. Hori, Y. Igarashi, S. Mihara, H. Nishiguchi, Y. Sato, M. Shimamoto, Y. Takeda, M. Uota
KEK, Ibaraki, Japan
M. Aoki, S. Hikida, H. Nakai
Osaka University, Osaka, Japan
Y. Hashimoto
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Proton beam extinction, defined as a residual to primary ratio of beam intensity, is one of the most important parameters to realize the future muon electron conversion experiment (COMET) proposed at J-PARC. To achieve the required extinction level of 10^-9, we started measuring extinction at main ring (MR) as its first step. According to the various measurements done at the different positions, empty RF buckets of RCS, which were considered to be swept away by the RF chopper, contained about 10^-7 ~ 10^-5 of the main beam pulse due to chopper inefficiency. We have developed a new beam monitor with improved performance for further studies at the abort line. In addition, we have started new measurements at the Hadron experimental hall by using slow-extracted beam. In this paper, we present recent results and future prospect of beam extinction measurements.

TUPC100

Longitudinal Beam Profile Measurement at J-PARC Separated Drift Tube Linac

beam-losses, cavity, linac, simulation

1245

T. Maruta
KEK/JAEA, Ibaraki-Ken, Japan
M. Ikegami
KEK, Ibaraki, Japan
A. Miura, G.H. Wei
JAEA/J-PARC, Tokai-mura, Japan
H. Sako
JAEA, Ibaraki-ken, Japan

We measured longitudinal beam profile at Separated Drift Tube Linac (SDTL) injection part by scanning beam transmission and beamloss at the downstream of SDTL section by changing SDTL injection phase. As the beam goes to acceptance edge, part of the beam which is out of acceptance isn't accelerate and finally it is lost by hitting to beam duct. Thus beam transmission shows sliced bunch shape by acceptance edge, it is possible to reconstruct the beam bunch shape. The result shows about 60% wider profile in both phi and E direction against to design.

TUPC103

Monitoring of the Betatron Tune and Amplitude at Multi-batch Injection of J-PARC MR

kicker, betatron, feedback, quadrupole

1254

S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan
M. Takagi
Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan
M. Tejima, T. Toyama
KEK, Ibaraki, Japan

The beam power of J-PARC Main Ring Synchrotron (MR) increased gradually from 2008, and came to be able regularly to supply the beam of 145kW February, 2011. Many of current beam losses are localized to the collimator located on the injection section. One of the problems of the beam injection is that the orbit of the beam transportation line is unstable. It causes sometimes large transverse injection error. Because the transverse injection error is essentially proportional to the amplitude of the betatron oscillation, it is possible to observe by measuring the turn-by-turn position for every bunch of injected beam by using BPMs located on the injection section. In this report, it is described the method how to measure injection error from beam position. It is also discussed about the effect of reflection wave of injection kicker magnets.

TUPC107

Some Preliminary Experiments using LIBERA BPMs in BEPCII*

coupling, resonance, kicker, feedback

1266

Y. Zhang, H.Z. Ma, J. Yue
IHEP Beijing, Beijing, People's Republic of China

Funding: Supported by the National Natural Science Foundation of China (10805051)
There are total 16 LIBERA BPMs in BEPCII, which is a double ring e⁺e⁻ collider. The turn-by-turn BPMs serve as only tune measurement system in most cases during normal operation. We tried to do some more machine study using them: the local coupling parameter at the BPM, the resonance driving term, the decoherence parameter which could be used to calibrate the strength of octupole in the ring. We also compare the difference from the different exciting method: single time kick with injection kicker or sinusoidal kick with feedback system.

TUPC112

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

photon, synchrotron, 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.

TUPC115

Application of Libera Brilliance Single Pass at NSRL Linac BPM System

brilliance, linac, controls, pick-up

1284

J.Y. Zou, J. Fang, P. Lu, T.J. Ma, B.G. Sun, Y.L. Yang, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Libera Brilliance Single Pass is a digital beam position processor with capabilities of single pass position measurement. This device can be used on the stripline beam position monitor (BPM) of the linac and transfer lines on light sources as well as injector system for the FELs. The linac of Hefei light source (HLS) was equipped with 2 stripline beam position monitors, which will be increased to 20 BPMs after upgrading. The existing BPM electronics were the homemade electronics with logarithm detector. To enhance the functionality of the BPM system, the Libera Brilliance Single Pass is employed to replace the existing BPM electronics. The newly buying devices have made test of characterization. The mapping of stripline BPM is made on a workbench with Libera Brilliance Single Pass. The beam position is tested at linac using Libera Brilliance Single Pass. And the results of these measurement performed on Libera are reported to compared to measurements with the linac’s existing BPM electronics.

TUPC135

Beam Loss Monitors Comparison at the CERN Proton Synchrotron

beam-losses, radiation, electron, proton

1341

S.S. Gilardoni, S. Aumon, E. Effinger, J. Gil Flores
CERN, Geneva, Switzerland
U. Wienands
SLAC, Menlo Park, California, USA

CERN is planning the renovation and upgrade of the beam loss detection system for the Proton Synchrotron (PS). Improved performance in speed–to be able to monitor beam loss on a bunch-by-bunch basis–and in long-term stability–to reduce or avoid the need for periodic calibration–are aimed for. To select the most suitable technology, different detectors were benchmarked in the machine with respect to the same beam loss. The characteristics of the different detectors, the results of the measurement campaign and their suitability as future monitors for the PS are presented.

TUPC136

Analysis of Fast Losses in the LHC with the BLM System

beam-losses, quadrupole, superconducting-magnet, proton

1344

E. Nebot Del Busto, T. Baer, B. Dehning, E. Effinger, J. Emery, E.B. Holzer, A. Marsili, A. Nordt, M. Sapinski, R. Schmidt, B. Velghe, J. Wenninger, C. Zamantzas, F. Zimmermann
CERN, Geneva, Switzerland
N. Fuster
Valencia University, Atomic Molecular and Nuclear Physics Department, Valencia, Spain
Z. Yang
EPFL, Lausanne, Switzerland

About 3600 Ionization Chambers are located around the LHC ring to detect beam losses that could damage the equipment or quench superconducting magnets. The BLMs integrate the losses in 12 different time intervals (from 40 us to 83.8 s) allowing for different abort thresholds depending on the duration of the loss and the beam energy. The signals are also recorded in a database at 1 Hz for offline analysis. During the 2010 run, a limiting factor in the machine availability were sudden losses appearing around the ring on the ms time scale and detected exclusively by the BLM system. It is believed that such losses originate from dust particles falling into the beam, or being attracted by its strong electromagnetic field. This document describes some of the properties of these "Unidentified Falling Objects" (UFOs) putting special emphasis on their dependence on beam parameters (energy, intensity, etc). The subsequent modification of the BLM beam abort thresholds for the 2011 run that were made to avoid unnecessary beam dumps caused by these UFO losses are also discussed.

TUPC137

UFOs in the LHC

beam-losses, kicker, simulation, acceleration

1347

T. Baer, M.J. Barnes, B. Goddard, E.B. Holzer, J.M. Jimenez, A. Lechner, V. Mertens, E. Nebot Del Busto, A. Nordt, J.A. Uythoven, B. Velghe, J. Wenninger, F. Zimmermann
CERN, Geneva, Switzerland

One of the major known limitations for the performance of the Large Hadron Collider are so called UFOs (”Unidentified Falling Objects”). UFOs were first observed in July 2010 and have since caused numerous protection beam dumps. UFOs are thought to be micrometer sized dust particles which lead to fast beam losses with a duration of about 10 turns when they interact with the beam. In 2011, the diagnostics for such events was significantly improved which allows estimates of the properties, dynamics and production mechanisms of the dust particles. The state of knowledge and mitigation strategies are presented.

TUPC144

Preliminary BPM Electrics Testing for the Taiwan Photon Source Project

brilliance, controls, electron, feedback

1362

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

The preliminary BPM electrics are developing and testing for Taiwan Photon Source (TPS), is a 3 GeV synchrotron light source which being in construction at NSRRC. This new BPM electronics with integrated FPGA based hardware, and will be testing in the TLS (Taiwan Light Source) with real beam at first. The enhance functionality of current generation will be adopted in the TPS. The electronic prototype testing and relative property will be reported in this report.

TUPC149

Measurements at the ALICE Tomography Section

quadrupole, emittance, simulation, background

1377

M.G. Ibison, K.M. Hock, D.J. Holder, B.D. Muratori, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Korostelev
The University of Liverpool, Liverpool, United Kingdom

Funding: STFC
This paper reports the results of tomography measurements of the electron beam transverse phase space distribution in the ALICE accelerator at Daresbury Laboratory. These measurements have two main aims. The first is to give a detailed picture of the phase space distribution of the electron beam injected from ALICE into the EMMA prototype non-scaling FFAG accelerator. The second is to provide data for the development and testing of a variety of techniques for tomographic reconstruction. We summarize the measurement results which we have obtained and discuss the advantages and disadvantages of some different tomography methods.

TUPC150

The Effect of Space-Charge on the Tomographic Measurement of Transverse Phase-Space in the EMMA Injection Line

space-charge, quadrupole, emittance, simulation

1380

M.G. Ibison, M. Korostelev
The University of Liverpool, Liverpool, United Kingdom
K.M. Hock, D.J. Holder, B.D. Muratori, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: STFC
Phase-space tomography for particle beams depends upon detailed knowledge of the particle transport through specified sections of a beam line. In the simplest case, only the effects of magnets (such as quadrupoles) and drift spaces need to be taken into account; however, in certain parameter regimes (high charge density and low energy) space charge forces may play a significant role. The ALICE accelerator is the electron source for EMMA, a prototype ns-FFAG machine. Results are presented of investigations into these effects on phase-space tomography in the injection line between ALICE and EMMA. The application of suitable correction techniques* to the EMMA injection line tomography measurements in the presence of space-charge is also discussed.
* D. Stratakis et al., Phys. Rev. ST Accel. Beams 9, 112801 (2006).

TUPC157

Design and Initial Results of a Turn-by-Turn Beam Position Monitoring System for Multiple Bunch Operation of the ATF Damping Ring

damping, single-bunch, feedback, extraction

1398

G.B. Christian, D.R. Bett, M.R. Davis, C. Perry
JAI, Oxford, United Kingdom
R. Apsimon, P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
B. Constance, A. Gerbershagen
CERN, Geneva, Switzerland
J. Resta-López
IFIC, Valencia, Spain

An FPGA-based monitoring system has been developed to study multi-bunch beam instabilities in the damping ring (DR) of the KEK Accelerator Test Facility (ATF), utilising a stripline beam position monitor (BPM) and existing BPM processor hardware. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR in single-bunch multi-train mode or the head bunch of up to three trains in multi-bunch mode, with a bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software were modified to record turn-by-turn data for up to six channels and 1–3 bunches in the DR. An overview of the system and initial results will be presented.

TUPC168

Results from the LHC BRAN Luminosity Monitor at Increased Luminosities

luminosity, emittance, radiation, simulation

1428

R. Miyamoto
BNL, Upton, Long Island, New York, USA
E. Bravin
CERN, Geneva, Switzerland
H.S. Matis, A. Ratti, W.C. Turner, H. Yaver, T. stezelberger
LBNL, Berkeley, California, USA

Funding: This work supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
The LHC BRAN luminosity monitors are used to monitor and optimize the luminosity at the LHC high luminosity interaction points IP1 and IP5. The Argon gas ionization chambers detect showers produced in the TAN absorbers by neutral particles emerging from pp collisions. The detectors have been operated during the 2010 run by counting the shower rate. As the current 2011 run has the multiplicity of proton-proton collisions per bunch crossing near ten, the detector sees more than one collision per bunch crossing. Therefore, the operation of the detector has been switched to pulse height mode to detect the average shower flux. This paper presents results from recent pulse height mode measurements, including the total and bunch-by-bunch luminosity as well as a determination of the crossing angle at these IPs. Comparisons with luminosity measurements from ATLAS and CMS are also presented.

TUPO012

Stable Planner Type Four-mirror Cavity Development for X-ray Production as Basic Development of Quantum Beam Technology Program

laser, cavity, superconducting-RF, target

1470

H. Shimizu, Y. Higashi, Y. Honda, J. Urakawa
KEK, Ibaraki, Japan

As the development of quantum beam technology program, a facility to produce a semi-monochromatic X-ray via inverse Compton scattering with an electron beam accelerated by a superconducting RF cavity and a fiber amplified high power laser stacked in an external optical cavity system are now under construction. To achieve high brightness of Compton X-ray, we introduced a chicane with about a 1m-long zero dispersion straight section that includes IP. Head on collision scheme improves the yield of X-ray, but to do so, a huge and stout external optical cavity system must be needed. According to this demand, we develop a quite tolerable planner type four-mirror cavity with movable mirror mount system. In this paper, results obtained by the cavity construction and also laser development activities are described.

TUPS017

The LHC Experimental Beam Pipe Neon Venting, Pumping and Conditioning

vacuum, ion, monitoring, shielding

1557

V. Baglin, G. Bregliozzi, D. Calegari, J.M. Jimenez, G. Lanza, G. Schneider
CERN, Geneva, Switzerland

The experimental vacuum chambers of the four LHC experiments (ATLAS, CMS, LHCb and ALICE) are mechanically optimized in order to be transparent to particles. In order to grant their mechanical stability and to avoid any overstress, every time there was a request for detector opening or closing and for working in the vicinity of the vacuum chamber, the experimental beam vacuum chambers have been vented to atmospheric pressure. Since the LHC start up a safety procedure has been applied to mechanically secure the four experimental beam pipes during each long technical stop. Ultra-pure neon was used to preserve at best the NEG pumping efficiency. Up to now more than 15 neon injections and pump down have been performed without detecting any reduction of the NEG efficiency. This paper describes the Gas Injection System performances and the main points of the venting and pumping procedure. Details of the experimental beam pipe vacuum recovery and conditioning are presented for each of the four LHC experiments (ATLAS, CMS, LHCb and ALICE).

TUPS026

Specification of New Vacuum Chambers for the LHC Experimental Interactions

vacuum, alignment, impedance, optics

1584

R. Veness, R.W. Assmann, A. Ball, A. Behrens, C. Bracco, G. Bregliozzi, R. Bruce, H. Burkhardt, G. Corti, M.A. Gallilee, M. Giovannozzi, B. Goddard, D. Mergelkuhl, E. Métral, M. Nessi, W. Riegler, J. Wenninger
CERN, Geneva, Switzerland
N. Mounet, B. Salvant
EPFL, Lausanne, Switzerland

The apertures for the vacuum chambers at the interaction points inside the LHC experiments are key both to the safe operation of the LHC machine and to obtaining the best physics performance from the experiments. Following the successful startup of the LHC physics programme the ALICE, ATLAS and CMS experiments have launched projects to improve physics performance by adding detector layers closer to the beam. To achieve this they have requested smaller aperture vacuum chambers to be installed. The first periods of LHC operation have yielded much information both on the performance of the LHC and the stability and alignment of the experiments. In this paper, the new information relating to the aperture of these chambers is presented and a summary is made of analysis of parameters required to safely reduce the vacuum chambers apertures for the high-luminosity experiments ATLAS and CMS.

TUPS033

Foil Scattering Loss Mitigation by the Additional Collimation System of J-PARC RCS

collimation, vacuum, septum, scattering

1605

K. Yamamoto, H. Harada, J. Kamiya, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the RCS, the significant losses were observed at the branch of H0 dump line and the Beam Position Monitor which was put at the downstream of the H0 dump branch duct. From the beam study, we were certain that these losses were caused by the scattering of the injection and circulating beam at the charge exchange injection foil. In order to mitigate these losses, we started to develop a new collimation system in the H0 branch duct. We presents a overview of this new collimation system.

TUPS052

An FPGA Based Controller for the MICE Target

target, controls, extraction, EPICS

1647

P.J. Smith, C.N. Booth, P. Hodgson, E. Overton, M. Robinson
Sheffield University, Sheffield, United Kingdom
J. Leaver, K.R. Long
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

Funding: UK Science and Technology Facilities Council
The MICE experiment uses a beam of low energy muons to test the feasibility of ionization cooling. This beam is derived parasitically from the ISIS accelerator at the Rutherford Appleton Laboratory. A target mechanism has been developed that rapidly inserts a small titanium target into the circulating proton beam immediately prior to extraction without unduly disturbing the primary ISIS beam. The original control electronics for the MICE target was based upon an 8-bit PIC. Although this system was fully functional it did not provide the necessary IO to permit full integration of the target electronics onto the MICE EPICS system. A three phase program was established to migrate both the target control and DAQ electronics from the original prototype onto a fully integrated FPGA system that is capable of interfacing with EPICS through a local PC. This paper discusses this upgrade program, the motivation behind it and the performance of the upgraded target controller.

TUPS077

Shaping of Ion Pulses from an Electron Beam Ion Source for Particle Injection into Accelerators

ion, electron, ion-source, proton

1716

F. Ullmann, A. Schwan
DREEBIT GmbH, Dresden, Germany
U. Hagen, O. Heid, H. von Jagwitz
Siemens AG, Healthcare Technology and Concepts, Erlangen, Germany
G. Zschornack
Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany

Electron Beam Ion Sources (EBISs) provide highly charged ions for many applications, amongst others for particle injection into accelerators. Although EBISs are limited in ion output they feature a lot of advantages which qualify them for accelerator injection. The ion pulses extracted from the ion sources can be directly injected into an accelerator sequence which however requires ion pulses with distinct shape and length. We present the production of ion pulses matching the requirements of particle injection. The ions are produced by trapping in a high density electron beam for a certain time with electrostatic potentials providing for their axial trapping. The ions are extracted by lowering the trapping potential, i.e. opening the trap. Due to the ion energy distribution within the trapping region ion extraction can be controlled by controlling the trapping potential. A specific time dependent control mode of the trapping potential thus allows to produce ion pulses with designated shape and length. Source parameters such as working gas pressure, electron beam current and energy are influencing the energy distribution of the ions which in turn is influencing pulse shaping.

TUPS078

Electron Beam Ion Sources – A New Access for Particle Acceleration

ion, electron, ion-source, emittance

1719

F. Ullmann, F. Grossmann, V.P. Ovsyannikov, A. Schwan
DREEBIT GmbH, Dresden, Germany
G. Zschornack
Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany

Electron Beam Ion Sources (EBISs) produce highly charged ions in a high density electron beam. Due to their operational principle EBISs have a lot of advantages although limited in ion output. Since the radial source region is given by a narrow electron beam the extracted ion beam features a very low transversal emittance. Moreover, the ions are ionized by a monoenergetic electron beam resulting in a small variation of the ion energy distribution, and thus in a very low longitudinal emittance. Together with a low basis pressure of less than 10^-9 mbar this result in a high quality ion beam. The ions can be extracted as continuous beam as well as ion pulses with distinct pulse shapes. Providing almost any element with any charge state of up to completely ionized ions gives a large number of different projectiles and kinetic energies. The use of EBISs whether based on permanent magnets or on cryogen-free superconducting magnets has been proven in a variety of fields and applications. In addition, their compact design makes them transportable, low in operational costs, and guarantee easy handling.

TUPS080

Low Energy Bunching with a Double Gap RF Buncher

bunching, ion, ion-source, proton

1725

H. von Jagwitz, U. Hagen, O. Heid, S. Setzer
Siemens AG, Erlangen, Germany

A compact double gap bunching system for low energy proton beams is presented. The system is designed for the bunching of a low current proton beam (less than 50μA) with an energy of 10 keV. The buncher operates at 150 MHz and bunches without significantly changing the beam energy. The beam is generated by an Electron Beam Ion Source and has to be bunched for the subsequent acceleration in a 150 MHz linear accelerator. The buncher contains two short gaps and an RF electrode inbetween. Thus the full length of the buncher in the beamline is in the range of 2 cm. The location of the bunch focus depends on the buncher power. The bunched beam was analysed at a distance of 550 mm with a fast faraday cup. The bunching effectivity was determined as 50%, which means that 50% of the protons of the beam were located in bunches with a width of 60°, which is a reasonable value of acceptance for a conventional accelerator cavity. Some theory and detailed results will be presented.

TUPZ001

90 m Optics Commissioning

optics, proton, coupling, scattering

1795

S. Cavalier
LAL, Orsay, France
H. Burkhardt, M. Fitterer, G.J. Müller, S. Redaelli, R. Tomás, G. Vanbavinckhove, J. Wenninger
CERN, Geneva, Switzerland

Special β* = 90 m optics have been developed for the two very high luminosity insertions of the LHC, as a first step towards to allow for very low angle precision measurements of the proton-proton collisions in the LHC. These optics were developed to be compatible with the standard LHC injection and ramp optics. The target value of β* = 90 m is reached by an un-squeeze from the injection β* = 11 m. We describe the implementation of this optics in the LHC and the first experience in the commissioning of these optics.

TUPZ003

Simulation of Electron-cloud Build-Up for the Cold Arcs of the LHC and Comparison with Measured Data

electron, simulation, dipole, vacuum

1801

G.H.I. Maury Cuna
CINVESTAV, Mérida, Mexico
G. Arduini, G. Rumolo, L.J. Tavian, F. Zimmermann
CERN, Geneva, Switzerland

The electron cloud generated by synchrotron radiation or residual gas ionization is a concern for LHC operation and performance. We report the results of simulations studies which examine the electron cloud build-up, at injection energy, 3.5 TeV for various operation parameters In particular we determine the value of the secondary emission yield corresponding to the multipacting threshold, and investigate the electron density, and heat as a function of bunch intensity for dipoles and field-free regions. We also include a comparison between simulations results and measured heat-load data from the LHC scrubbing runs in 2011

TUPZ004

The NICA Facility in Polarized Proton Operation Mode

collider, proton, ion, booster

1804

A.D. Kovalenko, N.N. Agapov, Y. Filatov, V.D. Kekelidze, R.I. Lednicky, I.N. Meshkov, V.A. Mikhaylov, A.O. Sidorin, A. Sorin, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia

Basic goal of the planned NICA facility at JINR is focused on the studying of heavy ion collisions over the energy range √s ~ 411 GeV/u. Capabilities of the proposed scheme were carefully analyzed in this case and reaching of the desired average luminosity, L = 1·10²⁷ cm^-2 s⁻¹ for gold-gold collisions at √s = 9 GeV/u, have been confirmed. The other important NICA research domain is the experiments with polarized proton beams at the highest possible energy, the highest luminosity and polarization degree as well. The main aim is to provide √s ~ 25 GeV and L ~ 1·10³¹ cm^-2 s⁻¹. The unsolved aspects of the problem are discussed, possible solutions are analyzed and necessary modifications of the NICA scheme are considered as well.

TUPZ006

Aperture Determination in the LHC Based on an Emittance Blowup Technique with Collimator Position Scan

beam-losses, emittance, optics, storage-ring

1810

R.W. Assmann, R. Bruce, M. Giovannozzi, G.J. Müller, S. Redaelli, F. Schmidt, R. Tomás, J. Wenninger, D. Wollmann
CERN, Geneva, Switzerland
M. Alabau
IFIC, Valencia, Spain

A new method to determine the LHC aperture was proposed. The new component is a collimator scan technique that refers the globally measured aperture limit to the shadow of the primary collimator, expressed in σs of rms beam size. As a by-product the BLM response to beam loss is quantified. The method is described and LHC measurement results are presented.

TUPZ013

Calculation Method for Safe Beta* in the LHC

luminosity, emittance, optics, collimation

1828

R. Bruce, R.W. Assmann, W. Herr, D. Wollmann
CERN, Geneva, Switzerland

One way of increasing the peak luminosity in the LHC is to decrease the beam size at the interaction points by squeezing to smaller values of beta*. The LHC is now in a regime where safety and stability determines the limit in beta*, as opposed to traditional optics limits. In this paper, we derive a calculation model to determine the safe beta*-values based on collimator settings and operational stability of the LHC. This model was used to calculate the settings for the LHC run in 2011. It was found that beta* could be decreased from 3.5 m to 1.5 m, which has now successfully been put into operation.

TUPZ016

First Run of the LHC as a Heavy-ion Collider

ion, luminosity, proton, heavy-ion

1837

J.M. Jowett, G. Arduini, R.W. Assmann, P. Baudrenghien, C. Carli, M. Lamont, M. Solfaroli Camillocci, J.A. Uythoven, W. Venturini Delsolaro, J. Wenninger
CERN, Geneva, Switzerland

A year of LHC operation typically consists of an extended run with colliding protons, ending with a month in which the LHC has to switch to its second role as a heavy ion collider and provide a useful integrated luminosity to three experiments. The first such run in November 2010 demonstrated that this is feasible. Commissioning was extremely rapid, with collisions of Pb nuclei achieved within 55 h of first injection. Stable beams for physics data-taking were declared a little over one day later and the final integrated luminosity substantially exceeded expectations.

TUPZ019

Transverse Emittance Preservation through the LHC Cycle

emittance, luminosity, extraction, controls

1843

V. Kain, B. Goddard, B.J. Holzer, J.M. Jowett, M. Meddahi, T. Mertens, F. Roncarolo
CERN, Geneva, Switzerland

The preservation of the transverse emittance is crucial for luminosity performance. At the LHC design stage the total allowed emittance increase was set to 7% throughout the LHC cycle. The proton run in 2010 showed that the injectors can provide beams with smaller emittances than nominal and higher bunch intensities. The LHC parameters are well under control and the emittances are kept below nominal until physics. The LHC luminosity goals for the first year of running could therefore be achieved with fewer bunches than initially foreseen. This paper will report on the measured emittance growth at injection from the SPS and the evolution of the emittance through the entire LHC cycle. Sources and possible cures for the observed emittance growth will be discussed.

TUPZ021

The SPS Beam Quality Monitor, from Design to Operation

extraction, dipole, quadrupole, luminosity

1849

G. Papotti, T. Bohl, F. Follin, E.N. Shaposhnikova
CERN, Geneva, Switzerland

The SPS Beam Quality Monitor is a system that monitors longitudinal beam parameters on a cycle-by-cycle basis and prevents extraction to the LHC in case the specifications are not met. This avoids losses, unnecessary stress of machine protection components and luminosity degradation, additionally helping efficiency during the filling process. The system has been operational since the 2009 LHC run, checking the beam pattern, its correct position with respect to the LHC references, individual bunch lengths and stability. In this paper the algorithms used, the hardware implementation and the operational aspects are presented.

TUPZ022

Longitudinal Beam Measurements at the LHC: The LHC Beam Quality Monitor

pick-up, controls, emittance, damping

1852

G. Papotti, T. Bohl, F. Follin, U. Wehrle
CERN, Geneva, Switzerland

The LHC Beam Quality Monitor is a system that measures individual bunch lengths and positions, similarly to the twin system SPS Beam Quality Monitor, from which it was derived. The pattern verification that the system provides is vital during the injection process to verify the correctness of the injected pattern, while the bunch length measurement is fedback to control the longitudinal emittance blow up performed during the energy ramp. In 2010 the system could for example clearly detect instances of longitudinal instabilities and beam excitation due to excess RF noise. The algorithms used, the hardware implementation and the system integration in the LHC control infrastructure are presented in this paper, along with possible improvements.

TUPZ023

Observation of Bunch to Bunch Differences due to Beam-beam Effects

luminosity, emittance, kicker, dynamic-aperture

1855

G. Papotti, R. Alemany-Fernandez, R. Giachino, W. Herr, T. Pieloni, M. Schaumann, G. Trad
CERN, Geneva, Switzerland

Due to the bunch filling schemes in the LHC the bunches experience a very different collision schedule and therefore different beam-beam effects. These differences and the effect on the performance have been observed and compared with the expectations. Possible limitations due to these effects are discussed.

TUPZ026

Alternative Working Point(s) at Injection for the LHC

coupling, optics, quadrupole, emittance

1861

R. Calaga, R. Miyamoto
BNL, Upton, Long Island, New York, USA
R. Tomás
CERN, Geneva, Switzerland
G. Vanbavinckhove
NIKHEF, Amsterdam, The Netherlands

Funding: This work partially supported by the US Department of Energy through the LHC Accelerator Research Program (LARP).
At present, the LHC operates with a different fractional tunes at injection and at collision energy due to improved dynamic aperture indicated by tracking studies. Therefore, a tune swing crossing the 10th order resonance is needed during the beta-squeeze. A new proposal to alter the working point to collision tunes already at injection and during an energy ramp is foreseen to avoid the tune jump. Simulations and measurements of the optics along with the beam emittances and lifetime are compared to the nominal injection tunes. Feasibility for a working point close to the 1/2 integer is also attempted.

TUPZ034

Impact of Arc Phase Advance on Chromatic Optics in RHIC

optics, quadrupole, ion, proton

1885

R. Calaga, R. Miyamoto, G. Robert-Demolaize, S.M. White
BNL, Upton, Long Island, New York, USA
R. De Maria, R. Tomás
CERN, Geneva, Switzerland
G. Vanbavinckhove
NIKHEF, Amsterdam, The Netherlands

Funding: This work is partially supported by the US Department of Energy through the LHC Accelerator Research program (LARP).
The phase advance between the two interaction points in RHIC is optimized for dynamic aperture for a initial design beta-star. This may not hold true as RHIC presently operates with a considerably reduced beta-star. Additionally the reduction of the available beam aperture due to an enlarged chromatic beta-beating is evident. Results from phase advance scans between the two IPs to reduce the chromatic beta-beating in model and measurements are presented. Impact on the single beam lifetime and momentum aperture is compared to the nominal optics.

TUPZ041

Site Studies for the SuperB Collider and Synchrotron Radiation Facility Project

site, ground-motion, collider, linac

1900

S. Tomassini, M.E. Biagini, P. Raimondi, C. Sanelli
INFN/LNF, Frascati (Roma), Italy
B. Bolzon
CERN, Geneva, Switzerland
G. Deleglise, A. Jeremie
IN2P3-LAPP, Annecy-le-Vieux, France
J.T. Seeman
SLAC, Menlo Park, California, USA

The SuperB project aims at the construction of a very high luminosity (10³⁶ cm^-2 s⁻¹) asymmetric electron-positron collider. Due to its large beam current (~2 A) high energy (~7 GeV) and low vertical emittance (less than 10^-11 m) the facility looks very attractive as an x-ray synchrotron radiation source, and therefore few beam lines are also foreseen. Possible locations are the campus of the University of Rome Tor Vergata or near another Italian INFN laboratory site. This paper presents and describes the status of the preliminary design of the civil infrastructure layout and related site issues.

WEOAA01

The ThomX Project

laser, feedback, cavity, synchrotron

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]

WEOBA02

KEK Digital Accelerator and its Beam Commissioning

ion, acceleration, induction, kicker

1920

K. Takayama, T. Arai, Y. Arakida, M. Hasimoto, T. Iwashita, E. Kadokura, T. Kawakubo, T. Kubo, H. Nakanishi, K. Okamura, H. Someya, A. Takagi, M. Wake
KEK, Ibaraki, Japan
T. Adachi, K.W. Leo
Sokendai, Ibaraki, Japan
K. Okazaki
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan

The digital accelerator (DA), which is a small-scale induction synchrotron no requiring a high-energy injector accelerator and capable of providing a wide variety of ions, has been constructed at KEK*. Since the last winter beam commissioning has been carried out. Preliminary results of the beam commissioning experiment as well as the accelerator itself will be presented at the conference. The KEK-DA consists of a 200 kV high voltage terminal, in which an ECRIS is embedded, 15 m long LEBT, electro-static injection kicker, and a 10 Hz rapid cycle synchrotron, which is the recycle use of the former 500 MeV Booster synchrotron. An ion pulse, which is chopped in 5 μs by the newly developed Marx generator driven chopper**, is guided through the LEBT and injected by the electrostatic kicker, which is turned off before the injected ion pulse completes the first turn. Then the ion pulse is captured with a pair of barrier voltages and accelerated with the induction acceleration voltage through a full acceleration period. Beam commissioning has been started with a He¹⁺ ion beam of 50 micro-ampere. Beam commissioning of other ions such as C, N, O, Ne, and Ar will be expected.
* T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.
** T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, these proceedings.

Slides WEOBA02 [4.268 MB]

WEPC009

Design of an Antiproton Injection and Matching Beam Line for the AD Recycler Ring

antiproton, acceleration, quadrupole, ion

2019

O. Karamyshev, G.A. Karamysheva
MPI-K, Heidelberg, Germany
O. Karamyshev, A.I. Papash
JINR, Dubna, Moscow Region, Russia
M.R.F. Siggel-King, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by STFC, the Helmholtz Association and GSI under contract VH-NG.328.
A small antiproton recycler ring (AD-Rec) for use in the MUSASHI beamline at the CERN AD has been designed by the QUASAR Group for operation at energies between 3 and 30 keV. A highly efficient beam line for capturing the beam after extraction from the trap, transporting and injecting it into the AD Rec is very important to minimize losses and full the ring up to its space charge limit. In this contribution, the beam optical and mechanical design of the injector is presented.

WEPC010

Investigations into Efficient Extraction and Acceleration of Beams from Ion Traps

antiproton, extraction, emittance, ion

2022

O. Karamyshev, G.A. Karamysheva
MPI-K, Heidelberg, Germany
O. Karamyshev, A.I. Papash
JINR, Dubna, Moscow Region, Russia
M.R.F. Siggel-King, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by STFC, the Helmholtz Association and GSI under contract VH-NG.328
A number of exotic ion species, such as for example radioactive isotopes or antiprotons, are highly desirable at very low energies of some tens of keV for fundamental studies. In order to obtain cooled beams with low emittance and low momentum spread, these particles are often first captured in an ion trap, cooled and then extracted and accelerated before being used in experiments. The extraction mechanism and subsequent beam handling impacts critically on the final beam quality. In this contribnution, an optimized scheme for efficient beam extraction and acceleration from ion traps is presented. Field maps from different existing ion trap setups, such as for example the Musashi trap at CERN, are used as a basis for simulation studies into the beam dynamics. Input and final beam emittances are analyzed as a function of the extraction and acceleration field geometries and the performance of different possible scenarios is directly compared.

WEPC016

Amplitude Dependent Orbit Shift and its Effect on Beam Injection

septum, betatron, sextupole, synchrotron

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.

WEPC025

Modeling Results of the ALBA Booster

booster, emittance, dipole, quadrupole

2058

G. Benedetti, D. Einfeld, U. Iriso, J. Marcos, Z. Martí, M. Muñoz, M. Pont
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The 3rd generation light source ALBA is in the process of being commissioned. The full energy 3 GeV booster synchrotron was commissioned in the during 2010, ramping the beam from extracted from the LINAC from an energy of 110 MeV to the 3 GeV required for injection in the storage ring. The lattice is based in combined function bending magnets, providing a small emittance beam (< 12 nmrad) at extraction. This paper reviews the agreement between the optics modeling and the measures performed during the commissioning, with special regard to the optics measurement during the ramping process. The results from the magnetic measurement for the combined magnets while ramping are included in the model to explain the movement of the tunes during the ramp.

WEPC028

Record Low Beta-beat of 10% in the LHC

optics, hadron, quadrupole, collider

2061

G. Vanbavinckhove
NIKHEF, Amsterdam, The Netherlands
M. Aiba
PSI, Villigen, Switzerland
R. Calaga, R. Miyamoto
BNL, Upton, Long Island, New York, USA
R. Tomás
CERN, Geneva, Switzerland

During the 2011 LHC run several measurements and correction campaigns were conducted. As a result a peak beta-beat of 10% level was achieved. This level, well below the specified tolerances of the LHC, improves the aperture margins and helps minimize the luminosity imbalance between the different experiments. A combination of local corrections at the insertion regions and an overall global correction were used to achieve this record low beta-beat. The sequence of the optics corrections and stability along the 2011 run are reported.

WEPC032

First Measurements of Higher Order Optics Parameters in the LHC

simulation, optics, resonance, kicker

2073

G. Vanbavinckhove
NIKHEF, Amsterdam, The Netherlands
M. Aiba
PSI, Villigen, Switzerland
R. Bartolini
Diamond, Oxfordshire, United Kingdom
R. Calaga, R. Miyamoto
BNL, Upton, Long Island, New York, USA
M. Giovannozzi, F. Schmidt, R. Tomás
CERN, Geneva, Switzerland
E.H. Maclean
JAI, Oxford, United Kingdom

Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these parameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed simulations are compared to the measurements together with discussions on the measurement limitations.

WEPC042

Implementation of Double Mini-beta Optics at the Diamond Light Source

optics, quadrupole, single-bunch, insertion

2103

B. Singh, R.T. Fielder, I.P.S. Martin, G. Rehm
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Funding: Diamond Light Source Ltd.
We report the results of the implementation of two vertical mini-beta and horizontally focusing optics at the Diamond light source, the first in August 2010 and the second in March 2011. Commissioning results of the two optics changes and experimental characterization of the optics are compared with the expected performance and theoretical modeling. The implications of a possible third customized optics are also investigated.

WEPC044

Minimizing Beam Motion in a Long-pulse Linear Induction Accelerator

induction, target, kicker, focusing

2109

C. Ekdahl, E.O. Abeyta, J.B. Johnson, K. Nielsen, M.E. Schulze
LANL, Los Alamos, New Mexico, USA
T.P. Hughes, C.H. Thoma
Voss Scientific, Albuquerque, New Mexico, USA
C.-Y. Tom
NSTec, Los Alamos, New Mexico, USA

Funding: This work was supported by the US National Nuclear Security Agency and the US Department of Energy under contract DE-AC52-06NA25396.
The Dual Axis Radiography for Hydrodynamic Testing (DARHT) Facility at Los Alamos uses two linear induction accelerators (LIAs) for flash radiography of explosively driven experiments from orthogonal viewpoints. The DARHT Axis-II long-pulse 1.8-kA, 16.5-MeV LIA is unique. It has a beam pulse with a 1600-ns flattop during which the kinetic energy varies < 2%. During this flattop, a kicker cleaves out four short micro-pulses, which are focused onto a high-Z target and converted to bremsstrahlung for multi-pulse flash radiography of the experiments. Asymmetric injection of the beam into the solenoidal focusing field, small temporal variations in accelerating potentials, and slight cell misalignments cause the beam position to wander during the flattop. This is undesirable for radiography, because it causes a displacement of the four radiographic source spots. Since the specific energy deposition from each micro-pulse can vaporize target material, succeeding pulses impact an asymmetric object causing a distortion of the source spot. This presentation will review the physics of the beam motion and the tuning procedures we have optimized to minimize the number of shots required.

WEPC050

New Optics for the SOLEIL Storage Ring

optics, coupling, undulator, vacuum

2124

P. Brunelle, F. Briquez, A. Loulergue, O. Marcouillé, A. Nadji, L.S. Nadolski, M.-A. Tordeux, J.F. Zhang
SOLEIL, Gif-sur-Yvette, France

SOLEIL, the French 2.75GeV synchrotron light source is delivering photons to 24 beam lines and is presently equipped with 22 insertion devices (ID) including a high field and small gap in-vacuum wiggler*. This paper presents the continuous work performed to reduce the strong non linear effects of several IDs. On one side, the ID defaults have been precisely identified using on-beam measurements, and magnetic correction developments are going on, especially for the in-vacuum wiggler and for the 10m long HU640 undulator. On the other side, a new optics has been optimised in terms of beta-functions (at the ID location) and non linear dynamics in order to improve the injection efficiency and the beam lifetime in the presence of IDs. The modified optics has been used daily in operation since November 2010 and ensures a beam lifetime greater than 10h for a 400mA stored beam with the users ID configuration. In parallel, an extensive experimental optimization has been performed to prepare the operation with an additional quadrupole triplet that provides double low vertical beta functions in one long straight section that will accommodate two canted in-vacuum insertion devices**.
* O. Marcouillé et al., IPAC10, p. 3102 (2010).
** A. Loulergue et al., IPAC10, p. 2496 (2010).

WEPC065

Design of a Low Energy Ion Beam Facility*

ion, antiproton, vacuum, quadrupole

2169

M.R.F. Siggel-King, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O. Karamyshev
JINR/DLNP, Dubna, Moscow region, Russia
G.A. Karamysheva
MPI-K, Heidelberg, Germany
A.I. Papash
JINR, Dubna, Moscow Region, Russia
M.R.F. Siggel-King
The University of Liverpool, Liverpool, United Kingdom

Funding: Work supported by STFC, the EU under GA-PITN-215080, the Helmholtz Association and GSI under VH-NG-328.
A small electrostatic ring, and associated electrostatic injection beamlines, are being designed and developed. The ring will make possible a variety of experiments using a choice of many types of recirculating ions (e.g., from protons, H-, and antiprotons up to and including large charged biomolecules). A reaction microscope will be incorporated into the ring to enable differential ionization experiments between the recirculating ion beam and gas jet targets. Two injection sections have been designed to cover a variety of ion sources. The facility will be portable to enable it to be moved between facilities and beamlines and it will be unique due to its combination of design elements, flexible beam properties, energy (ca 3-30 keV) and type of circulating particles. In this paper, we give an update on this project.

WEPC069

Impact of Nonlinear Resonances on Beam Dynamics at the SPring-8 Storage Ring

resonance, storage-ring, coupling, betatron

2181

M. Takao, J. Schimizu, Y. Shimosaki, K. Soutome
JASRI/SPring-8, Hyogo-ken, Japan

For a low emittance storage ring like high brilliant light sources, the improvement of nonlinear beam dynamics is necessary for the stable operation, or for providing large dynamic aperture and momentum acceptance for efficient injection and long Touschek lifetime. At the SPring-8 storage ring it is observed that injection efficiency is affected by the gap heights of the magnet arrays of the in-vacuum insertion devices. The fact that the injected beam of fundamentally oscillating in horizontal direction is limited by the vertical aperture means that coupling resonances influence the beam dynamics. To clarify the phenomena, we studied the nonlinear beam dynamics of transverse betatron motion by means of turn-by-turn method. Then, we found some nonlinear coupling resonances, such as the one by skew sextupole field, are excited to enhance vertical oscillation and to deteriorate the injection efficiency. By analyzing these results, we developed measures to suppress the effect of the nonlinear coupling resonances and to improve the injection efficiency.

WEPC075

ITEP-TWAC Progress Report

ion, proton, laser, target

2193

N.N. Alexeev, P.N. Alekseev, V. Andreev, A. Balabaev, V.I. Nikolaev, A.S. Ryabtsev, Yu.A. Satov, V.A. Schegolev, B.Y. Sharkov, A. Shumshurov, V.P. Zavodov
ITEP, Moscow, Russia

The program of the ITEP-TWAC Facility upgrade for next three years has been approved last year in the frame of National Research Center Kurchatov Institute taking up ITEP in accordance with government decision. It includes expanding of multimode using proton and heavy ion beams in different applications on a base of new accelerator technologies development. The laser ion source advantage of high temperature plasma generation has to be transformed to high current and high charge state ion beam of Z/A up to 0.4 for elements with A ~ 60 to be effectively stacked in the accumulator ring with multiple charge exchange injection technique. The new high current heavy ion RFQ section is in progress for the beam test. Accelerating system of accumulator ring U-10 is modified to increase compression voltage for stacked beam by factor of four. Design of proton injection and beam slow extraction for UK ring is performed for its utilizing as self-depending synchrotron in medical application and for imitation of cosmic radiation. The machine status analysis and current results of activities aiming at both subsequent improvement of beam parameters and expanding beam applications are presented.

WEPC078

Non-linear Chromaticity Studies of the LHC at Injection

octupole, dipole, optics, emittance

2199

E.H. Maclean, M. Giovannozzi, F. Schmidt, R.J. Steinhagen, E. Todesco, R. Tomás, G. Vanbavinckhove
CERN, Geneva, Switzerland
R. Bartolini
JAI, Oxford, United Kingdom

The non-linear chromaticity of the LHC has been studied. Measurements of variation in tune with dp/p on both beams at injection optics are being compared with Q'' and Q''' as calculated with the LHC effective model. This model uses the best currently available measurements of magnetic field harmonics. An attempt is being made to optimize the b4 and b5 pool-pieces corrections in view of the corresponding chromaticity terms.

WEPC079

Beta-beating in the Effective Model of the LHC Using PTC

optics, alignment, closed-orbit, quadrupole

2202

M.C. Alabau Pons, F. Schmidt, R. Tomás
CERN, Geneva, Switzerland
E.H. Maclean
JAI, Oxford, United Kingdom

An effective model of the LHC optics has been developed based on measurements of magnetic field, alignment errors and closed orbit. This model utilizes the Polymorphic Tracking Code with MAD-X as front-end to allow the inclusion of harmonics to an arbitrary order in thick lattice elements. Beta-beating calculations have been performed with this model at injection optics and at 3.5 TeV squeezed optics to 3.5 m beta-function at the interaction point. The model predictions are in remarkable agreement with the measurements performed in the 2010 LHC commissioning run.

WEPC102

Recent Developments for Efficient 3D Space Charge Computations Based on Adaptive Multigrid Discretizations

space-charge, simulation, brightness, optics

2253

G. Pöplau, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
M.J. de Loos
TUE, Eindhoven, The Netherlands
S.B. van der Geer
Pulsar Physics, Eindhoven, The Netherlands

Funding: Partly supported by BMBF under contract number 05K10HRC
Efficient and accurate space-charge computations are essential for the design of high-brightness charged particle sources. Recently a new adaptive meshing strategy based on multigrid was implemented in GPT and the capabilities were demonstrated. This new meshing scheme uses the solution of an intermediate step in the multigrid algorithm itself to define optimal mesh line positions. In this paper we discuss further developments of this adaptive meshing strategy. We compare the new algorithm with the current meshing scheme of GPT, where the mesh line positions are based upon the projected charge density.

WEPC111

Single Particle Tracking Simulation for Compact Cyclotron*

simulation, cyclotron, cavity, positron

2274

H.W. Kim, J.-S. Chai, B.N. Lee, Y.S. Lee, K.R. Nam, H.S. Song
SKKU, Suwon, Republic of Korea

Funding: Ministry of Education, Science and Technology, Republic of Korea. Department of Energy Science and School of Information and Communication Engineering of SungKyunKwan University.
Low energy compact cyclotrons for Positron emission tomography (PET) are needed for the production of radio-isotope. In the magnet design for those cyclotrons, single particle tracking simulation after the design is important to check the quality of designed magnetic field of the magnet. The study of single particle tracking simulation for cyclotron magnet is shown in this paper. Maximum beam energy of example cyclotron is 9 MeV for proton and pseudo accelerating gap is adapted for the simulation. 3D CAD program CATIA P3 V5 R18 is used for design the magnet and pseudo accelerating gap. All magnetic and electric field calculations had been performed by OPERA-3D TOSCA and the own-made program OPTICY is used for other calculations - phase slip, radial and axial tune.

WEPC158

The EMMA Accelerator, A Diagnostic Systems Overview

extraction, diagnostics, pick-up, EPICS

2355

R.J. Smith, M. Dufau, C. Hill, J.K. Jones, A. Kalinin, L. Ma, P.A. McIntosh, B.D. Muratori, B.J.A. Shepherd
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
J.S. Berg
BNL, Upton, Long Island, New York, USA
N. Bliss, G. Cox, A. Gallagher, A. Oates
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
R.G. Borrell
WareWorks Ltd, Manchester, United Kingdom
J.L. Crisp
FRIB, East Lansing, Michigan, USA
K.M. Hock, D.J. Holder
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M.G. Ibison, I. Kirkman
The University of Liverpool, Liverpool, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The ‘EMMA’ Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) international project is currently being commissioned at Daresbury Laboratory, UK. This accelerator has been equipped with a number of diagnostic systems to facilitate this. These systems include a novel time-domain-multiplexing BPM system, moveable screen systems, a time-of-flight instrument, Faraday cups, and injection/extraction tomography sections to analyse the single bunch beams. An upgrade still to implement includes the installation of a fast wall current monitor. This paper gives an overview of these systems and shows some data and results that have contributed to the successful demonstration of a serpentine acceleration by this novel accelerator.

WEPC170

Handling of BLM Abort Thresholds in the LHC

beam-losses, monitoring, quadrupole, proton

2382

E. Nebot Del Busto, B. Dehning, E.B. Holzer, S. Jackson, G. Kruk, M. Nemcic, A. Nordt, A. Orecka, C. Roderick, M. Sapinski, A. Skaugen, C. Zamantzas
CERN, Geneva, Switzerland

The Beam Loss Monitoring system (BLM) for the LHC consists of about 3600 Ionization Chambers located around the ring. Its main purpose is to request a beam abort when the measured losses exceed a certain threshold. The BLM detectors integrate the measured signals in 12 different time intervals (running from 40 us to 83.8 s) enabling for a different set of abort thresholds depending on the duration of the beam loss. Furthermore, 32 energy levels running from 0 to 7 TeV account for the fact that the energy density of a particle shower increases with the energy of the primary particle, i.e. the beam energy. Thus, about 1.3·10⁶ thresholds must be handled and send to the appropriate processing modules for the system to function. These thresholds are highly critical for the safety of the machine and depend to a large part on human judgment, which cannot be replaced by automatic test procedures. The BLM team has defined well established procedures to compute, set and check new BLM thresholds, in order to avoid and/or find non-conformities due to manipulation. These procedures, as well as the tools developed to automate this process are described in detail in this document.

WEPC174

A Failure Catalogue for the LHC

monitoring, extraction, vacuum, beam-losses

2394

S. Wagner, R. Schmidt, B. Todd, J.A. Uythoven, M. Zerlauth
CERN, Geneva, Switzerland

The LHC, with a stored energy of more than 360 MJ per beam, requires a complex machine protection system to prevent equipment damage. The system was designed based on a large number of possible failures in the subsystems and operational phases of the LHC. This led to a mixed system with active and passive protection. The active part monitors many thousand parameters (such as beam losses, temperatures in superconducting magnets, power converter currents, etc.) and triggers a beam dump in case a failure is detected. The passive part includes protection elements like collimators and beam absorbers to ensure the prevention of damage in case of single turn beam losses (e.g. during beam transfer and injection). So far, the knowledge of the possible failures is distributed over the different teams involved in the design, construction and operation of the LHC. A newly started project aims at bringing together this knowledge in a common failure catalogue. The chosen approach in addition is expected to allow for the identification of failures that might not have been considered yet or that require further measures. This paper introduces the approach and presents the first experience.

WEPO013

Septum and Kicker Magnets for the ALBA Booster and Storage Ring

kicker, booster, vacuum, storage-ring

2421

M. Pont, R. Nunez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
E. Huttel
KIT, Karlsruhe, Germany

At the ALBA Synchrotron light source 6 kicker and 3 septa magnets are installed for beam injection and extraction. A 100 MeV beam coming from the linac is injected on axis into the Booster. The full energy (3 GeV) beam is extracted from the booster and injected into the Storage Ring, where 4 kicker magnets bring the stored beam close to the septa. All septa are direct driven out-of-vacuum magnets with C shape iron laminated yoke. The magnets are excited by a full sine approx. 300 μs pulse length; the nominal field is 0.15/0.84/0.9 T (booster injection/extraction/storage-ring-injection). The stray field seen by the stored beam is less than 1 μT. The booster kicker magnets are in-vacuum magnets with C-ferrite yoke. The magnets are excited by a 0.4 μs flat top pulse; the nominal field is 0.03/0.04 T (booster injection/extraction). The storage ring kickers have a C-ferrite yoke and a 0.4 μm Ti coated ceramic vacuum chamber. The excitation is done by 6 μs half sine; the nominal field is 0.13 T. The paper will present the design of the elements and their magnetic characteristics. First results of their behaviour during commissioning will also be discussed.

WEPO028

Design of HTS Sector Magnets for the RCNP New Injector Cyclotron

cyclotron, dipole, neutron, cavity

2460

K. Hatanaka, M. Fukuda, N. Izumi, M. Kibayashi, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, H. Ueda, Y. Yasuda, T. Yorita
RCNP, Osaka, Japan
T. Kawaguchi
KT Science Ltd., Akashi, Japan

The RCNP cyclotron cascade system consists of K140 AVF cyclotron and K400 ring cyclotron and is providing high quality beams for various experiments. There are increasing demands for high intensity beams and even to improve the quality. In order to increase the physics research opportunities, a new injector cyclotron is recently proposed, which has four separated sector magnets and two accelerating cavities. Sector magnets are designed to use High Temperature Superconducting (HTS) wire. At RCNP we have been developing magnets with HTS wires for a decade. In this paper, we will report recent results of developed HTS magnets and the design of sector magnets for the new injector SSC.

WEPO031

The Magnetic Model of the LHC during Commissioning to Higher Beam Intensities in 2010-2011

quadrupole, dipole, optics, sextupole

2466

L. Deniau, N. Aquilina, L. Fiscarelli, M. Giovannozzi, P. Hagen, M. Lamont, G. Montenero, R.J. Steinhagen, M. Strzelczyk, E. Todesco, R. Tomás, W. Venturini Delsolaro, J. Wenninger
CERN, Geneva, Switzerland

The Field Description of the Large Hadron Collider (FiDeL) model is a set of semi-empirical equations linking the magnets behaviours established from magnetic measurements to the magnetic properties of the machine observed through beam measurements. The FiDeL model includes the parameterization of static components such as magnets residual magnetization, persistent currents, hysteresis and saturation as well as the decay and snap-back dynamic components. In the present paper, we outline the relationship between the beam observables (orbit, tune, chromaticity) and the model components during the commissioning to higher beam intensities in 2010-2011, with an energy of 3.5 TeV per beam. The main relevant issues are (i) the operation at 2 A/s and 10 A/s ramp rate and their influence on chromatic correction, (ii) the beta beating and its relation to the knowledge of the resistive quadrupoles transfer functions and (iii) the observed tune decay at injection energy and its possibles origins.

WEPS001

A New Lattice for the Beta-beam Decay Ring to Reduce the Head Tail Effects

lattice, dipole, ion, dynamic-aperture

2478

A. Chancé, J. Payet
CEA/DSM/IRFU, France
C. Hansen
CERN, Geneva, Switzerland

Funding: I acknowledge the financial support of the European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372.
The beta-beam concept relies on the production, by beta decay of radioactive ions of a very high flux, of an electron neutrino and anti-neutrino beam towards a distant detector. In this aim, the radioactive isotopes are stored in a long racetrack-shaped ring, called the decay ring, where they orbit until they decay or are lost. The intensities to store in the decay ring to obtain the required neutrino fluxes are very high (several amperes in average). Therefore, collective effects occur. Among them, the head tail effect, caused by transversal resonance impedance, is one of the main issues: the beam was shown to be unstable with the previous decay ring lattice. The transition gamma was reduced to mitigate this problem. For this purpose the lattice was changed by removing the injection from the arc to put it in a chicane which is added in one of the long straight sections. After presenting the limitation due to head tail effects, we will present the modification in the lattice and their impact on the dynamic aperture in the decay ring. Then the improvement on the beta-beam performance with respect to the lower transition gamma will be shown.

WEPS002

Limitations in Mitigating Collective Effects in the Beta-Beam Decay Ring by the Use of Octupoles

octupole, ion, damping, impedance

2481

C. Hansen
CERN, Geneva, Switzerland
E. Benedetto
National Technical University of Athens, Zografou, Greece
A. Chancé, J. Payet
CEA/DSM/IRFU, France

Funding: I acknowledge the financial support of the European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372.
The beta-beam concept relies on the production, by beta decay of radioactive ions of a very high flux, of an electron neutrino and anti-neutrino beam towards a distant detector. After production and acceleration in an accelerator complex consisting of a rapid cycling synchrotron, the CERN PS and the CERN SPS, the radioactive isotopes are injected into a long racetrack-shaped ring, called the decay ring, where they orbit until they decay or are lost. The required intensities to store in the decay ring to reach the aimed neutrino fluxes are very high. Among the collective effects, the head tail effect, caused by transversal resonance impedance, is one of the main issues: the beam was shown to be unstable with the previous decay ring lattice. The lattice was changed to handle this problem; e.g. octupoles were included to increase the stability limit with an amplitude detuning. We here report on the improvement on the beta-beam performance with respect to amplitude detuning in the decay ring and discuss other mitigation attempts.

WEPS003

SIS18 – Intensity Record with Intermediate Charge State Heavy Ions

ion, heavy-ion, beam-losses, acceleration

2484

P.J. Spiller
GSI, Darmstadt, Germany
L.H.J. Bozyk
FIAS, Frankfurt am Main, Germany
P. Puppel
HIC for FAIR, Frankfurt am Main, Germany

Funding: Project partly funded by the European Community DIRAC-PHASE-1 / Contract number: 515876
In order to reach the desired intensities of heavy ion beams for the experiments at FAIR, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 10¹¹ ions per cycle has never been demonstrated elsewhere and requires a dedicated upgrade program for SIS18 and a dedicated machine design for SIS100. The specific problems coming along with the intermediate charge state operation in terms of charge exchange processes at collisions with residual gas atoms, pressure bumps by ion induced desorption and corresponding beam loss appears far below the typical space charge limits. Thus, new design concepts and new technical equipment addressing these issues are developed and realized with highest priority. The upgrade program of SIS18 addressing the goal of minimum ionization beam loss and stable residual gas pressure conditions has been defined in 2005. A major part of this upgrade program has been successfully realized, with the result of a world record in accelerated number of intermediate charge state heavy ions.

WEPS004

Confinement, Accumulation and Diagnostic of Low Energy Ion Beams in Toroidal Fields

ion, diagnostics, electron, beam-transport

2487

M. Droba, A. Ates, O. Meusel, H. Niebuhr, U. Ratzinger, J.F. Wagner
IAP, Frankfurt am Main, Germany

An optimized design of a stellarator-type storage ring for low energy ion beams was numerically investigated. The magnetic field variation along the circumference and therefore magnetic heating is suppressed by using simple circular correction coils. Particle-in-Cell (PIC) simulations in a magnetic flux coordinate system show the ability of high current ion beam accumulation in such a configuration with unique features for clockwise and anticlockwise moving beams. Additionally scaled down experiments with two 30 degree room temperature toroidal segments were performed to demonstrate toroidal transport and to develop optical beam diagnostics. Properties of multi-component beams, redistribution of transversal momenta in the non-adiabatic part of the experimental configuration and investigation of strongly confined beam induced electron clouds will be addressed.

WEPS010

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

cavity, impedance, acceleration, synchrotron

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.

WEPS014

RF Systems and Bunch Formation at NICA

collider, ion, booster, cavity

2511

A.V. Eliseev, I.N. Meshkov, A.O. Sidorin, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia
O.I. Brovko
JINR/VBLHEP, Moscow, Russia
G.Y. Kurkin, V.M. Petrov
BINP SB RAS, Novosibirsk, Russia

The NICA facility being constructed at JINR will consists of two synchrotrons (Booster and Nuclotron) and collider working at constant magnetic field. To reach required luminosity level the collider rings will be operated with short ion bunches. The bunch formation in the collider as well as longitudinal dynamics in all the rings is described. The parameters and preliminary design of RF systems are presented.

WEPS017

Plans for the Upgrade of the LHC Injectors

linac, synchrotron, 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.

WEPS018

The Proposed CERN Proton-Synchrotron Upgrade Program

emittance, cavity, space-charge, electron

2520

S.S. Gilardoni, S. Bart Pedersen, W. Bartmann, S. Bartolome, O.E. Berrig, C. Bertone, A. Blas, D. Bodart, J. Borburgh, R.J. Brown, A.C. Butterworth, M.C.L. Buzio, C. Carli, P. Chiggiato, H. Damerau, T. Dobers, R. Folch, R. Garoby, B. Goddard, M. Gourber-Pace, S. Hancock, M. Hourican, P. Le Roux, L.A. Lopez Hernandez, A. Masi, G. Metral, Y. Muttoni, E. Métral, M. Nonis, J. Pierlot, S. Pittet, C. Rossi, I. Ruehl, G. Rumolo, L. Sermeus, R.R. Steerenberg, M. Widorski
CERN, Geneva, Switzerland

In the framework of the High-Luminosity LHC project, the CERN Proton Synchrotron would require a major upgrade to match the future beam parameters requested as pre-injector of the collider. The different beam dynamics issues, from space-charge limitations to longitudinal instabilities are discussed, as well as the proposed technical solutions to overcome them, covering the increase of the injection energy to RF related improvements.

WEPS019

Study of a Rapid Cycling Synchrotron to Replace the CERN PS Booster

extraction, booster, linac, lattice

2523

K. Hanke, O. Aberle, M. E. Angoletta, B. Balhan, W. Bartmann, M. Benedikt, J. Borburgh, D. Bozzini, C. Carli, P. Dahlen, T. Dobers, M. Fitterer, R. Garoby, S.S. Gilardoni, B. Goddard, J. Hansen, T. Hermanns, M. Hourican, S. Jensen, A. Kosmicki, L.A. Lopez Hernandez, M. Meddahi, B. Mikulec, A. Newborough, M. Nonis, S. Olek, M.M. Paoluzzi, S. Pittet, B. Puccio, V. Raginel, I. Ruehl, H.O. Schönauer, L. Sermeus, R.R. Steerenberg, J. Tan, J. Tückmantel, M. Vretenar, M. Widorski
CERN, Geneva, Switzerland

CERN’s proton injector chain is undergoing a massive consolidation and upgrade program in order to deliver beams meeting the needs of the LHC Luminosity Upgrade. As an alternative to the upgrade of the existing Proton Synchrotron Booster (PSB), the construction of a Rapid Cycling Synchrotron (RCS) has been studied. This machine would replace the PSB and deliver beams to the LHC as well as to CERN’s rich fixed-target physics program. This paper summarizes the outcome of the feasibility study along with a tentative RCS design.

WEPS020

Study of an Energy Upgrade of the CERN PS Booster

booster, power-supply, extraction, emittance

2526

K. Hanke, O. Aberle, M. E. Angoletta, W. Bartmann, S. Bartolome, C. Bertone, A. Blas, J. Borburgh, D. Bozzini, A.C. Butterworth, C. Carli, P. Dahlen, T. Dobers, A. Findlay, R. Folch, N. Gilbert, J. Hansen, T. Hermanns, S. Jensen, P. Le Roux, L.A. Lopez Hernandez, E. Mahner, A. Masi, B. Mikulec, Y. Muttoni, A. Newborough, D. Nisbet, M. Nonis, S. Olek, M.M. Paoluzzi, S. Pittet, B. Puccio, V. Raginel, I. Ruehl, J. Tan, B. Todd, W.J.M. Weterings, M. Widorski
CERN, Geneva, Switzerland

CERN’s LHC injector chain will have to deliver beams with ultimate brilliance as the LHC is heading for increased luminosity in the coming years. In order to overcome bottlenecks in the injector chain, an increase of the beam transfer energy from the CERN Proton Synchrotron Booster (PSB) to the Proton Synchrotron (PS) has been investigated as a possible upgrade scenario. This paper gives an overview of the technical solutions and summarizes the conclusions of the feasibility study.

WEPS022

Ions for LHC: Performance of the Injector Chain

ion, luminosity, linac, proton

2529

D. Manglunki, M. E. Angoletta, P. Baudrenghien, G. Bellodi, A. Blas, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, M. Chanel, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, S. Maury, E. Métral, S. Pasinelli, M. Schokker, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger
CERN, Geneva, Switzerland

The first LHC Pb ion run took place at 1.38 A TeV/c per beam in autumn 2010. After a short period of running-in, the injector chain was able to fill the collider with up to 137 bunches per ring, with an intensity of 10⁸ Pb ions/bunch, about 50% higher than the design value. This yielded a luminosity of 3E25 Hz/cm², allowing the experiments to accumulate just under 10 inverse microbarn each during the four week run. We review the performance of the individual links of the injector chain, and address the main issues limiting the LHC luminosity, in view of reaching 10²6 Hz/cm² in 2011, and substantially beyond when the LHC energy increases after the long shutdown in 2013-14.

WEPS023

A Possible RF System for CERN RCS

cavity, synchrotron, 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.

WEPS028

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

synchrotron, proton, extraction, ion

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.

WEPS032

Conceptual Study for the New HE-Linac at GSI

cavity, linac, DTL, acceleration

2553

G. Clemente, W.A. Barth, B. Schlitt
GSI, Darmstadt, Germany

The commissioning of the first three modules of the FAIR accelerator facility is planned to be completed in 2016. At that time the DTL section of the UNILAC will be more than 40 years old. Different proposals for a new high intensity, heavy ion linac which will replace the ALVAREZ DTL as synchrotron injector are under discussion. This new High Energy-UNILAC will be design accordingly to the advanced FAIR requirements and will allow for complete and reliable multi-ion-operation for at least the next 30 years. In a first step it is foreseen to replace the first two DTL cavity, up to 4.7 AMeV. 4 IH cavities will be used to accelerate U⁴⁺ to 3 AMeV and, after gas stripping, another cavity will provide the second step of acceleration for U³⁸⁺ to 4.77 AMeV. For the next upgrade different options concerning the injection energy are under investigation. The main target is to provide a higher charge state and a higher injection energy to increase the life time of the heavy ion beam inside the synchrotron. The paper presents the beam dynamics and RF investigation for the first upgrade together with a conceptual study design for the complete replacement of the GSI ALVAREZ DTL.

WEPS049

Floor Deformation of J-PARC Linac after the Tohoku Earthquake in Japan

linac, alignment, cavity, DTL

2601

T. Morishita, H. Asano
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
M. Ikegami
KEK, Ibaraki, Japan

J-PARC linac has finalized its precise alignment at the end of summer 2006, and the beam provision to the Rapid Cycling Synchrotron has been started at Sept. 2007. Since then, the deformation of the accelerator tunnel is small enough to keep the soundness of the alignment accuracy. Therefore, the linac has been operated without realignment of the accelerator components for these four years. However, the alignment has seriously been damaged due to the large earthquake at Mar. 11th, 2011 in eastern Japan. Now, work for restoration is being continued. In this paper, the deformation of the linac tunnel floor due to the earthquake is reported. Since then, aftershock happens frequently. We also report the stability of the tunnel floor.

WEPS070

Commissioning Status of Kolkata Superconducting Cyclotron

cyclotron, extraction, acceleration, ion

2664

C. Mallik, R.K. Bhandari
DAE/VECC, Calcutta, India

After completing the construction of the K~500 superconducting cyclotron at Kolkata, the internal beam acceleration was accomplished in August 2009 and several tests were conducted to confirm the acceleration. Earlier the superconducting magnet using Nb-Ti superconductor with 300 litre liquid helium cryostat and 80 tonne iron was commissioned and field mapped. The radiofrequency system spanning 9-27 MHz and with three independent resonators were integrated into the machine. Some difficulties were experienced with achieving the voltage related to ceramic failures. Finally, ~50 kV on the dees have been achieved with reasonable phase stability between the three dees. The cyclotron uses a 14 GHz external ECR ion source and the beam is injected through 28 metre long injection line. Till date several beams like neon, argon, nitrogen, oxygen etc. have been accelerated mostly in analogous mode and at around 14 MHz frequency and ~32 kG field. Valuable experience has been obtained with various systems. The paper would describe the experience with different subsystems and beam acceleration experience. Presently, beam extraction is being tried and will be achieved shortly.

WEPS072

A Superconducting Ring Cyclotron to Search for CP Violation in the Neutrino Sector

cavity, cyclotron, extraction, focusing

2670

L.A.C. Piazza, M.M. Maggiore
INFN/LNL, Legnaro (PD), Italy
L. Calabretta, D. Campo, D. Rifuggiato
INFN/LNS, Catania, Italy
A. Calanna
CSFNSM, Catania, Italy

Multi Megawatt accelerators are today requested for different use. In particular the experiment DAEdALUS*, recently proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector** and of a booster ring cyclotron has been proposed***. The booster Superconducting Ring Cyclotron, able to accelerate a H²⁺ molecule beam up to 800 MeV/n and average power higher than 1.6 MW, will be described. Although the average power is 1.6 MW, due to the low duty cycle, the peak power will be 8 MW. The main advantages to accelerate H²⁺ are a reduction of space charge effects, a simple extraction process, extraction of two beams at the same time from each booster cyclotron to simplify the beam dump. The features of the magnetic sector, of the superconducting coils and the magnetic forces evaluated by the code TOSCA are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too.
*J.Alonso etal., Novel Search for CP Violation in the Neutrino Sector: DAEdALUS, June2010;e-Print arXiv:10⁰⁶.0260.
**L.Calabretta, IPAC 2011,this conference.
***L.Calabretta, Cyclotrons 2010, Lanzhou.

WEPS074

H⁻ Injection Studies of FFAG Accelerator at KURRI

linac, beam-transport, proton, neutron

2676

K. Okabe, Y. Niwa, I. Sakai
University of Fukui, Faculty of Engineering, Fukui, Japan
Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, B. Qin, T. Uesugi, E. Yamakawa
KURRI, Osaka, Japan

Aiming to demonstrate the basic feasibility of the accelerator driven sub-critical reactor (ADSR), proton Fixed Field Alternating Gradient (FFAG) accelerator complex as a neutron production driver has been constructed in Kyoto University Research Reactor Institute (KURRI). In order to upgrade beam power of the FFAG neutron source, a project about a new H⁻ linac injector for FFAG main ring instead of present injector has been started. A charge exchange multi-turn beam injection has been performed for the first time at FFAG main ring in KURRI. In this paper, the detail of injection system and beam study of low energy H⁻ injection at FFAG is described.

WEPS078

Compact FFAG Accelerators for Medium Energy Hadron Applications

proton, hadron, extraction, linac

2688

B. Qin, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, K. Okabe, T. Uesugi, E. Yamakawa
KURRI, Osaka, Japan

Funding: This work was supported by Japan Science and Technology Agency under Strategic Promotion of Innovative Research and Development Program.
Medium energy hadron beams are widely applied in accelerator driven subcritical systems (ADSR), high intensity neutron sources and carbon therapy. Compactness feature is important for this energy region, especially in the case of medical use purposes. This paper introduces a novel superferric scheme with scaling fixed-field alternating gradient (FFAG) accelerators, which can deliver 400MeV/u carbon ions or 1.2GeV protons. By using high permeability materials, 5T magnetic field with high field index can be achieved to reduce accelerator circumference significantly. The lattice configuration and design of superferric magnet are described in details.

WEPS079

Serpentine Acceleration in Scaling FFAG

acceleration, proton, electron, closed-orbit

2691

E. Yamakawa, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, B. Qin, T. Uesugi
KURRI, Osaka, Japan
K. Okabe, I. Sakai
University of Fukui, Faculty of Engineering, Fukui, Japan

A serpentine acceleration in scaling FFAG accelerator has been examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is also derived analytically.

WEPS082

Development of FLNR JINR Heavy Ion Accelerator Complex in the Next Seven Years: New DC-280 Cyclotron Project

ion, cyclotron, target, extraction

2700

G.G. Gulbekyan, S.L. Bogomolov, O.N. Borisov, S.N. Dmitriev, J. Franko, B. Gikal, I.A. Ivanenko, I.V. Kalagin, V.I. Kazacha, N.Yu. Kazarinov, N.F. Osipov, A. Tikhomirov
JINR, Dubna, Moscow Region, Russia

At present time four isochronous cyclotrons: U-400, U-400M, U-200 and IC-100 are in operation at the JINR FLNR. Total operation time is about 10000 hours per year. The U400M is a primary beam generator and U400 is as postaccelerator in RIB (DRIBs) experiments to produce and accelerate exotic nuclides such as 6He, 8He etc. One of the basic scientific programs which are carried out in FLNR - synthesis of new elements which demands intensive beams of heavy ions. Now U-400 is capable to provide long term experiments on Ca 48 beams with intensity of 1 pμA.In order to improve efficiency of the experiments for the next 7 years it is necessary to obtain the accelerated ion beams with the following parameters. Ion energy 4/8 MeV/n Masses 10/238 Beam intensity (up to A=50) 10 pμA Beam emittance less 30 π mm·mrad These parameters have underlain the project of new cyclotron DC-280.

WEPS083

DC280 Cyclotron Central Region with Independent Flat-Top System

cyclotron, acceleration, ion, heavy-ion

2703

I.A. Ivanenko, B. Gikal, G.G. Gulbekyan, N.Yu. Kazarinov
JINR, Dubna, Moscow Region, Russia

At the present time, the activities on creation of the new isochronous cyclotron DC280 are carried out at the FLNR, JINR. The cyclotron DC280 is intended for accelerating the wide range of ion beams with A/Z= 4 - 7 to energy W= 4 - 8MeV/u and intensity up to 10pmcA. To achieve high-intensity ion beams the cyclotron is equipped with Flat-Top system. At the cyclotron DC280 the Flat-Top system is physically separated from main resonators. The investigation of the cyclotron centre region with independent Flat-Top is presented. The simulation of the beams acceleration is carried out by means of the computer code CENTR.

WEPS096

Injection Energy Recovery of J-PARC RCS

power-supply, beam-losses, impedance, septum

2730

N. Hayashi, H. Hotchi, J. Kamiya, P.K. Saha, T. Takayanagi, K. Yamamoto, M. Yamamoto, Y. Yamazaki
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC RCS is a high beam power Rapid-Cycling Synchrotron (RCS). The original designed injection energy is 400MeV, although presently it is 181MeV, and its beam power is limited to 0.6MW. Works to recover the Linac energy are ongoing and injection magnets power supplies upgrade are required in the RCS. In order to achieve 1MW designed beam power, new instrumentation is also planned simultaneously. Activities related injection energy recovery in the J-PARC RCS is presented.

WEPS098

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

collimation, synchrotron, simulation, scattering

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”.

WEPS099

Physics Design of CSNS RCS Injection and Extraction System

extraction, kicker, septum, emittance

2739

J. Qiu, N. Huang, J. Tang, S. Wang
IHEP Beijing, Beijing, People's Republic of China

In this paper, the injection and extraction system design for CSNS RCS are discussed. The injection system is designed to place all the injection devices in one uninterrupted long drift in one of the four dispersion free straight sections. Painting bumper magnets are used for both horizontal and vertical phase space painting. The beam extraction process from the CSNS RCS is a single turn two step process, requiring a group of kickers and a Lambertson septum magnet.

WEPS101

Lattice Design of a RCS as Possible Alternative to the PS Booster Upgrade

lattice, quadrupole, space-charge, booster

2745

M. Fitterer, M. Benedikt, H. Burkhardt, C. Carli, R. Garoby, B. Goddard, K. Hanke, H.O. Schönauer
CERN, Geneva, Switzerland
A.-S. Müller
KIT, Karlsruhe, Germany

In the framework of the LHC Injectors Upgrade (LIU) a new rapid cycling synchrotron as alternative to the PS Booster has been proposed. In this paper we present the lattice constraints and requirement as well as the current status of the RCS lattice design and beam dynamics studies.

WEPS104

Transverse Beam Dynamics for the ISIS Synchrotron with Higher Energy Injection

resonance, space-charge, simulation, synchrotron

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.

WEPS105

A Common Proton Driver for a Neutrino Factory and a Spallation Neutron Source Based on Megawatt Upgrades to ISIS

proton, neutron, linac, booster

2757

J.W.G. Thomason
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The Rutherford Appleton Laboratory (RAL) is home to ISIS, the world’s most productive spallation neutron source. Potential upgrades of the ISIS accelerators to provide beam powers of 2 – 5 MW in the few GeV energy range could be envisaged as the starting point for a proton driver shared between a short pulse spallation neutron source and the Neutrino Factory. The concept of sharing a proton driver between other facilities and the Neutrino Factory is an attractive, cost-effective solution which is already being studied in site-specific cases at CERN and FNAL. Although in the RAL case the requirements for the Neutrino Factory baseline proton energy and time structure are different from those for a spallation neutron source, an additional RCS or FFAG booster bridging the gap in proton energy and performing appropriate bunch compression seems feasible.

WEPS106

Status of Injection Upgrade Studies for the ISIS Synchrotron

space-charge, simulation, linac, synchrotron

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.

WEPZ005

Field Calculations to obtain Attosecond/Femtosecond Electron Bunches

cathode, laser, electron, radiation

2772

V.A. Papadichev
LPI, Moscow, Russia

Obtaining short electron bunches of attosecond and femtosecond duration in a combined quasi-static and laser electric field [* - ****] requires careful field formation in the cathode region. First, the maximum of laser electric field normal to the cathode plate, depending on the incidence angle, was found employing Fresnel formulae using complex dielectric permittivity of metals. Second, laser field enhancement on cathode spikes was calculated for the case of an ellipsoid in a qusi-static approximation (laser wavelength larger than spike dimensions). Field enhancement is approximately proportional to the square of the ratio of major to minor axes of ellipsoid. Thus, enhancement factors as large as 100 - 1000 are obtainable, allowing to reduce laser power by 10 thousand to 1 million times.
* V.A.Papadichev, Patent RU 2 269 877 C1, 10.02.06, Bull. 4.
** V.A.Papadichev, Proc. EPAC08, p.2812.
*** V.A.Papadichev, Proc. EPAC08, p.2815.
**** V.A.Papadichev, Proc. IPAC'10, p. 4372

WEPZ025

Study of Self-injection of an Electron Beam in a Laser-driven Plasma Cavity

electron, plasma, laser, simulation

2820

S. Krishnagopal, S.A. Samant, D. Sarkar
BARC, Mumbai, India
P. Jha
Lucknow University, Lucknow, India
A.K. Upadhyay
CBS, Mumbai, India

Over the last few years, remarkable advances in laser wakefield acceleration of electrons have been achieved, including quasi-monoenergetic beams and GeV energy in a few centimeters. However, it is necessary to achieve good beam quality (large current, low energy-spread and low emittance) for applications such as free-electron lasers. We study self-injection in two regimes of the laser-plasma interaction: the moderate intensity, self-guiding regime, and the low intensity, near-injection-threshold regime, both in a homogeneous plasma that completely fills the simulation volume. We find good beam quality with injection of on-axis electrons, especially at lower intensity. We also study the case when the laser has to travel through vacuum before entering the plasma. We find that injection here is completely different, from off-axis electrons, and the beam quality is poorer.

THYA01

Beam Dynamics in Positron Injector Systems for Next Generation B Factories

emittance, positron, linac, target

2857

N. Iida, H. Ikeda, T. Kamitani, M. Kikuchi, K. Oide, D.M. Zhou
KEK, Ibaraki, Japan

SuperKEKB, the upgrade plan of KEKB, aims to boost the luminosity up to 8x10³5 /cm²/s. The beam energy of the Low Energy Ring (LER) is 4 GeV for positrons, and that of the High Energy Ring is 7 GeV for electrons. SuperKEKB is designed to produce low emittance beams. The horizontal and vertical emittances of the injection beams are 12.5 nm and 0.9 nm, respectively, which are one or two orders smaller than those of KEKB. The normal and maximum required charges are 4 nC and 8nC, respectively. The positron injector system consists of the source, capture systems, L-band and S-band linacs, collimators, an energy compression system (ECS), a 1.1-GeV damping ring, a bunch compression system (BCS), S-band and C-band linacs, another ECS and a beam transport line into the LER. For the low emittance beam with a huge amount of the positron charge like 8nC, some kinds of issues by the instabilities will be predicted due to such as Coherent Synchrotron Radiation (CSR), beam loading, beam-beam effects, and so on. This paper reports a design of the positron beam injection system for SuperKEKB. In addition, comparisons with SuperB are described.

Slides THYA01 [7.572 MB]

THOBA01

Electron Cloud Observations in LHC

electron, vacuum, emittance, simulation

2862

G. Rumolo, G. Arduini, V. Baglin, H. Bartosik, P. Baudrenghien, N. Biancacci, G. Bregliozzi, S.D. Claudet, R. De Maria, J. Esteban Muller, M. Favier, C. Hansen, W. Höfle, J.M. Jimenez, V. Kain, E. Koukovini, G. Lanza, K.S.B. Li, G.H.I. Maury Cuna, E. Métral, G. Papotti, T. Pieloni, F. Roncarolo, B. Salvant, E.N. Shaposhnikova, R.J. Steinhagen, L.J. Tavian, D. Valuch, W. Venturini Delsolaro, F. Zimmermann
CERN, Geneva, Switzerland
C.M. Bhat
Fermilab, Batavia, USA
U. Iriso
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
N. Mounet, C. Zannini
EPFL, Lausanne, Switzerland

Operation of LHC with bunch trains different spacings has revealed the formation of an electron cloud inside the machine. The main observations of electron cloud build-up are the pressure rise measured at the vacuum gauges in the warm regions, as well as the increase of the beam screen temperature in the cold regions due to an additional heat load. The effects of the electron cloud were also visible as a strong instability and emittance growth affecting the last bunches of longer trains, which could be improved running with higher chromaticity and/or larger transverse emittances. A summary of the 2010 and 2011 observations and measurements and a comparison with existing models will be presented. The efficiency of scrubbing and scrubbing strategies to improve the machine running performance will be also briefly discussed.

Slides THOBA01 [2.911 MB]

THPC001

Progress Towards Implementation of Top-up at the Australian Synchrotron

radiation, storage-ring, photon, interlocks

2904

G. LeBlanc, P. Bennetto, M.J. Boland, S. Costantin, R.T. Dowd, Y.E. Tan, D. Zhu, E.D. van Garderen
ASCo, Clayton, Victoria, Australia

The Australian Synchrotron Light Source has enjoyed several years of stable operations with a high degree of availability. It is now time to move towards top-up operations to improve the stability and integrated flux of the photon beam. This paper describes the steps that have been taken and what remains to be done in order to implement top-up injection as the normal operation mode for the first user runs of 2012.

THPC010

Recent Developments at the Metrology Light Source

quadrupole, feedback, synchrotron, 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.

THPC027

Top-up Operational Experience at Elettra

storage-ring, booster, radiation, controls

2966

E. Karantzoulis, A. Carniel, S. Krecic
ELETTRA, Basovizza, Italy

Since May 2010 Elettra, the third generation Italian light source, operates regularly for users at both 2 and 2.4 GeV in top-up. In this paper the experience during more than a year of operation in top-up at both user energies is discussed and the machine up time statistics presented and compared with the before top up period.

THPC028

A Proposal of Short X-ray Pulse Generation from Compressed Bunches by mm-wave iFEL in the SPring-8 Upgrade Plan

storage-ring, wiggler, electron, simulation

2969

M. Masaki, K. Fukami, C. Mitsuda, T. Watanabe
JASRI/SPring-8, Hyogo-ken, Japan

In the SPring-8 upgrade plan, short pulse options are prepared for time-resolved experiments of pico-second order with high repetition rate. The best scenario is that selected bunches have equilibrium bunch length of 1 ps or less. A mm-wave storage-ring iFEL may be one possible solution for it. If resonant wavelength of the FEL is a few millimeters, which is about ten times longer than typical short bunch length of 0.3 mm corresponding to 1 ps, almost all electrons of a bunch can be confined in one valley of ponderomotive potentials formed by the FEL mechanism. The system consists of a helical wiggler with period length of several meters and a mm-wave resonator. Numerical simulations with coherent synchrotron radiation effect at bunch charge of 479 pC show that an ultra-short injection bunch is trapped in a mm-wave “bucket” and kept shorter than 1 ps (r.m.s.) even after twice the longitudinal damping time from the injection. The ultra-short bunches need to be injected from the XFEL linac. XFEL-to-Storage Ring beam transport line is designed to suppress dispersions which cause bunch lengthening. Tracking calculations show promising results for bunch qualities at the transport line.

THPC031

Measurement of Longitudinal Dynamics of Injected Beam in a Storage Ring

storage-ring, simulation, synchrotron, 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.

THPC032

Current Status of SPring-8 Upgrade Plan

lattice, emittance, electron, brilliance

2981

T. Watanabe, T. Asaka, H. Dewa, H. Ego, T. Fujita, K. Fukami, M. Masaki, C. Mitsuda, A. Mochihashi, T. Nakamura, H. Ohkuma, Y. Okayasu, Y. Shimosaki, K. Soutome, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan
T. Tanaka
RIKEN Spring-8 Harima, Hyogo, Japan

The SPring-8 upgrade plan has been discussed. The main goal is to replace the storage ring in the existing tunnel so that the resulting emittance will get as close to the diffraction limit in hard x-ray region as possible. For 10 keV photons, for instance, the diffraction limit corresponds to the emittance of as small as 10 pm.rad. For the challenging goal, the new ring features a multi-bend lattice with damping wigglers, which presumably enables us to reduce an emittance by two orders of magnitudes or more compared with the current double-bend lattice without damping wigglers. Up to now, a six-bend lattice has been mainly studied, which is supposed to generate a natural emittance of 60–70 pm.rad for 6 GeV. In addition, damping wigglers and coupling control should assist to reduce the emittance even more for approaching the ultimate goal. The major modification requires not only an advanced lattice design via manipulation of non-linear beam dynamics but also extensive technological developments in almost every component such as magnets, monitors, and RF systems. The overall review of the upgrade plan, including some detailed discussions on the critical issues, will be presented.

THPC034

Post-earthquake Recovery of PF Ring and PF-AR

vacuum, survey, alignment, storage-ring

2984

T. Honda, T. Aoto, S. Asaoka, K. Endo, K. Haga, K. Harada, Y. Honda, M. Izawa, Y. Kobayashi, A. Mishina, T. Miyajima, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, T. Ozaki, C.O. Pak, H. Sakai, S. Sakanaka, H. Sasaki, Y. Sato, K. Satoh, M. Shimada, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto
KEK, Ibaraki, Japan

When the unprecedented scale of earthquake occurred in Japan on the afternoon of March 11, 2011, PF ring and PF-AR, two synchrotron light sources in KEK, also suffered various damages. At PF ring, a formed bellows in a wall current monitor was broken, and atmospheric air rushed into the beam duct. At PF-AR, which is installed in the underground tunnel, the alignment of the ring magnets seemed to be disordered to an order of ten mm. At both rings, a lot of electronics racks and toolboxes in the control rooms or in the experimental halls were tilted or tipped over. It was extremely fortunate that the user operation had just been stopped on the morning of that day, and all the gate valves in the rings and to the beam lines had already been closed for the scheduled shutdown. A wide area blackout took place at the big earthquake, and the electric power for the accelerator was interrupted over the next two weeks because of temporal shortage of the electricity in the eastern part of Japan. In April, we could start detailed investigation of machine damages and repair works towards recommissioning of the rings before the summer and resumption of the user operations in the autumn.

THPC045

Design of a Compact Storage Ring for the TTX

cavity, kicker, scattering, emittance

3005

H.S. Xu, W.-H. Huang, C.-X. Tang
TUB, Beijing, People's Republic of China
S.-Y. Lee
IUCEEM, Bloomington, Indiana, USA

We study a compact storage ring with circumference 3-m, 4 dipoles, and two quadrupoles for the Tsinghua Thomson scattering X-ray (TTX) source. The effects of Touschek lifetime, rf system requirement, the Intra-beam scattering (IBS) and coherent synchrotron radiation (CSR) will be addressed. A top-up injection system will be designed to maximize the Photon flux. Conceptual laser cavity to enhance photon flux will be discussed. Expected performance of the compact X-ray source will be presented.

THPC052

Progress Towards Top-up Operation at SSRF

storage-ring, radiation, controls, photon

3008

Z.T. Zhao, H.H. Li, L. Yin, W.Z. Zhang
SINAP, Shanghai, People's Republic of China

The Shanghai Synchrotron Radiation Facility (SSRF) has been in operation for user experiments in decay mode since May 2009. In the meantime various activities to prepare top-up operation at SSRF, including safety analysis and simulation, dedicated instrumentations and interlocks, control software, radiation measurements, injection optimization and top-up operation tests, have been carried out. In this paper, the progress towards top-up operation at SSRF is described together with its achieved performance.

THPC057

Operation of the ALBA Injector

linac, booster, emittance, storage-ring

3023

M. Pont, U. Iriso, R. Muñoz Horta, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA injector made of a 100 MeV linac, operating at 110 MeV, and a full energy (3 GeV) booster synchrotron has been routinely in operation since October 2010. The stability of the linac and of the booster on reliability and performance is examined. Also results on the beam performance obtained with the installed diagnostic equipment will be discussed.

THPC059

Recent Improvements to the Lattices for the MAX IV Storage Rings

storage-ring, lattice, optics, dipole

3029

S.C. Leemann
MAX-lab, Lund, Sweden

Construction of the MAX IV facility started early this year. The facility will include two storage rings for the production of synchrotron radiation. The 3 GeV ring will house insertion devices for the production of x-rays while the 1.5 GeV ring will serve UV and IR users. Recently, the lattices for the storage rings in the MAX IV facility were updated. In the 3 GeV storage ring the vertical beam size in the long straights has been reduced. The lattice of the 1.5 GeV storage ring has been updated to take into account first results from detailed magnet and vacuum system designs. Additionally, a new injection method to facilitate commissioning of the storage rings has been studied. This paper summarizes the changes made in the lattices and the effect of these modifications.

THPC073

Study of Lower Emittance Lattices for SPEAR3

lattice, emittance, dynamic-aperture, sextupole

3062

X. Huang, Y. Nosochkov, J.A. Safranek, L. Wang
SLAC, Menlo Park, California, USA

We study paths to significantly reduce the emittance of the SPEAR3 storage ring. Lattice possibilities are explored with the GLASS technique. New lattices are designed and optimized for practical dynamic aperture and beam lifetime. Various techniques are employed to optimize the nonlinear dynamics, including the Elegant-based genetic algorithm. Experimental studies are also carried out on the ring to validate the lattice design.

THPC108

Commissioning of the 50 MeV Preinjector Linac for the BESSY II Facility

linac, booster, emittance, radiation

3140

T. Atkinson, M. Helmecke, D. Schüler, E. Weihreter
HZB, Berlin, Germany
V. Dürr
BESSY GmbH, Berlin, Germany
D. Jousse, J.-L. Pastre, A.S. Setty
THALES, Colombes, France

A turn key 50MeV linac manufactured by Thales has been installed in the BESSY II facility. This linac will replace the existing Microtron injector in the near future to provide more flexible bunch population patterns for the femto-slicing operation mode and a higher single bunch intensity for top-up injection. This paper describes the essential problems which have been faced during commissioning and presents the main results obtained in the site acceptance tests including the measurement of beam emittance and energy spread.

THPC123

Injector Layout and Beam Injection into Solaris

linac, gun, storage-ring, klystron

3173

A.I. Wawrzyniak, C.J. Bocchetta
Solaris, Krakow, Poland
S.C. Leemann, S. Thorin
MAX-lab, Lund, Sweden

Funding: European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG.02.01.00-12-213/09
The Solaris synchrotron radiation storage ring to be built in Krakow, Poland is based on the MAX IV 1.5 GeV design. The injector will be a linear accelerator and its components identical to those for the MAX IV project, however, injection is not at full energy and the injector layout is different. The linac and transfer line layout, optics and injection scheme into the storage ring is presented and an analysis of accumulation before energy ramping is discussed.

THPC137

Low Emittance Booster Design for CANDLE Storage Ring

booster, emittance, storage-ring, synchrotron

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.

THPC139

Study of a Pulsed Sextupole Magnet Injection System for LNLS

sextupole, power-supply, kicker, pulsed-power

3212

X.R. Resende, F.C. Arroyo, R.H.A. Farias, L. Liu, A.R.D. Rodrigues, P.P. Sanchez, G. Tosin
LNLS, Campinas, Brazil

An injection system consisting of a pulsed sextupole magnet (PSM) is being considered for Sirius, the project of a new 3rd generation 3 GeV synchrotron source in development in Brazil. This novel injection scheme will be implemented and tested in the existing UVX ring. This will also serve as an opportunity to get acquainted with the new technology and become ready for Sirius. On this paper we report on the ongoing PSM study at LNLS. In particular, details of injection dynamics calculations, magnet and pulsed power supply designs are described, as well as machine preparations for experimental tests in the UVX storage ring.

THPC140

Design, Tuning and Results of the Pulsed Magnetic Systems for the Beam Injection in the SOLEIL Storage Ring Operated in ‘Transparent’ Top Up Mode

septum, kicker, vacuum, storage-ring

3215

P. Lebasque, R. Ben El Fekih, M. Bol, J. Da Silva Castro, A. Hardy, C. Herbeaux, J.-P. Lavieville, A. Loulergue, J.L. Marlats, D. Muller, G. Renaud, J.P. Ricaud
SOLEIL, Gif-sur-Yvette, France

From the beginning, the SOLEIL Storage Ring was designed to operate in Top Up injection mode. So all equipments involved have been specified to generate as small as possible beam perturbations of the stored beam during the electron beam injection. This concerns many aspects of the design and realization of the injection pulsed magnets (kickers and septa), their vacuum chambers, pulsed power supplies and timing electronics. Despite quite satisfactory results of pulsed magnetic measurements in labs, a still too large perturbation was observed on the e^- beam orbit during the Storage Ring commissioning. Therefore a strong work of systematic measurements, analysis of each phenomena, tuning or modification of each device was led until reaching rather good and acceptable performances. This paper will present the results obtained. At this stage, the Storage Ring beam orbit is sufficiently stable in Top Up injection mode so that it is almost transparent to the 24 beam lines, even for the most sensitive ones. After a summary of the main significant topics, we present the developments foreseen to further improve the performances and make a new step towards a “perfect” Top Up injection.

THPC143

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

alignment, controls, betatron, synchrotron

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).

THPC147

TPS SR Kicker Prototype Installation Status*

kicker, storage-ring, high-voltage, vacuum

3230

Y.-H. Liu, C.K. Chan, C.-S. Chen, Y.L. Chu, K.H. Hsu, H.P. Hsueh, C.K. Kuan, C.Y. Kuo, C.-S. Yang
NSRRC, Hsinchu, Taiwan

The purpose of this paper is to illustrate the installation sequence of TPS SR kicker. Because of adding the rotation function in row direction, the position of every component of kicker must be very precise. The kicker magnet and EMI enclosure were fastened on the rotation motor plate which could rotate ±3.0 mrad. The ceramic chamber remain fixed on the bottom plate in order to let the bellow stress free during rotation. After installation, the inductance measurement and the high voltage breakdown test were also tested. The experimental results showed the good uniformity and reached the expected request. The field mapping and EMI prevention schemes will be tested in the future.

THPC154

Shimming of the Dynamic Field Integrals of the BESSY II U125 Hybrid Undulator

undulator, wiggler, permanent-magnet, electron

3248

J. Bahrdt, W. Frentrup, A. Gaupp, M. Scheer, I. Schneider, G. Wüstefeld
HZB, Berlin, Germany

Within a continuous program the BESSY II undulators are prepared for Topping-Up operation. The BESSY II U125 planar hybrid undulator has a period length of 125 mm and a pole width of only 60 mm. The horizontal defocusing of the 1.7 GeV e-beam may result in a significant reduction of the horizontal dynamic aperture, reducing the injection efficiency when injecting into the closed gap. The dynamic field integrals are derived from a 2D-Fourier decomposition of the 3D-field. An analytic description of the dynamic multipoles based on the Fourier coefficients is presented. Magic fingers have been installed in order to minimize the dynamic field integrals and to enlarge the good field region of the device.

THPC169

Short-Period RF Undulator for a Nanometer SASE Source

undulator, electron, cavity, radiation

3293

S.V. Kuzikov, M.E. Plotkin, A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
T.C. Marshall, G.V. Sotnikov
Omega-P, Inc., New Haven, Connecticut, USA

Funding: Sponsored in part by US Department of Energy, Office of High Energy Physics.
A room-temperature RF undulator to produce ~1 nm wavelength radiation using a relatively low energy electron beam (0.5 GeV) is considered. The design features include an effective undulator period of 0.45 cm, an undulator parameter of K = 0.4, an effective field length of 50 cm. These parameters could be be realized using a multi-MW RF power amplifier to drive the undulator (e.g., the 34 GHz pulsed magnicon at Yale or a 30 GHz gyroklystron at IAP) with microsecond pulse duration. Two undulator designs were considered that avoid problems with a co-propagating wave: a dual-mode cylindrical cavity [TE01 (counter propagating) - TE02 (co-propagating)] with an off-axis electron beam; and a traveling HE11 mode resonant ring with an on-axis beam.

THPO024

Development of a Non-Linear Kicker System to Facilitate a New Injection Scheme for the BESSY II Storage Ring

kicker, vacuum, storage-ring, impedance

3394

O. Dressler, T. Atkinson, M. Dirsat, P. Kuske
HZB, Berlin, Germany
H. Rast
DELTA, Dortmund, Germany

Top-Up injections without noticeable motion of the stored beam is a challenge. The common method of beam accumulation with a local bump formed by four independent pulsed dipole kicker magnets usually causes beam oscillations. The matching of the four independent kicker systems regarding pulse jitters and shapes is technologically limited. Afterward the beam excitation was reduced more when two kicker magnets on each side of the septum were powered in series by one pulser unit. An even more promising approach is to adopt an alternative injection method deploying a single non-linear kicker magnet with zero Bx,y-field in the center and an off-axis maximum, By, which is horizontally displaced by 10^-12 mm. There the injected beam gets kicked and looses half of its transverse momentum. Such a magnet was designed and built as a short in-vacuum magnet with a small vertical gap height. For first beam tests the kicker was placed in the second straight section after the injection point, and the 1.5 μs pulse was designed to deflect the 1.72 GeV beam by 1 mrad. In this paper, the calculations of the magnetic fields, the mechanical design as well as the electrical pulser circuit are described.
*New injection scheme using a pulsed quadrupole magnet in electron storage rings, Kentaro Harada, PHYSICAL REVIEW SPECIAL TOPICS - AB 10, 123501 (2007)

THPO028

Upgrade Design of the Bump System in the J-PARC 3-GeV RCS

power-supply, linac, betatron, resonance

3403

T. Takayanagi, N. Hayashi, M. Kinsho, Y. Watanabe
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The 3-GeV RCS aims at providing at least 300 kW output beam power with the injection beam at 181 MeV. In the second stage, the upgrade of the LINAC beam energy to 400 MeV was funded and started in March 2009. This plan will be completed in 2012. Consequently, the 3-GeV RCS will aim at 1 MW beam power. The injection bump system of the RCS is composed of the shift bump-magnets, the horizontal paint bump-magnets and the vertical paint magnets.

THPO035

Computer Investigation of Efficiency Enhancement in Coaxial Gyrotron Backward Wave Oscillators

electron, simulation, plasma, bunching

3418

V.M. Khoruzhiy
NSC/KIPT, Kharkov, Ukraine

The gyrotron backward wave oscillator (gyro-BWO) is a high frequency (HF) powerful oscillator for cm and mm wavelengths*,**,***.Gyro-oscillators are possible devices for accelerators techniques. For efficiency enhancement in gyro-devices we suggest profiling of guiding magnetic field Hg(z) at longitudinal direction z by special law, namely Hg(z)=Hg0*(1+alfa*(z/L)*f(z/L))**0.5 where Hg0 is amplitude of homogenous guiding magnetic field, alfa is non-homogeneity amplitude, L is waveguide length and function f(z/L))is similarly to the shape (envelope) of longitudinal distribution of HF electrical field E(z) in gyro-device along longitudinal coordinate z. For investigated gyro-BWO f(z/L)=(cos(pi*z/2L))**m, f(0)=1, f(L)=0, L=60cm, m=6 and pi=3.14. We obtained enhancing of gyro-BWO’s efficiency from 11% (homogenous distribution of guiding magnetic field) up to 32% (non-homogenous one) due to profiling of magnetic field under conditions above.
* A.V.Gaponov et al., Izv. VUZov(USSR), Radiofizika 10(9), 10, 1967.
** V.Khoruzhiy et al., Phys. J.of Ukraine 49(2), 126, 2004.
*** V.Khoruzhiy et al., Phys. J.of Ukraine 50(11), 1230, 2005.

THPS003

Status of Stochastic Cooling Predictions at the HESR

antiproton, accumulation, pick-up, kicker

3430

H. Stockhorst, R. Maier, D. Prasuhn, R. Stassen
FZJ, Jülich, Germany
T. Katayama
GSI, Darmstadt, Germany

Detailed theoretical studies of stochastic cooling have been performed in order to fulfil the requirements for internal target experiments at the High-Energy Storage Ring (HESR) of the future Facility for Antiproton and Ion Research (FAIR) at the GSI in Darmstadt. A Fokker-Planck model and a particle tracking code utilizing the Filter and time-of-flight momentum cooling method have been developed for the 2 to 4 GHz cooling system. A barrier bucket cavity is included to compensate the mean energy loss due to the beam-target interaction. The code has been experimentally verified at the cooler synchrotron COSY. Since the RESR accumulator ring is postponed in the modularized start version of FAIR it is proposed to include the anti-proton accumulation function in the HESR downstream of the Collector Ring. Applying the radial stacking scheme well established at CERN and FNAL would result in a completely new and additional cooling system in the HESR. Instead a different way of beam accumulation has been selected that uses the already designed stochastic cooling system and the barrier bucket cavity of the HESR. Simulation results of the anti-proton accumulation in the HESR are presented.

THPS033

Skew Quadrupole Effects on Multi-turn injection Efficiency in the SIS18

quadrupole, septum, emittance, coupling

3490

W.M. Daqa, I. Hofmann, J. Struckmeier
GSI, Darmstadt, Germany

Funding: DAAD ( Deutscher Akademischer Austausch Dienst)
One goal of the SIS18 upgrade scheme is concerned about improving the multi-turn injection (MTI) efficiency, in order to reach the required intensities at the targets and to operate effectively as a booster for SIS100. To improve the limitation of the MTI scheme, there were successful attempts in AGS and PS boosters, to use the skew injection scheme and later it was suggested for SIS18. The strength of the skew quadrupoles is optimized together with the horizontal tune, the difference in horizontal to vertical tunes, the incoming beam parameters and the geometrical limitation of SIS lattice. A good optimization implies the emittance exchange, due to linear coupling, to take place partially and just before the return of the beamlet back to its original position at the septum. The present work was done by simulation using the code PARMTRA and compared with measurements. The results show that, depending on the working point, the skew injection scheme can improve the MTI efficiency from 2% up to 12%, taking into account the loss on the septum from inside and on the vertical acceptance.

THPS035

Collimator Upgrade Plan of the J-PARC Main Ring

radiation, collimation, beam-losses, septum

3496

M.J. Shirakata, K. Ishii, C. Kubota, T. Oogoe, J. Takano
KEK, Ibaraki, Japan
Y. Kuniyasu
MELCO SC, Tsukuba, Japan
Y. Takiyama
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

A halo collimation system is prepared in the middle of injection-straight section in order to localize the beam loss occurred in main ring. It consists of three collimator units. The first unit scatters halo components, and the other two units work as halo catchers. The permitted amount of beam losses in the collimator section is designed to be 450 W at the present. The upgrade plan of halo collimation system is running in order to achieve about ten times larger beam loss capability for high-power beam operation. The collimator upgrade is planned by installing a new collimator set and radiation shields which cover the collimator section. New collimator units are designed to be able to line-out the jaw with a part of radiation shield including the mechanical devices. The design work of collimator units and radiation shields is presented in this report.

THPS038

Possibility of longitudinal painting injection with debuncher system in J-PARC linac

linac, simulation, cavity, controls

3505

G.H. Wei
KEK/JAEA, Ibaraki-Ken, Japan
M. Ikegami
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

J-PARC linac is presently operating with the output energy of 181 MeV and providing a negative hydrogen beam to the succeeding 3-GeV synchrotron. To achieve the design beam power of 1 MW from the synchrotron, we plan to upgrade the linac beam energy to 400 MeV. In the energy upgrade, we replace the debuncher system installed between the linac and synchrotron. The main roles of the debuncher system are to correct the momentum jitter and to control the momentum spread at the ring injection. Usually, we don’t assume acceleration or deceleration with the debuncher cavities except for passive momentum jitter correction. However, we are studying the possibility of actively controlling the center momentum with debuncher cavities to enable longitudinal painting injection into the succeeding ring as a potential new feature. If it finds feasible, it would provide an additional tuning knob to mitigate the beam loss in the synchrotron. In this paper, we show a beam dynamics design of the new debuncher system with emphasis on the possibility of its application for the longitudinal painting injection.

THPS040

Measurement of the Stripping Efficiency for HBC Stripper Foil in the 3-GeV RCS of J-PARC

extraction, proton, beam-losses, scattering

3511

P.K. Saha, H. Harada, S. Hatakeyama, H. Hotchi, M. Kinsho, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie, I. Sugai
KEK, Ibaraki, Japan

We have carried out experimental measurement of the stripping efficiency for the newly developed HBC (Hybrid type Boron doped Carbon) stripper foils. The HBC foil is used for charge-exchange injection in the RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex) and plays an important role for the RCS operation. We have developed a rather simple but very precise method using which stripping efficiencies for several HBC foils were determined accurately. Importance of knowing an accurate stripping efficiency so as to determine a realistic stripper foil for the RCS operation will be discussed.

THPS044

Study of Charge Exchange Injection in HITFiL

ion, synchrotron, 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.

THPS045

Beam Emittance Measurement in the Injection Beam Line for a Cyclotron Accelerator Mass Spectrometer

cyclotron, extraction, ion, emittance

3523

D.G. Kim, H.-C. Bhang
SNU, Seoul, Republic of Korea
J.-W. Kim
NCC, Korea, Kyonggi, Republic of Korea

Funding: This work was supported by National Research Foundation of Korea (NRF) Grant No. 20110018946, and also by World Class University project of the NRF.
A carbon beam was extracted and measured in the injection beam line built for an accelerator mass spectrometer (AMS) based on a cyclotron. The cyclotron AMS has been designed to realize a compact AMS having a mass resolving power of around 4000 for a negative 14C beam. The beam line is a prototype to ensure the capability to match the beam phase space with the acceptance of the cyclotron. The injection beam line consists of an ion source, Einzel lens, rf buncher, 90 degree dipole magnet and a beam diagnostic box with a slit system. The ion source with a hot filament is a commercial product, and all other elements were designed and built in house. Some measurement results of the beam line components as well as beam emittance will be presented.

THPS047

New Injection and Extraction at CRYRING for FLAIR

extraction, septum, ion, kicker

3529

A. Simonsson, L. Brännholm, S. Das, A. Källberg, P. Löfgren, A. Paal, J. Sjöholm
MSL, Stockholm, Sweden
H. Danared
ESS, Lund, Sweden
D. Reistad
Intégro Utbildnings AB, Sigtuna, Sweden

As a preparation for a future transfer of CRYRING to FLAIR at FAIR in Darmstadt, Germany, we have installed and tested a slow extraction system. At FLAIR CRYRING will be used for deceleration of antiprotons from 30 MeV to 0.3 MeV. The tests of the slow extraction show that the beam can be extracted during 2 s with 30-60% efficiency and with rather constant amplitude, apart from noise from 50 Hz harmonics. A new injection system has also been designed. It will be able to inject 30 MeV antiprotons from NESR as well as 0.3 MeV/u ions created in a separate ion source and accelerated in an RFQ.

THPS048

Design of Electrostatic Septa and Fast Deflector for MedAustron

septum, power-supply, cathode, synchrotron

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.

THPS049

Feasibility Study of a CERN PS Injection at 2 GeV

optics, kicker, septum, vacuum

3535

J. Borburgh, S. Aumon, W. Bartmann, S.S. Gilardoni, B. Goddard, L. Sermeus, R.R. Steerenberg
CERN, Geneva, Switzerland

In the framework of the potential CERN PS Booster (PSB) energy upgrade, a study was initiated to look into the possibilities and constraints to inject protons into the PS at kinetic energies up to 2 GeV, for LHC type beams and other (high intensity) beams. This paper highlights the identified bottlenecks and potential solutions and addresses the resulting requirements for the hardware in the transfer line and injection region of the PS. In conjunction with the proposed upgrade of the PSB-PS transfer line hardware the optics can be changed for different cycles. Optics solutions optimized for the different requirements of LHC type and other beams are presented.

THPS051

Development of Fragmented Low-Z Ion Beams for the NA61 Fixed-target Experiment at the CERN SPS

ion, target, secondary-beams, light-ion

3541

I. Efthymiopoulos, O.E. Berrig, T. Bohl, H. Breuker, M. Calviani, S. Cettour-Cave, K. Cornelis, D. Manglunki, S. Mataguez, S. Maury, J. Spanggaard, C. Valderanis
CERN, Geneva, Switzerland
Z. Fodor
KFKI, Budapest, Hungary
M. Gazdzicki
IKF, Frankfurt-am-Main, Germany
F. Gouber, A. Ivashkin
RAS/INR, Moscow, Russia
P. Seyboth
MPI-P, München, Germany
H. Stroebele
IAP, Frankfurt am Main, Germany

The NA61 experiment, aims to study the properties of the onset of deconfinement at low SPS energies and to find signatures of the critical point of strongly interacting matter. A broad range in T-μ_B phase diagram will be covered by performing an energy (13A-158A GeV/c) and system size (p+p, Be+Be, Ar+Ca, Xe+La) scan. In a first phase, fragmented ion beams of 7Be or 11C produced as secondaries with the same momentum per nucleon when the incident primary Pb-ion beam hits a thin Be target will be used. The H2 beam line that transports the beam to the experiment acts as a double spectrometer which combined with a new thin target (degrader) where fragments loose energy proportional to the square of their charge allows the separation of the wanted A/Z fragments. Thin scintillators and TOF measurement for the low energy points are used as particle identification devices. In this paper results from the first test of the fragmented ion beam done in 2010 will be presented showing that a pure Be beam can be obtained satisfying the needs of the experiment.

THPS052

Studies on Transverse Painting for H⁻ Injection into the PSB

emittance, linac, kicker, space-charge

3544

C. Bracco, C. Carli, T. Fowler, B. Goddard, G. Gräwer, J.-B. Lallement, M. Martini, M. Scholz, W.J.M. Weterings
CERN, Geneva, Switzerland

Linac4 will inject 160 MeV H− ions in to the CERN PS Booster (PSB). This will allow to reduce space charge effects and increase beam intensity but will require a substantial upgrade of the injection region, with the implementation of a charge-exchange multi-turn injection scheme. The PSB has to provide beam to several users with different requirements in terms of beam intensity and emittance. Four kicker magnets (KSW), which are already installed in the PSB lattice, will be used to accomplish painting in the horizontal phase space to match the injected beams to the required emittances. Double linear functions, with varying slopes for each user, have been defined for the KSW generators waveforms according to detailed beam dynamic studies for all target intensities and emittances. Effect of space charge, injection offsets, dispersion and betatron mismatch have been taken into account. Preliminary studies have been carried out to evaluate how to obtain the required vertical emittance and the option of a transverse painting, also in the vertical plane, is explored.

THPS054

Injection and Extraction Considerations for a 2 GeV RCS at CERN

extraction, quadrupole, septum, kicker

3550

W. Bartmann, B. Balhan, J. Borburgh, L. Ducimetière, M. Fitterer, B. Goddard, L. Sermeus
CERN, Geneva, Switzerland

Conceptual studies have been made for a 2 GeV RCS at CERN as a possible replacement of the four-ring PS Booster. The lattice design has to accommodate suitable straight sections for a 160 MeV H⁻ charge exchange injection system, and for a 2 GeV fast extraction system. The design constraints for the injection and extraction systems are described, together with the proposed concepts and potential equipment limitations. In particular, the features of different possible H⁻ injection configurations are compared.

THPS055

Controlling Beamloss at Injection into the LHC

beam-losses, emittance, kicker, shielding

3553

B. Goddard, F. Alessio, W. Bartmann, P. Baudrenghien, V. Boccone, C. Bracco, M. Brugger, K. Cornelis, B. Dehning, A. Di Mauro, L.N. Drosdal, E.B. Holzer, W. Höfle, R. Jacobsson, V. Kain, M. Meddahi, V. Mertens, A. Nordt, J.A. Uythoven, D. Valuch, S. Weisz, E.N. del Busto
CERN, Geneva, Switzerland
R. Appleby
UMAN, Manchester, United Kingdom

Losses at injection into the superconducting LHC can adversely affect the machine performance in several important ways. The high injected beam intensity and energy mean that precautions must be taken against damage and quenches, including collimators placed close to the beam in the injection regions. Clean injection is essential, to avoid spurious signals on the sensitive beam loss monitoring system which will trigger beam dumps. In addition, the use of the two injection insertions to house downstream high energy physics experiments brings constraints on permitted beam loss levels. In this paper the sources of injection beam loss are discussed together with the contributing factors and various issues experienced in the first full year of LHC operation. Simulations are compared with measurement, and the implemented and planned mitigation measures and diagnostic improvements are described. An outlook for future LHC operation is given.

THPS057

Stripping Foil Simulations for ISIS Injection Upgrades

simulation, proton, synchrotron, 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.

THPZ003

The SuperB Project: Accelerator Status and R&D

feedback, luminosity, quadrupole, emittance

3684

M.E. Biagini, S. Bini, R. Boni, M. Boscolo, B. Buonomo, T. Demma, E. Di Pasquale, A. Drago, L.G. Foggetta, S. Guiducci, S.M. Liuzzo, G. Mazzitelli, L. Pellegrino, M.A. Preger, P. Raimondi, U. Rotundo, C. Sanelli, M. Serio, A. Stecchi, A. Stella, S. Tomassini, M. Zobov
INFN/LNF, Frascati (Roma), Italy
M.A. Baylac, O. Bourrion, J.-M. De Conto, N. Monseu, C. Vescovi
LPSC, Grenoble, France
K.J. Bertsche, A. Brachmann, Y. Cai, A. Chao, M.H. Donald, R.C. Field, A.S. Fisher, D. Kharakh, A. Krasnykh, K.C. Moffeit, Y. Nosochkov, A. Novokhatski, M.T.F. Pivi, J.T. Seeman, M.K. Sullivan, S.P. Weathersby, A.W. Weidemann, U. Wienands, W. Wittmer, G. Yocky
SLAC, Menlo Park, California, USA
S. Bettoni
PSI, Villigen, Switzerland
A.V. Bogomyagkov, I. Koop, E.B. Levichev, S.A. Nikitin, I.N. Okunev, P.A. Piminov, D.N. Shatilov, S.V. Sinyatkin, P. Vobly
BINP SB RAS, Novosibirsk, Russia
B. Bolzon, M. Esposito
CERN, Geneva, Switzerland
F. Bosi
INFN-Pisa, Pisa, Italy
L. Brunetti, A. Jeremie
IN2P3-LAPP, Annecy-le-Vieux, France
A. Chancé
CEA, Gif-sur-Yvette, France
P. Fabbricatore, S. Farinon, R. Musenich
INFN Genova, Genova, Italy
E. Paoloni
University of Pisa and INFN, Pisa, Italy
C. Rimbault, A. Variola
LAL, Orsay, France
Y. Zhang
IHEP Beijing, Beijing, People's Republic of China

The SuperB collider project has been recently approved by the Italian Government as part of the National Research Plan. SuperB is a high luminosity (10³6 cm^-2 s^-1) asymmetric e⁺e⁻ collider at the Y(4S) energy. The design is based on a “large Piwinski angle and Crab Waist” scheme already successfully tested at the DAΦNE Phi-Factory in Frascati, Italy. The project combines the challenges of high luminosity colliders and state-of-the-art synchrotron light sources, with two beams (e⁺ at 6.7 and e^- at 4.2 GeV) with extremely low emittances and small beam sizes at the Interaction Point. As unique features, the electron beam will be longitudinally polarized at the IP and the rings will be able to ramp down to collide at the tau/charm energy threshold with one tenth the luminosity. The relatively low beam currents (about 2 A) will allow for low running (power) costs compared to similar machines. The insertion of beam lines for synchrotron radiation users is the latest feature included in the design. The lattice has been recently modified to accommodate insertion devices for X-rays production. A status of the project and a description of R&D in progress will be presented.

THPZ022

Operation Scheme and Statistics of KEKB

luminosity, cavity, sextupole, factory

3735

M. Tanaka
MELCO SC, Tsukuba, Japan
Y. Funakoshi
KEK, Ibaraki, Japan

The KEKB B-Factory(KEKB) started a collision experiment in 1999 and finished in June, 2010. The total operation time of KEKB from fiscal year 2000 was 55657 hours. The breakdowns of operation are physics run 73.8%, machine study 6.8%, machine tuning 4.8%, beam tuning 5.9%, trouble 5.3%, maintenance 2.1% and other 1.3%. The total integrated luminosity was 10⁴¹ fb-1 and the maximum peak luminosity was 21.083 nb-1s⁻¹. To increase the peak and integrated luminosity, the continuous injection scheme, the crab cavities and the skew sextupole magnets were effective. We finished over ten year operation of KEKB in June, 2010.

THPZ024

Updated Design of the Italian SuperB Factory Injection System

linac, positron, electron, emittance

3738

S. Guiducci, M.E. Biagini, R. Boni, M.A. Preger, P. Raimondi
INFN/LNF, Frascati (Roma), Italy
J. Brossard, O. Dadoun, P. Lepercq, C. Rimbault, A. Variola
LAL, Orsay, France
A. Chancé
CEA, Gif-sur-Yvette, France
J.T. Seeman
SLAC, Menlo Park, California, USA

The ultra high luminosity B-factory (SuperB) project of INFN requires a high performance and reliable injection system, providing electrons at 4 GeV and positrons at 7 GeV, to fulfill the very tight requirements of the collider. Due to the short beam lifetime, continuous injection of electrons and positrons in both HER and LER rings is necessary to keep the average luminosity at a high level. An updated version of the injection system, optimized at higher repetition frequency is presented. This scheme includes a polarized electron gun, a positron production scheme with electron/positron conversion at low energy 0.6 GeV, and a 1 GeV damping ring to reduce the injected emittance of the positron beam.

THPZ025

Stability of the LHC Transfer lines

extraction, ion, kicker, controls

3741

V. Kain, W. Bartmann, C. Bracco, L.N. Drosdal, B. Goddard, M. Meddahi, J.A. Uythoven, J. Wenninger
CERN, Geneva, Switzerland

The LHC is filled from the SPS through two 3 km transfer lines. The injected beam parameters need to be well under control for luminosity performance, machine protection and operational efficiency. Small fractions of beam loss on the transfer line collimation system create showers which can trigger the sensitive LHC beam loss monitor system nearby and cause a beam abort during filling. The stability of the transfer line trajectory through the collimators is particularly critical in this respect. This paper will report on the transfer line trajectory stability during the proton run in 2011, correlations with injection losses, correction frequency and the most likely sources for the observed oscillations.

THPZ029

Principles for Generation of Time-dependent Collimator Settings during the LHC Cycle

optics, collimation, controls, beam-losses

3753

R. Bruce, R.W. Assmann, S. Redaelli
CERN, Geneva, Switzerland

The settings of the LHC collimators have to be changed during the cycle of injection, ramp and squeeze to account for variations in the orbit, beam size and normalized distance to the beam center. We discuss the principles for how the settings are calculated and show a software tool that computes them as time-dependent functions from beam-based data and theoretical optics models.

THPZ035

Comparison of LHC Collimation Setups with Manual and Semi-automatic Collimator Alignment

alignment, collimation, beam-losses, insertion

3771

G. Valentino, R.W. Assmann, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, S. Redaelli, A. Rossi, N.J. Sammut, D. Wollmann
CERN, Geneva, Switzerland
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta

The LHC collimation system beam-based alignment procedure has recently been upgraded to a semi-automatic process in order to increase its efficiency. In this paper, we describe the parameters used to measure the accuracy, stability and performance of the beam-based alignment of the LHC collimation system. This is followed by a comparison of the results at 450 GeV and 3.5 TeV with (1) a manual alignment and (2) with the results for semi-automatic alignment.