IPAC2012 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOEPPB003	Status of the PRISM FFAG Design for the Next Generation Muon-to-Electron Conversion Experiment	solenoid, target, lattice, proton	79
	J. Pasternak, A. Alekou, M. Aslaninejad, R. Chudzinski, L.J. Jenner, A. Kurup, Y. Shi, Y. Uchida Imperial College of Science and Technology, Department of Physics, London, United Kingdom R. Appleby, H.L. Owen UMAN, Manchester, United Kingdom R.J. Barlow University of Huddersfield, Huddersfield, 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 Kyoto University, Research Reactor Institute, 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 BNL, Upton, Long Island, New York, USA T. Yokoi JAI, Oxford, United Kingdom
	The PRISM Task Force continues to study high intensity and high quality muon beams needed for next generation lepton flavor violation experiments. In the PRISM case such beams have been proposed to 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. This paper summarizes the current status of the PRISM design obtained by the Task Force. In particular various designs for the PRISM FFAG ring are discussed and their performance compared to the baseline one, the injection/extraction systems and matching to the solenoid channels upstream and downstream of the FFAG ring are presented. The feasibility of the construction of the PRISM system is discussed.

MOPPC001	Simulation of electron-cloud heat load for the cold arcs of the large hadron collider	electron, simulation, dipole, photon	115
	G.H.I. Maury Cuna CINVESTAV, Mérida, Mexico G. Iadarola Naples University Federico II, Science and Technology Pole, Napoli, Italy G. Rumolo, F. Zimmermann CERN, Geneva, Switzerland
	The heat load due to the electron cloud in the Large Hadron Collider (LHC) cold arcs is a concern for its performance near and beyond nominal beam current. We report the results of simulation studies, which examine the electron-cloud induced heat load for different values of low-energy electron reflectivity and secondary emission yield at injection energy, as well as at beam energies of 4 TeV and 7 TeV, for two different bunch spacing: 25 ns and 50 ns. Benchmarking the simulations against heat-load observations at different beam energies and bunch spacing allows an estimate of the secondary emission yield in the cold arcs of the LHC and of its evolution as a function of time.

MOPPC004	Experiments on the Margin of Beam Induced Quenches for LHC Superconducting Quadrupole Magnet in the LHC	proton, quadrupole, kicker, monitoring	124
	C. Bracco, W. Bartmann, M. Bednarek, B. Goddard, E.B. Holzer, A. Nordt, M. Sapinski, R. Schmidt, M. Solfaroli Camillocci, M. Zerlauth, E.N. del Busto CERN, Geneva, Switzerland
	Protection of LHC equipment relies on a complex system of collimators to capture injected or circulating beam in case of LHC injection kicker magnet failures. However, for specific failures of the injection kicker, the beam can graze the injection protection collimators and induce quenches of downstream superconducting magnets. This occurred twice during 2011 operation and can also not be excluded during further operation. Tests were performed during Machine Development periods of the LHC to assess the quench margin of the quadrupole located just downstream of the last injection protection collimator in point 8. In addition to the existing Quench Protection System, a special monitoring instrumentation was installed at this magnet to detect any resistance increase below the quench limit. The correlation between the magnet and Beam Loss Monitor signals was analysed for different beam intensities and magnet current. The results of the experiments are presented in this paper.

MOPPC006	90m Optics Studies and Operation in the LHC	optics, proton, quadrupole, target	130
	H. Burkhardt, G.J. Müller, S. Redaelli, R. Tomás, G. Vanbavinckhove, J. Wenninger CERN, Geneva, Switzerland S. Cavalier LAL, Orsay, France
	A high β^* = 90 m optics was commissioned and used for first very forward physics operation in the LHC in 2011. The experience gained from working with this optics in 5 studies and operation periods in 2011 was very positive. The target β^* = 90 m was reached by a de-squeeze from the standard 11 m injection and ramp optics on the first attempt and collisions and first physics results obtained in the second study. The optics was measured and corrected with good precision. The running conditions were very clean and allowed for measurements with roman pots very close to the beam.

MOPPC011	Optics and Layout Solutions for the HL-LHC with Large Aperture Nb3Sn and Nb-Ti Inner Triplets	optics, quadrupole, dynamic-aperture, insertion	145
	S.D. Fartoukh, R. De Maria CERN, Geneva, Switzerland
	Funding: The research leading to these results has received funding from the European Commission under the FP7 project HiLumi LHC, GA no. 284404, co-funded by the DoE, USA and KEK, Japan. The LHC Upgrade studies, formalized into the High-Luminosity LHC (HL-LHC) project, relies on the feasibility of very low β^, and in particular on a novel achromatic squeezing mechanism, the ATS scheme which is presently under test in the LHC. We present two optics and layout scenario for the HL-LHC using the ATS scheme, one based on Nb3Sn triplet quadrupoles with a coil aperture compatible with an operational gradient of 150T/m and a backup scenario based on NbTi compatible with an operational gradient of 100T/m. The solution obtained are analyzed in terms of β^* reach (flat or round), mechanical acceptance, optics flexibility, chromatic properties, and impact on the dynamic aperture due to the large beta-beating waves induced in the arcs by the ATS scheme. * S. Fartoukh et al., "The Achromatic Telescopic Squeezing (ATS) scheme: from initial motivations to basic principles, and first demonstration at the LHC," these proceedings.

MOPPC015	Proposal for an RF Roadmap Towards Ultimate Intensity in the LHC	cavity, klystron, feedback, beam-loading	154
	P. Baudrenghien, T. Mastoridis CERN, Geneva, Switzerland
	The LHC is currently operated with 1380 bunches at 50 ns spacing and 1.4 E11 p per bunch (0.35A DC). In this paper the RF operation with ultimate bunch intensity (1.7 E11 p per bunch) and 25 ns spacing (2808 bunches per beam) summing up to 0.86A DC is presented. With the higher beam current, the demanded klystron power will be increased and the longitudinal stability margin reduced. In addition one must consider the impact of a klystron trip (voltage and power transients in the three turns latency before the beam is actually dumped). In this work a scheme is proposed that can deal with ultimate bunch intensity, without modification to the RF power system. Only a minor upgrade of the LLRF will be necessary: the field set point will be modulated according to the phase shift produced by the transient beam loading, thus minimizing the requested RF power while keeping the strong feedback for stability and reduction of RF noise.

MOPPC016	Combined Ramp and Squeeze at the Large Hadron Collider	optics, quadrupole, collider, dipole	157
	S. Redaelli, M. Lamont, G.J. Müller, R. Tomás, J. Wenninger CERN, Geneva, Switzerland N. Ryckx EPFL, Lausanne, Switzerland
	In the first two years of operation of the CERN Large Hadron Collider (LHC), the betatron squeeze has been carried out at constant flat top energy of 3.5 TeV. Squeeze setting functions are separated from the energy ramp functions. This ensured a maximum flexibility during commissioning because stopping at all intermediate optics for detailed measurements was possible. In order to then improve the efficiency of the operational cycle, combining the ramp and squeeze has been considered. In this paper, the various possibilities for this scheme are reviewed, and proposals of optimized operational cycles with combined ramp and squeeze are presented for different energies. Results of beam tests are also discussed.

MOPPC017	Causes and Solutions for Emittance Blow-Up During the LHC Cycle	emittance, luminosity, proton, feedback	160
	M. Kuhn Uni HH, Hamburg, Germany G. Arduini, B.J. Holzer, J.M. Jowett, V. Kain, F. Roncarolo, M. Schaumann, R. Versteegen, J. Wenninger CERN, Geneva, Switzerland
	Emittance measurements during the run 2011 indicated a blow-up of 20 % to 30 % from LHC injection to collisions. At the LHC design stage the total allowed emittance increase through the cycle was set to 7 %. One of the goals of the 2012 LHC run is therefore to understand and counteract the blow-up. Emittance growth measurements through the LHC cycle along with correlations with possible sources are presented in this paper. Solutions are proposed where possible. The emittance determination accuracy relies on the knowledge of the beam optics and on the present performance of the transverse profile monitors. Possible improvements of the diagnostics and of the related data analysis are also discussed.

MOPPC030	Status of the Decay Ring Design for the IDS Neutrino Factory	kicker, lattice, insertion, optics	199
	D.J. Kelliher, C.R. Prior STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom N. Bliss, N.A. Collomb STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	In the International Design Study for the Neutrino Factory (IDS-NF) a racetrack design has been adopted for the decay ring. The injection system into the decay ring is described. The feasibility of injecting both positive and negative muons into the ring is explored from the point of view of injection timing. Considerations for the design of a decay ring for a 10 GeV neutrino factory are included. ”International Design Study for the Neutrino Factory – interim design report”, RAL-TR-2011-018 (2011)

MOPPC032	Injection and Broadband Matching for the PRISM Muon FFAG	betatron, solenoid, target, dipole	202
	J. Pasternak, R. Chudzinski, A. Kurup Imperial College of Science and Technology, Department of Physics, London, United Kingdom J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom A. Sato Osaka University, Osaka, Japan
	The next generation of lepton flavor violation experiments requires high intensity and high quality muon beams. Such conditions can be met using phase rotation of short muon pulses in an FFAG ring, as was proposed for the PRISM project. The very large initial momentum spread and transverse emittance of the muon beam poses a significant challenge for the injection system into the PRISM FFAG. Also, the matching optics between the solenoidal transfer channel and the ring needs to create a specific orbit excursion in the horizontal plane, suppress any vertical dispersion and produce good betatron conditions in both planes. Candidate geometries for the matching and injection systems are presented and their performances are tested in tracking studies.

MOPPC043	Injection/Extraction of Achromat-based 6D Ionization Cooling Rings for Muons	solenoid, kicker, dipole, extraction	229
	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, F.E. Mills Particle Beam Lasers, Inc., Northridge, California, USA
	Funding: This work was supported in part by the US Department of Energy in part under award numbers DE-FG02-92ER40695 (UCLA), DE-AC02-98CH10886 (BNL) and DE-FG02-07ER84855 (Particle Beam Lasers, Inc.). An achromat-based cooing ring using dipoles and solenoids is introduced and it can cool muons by large factors in six dimensions to achieve the necessary luminosity for a muon collider. The ring is designed with sufficient space in each superperiod for injection and extraction magnets. We estimate the parameters for the injection system into the solenoid-dipole ring cooler. We also present some simulations for injection/extraction system and discuss the injection/extraction requirements. Al Garren, J.S. Berg, D. Cline, X. Ding, H.G. Kirk, “Robust 6D μ± cooling using a solenoid-dipole ring cooler for a muon collider”, NIM A 654 (2011) 40-44.

MOPPC061	An Antiproton Recycler for Atom-Antiproton Collision Experiments	antiproton, ion, acceleration, target	274
	M.R.F. Siggel-King, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom O. Karamyshev, A.I. Papash MPI-K, Heidelberg, Germany M.R.F. Siggel-King The University of Liverpool, Liverpool, United Kingdom
	Funding: Work supported by the Helmholtz Association and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080 and STFC. Collision experiments with low energy antiprotons and different gas jet targets on the level of differential cross sections would be very desirable to use to investigate the details of this fundamental process. At present, such experiments are, however, not feasible, since the only source of antiprotons in the world, the AD at CERN, cannot provide beams of the required energy and quality. A small electrostatic ring has been designed and developed by the QUASAR Group. Serving at the same time as a prototype for the future ultra-low energy storage ring (USR), to be integrated at the facility for low-energy antiproton and ion research (FLAIR), this small accelerator is unique due to its combination of size, electrostatic nature, and energy of the circulating particles. In this contribution, the design of the ring is described in detail and possible operation scenarios in the ASACUSA beam line and behind the ELENA ring are compared with each other.

MOPPC078	Simulation Studies of Injection Scheme in TPS Storage Ring	lattice, simulation, storage-ring, alignment	316
	Y.C. Lee, H.-P. Chang, P.J. Chou NSRRC, Hsinchu, Taiwan
	Funding: NSRRC, Hsinchu, Taiwan. The baseline lattice of TPS storage ring was finalized in October 2009. Later upon users’ request, we plan to implement the double mini-βy lattice in three 12-m straight sections of TPS storage ring. These locations were chosen to maintain the symmetry of the storage ring lattice. Particle tracking for the first few turns were used to check the injection scheme of storage ring, including errors introduced in manufacturing and installation process. Results of simulation studies will be presented.

MOPPC079	Modelling of the EMMA ns-FFAG Ring Using GPT	space-charge, emittance, quadrupole, electron	319
	R.T.P. D'Arcy, S. Jolly UCL, London, United Kingdom J.K. Jones, B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom S.B. van der Geer Pulsar Physics, Eindhoven, The Netherlands
	EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed-Field Alternating Gradient (ns-FFAG) accelerator whose construction at Daresbury Laboratory, UK, was completed in the autumn of 2010. The energy recovery linac ALICE will serve as an injector for EMMA, within an energy range of 10 to 20 MeV. The injection line consists of a symmetric 30 degree dogleg to extract the beam from ALICE, a matching section and a tomography section for transverse emittance measurements. This is followed by a transport section to the injection point of the EMMA ring. The ring is composed of 42 cells, each containing one focusing and one defocusing quadrupole. Acceleration over many turns of the EMMA machine has recently been confirmed. In some cases the bunch will traverse upwards of 100 turns, at which point the effects of space-charge may be significant. It is therefore necessary to model the electron beam transport in the ring using a code capable of both calculating the effect of and compensating for space-charge. Therefore the General Particle Tracer (GPT) code has been used. A range of injection beam parameters have been modeled for comparison with experimental results.

MOPPD007	Towards Routine Operation of the Scintillation Profile Monitor at COSY	electron, vacuum, synchrotron, proton	382
	V. Kamerdzhiev, J. Dietrich, K. Reimers FZJ, Jülich, Germany C. Böhme ESS, Lund, Sweden A. Pernizki INP, Jülich, Germany
	The optics of the Scintillation Profile Monitor (SPM) was modified to correct the large error observed in previous measurements. Beam profile measurements were carried out after reinstallation in the COSY ring, showing reasonable agreement with profiles, measured with the ionization profile monitor. Performance of the SPM is analyzed. Application of the method in a proton synchrotron is discussed.

MOPPD013	Observation of 2-Component Bunched Beam Signal with Laser Cooling	laser, betatron, ion, coupling	397
	H. Souda, M. Nakao, A. Noda, H. Tongu Kyoto ICR, Uji, Kyoto, Japan M. Grieser MPI-K, Heidelberg, Germany Z.Q. He TUB, Beijing, People's Republic of China K. Ito, H. Okamoto HU/AdSM, Higashi-Hiroshima, Japan K. Jimbo Kyoto University, Institute for Advanced Energy, Kyoto, Japan Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	Funding: Work supported by Advanced Compact Accelerator Development Project of MEXT, Global COE program "The Next Generation of Physics, Spun from Universality and Emergence" and Grant-in-Aid for JSPS Fellows. Longitudinal beam temperature during a laser cooling was measured through bunch length measurement at S-LSR. 40keV 24Mg+ beams were bunched by an RF voltage with a harmonic number of 5 and were cooled by a co-propagating laser with a wavelength of 280nm. Bunch length was measured by time-domain signal from a pair of parallel-plate electrostatic pickups with a length of 140mm. Injected non-cooled beams gave a bunch length of 2.5m (2-σ) and cooled beam has a 2-component of broad and sharp distribution. Broad distribution had a longitudinal length of 2.2m, which is close to that of initial beam. The length of the sharp distribution shrunk to 0.25m and is considered as a cooled part. Capture efficiency of cooling, which represents the ratio of the particle numbers of cooled part and the total particle number, varies by the change of the detuning of the laser (fixed frequency or scanning). With scanning range of 2GHz, capture efficiency was improved from 66% to 92%, whereas the bunch became longer by 10% with scanning. Approach to improve the number of cooled particle and cut uncooled part* will be applied to attain a strong signal with a low-current beam with a low temperature. * J. S. Hangst et al., Phys. Rev. Lett. 74, 4432 (1995). ** A. Noda et al., these proceedings.

MOPPD019	Vertical Orbit Excursion FFAG Accelerators with Edge Focussing	proton, lattice, neutron, dynamic-aperture	406
	S.J. Brooks STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	FFAGs with vertical orbit excursion (VFFAGs) provide a promising alternative design for the magnets in fixed-field machines. They have a vertical magnetic field component that increases with height in the vertical aperture, yielding a skew quadrupole focussing structure. The end fields of such magnets with edge angles provide an alternating gradient without the need for reverse bends, thus reducing the machine circumference. Similarly to spiral scaling horizontal FFAGs (but unlike non-scaling versions), the machine has fixed tunes and no intrinsic limitation on momentum range. Rings capable of boosting the 150mm.mrad geometric emittance beam from the ISIS proton synchrotron to 3, 5 and 12GeV using superconducting magnets are presented, the latter corresponding to 2.5MW beam power.

MOPPD020	A Model for a High-Power Scaling FFAG Ring	dynamic-aperture, lattice, extraction, proton	409
	G.H. Rees, D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	High-power FFAG rings are under study to serve as drivers for neutron spallation, muon production, and accelerator-driven reactor systems. In this paper, which follows on from earlier work, a 20 - 70 MeV model for a high-power FFAG driver is described. This model would serve as a test bed to study topics such as space charge and injection in such rings. The design incorporates a long straight to facilitate H^- charge exchange injection. The dynamic aperture is calculated in order to optimize the working point in tune space. The injection scheme is also described. A separate design for an ISIS injector, featuring a novel modification to the scaling law, was also studied. G.H. Rees and D.J. Kelliher, “New, high power, scaling, FFAG driver ring designs” HB2010, Morschach, September 2010, MOPD07, p. 54, http://www. JACoW.org

MOPPD024	C70 Arronax in the Hands-On Phase	target, cyclotron, proton, simulation	418
	F. Poirier, S. Auduc, L. Lamouric SUBATECH, Nantes, France S. Girault, F. Gomez, E. Mace Cyclotron ARRONAX, Saint-Herblain, France C. Huet EMN, Nantes, France
	The C70 Arronax, is a high-intensity (2x375 μA) and high-energy (70 MeV) multiparticle cyclotron that started its hands-on phase in December 2010. The operating and maintenance group is accumulating experience on this machine. A review of the machine status and present possibilities in terms of beam capacities is thus presented in this paper. The status of the beamline simulations is also given.

MOPPD026	A Superconducting Ring Cyclotron for the DAEδALUS Experiment	cyclotron, extraction, proton, focusing	421
	L. Calabretta INFN/LNS, Catania, Italy A. Calanna, D. Campo CSFNSM, Catania, Italy M.M. Maggiore, L.A.C. Piazza INFN/LNL, Legnaro (PD), Italy F. Méot BNL, Upton, Long Island, New York, USA
	Funding: Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud. The experiment DAEδALUS, 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 is able to accelerate a H²⁺ molecule beam up to 800 MeV/n with a peak current of 10 mA and average power higher than 1.6 MW. To simplify the design of the superconducting magnetic coils, to minimize the radial force shift and to increase the room to host the RF cavities, the previous study has been updated increasing the injection energy of the H²⁺ and also the injection energy. The updated study on the magnetic sector configuration, on the superconducting coils and the magnetic forces are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too. J. Alonso et al., Jun2010 e-Print: arXiv:1006.0260 L. Calabretta, Proc. IPAC 2011, WEPS073 (2011). * L. Calabretta, Cyclotrons 2010, Lanzhou.

MOPPD028	Observation of Longitudinal Space Charge Effects in the Injection Beam Line of NIRS-930 Cyclotron	bunching, cyclotron, space-charge, simulation	427
	S. Hojo, A. Goto, T. Honma, K. Katagiri, A. Sugiura NIRS, Chiba-shi, Japan
	Dependence of bunching efficiencies on the position of a beam buncher was measured for the AVF cyclotron at the National Institute of Radiological Sciences (NIRS) for 30 MeV proton beams with intensities up to 100 microamperes at injection. The measurement was carried out for two positions: 1.53 m and 2.33 m upstream from the inflector. For the buncher position of 2.33 m the bunching efficiency decreased, as the beam intensity increased, to about half of that at low intensities, while for 1.5 m it was constant up to 100 microamperes. The intensity distributions of extracted beam with respect to the buncher phase were also measured for the two buncher positions. The dependence of bunch width on the beam intensity is discussed by comparing the data with one-dimensional simulations on longitudinal space charge effects.

MOPPD034	Flux-coupled Stacking of Cyclotrons for a High-power ADS Fission Driver	cyclotron, cavity, focusing, target	439
	A. Sattarov, S. Assadi, K.E. Badgley, J.N. Kellams, T.L. Mann, A.D. McInturff, P.M. McIntyre, N. Pogue Texas A&M University, College Station, Texas, USA
	Funding: This work is funded by grants from the State of Texas (ASE) and the Mitchell Family Foundation. The sector magnets for an isochronous cyclotron are configured as a flux-coupled stack of apertures, each forming an independent cyclotron, separated sufficiently to accommodate independent superconducting rf cavities. The stack strategy makes it possible to deliver any amount of proton beam power consistent with the limitations of each individual cyclotron, and to deliver the aggregate power to a number of spallation targets as dictated by optimum coupling for accelerator-driven subcritical (ADS) fission and by limitations in target transfer.

MOPPD054	Effect of the 2011 Great East Japan Earthquake in the Injection and Extraction of the J-PARC 3-GeV RCS	extraction, septum, beam-transport, simulation	490
	P.K. Saha, H. Harada, H. Hotchi, S.I. Meigo, N. Tani, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the injection and extraction systems play important roles for the beam injection and extraction, respectively. Unfortunately, the 2011 great east Japan earthquake had a serious impact on the ongoing schedule due to the big damage of the whole accelerator facility and the infrastructure as well. The injection and extraction including the beam transport lines magnets suffered a noticeable displacement resulting with alignment errors. As realignment of the RCS magnets can not be done in this year, then based on the post earthquake measured alignment data, we have estimated the effect as well as possible solutions on the injected and extracted beam for as usual operation. Fortunately, the simulation results shows that there would not be any serious impact on both injected as well as extracted beam with present alignment errors and thus user operation can be resume as expected. The simulation result together with some experimental results will be presented.

MOPPD057	CERN PSB-to-PS Transfer Modifications for the 2 GeV Upgrade	optics, quadrupole, dipole, septum	493
	W. Bartmann, J. Borburgh, S.S. Gilardoni, B. Goddard, A. Newborough, S. Pittet, R. Steerenberg CERN, Geneva, Switzerland C.H. Yu IHEP, Beijing, People's Republic of China
	Within the frame of the CERN PS Booster (PSB) energy upgrade from 1.4 to 2 GeV, the PSB to PS transfer line will be adapted for pulse-to-pulse modulated operation. A modified lattice is presented including a re-design of the switching dipole between ISOLDE and PS and additional collimators to protect the PS injection septum. Optics solutions optimized for small emittance LHC beams as well as for the large emittance high-intensity beams are shown.

MOPPD058	LHC Abort Gap Cleaning Studies during Luminosity Operation	luminosity, kicker, emittance, beam-losses	496
	E. Gianfelice-Wendt Fermilab, Batavia, USA W. Bartmann, A. Boccardi, C. Bracco, E. Bravin, B. Goddard, W. Höfle, D. Jacquet, A. Jeff, V. Kain, M. Meddahi, F. Roncarolo, J.A. Uythoven, D. Valuch CERN, Geneva, Switzerland
	The presence of significant intensities of un-bunched beam is a potentially serious issue in the LHC. Procedures using damper kickers for cleaning both Abort Gap (AG) and buckets targeted for injection, are currently in operation at flat bottom. Recent observations of relatively high population of the AG during physics runs brought up the need for AG cleaning during luminosity operation as well. In this paper the results of experimental studies performed in October 2011 are presented.

MOPPD062	Aperture Measurements in the LHC Interaction Regions	emittance, luminosity, optics, resonance	508
	S. Redaelli, M.C. Alabau Pons, R.W. Assmann, R. Bruce, M. Giovannozzi, G.J. Müller, M. Pojer, J. Wenninger CERN, Geneva, Switzerland
	The aperture of the LHC interaction regions is crucial for the LHC performance because it determines the smaller β^* that can be achieved. The aperture has been measured at a maximum energy of 3.5 TeV and at different β^* values, following optimized procedure to allow safe measurements at high energy. In this paper, the results of these aperture measurements, which are used as a reference for β^* reach and crossing scheme estimates at the LHC interaction points, are presented.

MOPPD063	A 180 MeV Injection System for the ISIS Synchrotron	dipole, synchrotron, electron, simulation	511
	B. Jones, D.J. Adams, M.C. Hughes, S.J.S. Jago, H. V. Smith, C.M. Warsop, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. It operates at 50 Hz accelerating 3x10¹³ protons per pulse via a 70 MeV H⁻ linac and an 800 MeV proton synchrotron, delivering a mean beam power of 0.2 MW. A favoured first step to upgrade ISIS towards the megawatt regime is replacement of the linac with a new 180 MeV injector. Studies of this upgrade, which aims to increase mean beam power up to 0.5 MW are continuing. This paper summarises designs for a new injection region including beam dynamics and related hardware.

MOPPD064	Simulation of Double Layer Carbon Stripping Foils for ISIS Injection Upgrades	simulation, radiation, scattering, proton	514
	H. V. Smith, D.J. Adams, B. Jones, C.M. Warsop STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom Y. Irie, Y. Takeda KEK, Ibaraki, Japan
	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, 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, continue to be studied. This paper highlights recent results from temperature studies of double layer carbon foils, suitable for injection at 180 MeV into ISIS, using ANSYS. Experimental data from KEK was used to benchmark models and the variation of temperature as a function of foil separation was considered.

MOPPD069	Challenges for the SNS Ring Energy Upgrade	electron, kicker, septum, extraction	520
	M.A. Plum, T.V. Gorlov, J.A. Holmes, T. Hunter, R.T. Roseberry, J. G. Wang ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. The Oak Ridge Spallation Neutron Source accumulator ring presently operates at a beam power of about 1 MW and a beam energy of 925 MeV. A power upgrade is planned to increase the beam energy to 1.3 GeV. For the accumulator ring this mostly involves modifications to the injection and extraction sections. A variety of modifications to the existing injection section were necessary to achieve 1 MW, and the tools developed and the lessons learned from this work are now being applied to the design of the new injection section. This paper will discuss the tools and the lessons learned, and also present the design and status of the upgrades to the accumulator ring.

MOPPD070	A SVD-based Orbit Steering Algorithm for RHIC Injection	ion, heavy-ion, proton, controls	523
	C. Liu, A. Marusic, M.G. Minty, V. Ptitsyn BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The RHIC physics programs involve experiments with polarized proton and several species of ion beams. In the past, when switching between physics programs, first turn and circulating beam in RHIC was established manually by adjustments to the corrector dipoles for minimum beam loss. In this report, we introduce a new steering scheme based on an SVD algorithm which uses a single-pass orbit response matrix for first turn steering. The new scheme was implemented into the controls system and demonstrated successfully in Run-11. Establishing circulating beam using this automated approach has been shown to dramatically reduce the beam setup time.

MOPPD073	Development of Transportation System for Low Energy Electron Group	electron, solenoid, collimation, simulation	532
	S. Kato Tohoku University, Graduate School of Science, Sendai, Japan M. Kinsho, K. Yamamoto, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	There is a time that we want to measure the electron which occurred in the accelerator in the small situation of a noise. In that case, it is one method that we transport these electrons to the place distant form the accelerator where a noise is small. In order to realize that, development of transport line for low energy electrons is required. So, we start to develop transport line using solenoid magnets. We present status of development of this transportation system.

MOPPD074	Localization of Large Angle Foil Scattering Beam Loss Caused by Multi-Turn Charge-Exchange Injection	collimation, simulation, scattering, insertion	535
	S. Kato Tohoku University, Graduate School of Science, Sendai, Japan H. Harada, S. Hatakeyama, J. Kamiya, M. Kinsho, K. Yamamoto, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the J-PARC RCS, the significant losses were observed at the branch of H⁰ dump line and the Beam Position Monitor which was put at the downstream of the H⁰ dump branch duct. These losses were caused by the large angle scattering of the injection and circulating beam at the charge exchange foil. To realize high power operation, we have to mitigate these losses. So, we started to develop a new collimation system in the H⁰ branch duct and installed in October 2011. In order to optimize this system efficiently, we primarily focused on the relative angle of collimator block from scattering particles. We simulated behavior of particles scattered by foil and produced by collimator block and researched most optimized position and angle of the collimator block. In this process, we devised the method of angular regulation of collimator block. We present the method of angular regulation and performance of this new collimation system.

MOPPD075	Optimization of the Collimation System for the CSNS/RCS	collimation, closed-orbit, beam-losses, scattering	538
	N. Wang, M.Y. Huang, S. Wang, S.Y. Xu IHEP, Beijing, People's Republic of China
	Beam loss induced activation of the accelerator components is one of the primary concerns in designing a high intensity machine. The uncontrolled beam loss is required to be less than 1 W/m for hands-on maintenance of the machine. A two stage collimation system is designed in the Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) to localize the beam losses in a restricted area. The parameters of the collimator are optimized in order to obtain high collimation efficiency. The final design of the collimation system is presented. The reliability of the collimation system is estimated for different working points and with closed orbit errors.

MOPPD083	Improving the Fermilab Booster Notching Efficiency, Beam Losses and Radiation Levels	booster, kicker, radiation, beam-losses	562
	I.L. Rakhno, A.I. Drozhdin, N.V. Mokhov, V.I. Sidorov, I.S. Tropin Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. Currently a fast vertical 1.08-m long kicker (notcher) located in the Fermilab Booster Long-5 straight section is used to remove 3 out of 84 circulating bunches after injection to generate an abort gap. With magnetic field of 72.5 Gauss it removes only 87% of the 3-bunch intensity at 400 MeV, with 75% loss on pole tips of the focusing Booster magnets, 11% on the Long-6 collimators, and 1% in the rest of the ring. We propose to improve the notching efficiency and reduce beam loss in the Booster by using two horizontal kickers in the Long-12 section. The STRUCT calculations show that using such horizontal notchers, one can remove up to 99% of the 3-bunch intensity at 400-700 MeV, directing 96% of it to a new beam dump at the Long-13 section. This fully decouples notching and collimation. The beam dump absorbs most of the impinging proton energy in its jaws. The latter are encapsulated into an appropriate radiation shielding that reduces impact on the machine components, personnel and environment to the tolerable levels. The MARS simulations show that corresponding prompt and residual radiation levels can be reduced ten times compared to the current ones.

MOPPP031	A New Injection System for an Electron/Positron Linac	linac, electron, gun, positron	628
	C. Liebig, M. Hüning, M. Schmitz DESY, Hamburg, Germany
	For the Linac II, which supplies the accelerator chain at DESY with electrons and positrons, a new injection system is planned. It is supposed to ensure reliable operation and to avoid the beam loss of about 60% before the positron converter and the associated activation. The main components are a 6 A/100 kV triode gun, buncher and a dispersive section for energy collimation. The output energy is 5 MeV. The new buncher structure is a hybrid of a standing wave and traveling wave structure and allows a compact design and good electron capture. Its main part is a traveling wave structure in 2π/3 mode, to which one capture cell is coupled in π mode. The function of the injector components, the entire injection system and the acceleration in the linac sections were optimized in simulations. In addition, the design is analysed in a test rig before final installation. Test rig and subsequent injector are equipped with extensive diagnostics. Besides the design of the injection system results of simulations and measurements on the test rig will be presented.

MOPPP051	NSLS-II Transport Line Progress	booster, linac, storage-ring, diagnostics	676
	R.P. Fliller, A.T. Anderson, B. Benish, W. DeBoer, G. Ganetis, R. Heese, H.-C. Hseuh, J. Hu, M.P. Johanson, B.N. Kosciuk, D. Padrazo, K. Roy, T.V. Shaftan, O. Singh, J.L. Tuozzolo, B. Wahl, G.M. Wang BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The National Synchrotron Light Source II (NSLS-II) is a state-of-the-art 3-GeV third generation light source currently under construction at Brookhaven National Laboratory. The NSLS-II injection system consists of a 200 MeV linac, a 3-GeV booster synchrotron and associated transfer lines. The first part of the Linac to Booster Transport (LBT) line has been installed for linac commissioning. This part includes all components necessary to commission the NSLS-II linac. The second part of this transport line is undergoing installation. Initial results of hardware commissioning will be discussed. The Booster to Storage Ring (BSR) transport line underwent a design review. The first part of the BSR transport line, consisting of all components necessary to commission the booster will be installed in 2012 for booster commissioning. We report on the final design of the BSR line along with the plan to commission the booster.

MOPPP052	Booster Synchrotron for SIRIUS Light Source	booster, dipole, extraction, emittance	679
	F. H. de Sá, L. Liu, A.R.D. Rodrigues LNLS, Campinas, Brazil
	A full energy 3 GeV booster for the new Brazilian Synchrotron Light Laboratory (LNLS) third generation light source, SIRIUS, is proposed. The 144 m circumference magnetic lattice consists of two super-periods of FODO cells with defocusing dipoles and focusing quadrupoles. The optics provides a low emittance beam of 38 nm.rad at 3 GeV, high horizontal betatron and zero dispersion functions at straight sections. The top-up operation requires a cycling energy ramp from 150 MeV to 3 GeV with repetition rate of 1 Hz.

MOPPP053	Failure Mode Analysis in Preparation for Top-up Injection at the Canadian Light Source (CLS)	storage-ring, dipole, kicker, simulation	682
	L.O. Dallin CLS, Saskatoon, Saskatchewan, Canada
	Top-up injection involves injecting beam with beamline safety shutters open. Consequently it is extremely important that no electrons enter the beamlines where they could be a potential safety hazard to beamline personnel. To investigate the likelihood that electrons could exit the storage ring various failure mode simulations have been done. The approach is to account for all possible injection trajectories and show that these particles will be intercepted by various storage ring apertures before they reach an amplitude that is deemed unsafe. This amplitude was chosen to be 50 mm and the field roll-off of all storage ring magnets were defined to this amplitude. Failure modes invested included injection kicker failures, uncorrected misalignment errors, off-energy injection and shorted storage ring magnet coils. Errors that would render it impossible to store beam were not investigated. As some particles reached amplitudes beyond the safe limit measures have been devised to eliminate these unsafe scenarios.

MOPPP054	Study of a New Injection Scheme for the SSRF Storage Ring	kicker, storage-ring, emittance, dynamic-aperture	685
	M.Z. Zhang, B.C. Jiang, L. Ouyang, Q.L. Sun, S.Q. Tian SINAP, Shanghai, People's Republic of China
	A low emittance configuration of the SSRF storage ring had been designed and commissioned. Along with reducing the emittance, the dynamic aperture decreases quickly. It doesn’t meet aperture require of the normal injection scheme anymore and the injection efficiency is lower. The pulsed multi-pole magnets give the opportunity to overcome the smaller dynamic aperture. Pulsed quadrupole and sextupole both are study for the injection scheme. With and without the orbit bump kickers are also considered in this study. The injection scheme suggestions are presented in this paper.

MOPPP056	Injection Transient Motion at PLS-II	kicker, septum, electron, linac	688
	I. Hwang, T. Ha, Y.D. Joo, C. Kim, M. Kim, S.H. Kim, B.-J. Lee, E.H. Lee, S. Shin PAL, Pohang, Kyungbuk, Republic of Korea
	PLS-II is an upgraded third generation synchrotron which includes many insertion devices with improved beam properties. Top-up operation is short time-interval injection to make roughly constant current and is essential to provide high intensity beam. When the electrons are injected to synchrotron, the stored beam is disturbed by small error of the injection system and the beam quality at the beamline can be decreased. We present this injection transient motion at PLS-II.

MOPPP057	Optimization of the Low-emittance Lattice of the APS Booster Synchrotron	booster, lattice, emittance, sextupole	690
	C. Yao, V. Sajaev, N. Sereno, H. Shang ANL, Argonne, USA
	Funding: Work supported by U.S. Department of Energy, Offices of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06- CH11357. The APS booster is a 7GeV electron synchrotron. Three lattices have been originally designed with a nominal beam emittance of 132, 109, and 92 nm, respectively. In the past we have mostly operated the booster with the 132 nm lattice because of its better stability. The lower-emittance lattices are not utilized. In early 2010 we upgraded the booster ramp correction and reduced the 360Hz current ripples of the ramp supplies. Current ramp errors have been significantly reduced. This raises our interest in running the low- emittance lattice to improve APS storage ring injection efficiency and reduce radiation losses. This report presents the optimization methods and measurement results of booster beam performance of the booster 92nm lattice.

MOPPP058	Improvements to the APS Booster Injection Controllaw Process	controls, booster, lattice, synchrotron	693
	C. Yao, F. Lenkszus, H. Shang, S. Xu ANL, Argonne, USA
	Funding: Work supported by U.S. Department of Energy, Offices of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06- CH11357. The APS booster is a 7-GeV electron synchrotron with a 0.5-second cycle time. The booster runs a set of injection control programs that corrects the injection beam trajectory based on the beam history of two BPMs. An IOC process calculates the I and Q components of beam oscillation from turn-by turn beam position samples over the first 64 turns. The booster injection control programs apply phase, energy, and transverse angle correction based on the result of the IOC processing. The initial system was installed in 2007. Since installation the system has mostly worked well for normal user operations. However, occasionally the system has yielded inconsistent results. Recently we reviewed the signal and processes involved in this system and made necessary upgrades to some components, including selection of a new set of two input BPMs, optimization of FFT parameters, and addition of an injection tune control program. These upgrades have significantly improved the effectiveness and consistency of the system. We report the findings, analysis, and results.

MOPPP060	Top-Off Mode of Operations: Setting Limits on the Extracted Beam Energy by Constraining Currents of Multiple Booster Dipole Power Supplies.	dipole, booster, extraction, lattice	696
	T.V. Shaftan BNL, Upton, Long Island, New York, USA
	In preparation for top-off mode of the NSLS-II operations we have studied impact of errors in the dipole power supply current on the extracted beam energy, which has to be interlocked so to satisfy the safety requirements. The NSLS-II booster dipole circuits are combined into 3 independent PS circuits, which adds complexity to the analysis of the extracted beam energy limits.

MOPPR002	Overview of the Beam Diagnostics in the MedAustron Accelerator: Design Choices and Test Beam Commissioning	emittance, synchrotron, extraction, proton	774
	F. Osmic, M. Feurstein, A. Gyorgy, A. Kerschbaum, M. Repovz, S.M. Schwarz EBG MedAustron, Wr. Neustadt, Austria G. Burtin CERN, Geneva, Switzerland
	The MedAustron center is a synchrotron based accelerator complex for cancer treatment and for clinical and non-clinical research with protons and light ions, currently under construction in Wiener Neustadt, Austria. The accelerator complex is based on the CERN-PIMMS study and its technical implementation by the Italian CNAO foundation in Pavia. The MedAustron beam diagnostics system is based on sixteen different monitor types (153 devices in total) and will allow measuring all relevant beam parameters from the source to the irradiation rooms. The monitors will have to cope with large intensity and energy ranges. Currently, one ion source, the low energy beam transfer line and the RFQ are being commissioned in the Injector Test Stand (ITS) at CERN. This paper gives an overview of all beam monitors foreseen for the MedAustron accelerator, elaborates some of the design choices, and reports the first beam commissioning results from the ITS.

MOPPR008	The Beam Loss Monitoring System at ELSA	extraction, electron, booster, monitoring	786
	D. Proft, A. Balling, F. Frommberger, W. Hillert ELSA, Bonn, Germany
	A new diagnostic tool to monitor beam loss in the storage ring at the Electron Stretcher Facility ELSA has been set up. It enables the investigation of causes for electron loss in real time, providing an essential tool needed to achieve the planned beam current upgrade from 30 mA to 200 mA. The monitoring system consists of 32 pin-diode based radiation detectors spread around the storage ring. Therefore, individual electron loss can be localized after each quadrupole. The readout system was designed to allow an integration of single loss events within 70 μs in order to be able to correlate these events to machine state changes. The used monitoring hardware and readout system will be detailed. Furthermore first measurements of the beam loss during injection, the fast energy ramp during acceleration and the extraction phase will be presented.

MOPPR015	Bunch-by-bunch Feedback Systems at the DELTA Storage Ring	feedback, kicker, electron, synchrotron	807
	M. Höner, M. Bakr, H. Huck, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk, M. Zeinalzadeh DELTA, Dortmund, Germany
	Funding: Work supported by BMBF (05K10PEB) At the DELTA 1.5-GeV electron storage ring operated as a synchrotron radiation source by the TU Dortmund University, bunch-by-bunch feedback systems have been recently installed and commissioned to detect and suppress longitudinal as well as transverse multibunch instabilities. Besides that, the feedback systems are used as a diagnostics tool. Growth rates of multibunch instabilities and their dependence on the beam current have been measured. Additionally, the oscillation amplitudes of electron bunches have been studied during the injection process.

MOPPR025	The BPM DAQ System Upgrade for SuperKEKB Injector Linac	linac, electron, emittance, positron	834
	M. Satoh, K. Furukawa, F. Miyahara, T. Suwada KEK, Ibaraki, Japan T. Kudou, S. Kusano MELCO SC, Tsukuba, Japan
	The non-destructive beam position monitor (BPM) is indispensable diagnostic tool for the stable beam operation. In the KEK Linac, approximately nineteen BPMs with the strip-line type electrodes are used for the beam orbit measurement and feedback. In addition, some of them are also used for the beam energy feedback loops. The current DAQ system consists of the fast digital oscilloscopes. A signal from each electrode is analyzed with a predetermined response function up to 50 Hz. The beam position resolution of current system is limited to about 0.5 mm because of ADC resolution. Towards SuperKEKB project, we have a plan to upgrade the BPM DAQ system since the Linac should provide the smaller emittance beam. We will report the system description of the new DAQ system and the results of performance test in detail.

MOPPR028	Upgrade Plan of BLM System of J-PARC MR	extraction, proton, ion, monitoring	837
	K. Satou, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The upgrade plan of BLM system of J-PARC Main Ring synchrotron (MR) will be described. Existing proportional chamber beam loss monitors (P-BLMs) have fast signal rise time of about 100ns and high gas gain of about 2·10⁴ at the maximum. These abilities were quite advantageous for the early beam commissioning stage. On the other hand, the gas gain is degraded with increasing output current. The P-BLM is suitable for a measurement of a low level beam loss event, however, vulnerable to a measurement of an accidental beam loss event (fast loss) causing high radiation. To enhance the dynamic range of the system, 1m long Air Ionization Chambers (AICs) will be installed and operated with the P-BLM. Experiments using the real beam loss at collimator area and at the Co60 radiation facility have demonstrated the stable operations up to the radiation level activated by the maximum beam loss power of the collimator area. A new data taking system is now under development, and its performances will also be presented.

MOPPR030	Various Methods to Measure the Betatron Tune of the Synchrotoron	betatron, closed-orbit, pick-up, synchrotron	843
	S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan
	Generally in the synchrotron, the frequency of transverse oscillation of the bunched beam for each single turn (usually called betatron tune or just "tune") is one of fundamental controllable knobs to avoid the instability of the accelerator. In this report, it is not mentioned about the effect to the beam instability but it is focused to various methods to measure the betatron tune by using bunch-by-bunch transverse beam position. The following items will be presented, (1) least square fitting to the time-domain beam position at specific location. (2) peak finding of the frequency-domain beam position at specific location. (3) phase space analysis of the beam position at specific location.(4) frequency-domain analysis of the beam position in the normalized coordinate at many locations in the ring orbit. For the application to the real accelerator, data of the J-PARC (Japan Proton Accelerator Research Complex) will be shown.

MOPPR031	BPM Data Processing Based on EPICS Soft IOC at HLS	EPICS, brilliance, storage-ring, controls	846
	T.J. Ma, P. Lu, B.G. Sun, Y.L. Yang, Z.R. Zhou, J.Y. Zou USTC/NSRL, Hefei, Anhui, People's Republic of China
	A data analysis program has been developed and verified successfully for the new beam position monitor (BPM) system of the storage ring at Hefei Light Source (HLS). The new BPM system will be equipped with Libera Brilliance BPM processors in the upgrade project of HLS. The embedded system on Libera has completed some basic work, including data acquisition, position calculation, and EPICS IOC data output. A new record type was developed to accomplish the beam position recalculation by log-ratio method. The new position signal’s character was studied in the time and frequency domain, including distribution, RMS noise, spectrum, tune, digital filter, signal correlation, etc. Recalculation beam position showed higher sensitivity and greater linear range.

MOPPR038	Bunch by Bunch Beam Diagnostics in SSRF	damping, betatron, wakefield, diagnostics	861
	Y.B. Leng, J. Chen, Z.C. Chen, Y.B. Yan, N. Zhang SSRF, Shanghai, People's Republic of China B.P. Wang SINAP, Shanghai, People's Republic of China
	A set of broadband beam instruments including filling pattern monitor, scope based BPM processor and streak camera has been implemented in the storage ring of SSRF. Several parameters such as charge, lifetime, transverse position, betatron tune and beam length, can be measured for individual bunch by these devices. The operation experience and measurement results will be introduced. The preliminary effort to retrieve wake field information from these measurements will be presented as well.

MOPPR051	TLS Transportline BPM Upgrade	booster, EPICS, diagnostics, storage-ring	897
	P.C. Chiu, J. Chen, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.H. Kuo, C.Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	There are seven stripline beam position monitor (BPM) installed in TLS booster to storage ring transport line. In order to provide the BPM system with better performance and functionalities, the latest generation BPM electronics Libera SinglePass had been adopted in TLS transport line for these stripline BPM. One unit had been tested in early 2011 and delivered the reliable and satisfactory results therefore extra six units had been purchased later. Currently, all of the new 7 units have replaced the past BPM electronics. The application had also been continuously developed. On the other hand, it is expected that the upgrade could enhance diagnostic functionalities for the related injection study. In this report, the injection stability and efficiency had been investigated.

MOPPR059	Modeling Space-charge and its Influence on the Measurement of Phase Space in ALICE by Tomographic Methods	space-charge, quadrupole, electron, diagnostics	918
	M.G. Ibison, D.J. Holder The University of Liverpool, Liverpool, United Kingdom K.M. Hock, B.D. Muratori, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: STFC. ALICE is an experimental electron accelerator designed to operate over a range of energies up to 35 MeV, and with up to 80 pC bunch charge. A dedicated tomography diagnostic section allows measurement of the transverse phase space with different beam parameters. In the low-energy, high-charge regime, space charge effects must be considered: to quantify these effects, the tracking code GPT has been used to simulate beams in the tomography diagnostic section. The results can be compared with simplified models, and with experimental measurements.

MOPPR060	Calibration of the EMMA Beam Position Monitors: Position, Charge and Accuracy	pick-up, quadrupole, simulation, diagnostics	921
	I.W. Kirkman The University of Liverpool, Liverpool, United Kingdom J.S. Berg BNL, Upton, Long Island, New York, USA G. Cox STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	The accurate determination of transverse beam position is essential to understanding the performance of an accelerator system, and this is particularly the case with non-scaling FFAG machines such as EMMA, where, due to fundamental principles of design, the beam may deviate widely from the central beampipe axis. This paper describes the various modelling approaches taken for the three different button pickup assemblies used in EMMA, and the subsequent methods of calibration (‘mappings’) which allow beam position and charge to be deduced from the processed BPM signals. The use and validity of the modelling and mapping approach adopted is described, and the contributions to positional and bunch charge uncertainty arising from these procedures is discussed.

MOPPR061	Computing Bunch Charge, Position, and BPM Resolution in Turn-by-Turn EMMA BPMs	pick-up, EPICS, controls, quadrupole	924
	A. Kalinin, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R.G. Borrell WareWorks Ltd, Manchester, United Kingdom G. Cox STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom I.W. Kirkman Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The NS-FFAG electron model ‘EMMA’ and its Injection and Extraction Lines are equipped with a total of 53 EPICS VME BPMs. In the BPMs, each opposite button signal pair is time-domain-multiplexed into one channel as a pulse doublet. The recording of turn-by-turn data into the BPM memory is triggered by the bunch itself on each of its passages. For each accelerating cycle, the BPMs deliver a snapshot of a turn-by-turn trajectory measured in each of 42 cells. Additional BPMs (two pairs) are used to obtain a Poincare map. We describe the EPICS architecture, and a set of Python data processing algorithms that are used to automatically set a BPM intensity range, to eliminate an error due to tails of the doublet pulses, to calculate the bunch charge and position, and, for a set of injections, to find the BPM resolution. We use three types of button pickup mappings* that allow: to eliminate bunch charge signal dependence on offset, to get a linear offset response, and to eliminate ‘quadrupole’ signal dependence on offset as well (which is used in resolution calculation). We present beam measurement results collected in 2011 runs. * A. Kalinin et al., Proc. of IPAC’10, MOPE068, p. 1134, (2010. ** I. Kirkman, these proceedings.

TUXA02	Upgrade Plans for the LHC Injector Complex	linac, electron, vacuum, feedback	1010
	R. Garoby, H. Damerau, S.S. Gilardoni, B. Goddard, K. Hanke, A.M. Lombardi, M. Meddahi, B. Mikulec, E.N. Shaposhnikova, M. Vretenar CERN, Geneva, Switzerland
	Challenging beams with much higher brightness than today are required for the LHC to achieve its high luminosity objective after the year 2020. It is the purpose of the LHC Injectors Upgrade (LIU) Project to achieve this result, consolidating and upgrading the existing set of ageing synchrotrons (PSB, PS and SPS), and using the new linac presently in construction (Linac4). The anticipated beam characteristics are described and compared to the known limitations in the different accelerators. The foreseen solutions are outlined as well as the planning for their implementation.
	Slides TUXA02 [72.367 MB]

TUYA03	Performance and Prospects of BEPCII	luminosity, coupling, optics, feedback	1030
	Q. Qin IHEP, Beijing, People's Republic of China
	BEPCII, the upgrade project of Beijing Electron Positron Collider (BEPC), has been put into operation for both high energy physics experiments as well as synchrotron radiation application since its completion in 2009. The peak luminosity reaches 6.5*10³² cm^-2 s^-1 at 1.89 GeV with e⁺e⁻ collisions of each beam current 700 mA. The collider operates for dedicated synchrotron radiation mode with 250 mA electron beams at 2.5 GeV. The performance of BEPCII should be reported and the measures to upgrade its luminosity described.
	Slides TUYA03 [5.529 MB]

TUPPC019	Beam Dynamics Simulations of J-PARC Main Ring for Damage Recovery from the Tohoku Earthquake in Japan and Upgrade Plan of Fast Extraction Operation	alignment, simulation, acceleration, linac	1200
	Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori KEK, Ibaraki, Japan H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Magnets of Japan Proton Accelerator Research Complex (J-PARC) were shaken by the Tohoku Earthquake in Japan on March 11th, 2011. The alignment of J-PARC Main Ring (MR) received 20 mm displacement horizontally and 6 mm vertically. Beam dynamics simulations were performed to estimate the effect of the displacement on closed orbit distortions and beam loss in fast extraction (FX) operation of J-PARC MR. Based on the simulation results, we concluded that re-alignment of J-PARC MR was needed to achieve high-power beam. The re-alignment of MR was finished on October 28th, 2011. We also considered the effects of the earthquake on the upstream of MR to establish our upgrade plan, which was based on beam dynamics simulations optimizing collimator balance of injection beam transport (3-50BT) and MR, and RF patterns. J-PARC MR FX operation was resumed from December 2011.

TUPPC050	Beam Transport and Storage with Cold Neutral Atoms and Molecules	sextupole, solenoid, multipole, quadrupole	1281
	P.L. Walstrom, M.D. Di Rosa LANL, Los Alamos, New Mexico, USA
	Funding: US Department of Energy Paramagnetic neutral atoms and molecules are subject to magnetic-field-gradient forces on their magnetic moments. Li atoms and CaH molecules both have an effective magnetic moment of about one Bohr magneton, and in the presence of a strong (~1 T) magnetic field, acquire a Zeeman energy of one of two values, ±μ\|B\|. Particles with positive (negative) energy are repelled by (attracted toward) increasing fields. Li and CaH can be laser-cooled to speeds of tens of m/s and the corresponding magnetic fields needed for transport and injection are on the order of 1 T. The stable stored state is the field-repelled state. Many concepts of accelerator physics apply to our neutral particles. The analog of charge-exchange injection into storage rings is laser-based optical pumping from a field-seeking state to a field-repelled state. The role of dipoles in charged-particle optics is played by quadrupoles in neutral particle optics, and the role of quadrupoles by sextupoles. We present our design and tracking results for a neutral atom/molecule accumulator including an injection chicane with a laser-stimulated state-flip.

TUPPC057	RHIC Spin Flipper Commissioning Results	dipole, resonance, polarization, proton	1302
	M. Bai, W.C. Dawson, J. Kewisch, Y. Makdisi, P. Oddo, C. Pai, P.H. Pile, T. Roser BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The five ac dipole design of RHIC spin flipper in the Blue ring was first commissioned during the RHIC 2012 polarized proton operation. The advantage of this design is to eliminate the vertical coherent betatron oscillations outside the spin flipper. Spin flipping efficiency was measured with both 100 GeV and 250 GeV polarized proton beams. This paper presents the latest commissioning results. M. Bai , T. Roser, C. Dawson, Y. Makdisi, W. Meng, F. Meot, P. Oddo, C. Pai, P. Pile, RHIC Spin Flipper New Design and Commissioning Plan, IPAC10 proceedings, IPAC 2010, Kyoto, Japan, 2010

TUPPC062	Transfer of Polarized 3He Ions in the AtR Beam Transfer Line	ion, extraction, dipole, proton	1317
	N. Tsoupas, W.W. MacKay, F. Méot, T. Roser, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US Department of Energy In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will also facilitate the collisions of electrons with polarized 3He ions. The AGS is the last acceleration stage of ions before injection into one RHIC for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized 3He ions from AGS into one of the RHIC’s collider rings. In this paper we investigate the extraction energy of the polarized 3He ions from the AGS which will optimize the polarization of 3He ions injected into RHIC. Some of the peculiarities (interleaved horizontal and vertical bends) of the AtR line's layout may degrade this spin matching of the polarized 3He ions. We will also discuss possible simple modifications of the AtR line to accomplish a perfect “spin matching” of the injected 3He beam with that of the stable spin direction at the injection point of the RHIC ring.

TUPPC063	The AGS Synchrotron with Four Helical Magnets	resonance, betatron, optics, quadrupole	1320
	N. Tsoupas, H. Huang, W.W. MacKay, T. Roser, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US Department of Energy. The idea of using two partial helical magnets was applied successfully to the AGS synchrotron, to preserve the proton beam polarization. In this paper we explore in details the idea of using four helical magnets placed symmetrically in the AGS ring. This modification provides many advantages over the present setup of the AGS that uses two partial helical magnets. First, the symmetric placement of the four helical magnets allows for a better control of the AGS optics with reduced values of the beta functions especially near beam injection, second, the vertical spin direction during beam injection and extraction is closer to vertical, and third, it provides a larger “spin tune gap” for the placement of both the vertical and horizontal tunes of the AGS during acceleration, second. Although the same spin gap can be obtained with two partial helices of equal strength, the required strength of the two helices makes it impractical. In this paper we will provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and comparison of these results with the present setup of the AGS that uses two partial helical magnets. T. Roser et al., Proc. EPAC04, p. 1577 (2004). H. Huang et al., PRL 99, 154801(2007). * N. Tsoupas et. al., these proceedings.

TUPPC080	Investigations of Scaling Laws of Dynamic Aperture with Time for Numerical Simulations including Weak-Strong Beam-Beam Effects	simulation, dynamic-aperture, beam-beam-effects, lattice	1359
	M. Giovannozzi CERN, Geneva, Switzerland E. Laface ESS, Lund, Sweden
	A scaling law describing the time-dependence of the dynamic aperture, i.e., the region of phase space where stable motion occurs, was proposed in previous papers about ten years ago. It was shown that dynamic aperture has a logarithmic dependence on time, which would be suggested by some fundamental theorems of the theory of dynamical systems. So far, such a law was applied to single-particle effects only, i.e., the only source of non-linear effects was the magnetic imperfections. In this paper an attempt is made to extend the scaling law to the case of weak-strong beam-beam effects. The results of numerical simulations performed, including both non-linear magnetic imperfections and weak-strong beam-beam effects, are presented and discussed in detail.

TUPPC081	First Experimental Observations from the LHC Dynamic Aperture Experiment	dynamic-aperture, kicker, beam-losses, synchrotron	1362
	M. Giovannozzi, M. Albert, G.E. Crockford, S.D. Fartoukh, W. Höfle, E.H. Maclean, A. Macpherson, L. Ponce, S. Redaelli, H. Renshall, F. Roncarolo, R.J. Steinhagen, E. Todesco, R. Tomás, W. Venturini Delsolaro CERN, Geneva, Switzerland R. Miyamoto BNL, Upton, Long Island, New York, USA
	Following intensive numerical simulations to compute the dynamic aperture for the LHC in the design phase, the successful beam commissioning and the ensuing beam operations opened the possibility of performing beam measurements of the dynamics aperture. In this paper the experimental set-up and the first observations based on the few experimental sessions performed will be presented and discussed in detail.

TUPPD001	The Mice Muon Beamline and Host Accelerator Beam Bump	target, proton, controls, extraction	1404
	A.J. Dobbs, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom D.J. Adams STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom E. Overton, P.J. Smith Sheffield University, Sheffield, United Kingdom
	Funding: Science and Technology Facilities Council The international Muon Ionization Cooling Experiment (MICE) is designed provide a proof of principle of the technique of ionization cooling, that is the reduction of the phase space of a muon beam via ionization energy loss in absorbers. Subsequent reacceleration is then provided by RF cavities (‘‘sustainable cooling''). Ionization cooling represents an important step toward future facilities based on stored muons beams, such as a future Neutrino Factory or Muon Collider. The MICE Muon Beam begins with the decay of pions produced by a cylindrical titanium target dipped into the circulating proton beam of the 800 MeV ISIS synchrotron at the Rutherford Appleton Laboratory, U.K. This generates a pion shower which is captured and subsequently decays producing the muon beam. A secondary effect of the MICE target is to cause an increase in the number of protons lost from the ISIS beam. It is important that this effect be minimized. An overview is presented here of the MICE Muon Beam, including the results of a study in to the effect of raising the vertical position of the ISIS beam (a ‘‘beam bump'') in the vicinity of the MICE target.

TUPPD005	Design Concept for Nu-STORM: an Initial “Very Low-Energy Neutrino Factory”	storage-ring, target, proton, factory	1413
	D.V. Neuffer, A.D. Bross, S. Geer, A. Liu, M. Popovic Fermilab, Batavia, USA C.M. Ankenbrandt, T.J. Roberts Muons, Inc, Batavia, USA
	Funding: US DOE under contract DE-AC02-07CH11359 We present a design concept for a Nu-source from a STORage ring for Muons - NuSTORM. In this initial design a high-intensity proton beam produces ~5 GeV pions that provide muons that are captured using “stochastic injection” within a ~3.6 GeV racetrack storage ring. In “stochastic injection”, the ~53 GeV pion beam is transported from the target into the storage ring, dispersion-matched into a long straight section. (Circulating and injection orbits are separated by momentum.) Decays within that straight section provide muons that are within the ~2 GeV/c ring momentum acceptance and are stored for the muon lifetime of ~1000 turns. Muon (and pion) decays in the long straight sections provide neutrino beams that can be used for precision measurements of neutrino interactions, and neutrino oscillations or disappearance at L/E=~1 m/MeV. The facility is described and variations are discussed.

TUPPD020	An EMMA Racetrack	dipole, quadrupole, extraction, electron	1452
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom H.L. Owen UMAN, Manchester, United Kingdom
	EMMA (Electron Machine for Many Applications) is the world’s first 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. Alternative methods of injection and extraction into the EMMA ring are explored together with their feasibility and implications. The option of developing nested racetracks to achieve a particular desired energy is also explored.

TUPPD044	Conceptual Gas Jet as a Stripping Target for Charge Exchange Injection	target, ion, laser, proton	1500
	V.G. Dudnikov, C.M. Ankenbrandt Muons, Inc, Batavia, USA
	Stripping targets for charge exchange injection now uses thin carbon or Al2O3 foils. During long time injection for high intense beam accumulation by low current injection a foil life time can be compromised by overheating and alternative stripping targets need be developed. A pulsed supersonic gas jet was used as a stripping target in first realization of charge exchange injection with H⁻ ion energy 1.5 MeV and stationary gas jets are used as internal targets in experiments with super high vacuum. A stripper target thickness is proportional to the injection energy and for energy 1GeV should be ~0.3 mg/cm² of carbon. The pulsed gas target with such thickness acceptable for long time charge exchange injection can be produced with using of heavy hydrocarbon molecules used in the diffusion or booster vacuum pumps. Formation of the pulsed gas jet stripping targets will be considered.

TUPPD057	High Charge Low Emittance RF Gun for SuperKEKB	gun, cathode, emittance, laser	1533
	T. Natsui, Y. Ogawa, M. Yoshida, X. Zhou KEK, Ibaraki, Japan
	We are developing a new RF gun for SuperKEKB. We are upgrading KEKB to SuperKEKB now. High charge low emittance electron and positron beams are required for SuperKEKB. We will generate 7.0 GeV electron beam at 5 nC 20 mm-mrad by J-linac. In this linac, a photo cathode S-band RF gun will be used as the electron beam source. For this reason, we are developing an advanced RF gun. Now, we are testing a Disk and Washer (DAW) type RF gun. Its photo cathode material is LaB6. Normally, LaB6 is used as a thermionic cathode, but it is suitable for　long-life photo cathode operation. This gun has a strong focusing field at the cathode and the acceleration field distribution also has a focusing effect. We will obtain 3.2 MeV beam energy with the gun. The design of RF gun and experimental results will be shown.

TUPPD061	High-Power RF Test of an RF-Gun for PAL-XFEL	gun, laser, emittance, electron	1539
	J.H. Hong, J.H. Han, H.-S. Kang, C. Kim, S.H. Kim, C.-K. Min, S.S. Park, S.J. Park, Y.J. Park PAL, Pohang, Kyungbuk, Republic of Korea M.S. Chae, I.S. Ko, Y.W. Parc POSTECH, Pohang, Kyungbuk, Republic of Korea
	A photocathode RF-gun for the X-ray free electron laser (XFEL) at the Pohang Accelerator Laboratory (PAL) has been fabricated and tested at PAL. This RF-gun is based on a 1.6-cell cavity with dual-feed waveguide ports and two pumping ports. The RF gun was designed by PAL and POSTECH. The RF-gun has been successfully tested with a cathode electric field gradient up to 126MV/m at a repetition rate of 30 Hz. This paper reports the recent results on the beam test of the RF-gun with high power RF at the gun test facility. We present and discuss the measurements of the basic beam parameters such as charge, energy, energy spread, and transverse emittance.

TUPPD065	An Electron Gun Test Stand to Prepare for the MAX IV Project	gun, cathode, coupling, linac	1551
	S. Werin, E. Elafifi, M. Eriksson, D. Kumbaro, F. Lindau, S. Thorin MAX-lab, Lund, Sweden E. Mansten Lund University, Division of Atomic Physics, Lund, Sweden
	The MAX IV facility, currently under construction, will include a 3 GeV linac injector with two RF guns providing beams for the two operations modes: ring injection and the Short Pulse Facility. The ring injection will be done by a thermionic 3 GHz RF gun developing from the current MAX-lab RF gun. The SPF gun will be a laser driven photo cathode 3 GHz RF gun based on the 1.6 cell BNL/SLAC type. The guns will be operated with short (0.7 us) RF pulses from a SLED system. A test stand to fine tune the operation of the two different systems has been assembled at the MAX IV laboratory (former MAX-lab). The experience in RF commissioning and initial measurements of energy, charge and quantum efficiency will be reported and the extension of the test stand for full emittance characterization will be outlined.

TUPPD077	SPEAR3 Booster RF System Upgrade: Performance Requirements and Evaluation of Resources	booster, klystron, cavity, linac	1578
	S. Park, W.J. Corbett, R.O. Hettel, J.F. Schmerge, J.J. Sebek, J.W. Wang SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy Contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences. The SPEAR2 accelerator system originally had 3 RF stations (2 for storage ring, 1 Booster) operating at 358.5 MHz. SPEAR3 now operates at 476.3 MHz with PEP-II type RF system, while the Booster RF frequency remains unchanged. For top-off operation, the Booster injects single 3.0 GeV electron bunches into SPEAR3 at 10 Hz every 5 minutes to replenish lost charge. Due to the frequency mismatch between SPEAR3 and the Booster, only one SPEAR3 bucket can injected per shot limiting injection rate and overall system flexibility. The aging high-power RF subsystems of the Booster pose a reliability issue as well. In order to remove these constraints, studies are underway to replace the Booster RF system using the PEP-II type RF system as a baseline. The new Booster RF system will be tuned to 475.036 MHz, and phase-locked to the SPEAR3 RF system. The project calls for ramping the Booster cavity gap voltage to 0.80 MV at 10 Hz, each with a 40 ms acceleration interval. With very low beam loading and low average RF power, there are many subsystems that can be operationally simplified. In this paper we present the results of analysis leading to a new Booster RF system.

TUPPP001	Beam Based Measurements with Superconducting Wigglers at the Canadian Light Source with Applications to Nonlinear Beam Dynamics	wiggler, dynamic-aperture, optics, multipole	1599
	W.A. Wurtz, L.O. Dallin, M.J. Sigrist CLS, Saskatoon, Saskatchewan, Canada
	The Canadian Light Source (CLS) employs two superconducting wigglers for the production of hard x-rays. These wigglers cause a large decrease in injection efficiency. While such a decrease is not unexpected due to the large distortion to the linear optics, a correction to the linear optics does not restore injection efficiency. This inability to restore injection is not predicted by a kickmap model of the wiggler. We performed beam based measurements to construct a phenomenological, nonlinear model of the wiggler. Particle tracking with this wiggler model shows that the reduction in dynamic aperture is due to the amplitude dependent tune shift crossing a resonance, even with the linear optics corrected. Moving the tunes allows us to avoid this resonance and measurements at these tunes show that injection efficiency is not greatly affected by the wigglers.

TUPPP004	Low-alpha Operation for the SOLEIL Storage Ring	optics, coupling, radiation, photon	1608
	M.-A. Tordeux, J. Barros, A. Bence, P. Brunelle, N. Hubert, M. Labat, P. Lebasque, A. Nadji, L.S. Nadolski, J.-P. Pollina SOLEIL, Gif-sur-Yvette, France C. Evain PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
	The low momentum compaction factor (alpha) operation has been recently established on the SOLEIL Storage Ring. Both time resolved X-ray and THz radiation user communities are taking benefit from a hybrid filling pattern with a 4.7 ps RMS bunch length. At a value of 1.7 10^-5 (nominal alpha /25) and a current per bunch of 65 μA, stable THz radiation is produced in the range of 8 - 20 cm^-1 (measurements and comparison with Coherent Synchrotron Radiation (CSR) modeling are reported elsewhere, ). Several low-alpha optics have been investigated and the optics presented at IPAC’11 has been selected for the operation. This paper presents the comprehensive experimental characterization of this optics. Specificities of the low-alpha operation, driven by the very demanding user experiments, are reviewed: closed orbit stability issues, extremely tight injected current step when refilling which implies a specific Linac tuning, low current diagnostics optimization, short bunch measurements, insertion devices effect on the CSR characteristics and radiation safety aspects justified by beam losses at injection. C. Evain, A. Loulergue et al., this conference. ** E. Roussel et al., this conference.

TUPPP016	Recent Development of PF Ring and PF-AR	undulator, polarization, linac, vacuum	1641
	Y. Tanimoto, T. Aoto, S. Asaoka, K. Endo, K. Haga, K. Harada, T. Honda, 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, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto KEK, Ibaraki, Japan H. Takaki ISSP/SRL, Chiba, Japan
	After the earthquake of March 11, two light sources of KEK, PF ring and PF-AR, have recovered the regular operation from October, 2011. We installed tandem variably-polarized undulators at PF ring in 2009. Recently, the orbit switching system has been completed with sufficient feed-forward orbit compensation at 10-Hz. PF ring is usually operated at 450 mA with a top-up injection using the pulsed sextupole magnet instead of the conventional kicker magnets. The transverse and longitudinal instabilities are suppressed by a digital feedback system using the iGp signal processor. In the longitudinal direction, we observed unstable quadrupole mode oscillation which could not be controlled by the feedback system. We had applied the phase modulation of the main RF cavity to stabilize the quadrupole oscillation before. Old-type RF-shielded gate valves damaged by the earthquake were removed from the ring during the summer maintenance. In the operation after autumn, the quadrupole oscillation can be cured by dividing the bunch train of partial-filling. Without the phase modulation, the effective brightness of SR beam has been improved especially at beam lines of finite dispersion function.

TUPPP018	Design and Commissioning of the Very Low Emittance Optics in the SSRF Storage Ring	emittance, optics, storage-ring, lattice	1647
	S.Q. Tian, J. Chen, B.C. Jiang, Y.B. Leng, H.H. Li, L.Y. Yu, M.Z. Zhang, W.Z. Zhang, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	In synchrotron radiation light sources, there are continuous efforts to lower the storage ring emittance and thus increase its photon beam brightness. The lowest effective emittance of SSRF is found by a systematic method. Results of design and commissioning of this kind of optics are presented, of which the beam emittance is smaller than the nominal one by 1 nm.rad. The measured beam parameters agree well with the design ones.

TUPPP025	Resurrection of RESOLVE at NSRRC Prepared for the First Turn Beam Steering of the TPS Commissioning	storage-ring, controls, quadrupole, kicker	1665
	H.-P. Chang, H.H. Chen, P.C. Chiu, P.J. Chou, K.T. Hsu, S.J. Huang, Y.-C. Liu, F.H. Tseng NSRRC, Hsinchu, Taiwan
	MATLAB based high level application software prepared for the 3GeV Taiwan Photon Source has been built and tested on the 1.5GeV Taiwan Light Source continuously. The RESOLVE program is surveyed and resurrected at NSRRC to support and help the first turn beam steering in the coming commissioning of the TPS accelerator complex. Due to the RESOLVE’s history, it contributed a lot in the past commissioning of SLC at SLAC National Accelerator Laboratory, we believe it may give help although most of the first turn beam steering of current light source machines may pass smoothly with well machine construction. In order to make the revised RESOLVE working, not only the compiling problem but also some memory bugs have been fixed, the updated RESOLVE now can be run on PC/Linux and Mac/OSX computer systems. We are trying to apply and test it on the TLS SR with the turn-by-turn digital BPM system. Some exercises of the error finding in beam steering of the off-axis injection beam are performed for presentation.

TUPPP026	RF Rescue Option for TPS Linac	electron, linac, bunching, booster	1668
	K.L. Tsai, H.-P. Chang, C.-T. Chen, C.-S. Fann, K.T. Hsu, S.Y. Hsu, K.-K. Lin, H.M. Shih NSRRC, Hsinchu, Taiwan K. Dunkel, C. Piel RI Research Instruments GmbH, Bergisch Gladbach, Germany
	The 150 MeV linac of Taiwan Photon Source was commissioned in June 2011. It consists of 90 keV electron source, bunching system and three S-band accelerating sections driven by three high-power klystrons. The rf system is equipped with rescue option such that the rf power from second klystron can be split and fed into both accelerating section 1 and 2. The rescue operation will be needed in the event of a failure occurred at the first klystron. In the report, the rescue capability will be illustrated and the test results will also be discussed.

TUPPR030	Thermo-mechanical Analysis of the CLIC Post-Linac Energy Collimators	linac, simulation, collimation, betatron	1882
	J. Resta-López IFIC, Valencia, Spain J.L. Fernández-Hernando STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom A. Latina CERN, Geneva, Switzerland
	Funding: FPA2010-21456-C02-01 The post-linac energy collimation system of the Compact Linear Collider (CLIC) has been designed for passive protection of the Beam Delivery System (BDS) against mis-steered beams due to failure modes in the main linac. In this paper, a thermo-mechanical analysis of the CLIC energy collimators is presented. This study is based on simulations using the codes FLUKA and ANSYS when an entire bunch train hit the collimators. Different failure mode scenarios in the main linac are considered. Moreover, we discuss the results for different collimator materials. The aim is to improve the collimator design in order to make a reliable and robust design so that it survives without damage from the impact of a full bunch train in case of likely events generating energy errors.

TUPPR034	Beam-based Alignment in CTF3 Test Beam Line	quadrupole, alignment, feedback, beam-losses	1894
	G. Sterbini, S. Döbert, R.L. Lillestøl, E. Marín, D. Schulte CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway
	The CLIC linear collider is based on the two beams acceleration scheme. During acceleration, the drive beam suffers a large increase in its energy spread. In order to efficiently transport such a beam, beam-based alignment techniques together with tight pre-alignment tolerances are crucial. A beam-based steering campaign has been conducted at the Test Beam Line of the CLIC Test Facility to evaluate the performance of several algorithms. In the following we present and discuss the obtained results.

TUPPR035	A Comparative Study for the CLIC Drive Beam Decelerator Optics	optics, quadrupole, alignment, lattice	1897
	G. Sterbini, D. Schulte CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway
	The baseline for the CLIC drive beam decelerators optics consists of a 2-m-long FODO cell. This solution was adopted to have strong focusing in order to mitigate the effect of the PETS wakefields and to minimize the drive beam envelope. Taking into account the most recent PETS design, we compare the performance of the baseline FODO cell with a proposal that consider twice longer FODO cell. Despite of the expected cost in term of performance, the reduction of the complexity of the system due to the halving of the number of quadrupoles can be beneficial for the overall optimization of the decelerator design.

TUPPR054	Internal H⁰/H⁻ Dump for the Proton Synchrotron Booster Injection at CERN	vacuum, booster, linac, radiation	1942
	M. Delonca, C. Maglioni, A.A. Patapenka, A. Sarrió Martínez CERN, Geneva, Switzerland
	In the frame of the LHC Injectors Upgrade Project at CERN (LIU), the new 160MeV H⁻ Linac4 will inject into the four existing PS Booster rings after the conversion of H⁻ into H⁺ in a stripping foil. Given a limited stripping efficiency and possible foil failures, a certain percentage of the beam is foreseen to remain partially (H⁰) or completely (H⁻) unstripped. An internal dump installed into the chicane magnet to stop these unstripped beams is therefore required. This paper presents the conceptual design of the internal dump, reviewing loading assumptions, design constraints, limitations and integration studies. Power evacuation through the thermal contact between the core and the external active cooling is addressed and, finally, results from the numerical thermo-mechanical analyses are reported.

TUPPR068	The Achromatic Telescopic Squeezing Scheme: Basic Principles and First Demonstration at the LHC	optics, sextupole, insertion, quadrupole	1978
	S.D. Fartoukh, R. De Maria, B. Goddard, W. Höfle, M. Lamont, G.J. Müller, L. Ponce, S. Redaelli, R.J. Steinhagen, M. Strzelczyk, R. Tomás, G. Vanbavinckhove, J. Wenninger CERN, Geneva, Switzerland R. Miyamoto ESS, Lund, Sweden
	The Achromatic Telescopic Squeezing (ATS) scheme [1] is a novel squeezing mechanism enabling the production of very low β^* in circular colliders. The basic principles of the ATS scheme will be reviewed together with its strong justification for the High-Luminosity LHC Project. In this context, a few dedicated beam experiments were meticulously prepared and took place at the LHC in 2011. The results obtained will be highlighted, demonstrating already the potential of the ATS scheme for any upgrade project relying on a strong reduction of β^. [1] S. Fartoukh, "An Achromatic Telescopic Squeezing (ATS) Scheme For The LHC Upgrade," IPAC'11, WEPC037, p. 2088 (2001).*

TUPPR087	Status of NSCL Cyclotron Gas Stopper	ion, cyclotron, extraction, emittance	2029
	N.S. Joshi, G. Bollen, M. Brodeur, D.J. Morrissey, S. Schwarz NSCL, East Lansing, Michigan, USA
	A gas-filled reverse cyclotron for the thermalization of energetic beams is under construction at NSCL/MSU. Rare isotopes produced via projectile fragmentation after in-flight separation will be injected into the device and converted into low-energy beams through buffer gas interactions as they spiral towards the center of the device. The extracted thermal beams will be used for low energy experiments such as precision mass measurements with traps or laser spectroscopy, and further transport for reacceleration. Detailed calculations have been performed to optimize the magnetic field design as well as the transport and stopping of ions inside the gas. An RF-carpet will be used to transport the thermal ions to the axial extraction point. The calculations indicate that the cyclotron gas stopper will be much more efficient for the thermalization of light and medium mass ions compared to linear gas cells. In this contribution we will discuss simulations of the overall performance and acceptance of machine, the beam matching calculations to the fragment separator emittance, and the construction status.

TUPPR088	Baseline Design of the SuperB Factory Injection System	linac, positron, electron, emittance	2032
	S. Guiducci, A. Bacci, M.E. Biagini, R. Boni, M. Boscolo, D. Pellegrini, M.A. Preger, P. Raimondi, A.R. Rossi, M. Zobov INFN/LNF, Frascati (Roma), Italy M.A. Baylac LPSC, Grenoble, France J. Brossard, S. Cavalier, O. Dadoun, T. Demma, P. Lepercq, E. Ngo Mandag, C. Rimbault, A. Variola LAL, Orsay, France J.T. Seeman SLAC, Menlo Park, California, USA D.N. Shatilov BINP SB RAS, Novosibirsk, Russia
	The injection complex of the SuperB, B-factory project of INFN consists of a polarized electron gun, a positron production system, electron and positron linac sections, a positron damping ring and the transfer lines connecting these systems and the collider main rings. To keep the ultra high luminosity nearly constant, continuous injection of 4 GeV electrons and 7 GeV positrons in both Low Energy Ring (LER) and High Energy Ring (HER) is necessary. In this paper we describe the baseline design and the beam dynamics studies performed to evaluate the system performance.

TUPPR089	Design Study of Beam Injection for SuperKEKB Main Ring	septum, synchrotron, optics, emittance	2035
	T. Mori, N. Iida, M. Kikuchi, T. Mimashi, Y. Sakamoto, H. Sugimoto, S. Takasaki, M. Tawada KEK, Ibaraki, Japan
	The SuperKEKB project is in progress toward the initial physics run in the year 2015. It assumes the nano-beam scheme, in which the emittance of the colliding beams is ε=4.6 nm. The emittance of the injected beam is ε=1.46 nm. To achieve such a low emittance, it is vitally important to preserve the emittance during the transport of the beam from the linac to the main ring. One of the most difficult parts is the injection system. We are considering the synchrotron injection for the electron-line to avoid a beam blowup in the ring after injection, which is caused by a beam-beam interaction with the stored beam. The optics study for electron injection and the current R&D status for the septum magnet will be reported in this paper.

TUPPR090	Analysis of Ferrite Heating of the LHC Injection Kickers and Proposals for Future Reduction of Temperature	kicker, vacuum, impedance, coupling	2038
	M.J. Barnes, L. Ducimetière, N. Garrel, B. Goddard, V. Mertens, W.J.M. Weterings CERN, Geneva, Switzerland
	The two LHC injection kicker magnet (MKI) systems produce a kick of 1.3 T-m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. A beam screen, consisting of a ceramic tube with conductors on the inner wall, is placed in the aperture of the magnets. The conductors provide a path for the image current of the, high intensity, LHC beam and screen the ferrite against wake fields. The conductors initially used gave adequately low beam coupling impedance however inter-conductor discharges occurred during pulsing of the magnet; hence an alternative design was implemented to meet the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time and good high voltage behaviour. During 2011 the LHC has been operated with high intensity beam, coasting for many hours at a time, resulting in heating of both the ferrite yoke and beam impedance reduction ferrites, of the MKIs. This paper presents an analysis of thermal measurement data and an extrapolation of the heating for future operation; in addition means are discussed for reducing ferrite heating and improving cooling.

TUPPR091	Status of the 160 MeV H⁻ Injection into the CERN PSB	emittance, vacuum, simulation, proton	2041
	W.J.M. Weterings, B. Balhan, E. Benedetto, J. Borburgh, C. Bracco, C. Carli, B. Goddard, K. Hanke, B. Mikulec, A. Newborough, R. Noulibos, J. Tan CERN, Geneva, Switzerland
	The 160 MeV H⁻ beam from the LINAC4 will be injected into the 4 superimposed rings of the PS Booster (PSB) with an new H⁻ charge-exchange injection system. This entails a massive upgrade of the injection region. The hardware requirements and constraints, the performance specifications and the design of the H⁻ injection region are described.

TUPPR092	Transient Beam Losses in the LHC Injection Kickers from Micron Scale Dust Particles	kicker, beam-losses, vacuum, electron	2044
	B. Goddard, P. Adraktas, T. Baer, M.J. Barnes, F. Cerutti, A. Ferrari, N. Garrel, A.H.J. Gerardin, M. Guinchard, A. Lechner, A. Masi, V. Mertens, R. Morón Ballester, S. Redaelli, J.A. Uythoven, V. Vlachoudis, F. Zimmermann CERN, Geneva, Switzerland
	Transient beam losses on a time scale of a few ms have been observed in the LHC injection kickers, occurring mainly shortly after beam injection with a strong correlation in time to the kicker pulsing. The beam losses, which have at times affected LHC availability, are attributed to micron scale ceramic dust particles detached from the alumina beam pipe and accelerated into the beam. The beam related observations are described, together with laboratory measurements of beam pipe contamination and kicker vibration, simulations of electric field in the beam pipe and the basic dynamic model. Energy deposition simulations modelling the beam losses are presented and compared to measurement. Extrapolations to future LHC operation at higher intensities and energies are made, and prospects for mitigation are discussed.

TUPPR093	Sources and Solutions for LHC Transfer Line Stability Issues	extraction, kicker, septum, controls	2047
	L.N. Drosdal, W. Bartmann, C. Bracco, B. Goddard, V. Kain, G. Le Godec, M. Meddahi, J.A. Uythoven CERN, Geneva, Switzerland
	The LHC is filled through two 3km transfer lines from the last pre-injector, the SPS. Safe injection into the LHC requires stable trajectories in the transfer lines. During the LHC proton operations 2011 instabilities were observed. In particular shot-by-shot and bunch-by-bunch variations cause difficulties for steering of the beam and can potentially cause high beam losses at injection. The causes of these instabilities have been studied and will be presented in this paper. Based on the studies solutions will be proposed and finally the effects of the solutions will be studied.

TUPPR094	SPS Transverse Beam Scraping and LHC Injection Losses	emittance, luminosity, proton, controls	2050
	L.N. Drosdal, W. Bartmann, C. Bracco, K. Cornelis, B. Goddard, V. Kain, M. Meddahi, E. Veyrunes CERN, Geneva, Switzerland
	Machine protection sets strict requirements for the quality of the injected beam, in particular in the transverse plane. Losses at aperture restrictions and protection elements have to be kept at a minimum. Particles in the beam tails are lost at the tight transfer line collimators and can trigger the LHC beam abort system. These particles have to be removed by scrapers in the vertical and horizontal plane in the SPS. Scraping has become vital for high intensity LHC operation. This paper shows the dependence of injection quality on the SPS scraping and discusses an improved scraper setting up strategy for better reproducibility with the current scraper system.

TUPPR096	Angular Alignment of the LHC Injection Protection Stopper	alignment, kicker, proton, beam-losses	2056
	C. Bracco, R.W. Assmann, W. Bartmann, B. Goddard, V. Kain, J.A. Uythoven CERN, Geneva, Switzerland
	Machine safety depends critically on the correct setup of the protection elements. One of the injection protection collimators is constituted by exceptionally long jaws (4 m). For this element, an angular offset of the jaws could affect significantly the measured beam size and, as a consequence, the correct setup with respect to the beam. Dedicated studies and cross-calibrations have been performed to quantify the effect of tilts and offsets on the setup of this collimator and to check the provided passive protection.

TUPPR098	Comparison of LHC Collimator Beam-Based Alignment Centers to BPM-Interpolated Centers	alignment, hadron, collimation, collider	2062
	G. Valentino, N.J. Sammut University of Malta, Information and Communication Technology, Msida, Malta R.W. Assmann, R. Bruce, G.J. Müller, S. Redaelli, A. Rossi, G. Valentino CERN, Geneva, Switzerland L. Lari IFIC, Valencia, Spain
	The beam centers at the Large Hadron Collider collimators are determined by beam-based alignment, where both jaws of a collimator are moved in separately until a loss spike is detected on a Beam Loss Monitor downstream. Orbit drifts of more than a few hundred micrometers cannot be tolerated, as they would reduce the efficiency of the collimation system. Beam Position Monitors (BPMs) are installed at various locations around the LHC ring, and a linear interpolation of the orbit can be obtained at the collimator positions. In this paper, the results obtained from beam-based alignment are compared with the orbit interpolated from the BPM data throughout the 2011 LHC proton run. The stability of the orbit determined by collimator alignment during the run is evaluated.

WEYA03	Overview of B-Factories	emittance, sextupole, quadrupole, collider	2086
	M.E. Biagini INFN/LNF, Frascati (Roma), Italy
	An overview of the two recently approved high luminosity B-Factories, the SuperB in Italy and the SuperKEKB in Japan, will be presented. The main design features to reach the very high luminosity requested and a status of progress in design and construction will be given.
	Slides WEYA03 [6.151 MB]

WEOAA01	Injected Beam Imaging at SPEAR 3 with a Digital Optic Mask	synchrotron, storage-ring, target, quadrupole	2116
	H.D. Zhang, R.B. Fiorito, A.G. Shkvarunets UMD, College Park, Maryland, USA W.J. Corbett, A.S. Fisher, K. Tian SLAC, Menlo Park, California, USA
	Funding: *This work is partially funded by the Office of Naval Research and the DOD Joint Technology Office. At SPEAR3, the light source operates in top-up injection mode with 273nC charge circulating in the storage ring (350mA). Each individual injection pulse contains only 40pC, or a contrast ration of 1:6800. In order to monitor injected beam dynamics during User operations, it is desirable to optically image the injected charge distribution on a turn-by-turn basis in the presence of the bright stored beam. The measurement is made by re-imaging visible synchrotron radiation onto a 1024x768 pixel Digital-Micro-Array mirror device (DMD) which is used to 'mask' light from the central stored beam while observing the weak injected beam signal on an intensified, fast-gated CCD camera. Complex beam dynamics are observed after only a few 10's of turns around the synchrotron. In this paper we report on the DMD optical configuration, masking considerations, measurement timing and initial tests imaging the injected beam in the presence of stored beam.
	Slides WEOAA01 [1.874 MB]

WEOAA03	Development of the Beam Halo Monitor in the J-PARC 3-GeV RCS	extraction, electron, beam-losses, gun	2122
	M. Yoshimoto, N. Hayashi, H. Hotchi, M. Kinsho, S.I. Meigo, K. Okabe, P.K. Saha, K. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Transverse beam halo is one of the most important beam parameters due to limit the performance of the high intensity beam accelerator. Therefore the transverse beam halo measurement is required to increase the beam power of the J-PARC 3-GeV RCS. Transverse halo monitors, which are horizontal and vertical scanning aluminum plates type, has been installed in the extraction beam line. But the residual secondary electrons hindered the beam halo diagnostic. Thus we develop the new beam halo monitor with vibrating wire monitor.
	Slides WEOAA03 [6.701 MB]

WEOAB01	New Results from the EMMA Experiment	acceleration, resonance, betatron, electron	2134
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C.S. Edmonds, K.M. Hock, M.G. Ibison, I.W. Kirkman The University of Liverpool, Liverpool, United Kingdom J.M. Garland, H.L. Owen UMAN, Manchester, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After demonstration of acceleration in the serpentine channel in April 2011, the beam study with EMMA continues to explore the large transverse and longitudinal acceptance and effects of integer tune crossing with slower rate on the betatron amplitude. Together with a comparison of detailed models based on measured field maps and the experimental mapping of the machine by relating the initial and final phase space coordinates. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.
	Slides WEOAB01 [2.120 MB]

WEEPPB002	Plasma Acceleration Experiment at SPARC_LAB with External Injection	plasma, electron, laser, acceleration	2169
	L. Serafini, A. Bacci Istituto Nazionale di Fisica Nucleare, Milano, Italy M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, A.R. Rossi, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy C. Maroli, V. Petrillo Universita' degli Studi di Milano, Milano, Italy A. Mostacci URLS, Rome, Italy P. Tomassini Università degli Studi di Milano, Milano, Italy
	At the SPARC-LAB facility of INFN-LNF we are installing two transport lines for ultra-short electron bunches and an ultra-intense laser pulses, generated by the SPARC photo-injector and by the FLAME laser in a synchronized fashion at the tens of fs level, to co-propagate inside a hydrogen filled glass capillary, in order to perform acceleration of the electron bunch by a plasma wave driven by the laser pulse. The main aim of this experiment is to demonstrate that a high brightness electron beam can be accelerated by a plasma wave without any significant degradation of its quality. A 10 pC electron bunch, 10 fs long is produced by SPARC and transported to injection into the capillary, which is 100 micron wide, at a gas density around 5*10¹⁷ ne/cm³ . The laser pulse, 25 fs long, focused down to 30 microns into the capillary is injected ahead of the bunch, drives a weakly non-linear plasma wave with wavelength of about 120 microns. A proper phasing of the two pulses allows acceleration of electrons from the injection energy of 150 MeV up to about 1 GeV for a 10 cm long capillary. Installation of the beam lines is foreseen by the end of 2012 and first tests starting in mid 2013.

WEEPPB014	The Magnetic Model of the LHC during the 3.5 TeV Run	quadrupole, dipole, controls, optics	2194
	E. Todesco, N. Aquilina, M. Giovannozzi, M. Lamont, F. Schmidt, R.J. Steinhagen, M. Strzelczyk, R. Tomás CERN, Geneva, Switzerland N.J. Sammut University of Malta, Information and Communication Technology, Msida, Malta
	The magnetic model of the LHC is based on a fit of the magnetic measurements through equations that model the field components (geometric, saturation, persistent) at different currents. In this paper we will review the main results related to the magnetic model during the run of the LHC in 2010-2011: with a top energy of 3.5 TeV, all components of the model but the saturation are visible. We first give an estimate of the reproducibility of the main components and multipolar errors as they can be deduced from beam measurements, i.e. orbit, tune, chromaticity, beta beating and coupling. We then review the main results relative to the decay at injection plateau, dependence on powering history, and snapback at the beginning of the ramp for both tune and chromaticity. We discuss the precision obtained in tracking the magnets during the ramp, where the persistent current components gradually disappear. We conclude by presenting the behaviour of the quadrupoles model during the squeeze. A list of the major changes implemented during the operation together with what are considered as the main open issues is given.

WEPPC059	A Two-stage Injection-locked Magnetron for Accelerators with Superconducting Cavities	linac, simulation, cavity, controls	2348
	G.M. Kazakevich, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer Muons, Inc, Batavia, USA B. Chase, S. Nagaitsev, R.J. Pasquinelli, N. Solyak, V. Tupikov, D. Wolff, V.P. Yakovlev Fermilab, Batavia, USA
	Funding: Supported in part by SBIR Grant 4743 11SC06261 A concept for a two-stage injection-locked CW magnetron intended to drive Superconducting Cavities (SC) for intensity-frontier accelerators has been proposed. The concept is based on a theoretical model that considers a magnetron as a forced oscillator; the model has been experimentally verified with a 2.5 MW pulsed magnetron. The two-stage CW magnetron can be used as a RF power source for Fermilab’s Project-X to feed separately each of the SC of the 8 GeV pulsed linac. For Project-X the 1.3 GHz two-stage magnetron with output power of 20-25 kW and expected output/input power ratio of about 35-40 dB would operate in a quasi-CW mode with a pulse duration ≤ 10 ms and repetition rate of 10 Hz. The magnetrons for both stages should be based on the commercial prototypes to decrease the cost of the system. An experimental model of the two-stage CW S-band magnetron with peak power of 1 kW, with pulse duration of 1-10 ms, has been developed and built for study. A description of the theoretical and experimental models, simulations, and experimental results are presented and discussed in this work.

WEPPC060	A High-power 650 MHz CW Magnetron Transmitter for Intensity Frontier Superconducting Accelerators	controls, proton, LLRF, linac	2351
	G.M. Kazakevich, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer Muons, Inc, Batavia, USA B. Chase, S. Nagaitsev, R.J. Pasquinelli, V.P. Yakovlev Fermilab, Batavia, USA T.A. Treado CPI, Beverley, Massachusetts, USA
	A concept of a 650 MHz CW magnetron transmitter with fast control in phase and power, based on two-stage injection-locked CW magnetrons, has been proposed to drive Superconducting Cavities (SC) for intensity-frontier accelerators. The concept is based on a theoretical model considering a magnetron as a forced oscillator and experimentally verified with a 2.5 MW pulsed magnetron. To fulfill fast control of phase and output power requirements of SC accelerators, both two-stage injection-locked CW magnetrons are combined with a 3-dB hybrid. Fast control in output power is achieved by varying the input phase of one of the magnetrons. For output power up to 250 kW we expect the output/input power ratio to be about 35 to 40 dB in CW or quasi-CW mode with long pulse duration. All magnetrons of the transmitter should be based on commercially available models to decrease the cost of the system. An experimental model using 1 kW, CW, S-band, injection-locked magnetrons with a 3-dB hybrid combiner has been developed and built for study. A description of the model, simulations, and experimental results are presented and discussed in this work.

WEPPC063	Superconducting RF Cavity for High-current Cyclotrons	cavity, cyclotron, focusing, extraction	2354
	N. Pogue, P.M. McIntyre, A. Sattarov Texas A&M University, College Station, Texas, USA
	Funding: This work is supported by grants from the State of Texas (ASE) and the Mitchell Family Foundation. A novel superconducting cavity is presented for applications in cyclotrons. The cavity is in effect an extrusion of a 2-D double-quarter-wave structure, in which the ends of the extrusion are wrapped around and joined so that the cavity has no end perturbations. Power is applied to a linear array of input coupling loops, so that rf sheet current is launched in a laminar flow that matches the power coupled to the orbits of the cyclotron. Each loop is driven by an independent solid-state rf source. A strategy is presented for using to advantage the independent control of phase and amplitude to suppress transient phenomena. Longitudinal modes can be strongly suppressed. These provisions are of importance to suppress phenomena that can limit beam current.

WEPPD015	Saturation Behaviour of the LHC NEG Coated Beam Pipes	vacuum, simulation, site, insertion	2525
	G. Bregliozzi, V. Baglin, J.M. Jimenez, G. Lanza, T. Porcelli CERN, Geneva, Switzerland
	In the CERN Large Hadron Collider (LHC), about 6 km of the UHV beam pipe are at room temperature and serve as experimental or utility insertions. TiZrV non-evaporable getter (NEG) coating is used to maintain the design pressure during beam operation. Molecular desorption due to dynamic effects is stimulated during protons operation at high intensity. This phenomenon produces an important gas load from the vacuum chamber walls which could lead to a partial or total saturation of the NEG coating. To keep the design vacuum performances and to schedule technical interventions for NEG re-activation, it is necessary to take in account all these aspects and to regularly evaluate the saturation level of the NEG coating. Experimental studies in a typical LHC vacuum sector were conducted in order to identify the best method to assess the saturation level of the beam pipe. Partial saturation of the NEG was performed and the effects in the variations of pressure reading, effective pumping speed, transmission and capture probability are analysed. Finally, based on these results, a detailed analysis of the NEG coating saturation level of some area of the LHC is presented and analysed.

WEPPD018	LHC Beam Vacuum During 2011 Machine Operation	vacuum, electron, kicker, proton	2534
	G. Lanza, V. Baglin, G. Bregliozzi, J.M. Jimenez CERN, Geneva, Switzerland
	During the year 2011 the LHC operated for 682 fills, meaning 247 days and 2 hours of stable beam in total. From 368 bunches per beam at 150 ns bunch spacing circulating in the ring in December 2010, the 2011 proton physic ended with 1380 bunches per beam circulating with 50 ns bunch spacing. The machine performances increased in parallel with the vacuum improvement thanks to a well performed scrubbing run in April 2011 and a continuous conditioning of the beam pipes while the machine was running. The 2011 LHC operation ended with one month of ions physic runs. During the machine operation various phenomena of beam - vacuum interaction were detected, analyzed and solved. This paper describes the pressure behavior along the machine layout and mainly in specific components position like TDI and MKI. The “pressure spike” phenomena near the experiment CMS and in some Dipole 1 (D1) regions are discussed. Finally, results obtained during the 25 ns machine developments are presented.

WEPPD047	Sequencer Design of Timing System for the Taiwan Photon Source	controls, booster, gun, EPICS	2621
	C.Y. Wu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, C.Y. Liao NSRRC, Hsinchu, Taiwan
	The timing system of the Taiwan Photon Source is used to distribute trigger signals and synchronously clocks to all the equipment of the machine which need them. The timing system basically works by sending event codes from one event generator (EVG) through tree structured, bidirectional optical fiber network to many event receivers. To accommodate various operation and injection scenarios of the TPS storage ring and booster synchrotron and LINAC, timing sequencer design and control is crucial. The sequencer (event code) is stored at sequence RAM of the EVG module. In order to manage sequence RAM of EVG, the timing sequence control is considered to use Matlab scripts embedded in the timing master EPICS IOC. The timing sequencer design will be summarized in this paper.

WEPPD050	Upgrade of the RF Reference Distribution System for 400 MeV LINAC at J-PARC	linac, controls, acceleration, klystron	2630
	K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	In J-PARC, the accelerator systems are controlled using the 12 MHz master clock in center control building. In the present J-PARC Linac, the negative hydrogen is accelerated by 181 MeV using the RFQ, DTLs, and SDTLs which have the resonance frequency of 324 MHz. The low-level radio frequency (LLRF) system is based on the reference signal of 312 MHz (LO) synchronized with the master clock. We are planning to upgrade Linac by the accelerated energy to 400 MeV by the installation of ACS cavities with the resonance frequency of 972 MHz. Then, not only 312 MHz but also 960 MHz reference signals are necessary. Therefore, a new RF reference signal oscillator was installed at J-PARC LINAC. The phase noise of the output signal in this module was measured by the signal source analyzer. The jitter of the output signal, which was estimated from the integration of phase noise from 10 Hz to 1 MHz, becomes about 40 fs and was two order smaller than that of the old system (about 1700 fs) by the installation of new oscillator and the optimization of the path of the master clock. It can be expected to improve the operating ratio in J-PARC LINAC.

WEPPD064	Quick Recovery of the KEK e⁻/e⁺ Injector Linac from the Great East Japan Earthquake	linac, vacuum, positron, electron	2669
	A. Enomoto KEK, Ibaraki, Japan
	The KEK e⁻/e⁺ injector linac is under operation for the KEK Photon Factory (PF) storage ring and Photon Factory - Advanced Ring (PF-AR). And the linac has just started the upgrade for the SuperKEKB project. On March 11, the linac suffered great damage from the Great East Japan Earthquake. Due to an extraordinary strong vibration, many bellows of vacuum pipes were violently torn and the entire linac vacuum was exposed to the atmosphere. Without electricity, highly humid air entered the inside of accelerator structures. Some people supposed the linac would not be recovered within a year. However, it resumed operation after only two months. We report the memorable disaster and how we recovered the linac so quickly.

WEPPD071	The FLUKA LineBuilder and Element DataBase: Tools for Building Complex Models of Accelerator Beam Lines	optics, simulation, insertion, proton	2687
	A. Mereghetti UMAN, Manchester, United Kingdom V. Boccone, F. Cerutti, R. Versaci, V. Vlachoudis CERN, Geneva, Switzerland
	Extended FLUKA models of accelerator beam lines can be extremely complex: heavy to manipulate, poorly versatile and prone to mismatched positioning. We developed a framework capable of creating the FLUKA model of an arbitrary portion of a given accelerator, starting from the optics configuration and a few other information provided by the user. The framework includes a builder (LineBuilder), an element database and a series of configuration and analysis scripts. The LineBuilder is a Python program aimed at dynamically assembling complex FLUKA models of accelerator beam lines: positions, magnetic fields and scorings are automatically set up, and geometry details such as apertures of collimators, tilting and misalignment of elements, beam pipes and tunnel geometries can be entered at user's will. The element database (FEDB) is a collection of detailed FLUKA geometry models of machine elements. This framework has been widely used for recent LHC and SPS beam-machine interaction studies at CERN, and led to a drastic reduction in the time otherwise required to rework old machine models, and to a coherent and traceable description of the inputs used for all the simulations.

WEPPP017	Recent Results at the SPARC_LAB Facility	laser, electron, plasma, photon	2758
	M. Ferrario, D. Alesini, M.P. Anania, M. Bellaveglia, R. Boni, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, A. Esposito, A. Gallo, C. Gatti, G. Gatti, A. Ghigo, T. Levato, E. Pace, L. Pellegrino, R. Pompili, A.R. Rossi, B. Spataro, P. Tomassini, C. Vaccarezza, F. Villa INFN/LNF, Frascati (Roma), Italy A. Bacci, C. De Martinis, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy G. Dattoli, E. Di Palma, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, I.P. Spassovsky, V. Surrenti ENEA C.R. Frascati, Frascati (Roma), Italy D. Di Giovenale INFN-Roma II, Roma, Italy U. Dosselli INFN, Roma, Italy R. Faccini INFN-Roma, Roma, Italy R. Fedele Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli, Italy M. Gambaccini INFN-Ferrara, Ferrara, Italy D. Giulietti UNIPI, Pisa, Italy L.A. Gizzi, L. Labate CNR/IPP, Pisa, Italy P. Londrillo INFN-Bologna, Bologna, Italy S. Lupi Università di Roma I La Sapienza, Roma, Italy A. Mostacci, L. Palumbo Rome University La Sapienza, Roma, Italy G. Passaleva INFN-FI, Sesto Fiorentino, Italy V. Petrillo Universita' degli Studi di Milano, Milano, Italy J.V. Rau ISM-CNR, Rome, Italy G. Turchetti Bologna University, Bologna, Italy
	A new facility named SPARC_LAB (Sources for Plasma Accelerators and Radiation Compton with Lasers and Beams) has been recently launched at the INFN National Labs in Frascati, merging the potentialities of the old projects SPARC and PLASMONX. The SPARC project, a collaboration among INFN, ENEA and CNR, is now completed, hosting a 150 MeV high brightness electron beam injector which feeds a 12 meters long undulator. Observation of FEL radiation in the SASE, Seeded and HHG modes has been performed from 500 nm down to 40 nm wevelength. A second beam line has been also installed to drive a narrow band THz radiation source. In parallel to that, INFN decided to host a 300 TW laser that will be linked to the linac and devoted to explore laser-matter interaction, in particular with regard to laser-plasma acceleration in the self injection and external injection modes, (the PLASMONX experiments). The facility will be also used for particle driven plasma acceleration experiments (the COMB experiment). A Thomson scattering experiment coupling the electron bunch to the high-power laser to generate coherent monochromatic X-ray radiation is also in the commissioning phase.

WEPPP018	A New Beam Injection Scheme for a Compact Low-energy Storage Ring	kicker, damping, storage-ring, acceleration	2761
	Y. Honda KEK, Ibaraki, Japan
	A very compact storage ring at low energy has an unique application such as Compton X-ray source. Scheme for efficient injection is an issue for such a compact storage ring. Utilizing a phase-shift in the non-relativistic energy region, a new idea for accumulating the incoming bunch on an already circulating bunch without any kicker or orbit bump has been presented. Its applicable parameter range will be presented.

WEPPP019	Designing of Photonic Crystal Accelerator for Radiation Biology	laser, electron, vacuum, acceleration	2763
	K. Koyama, Y. Matsumura University of Tokyo, Tokyo, Japan A. Aimidula, M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan T. Natsui, M. Yoshida KEK, Ibaraki, Japan
	Funding: This work was performed as part of the Global COE Program (Nuclear Education and Research Initiative, MEXT, Japan. A photonic crystal accelerator with a combination of a fiber laser is under development in order to apply it to the radiation biology. In order to investigate fundamental biological processes in a cell, a DNA is precisely shot by an electron bunch with an in situ observation of a radiation interaction using a microscope. Required beam diameter, bunch length, and beam energy are nanometer, attosecond, and 100 keV to 1 MeV, respectively. A photonic crystal or dielectric laser accelerator energized by a fiber laser is suitable for producing such a fine beam with a palm top device. A preliminary estimation shows that 200 keV electron bunch is available from a 0.8-mm-long accelerator and a few cm electron gun, which is driven by a few μJ, 5-ps laser pulse. We are developing a fiber laser in order to drive the photonic crystal accelerator. The Yb-fiber oscillator delivers mode-locked pulse train of ≈5 nJ/pulse at the repetition frequency of 62.5 MHz. The output pulse will be increased to several μJ by adopting a fiber amplifier

WEPPP062	Characterization and Stabilization of Multi-Bunch Instabilities at the ANKA Storage Ring	feedback, kicker, storage-ring, controls	2849
	E. Huttel FZK, Karlsruhe, Germany N. Hiller, E. Huttel, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, N.J. Smale KIT, Karlsruhe, Germany
	ANKA is a 2.5 GeV storage ring for synchrotron radiation. Up to 200 mA are accumulated at 0.5 GeV and then ramped to 2.5 GeV. In the past storage ring operation suffered from vertical multi-bunch instabilities. These could partially be cured by increased chromaticity, a large gap in the filling structure and by keeping the beam longitudinally unstable. A vertical digital bunch-by-bunch system from ITECH has been installed that allows an operation of the storage ring without exciting the longitudinal modes. In addition, the system allows analyzing multi-bunch instabilities both transverse and longitudinal and their dependence from cavity temperature, filling structure and chromaticity. This paper reports on our experience operating this system and presents an investigation of multi-bunch modes in the ANKA storage ring.

WEPPP083	Near Real-time Response Matrix Calibration for 10-Hz GOFB	feedback, dipole, damping, quadrupole	2903
	C. Liu, R.L. Hulsart, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The 10-Hz global orbit feedback, for damping the trajectory perturbation (~10 Hz) due to the vibrations of the triplets, is operational for injection and store in RHIC. The operation of the system has been performed using transfer functions between the beam position monitors and correctors obtained from the online optics model and a correction algorithm based on singular value decomposition (SVD). Calibration of the transfer functions by measuring the beam position oscillations while modulating the dedicated correctors has been carried out. The feedback results with model matrix and measured matrix will be compared.

WEPPP085	Study on the Realignment Plan for J-PARC 3 GeV RCS after the Tohoku Earthquake in Japan	extraction, quadrupole, survey, alignment	2909
	N. Tani, H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	J-PARC 3GeV RCS suffered the big damage to its building and cooling and electric facilities by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. After the earthquake, RCS magnets were measured to confirm the state of accelerator beam line. As a result, it was found out that there was an alignment error of several millimeters in both horizontal and vertical directions that caused a deformation in the J-PARC 3GeV RCS tunnel. In this paper, we report the survey result in the accelerator tunnel after the earthquake and the realignment plan for J-PARC 3GeV RCS.

WEPPR005	Study of Electron Cloud Instability in Fermilab Main Injector	electron, simulation, proton, damping	2943
	K. Ohmi KEK, Ibaraki, Japan R.M. Zwaska Fermilab, Batavia, USA
	Electron cloud has been observed in Fermilab main injector. Electron signal is enhanced near the transition. The slippage factor which suppress instabilities approach to zero at the transition. Instabilities must be most serious near the transition. The instability caused by the electron cloud is an important issue for high intensity operation and the future toward Project-X. Simulations of electron cloud instability near the transition is presented.

WEPPR006	Serpentine Acceleration in Scaling FFAG	acceleration, proton, closed-orbit, betatron	2946
	E. Yamakawa, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, T. Uesugi Kyoto University, Research Reactor Institute, Osaka, Japan K. Okabe, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan
	A serpentine acceleration in scaling FFAG accelerator is examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is derived analytically. Experiment to demonstrate a serpentine acceleration in scaling FFAG is done.

WEPPR007	Simulation Calculation of Longitudinal Beam Distribution in J-PARC MR	beam-loading, acceleration, simulation, extraction	2949
	K. Hara, T. Koseki, C. Ohmori KEK, Tokai, Ibaraki, Japan Y. Sato J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The J-PARC accelerator complex consists of 3 accelerators, a linear accelerator, a rapid cycle synchrotron (RCS) and a Main Ring (MR) synchrotron. Simulation calculation of longitudinal beam distribution in J-PARC Main Ring has been performed. The effect that RF voltage pattern, space charge, and beam loading gave was examined.

WEPPR018	Beam Experiments towards High-intensity Beams in RHIC	proton, vacuum, cryogenics, radiation	2979
	C. Montag, L. A. Ahrens, M. Blaskiewicz, J.M. Brennan, K.A. Drees, W. Fischer, T. Hayes, H. Huang, K. Mernick, G. Robert-Demolaize, K.S. Smith, R. Than, P. Thieberger, K. Yip, K. Zeno, S.Y. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Proton bunch intensities in RHIC will be increased from 210¹¹ to 310¹¹ protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results will be presented.

WEPPR038	Independent Component Analysis (ICA) Applied to Long Bunch Beams in the Los Alamos Proton Storage Ring	betatron, linac, extraction, coupling	3018
	J.S. Kolski, R.J. Macek, R.C. McCrady, X. Pang LANL, Los Alamos, New Mexico, USA
	Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis (PCA), which is the BSS foundation of the well known model independent analysis (MIA), ICA is more robust to noise, coupling, and nonlinearity. ICA of turn-by-turn beam position data has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch and discuss the source signals identified as betatron motion and longitudinal beam structure.

WEPPR058	The Vertical Impedance Distribution Measurement Using Response Matrix Method at BEPCII BPR	impedance, kicker, feedback, betatron	3057
	Y. Wei, D. Ji IHEP, Beijing, People's Republic of China
	Funding: Work supported by the Chinese National Foundation of Natural Sciences, contract 111100512108. In the last run of BEPCII, the single bunch current is limited to about 8mA by the beam-beam effect. To obtain the design luminosity, larger number of bunches are necessary. But higher total current may be limited by the collective effects. A good understanding of the transverse impedance distribution around the BEPCII storage ring is required. Response matrix method has been applied successfully in BEPCII to fit the quadrupole errors and restore the optics. We can also calculate the variation of betatron phase advance around the ring with different single bunch current using the response matrix method and the transverse impedance distribution is thus deduced. In this paper, the first measurement of transverse impedance in BEPCII is presented.

WEPPR065	Electromagnetic Simulations of the Impedance of the LHC Injection Protection Collimator	simulation, impedance, vacuum, wakefield	3075
	B. Salvant, V. Baglin, B. Goddard, A. Grudiev, E. Métral, M.A. Timmins CERN, Geneva, Switzerland
	During the 2011 LHC run, significant vacuum and temperature increase were observed at the location of the LHC injection protection collimators (TDI) during the physics fills. Besides, measurements of the LHC transverse tune shift while changing the TDI gap showed that the impedance of the TDI was significantly higher than the LHC impedance model prediction based on multilayer infinite length theory. This contribution details the electromagnetic simulations performed with a full 3D model of the TDI to obtain both longitudinal and transverse impedances and their comparison with measured observables.

WEPPR069	Measurements and Simulations of Transverse Coupled-Bunch Instability Rise Times in the LHC	simulation, octupole, feedback, impedance	3087
	N. Mounet, R. Alemany-Fernandez, W. Höfle, D. Jacquet, V. Kain, E. Métral, L. Ponce, S. Redaelli, G. Rumolo, R. Suykerbuyk, D. Valuch CERN, Geneva, Switzerland
	In the current configuration of the LHC, multibunch instabilities due to the beam-coupling impedance would be in principle a critical limitation if they were not damped by the transverse feedback. For the future operation of the machine, in particular at higher bunch intensities and/or higher number of bunches, one needs to make sure the coupled-bunch instability rise times are still manageable by the feedback system. Therefore, in May 2011 experiments were performed to measure those rise times and compare them with the results obtained from the LHC impedance model and the HEADTAIL wake fields simulation code. At injection energy, agreement turns out to be very good, while a larger discrepancy appears at top energy.

WEPPR071	Evaluation of the Beam Coupling Impedance of New Beam Screen Designs for the LHC Injection Kicker Magnets	impedance, kicker, coupling, simulation	3093
	H.A. Day, R.M. Jones UMAN, Manchester, United Kingdom M.J. Barnes, F. Caspers, H.A. Day, E. Métral, B. Salvant CERN, Geneva, Switzerland
	During the 2011 run of the LHC there was a measured temperature increase in the LHC Injection Kicker Magnets (LHC-MKI) during operation with 50ns bunch spacing. This was suspected to be due to increased beam-induced heating of the magnet due to beam impedance. Due to concerns about future heating with the increased total intensity to nominal and ultimate luminosities a review of the impedance reduction techniques within the magnet was required. A number of new beam screen designs are proposed and their impedance evaluated. Heating estimates are also given with a particular attention paid to future intensity upgrades to ultimate and HL-LHC parameters.

WEPPR072	Increasing Instability Thresholds in the SPS by Lowering Transition Energy	optics, emittance, extraction, coupling	3096
	H. Bartosik, G. Arduini, T. Argyropoulos, T. Bohl, S. Cettour-Cave, K. Cornelis, J. Esteban Muller, W. Höfle, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova CERN, Geneva, Switzerland

Paper

Title

Other Keywords

Page

MOEPPB003

Status of the PRISM FFAG Design for the Next Generation Muon-to-Electron Conversion Experiment

solenoid, target, lattice, proton

79

J. Pasternak, A. Alekou, M. Aslaninejad, R. Chudzinski, L.J. Jenner, A. Kurup, Y. Shi, Y. Uchida
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
R. Appleby, H.L. Owen
UMAN, Manchester, United Kingdom
R.J. Barlow
University of Huddersfield, Huddersfield, 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
Kyoto University, Research Reactor Institute, 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
BNL, Upton, Long Island, New York, USA
T. Yokoi
JAI, Oxford, United Kingdom

The PRISM Task Force continues to study high intensity and high quality muon beams needed for next generation lepton flavor violation experiments. In the PRISM case such beams have been proposed to 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. This paper summarizes the current status of the PRISM design obtained by the Task Force. In particular various designs for the PRISM FFAG ring are discussed and their performance compared to the baseline one, the injection/extraction systems and matching to the solenoid channels upstream and downstream of the FFAG ring are presented. The feasibility of the construction of the PRISM system is discussed.

MOPPC001

Simulation of electron-cloud heat load for the cold arcs of the large hadron collider

electron, simulation, dipole, photon

115

G.H.I. Maury Cuna
CINVESTAV, Mérida, Mexico
G. Iadarola
Naples University Federico II, Science and Technology Pole, Napoli, Italy
G. Rumolo, F. Zimmermann
CERN, Geneva, Switzerland

The heat load due to the electron cloud in the Large Hadron Collider (LHC) cold arcs is a concern for its performance near and beyond nominal beam current. We report the results of simulation studies, which examine the electron-cloud induced heat load for different values of low-energy electron reflectivity and secondary emission yield at injection energy, as well as at beam energies of 4 TeV and 7 TeV, for two different bunch spacing: 25 ns and 50 ns. Benchmarking the simulations against heat-load observations at different beam energies and bunch spacing allows an estimate of the secondary emission yield in the cold arcs of the LHC and of its evolution as a function of time.

MOPPC004

Experiments on the Margin of Beam Induced Quenches for LHC Superconducting Quadrupole Magnet in the LHC

proton, quadrupole, kicker, monitoring

124

C. Bracco, W. Bartmann, M. Bednarek, B. Goddard, E.B. Holzer, A. Nordt, M. Sapinski, R. Schmidt, M. Solfaroli Camillocci, M. Zerlauth, E.N. del Busto
CERN, Geneva, Switzerland

Protection of LHC equipment relies on a complex system of collimators to capture injected or circulating beam in case of LHC injection kicker magnet failures. However, for specific failures of the injection kicker, the beam can graze the injection protection collimators and induce quenches of downstream superconducting magnets. This occurred twice during 2011 operation and can also not be excluded during further operation. Tests were performed during Machine Development periods of the LHC to assess the quench margin of the quadrupole located just downstream of the last injection protection collimator in point 8. In addition to the existing Quench Protection System, a special monitoring instrumentation was installed at this magnet to detect any resistance increase below the quench limit. The correlation between the magnet and Beam Loss Monitor signals was analysed for different beam intensities and magnet current. The results of the experiments are presented in this paper.

MOPPC006

90m Optics Studies and Operation in the LHC

optics, proton, quadrupole, target

130

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

A high β^* = 90 m optics was commissioned and used for first very forward physics operation in the LHC in 2011. The experience gained from working with this optics in 5 studies and operation periods in 2011 was very positive. The target β^* = 90 m was reached by a de-squeeze from the standard 11 m injection and ramp optics on the first attempt and collisions and first physics results obtained in the second study. The optics was measured and corrected with good precision. The running conditions were very clean and allowed for measurements with roman pots very close to the beam.

MOPPC011

Optics and Layout Solutions for the HL-LHC with Large Aperture Nb3Sn and Nb-Ti Inner Triplets

optics, quadrupole, dynamic-aperture, insertion

145

S.D. Fartoukh, R. De Maria
CERN, Geneva, Switzerland

Funding: The research leading to these results has received funding from the European Commission under the FP7 project HiLumi LHC, GA no. 284404, co-funded by the DoE, USA and KEK, Japan.
The LHC Upgrade studies, formalized into the High-Luminosity LHC (HL-LHC) project, relies on the feasibility of very low β^*, and in particular on a novel achromatic squeezing mechanism, the ATS scheme which is presently under test in the LHC*. We present two optics and layout scenario for the HL-LHC using the ATS scheme, one based on Nb3Sn triplet quadrupoles with a coil aperture compatible with an operational gradient of 150T/m and a backup scenario based on NbTi compatible with an operational gradient of 100T/m. The solution obtained are analyzed in terms of β^* reach (flat or round), mechanical acceptance, optics flexibility, chromatic properties, and impact on the dynamic aperture due to the large beta-beating waves induced in the arcs by the ATS scheme.
* S. Fartoukh et al., "The Achromatic Telescopic Squeezing (ATS) scheme: from initial motivations to basic principles, and first demonstration at the LHC," these proceedings.

MOPPC015

Proposal for an RF Roadmap Towards Ultimate Intensity in the LHC

cavity, klystron, feedback, beam-loading

154

P. Baudrenghien, T. Mastoridis
CERN, Geneva, Switzerland

The LHC is currently operated with 1380 bunches at 50 ns spacing and 1.4 E11 p per bunch (0.35A DC). In this paper the RF operation with ultimate bunch intensity (1.7 E11 p per bunch) and 25 ns spacing (2808 bunches per beam) summing up to 0.86A DC is presented. With the higher beam current, the demanded klystron power will be increased and the longitudinal stability margin reduced. In addition one must consider the impact of a klystron trip (voltage and power transients in the three turns latency before the beam is actually dumped). In this work a scheme is proposed that can deal with ultimate bunch intensity, without modification to the RF power system. Only a minor upgrade of the LLRF will be necessary: the field set point will be modulated according to the phase shift produced by the transient beam loading, thus minimizing the requested RF power while keeping the strong feedback for stability and reduction of RF noise.

MOPPC016

Combined Ramp and Squeeze at the Large Hadron Collider

optics, quadrupole, collider, dipole

157

S. Redaelli, M. Lamont, G.J. Müller, R. Tomás, J. Wenninger
CERN, Geneva, Switzerland
N. Ryckx
EPFL, Lausanne, Switzerland

In the first two years of operation of the CERN Large Hadron Collider (LHC), the betatron squeeze has been carried out at constant flat top energy of 3.5 TeV. Squeeze setting functions are separated from the energy ramp functions. This ensured a maximum flexibility during commissioning because stopping at all intermediate optics for detailed measurements was possible. In order to then improve the efficiency of the operational cycle, combining the ramp and squeeze has been considered. In this paper, the various possibilities for this scheme are reviewed, and proposals of optimized operational cycles with combined ramp and squeeze are presented for different energies. Results of beam tests are also discussed.

MOPPC017

Causes and Solutions for Emittance Blow-Up During the LHC Cycle

emittance, luminosity, proton, feedback

160

M. Kuhn
Uni HH, Hamburg, Germany
G. Arduini, B.J. Holzer, J.M. Jowett, V. Kain, F. Roncarolo, M. Schaumann, R. Versteegen, J. Wenninger
CERN, Geneva, Switzerland

Emittance measurements during the run 2011 indicated a blow-up of 20 % to 30 % from LHC injection to collisions. At the LHC design stage the total allowed emittance increase through the cycle was set to 7 %. One of the goals of the 2012 LHC run is therefore to understand and counteract the blow-up. Emittance growth measurements through the LHC cycle along with correlations with possible sources are presented in this paper. Solutions are proposed where possible. The emittance determination accuracy relies on the knowledge of the beam optics and on the present performance of the transverse profile monitors. Possible improvements of the diagnostics and of the related data analysis are also discussed.

MOPPC030

Status of the Decay Ring Design for the IDS Neutrino Factory

kicker, lattice, insertion, optics

199

D.J. Kelliher, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
N. Bliss, N.A. Collomb
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

In the International Design Study for the Neutrino Factory (IDS-NF) a racetrack design has been adopted for the decay ring*. The injection system into the decay ring is described. The feasibility of injecting both positive and negative muons into the ring is explored from the point of view of injection timing. Considerations for the design of a decay ring for a 10 GeV neutrino factory are included.
* ”International Design Study for the Neutrino Factory – interim design report”, RAL-TR-2011-018 (2011)

MOPPC032

Injection and Broadband Matching for the PRISM Muon FFAG

betatron, solenoid, target, dipole

202

J. Pasternak, R. Chudzinski, A. Kurup
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
A. Sato
Osaka University, Osaka, Japan

The next generation of lepton flavor violation experiments requires high intensity and high quality muon beams. Such conditions can be met using phase rotation of short muon pulses in an FFAG ring, as was proposed for the PRISM project. The very large initial momentum spread and transverse emittance of the muon beam poses a significant challenge for the injection system into the PRISM FFAG. Also, the matching optics between the solenoidal transfer channel and the ring needs to create a specific orbit excursion in the horizontal plane, suppress any vertical dispersion and produce good betatron conditions in both planes. Candidate geometries for the matching and injection systems are presented and their performances are tested in tracking studies.

MOPPC043

Injection/Extraction of Achromat-based 6D Ionization Cooling Rings for Muons

solenoid, kicker, dipole, extraction

229

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, F.E. Mills
Particle Beam Lasers, Inc., Northridge, California, USA

Funding: This work was supported in part by the US Department of Energy in part under award numbers DE-FG02-92ER40695 (UCLA), DE-AC02-98CH10886 (BNL) and DE-FG02-07ER84855 (Particle Beam Lasers, Inc.).
An achromat-based cooing ring using dipoles and solenoids is introduced and it can cool muons by large factors in six dimensions to achieve the necessary luminosity for a muon collider. The ring is designed with sufficient space in each superperiod for injection and extraction magnets. We estimate the parameters for the injection system into the solenoid-dipole ring cooler. We also present some simulations for injection/extraction system and discuss the injection/extraction requirements*.
* Al Garren, J.S. Berg, D. Cline, X. Ding, H.G. Kirk, “Robust 6D μ± cooling using a solenoid-dipole ring cooler for a muon collider”, NIM A 654 (2011) 40-44.

MOPPC061

An Antiproton Recycler for Atom-Antiproton Collision Experiments

antiproton, ion, acceleration, target

274

M.R.F. Siggel-King, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O. Karamyshev, A.I. Papash
MPI-K, Heidelberg, Germany
M.R.F. Siggel-King
The University of Liverpool, Liverpool, United Kingdom

Funding: Work supported by the Helmholtz Association and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080 and STFC.
Collision experiments with low energy antiprotons and different gas jet targets on the level of differential cross sections would be very desirable to use to investigate the details of this fundamental process. At present, such experiments are, however, not feasible, since the only source of antiprotons in the world, the AD at CERN, cannot provide beams of the required energy and quality. A small electrostatic ring has been designed and developed by the QUASAR Group. Serving at the same time as a prototype for the future ultra-low energy storage ring (USR), to be integrated at the facility for low-energy antiproton and ion research (FLAIR), this small accelerator is unique due to its combination of size, electrostatic nature, and energy of the circulating particles. In this contribution, the design of the ring is described in detail and possible operation scenarios in the ASACUSA beam line and behind the ELENA ring are compared with each other.

MOPPC078

Simulation Studies of Injection Scheme in TPS Storage Ring

lattice, simulation, storage-ring, alignment

316

Y.C. Lee, H.-P. Chang, P.J. Chou
NSRRC, Hsinchu, Taiwan

Funding: NSRRC, Hsinchu, Taiwan.
The baseline lattice of TPS storage ring was finalized in October 2009. Later upon users’ request, we plan to implement the double mini-βy lattice in three 12-m straight sections of TPS storage ring. These locations were chosen to maintain the symmetry of the storage ring lattice. Particle tracking for the first few turns were used to check the injection scheme of storage ring, including errors introduced in manufacturing and installation process. Results of simulation studies will be presented.

MOPPC079

Modelling of the EMMA ns-FFAG Ring Using GPT

space-charge, emittance, quadrupole, electron

319

R.T.P. D'Arcy, S. Jolly
UCL, London, United Kingdom
J.K. Jones, B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.B. van der Geer
Pulsar Physics, Eindhoven, The Netherlands

EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed-Field Alternating Gradient (ns-FFAG) accelerator whose construction at Daresbury Laboratory, UK, was completed in the autumn of 2010. The energy recovery linac ALICE will serve as an injector for EMMA, within an energy range of 10 to 20 MeV. The injection line consists of a symmetric 30 degree dogleg to extract the beam from ALICE, a matching section and a tomography section for transverse emittance measurements. This is followed by a transport section to the injection point of the EMMA ring. The ring is composed of 42 cells, each containing one focusing and one defocusing quadrupole. Acceleration over many turns of the EMMA machine has recently been confirmed. In some cases the bunch will traverse upwards of 100 turns, at which point the effects of space-charge may be significant. It is therefore necessary to model the electron beam transport in the ring using a code capable of both calculating the effect of and compensating for space-charge. Therefore the General Particle Tracer (GPT) code has been used. A range of injection beam parameters have been modeled for comparison with experimental results.

MOPPD007

Towards Routine Operation of the Scintillation Profile Monitor at COSY

electron, vacuum, synchrotron, proton

382

V. Kamerdzhiev, J. Dietrich, K. Reimers
FZJ, Jülich, Germany
C. Böhme
ESS, Lund, Sweden
A. Pernizki
INP, Jülich, Germany

The optics of the Scintillation Profile Monitor (SPM) was modified to correct the large error observed in previous measurements. Beam profile measurements were carried out after reinstallation in the COSY ring, showing reasonable agreement with profiles, measured with the ionization profile monitor. Performance of the SPM is analyzed. Application of the method in a proton synchrotron is discussed.

MOPPD013

Observation of 2-Component Bunched Beam Signal with Laser Cooling

laser, betatron, ion, coupling

397

H. Souda, M. Nakao, A. Noda, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
M. Grieser
MPI-K, Heidelberg, Germany
Z.Q. He
TUB, Beijing, People's Republic of China
K. Ito, H. Okamoto
HU/AdSM, Higashi-Hiroshima, Japan
K. Jimbo
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

Funding: Work supported by Advanced Compact Accelerator Development Project of MEXT, Global COE program "The Next Generation of Physics, Spun from Universality and Emergence" and Grant-in-Aid for JSPS Fellows.
Longitudinal beam temperature during a laser cooling was measured through bunch length measurement at S-LSR. 40keV 24Mg+ beams were bunched by an RF voltage with a harmonic number of 5 and were cooled by a co-propagating laser with a wavelength of 280nm*. Bunch length was measured by time-domain signal from a pair of parallel-plate electrostatic pickups with a length of 140mm. Injected non-cooled beams gave a bunch length of 2.5m (2-σ) and cooled beam has a 2-component of broad and sharp distribution. Broad distribution had a longitudinal length of 2.2m, which is close to that of initial beam. The length of the sharp distribution shrunk to 0.25m and is considered as a cooled part. Capture efficiency of cooling, which represents the ratio of the particle numbers of cooled part and the total particle number, varies by the change of the detuning of the laser (fixed frequency or scanning). With scanning range of 2GHz, capture efficiency was improved from 66% to 92%, whereas the bunch became longer by 10% with scanning. Approach to improve the number of cooled particle and cut uncooled part** will be applied to attain a strong signal with a low-current beam with a low temperature.
* J. S. Hangst et al., Phys. Rev. Lett. 74, 4432 (1995).
** A. Noda et al., these proceedings.

MOPPD019

Vertical Orbit Excursion FFAG Accelerators with Edge Focussing

proton, lattice, neutron, dynamic-aperture

406

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

FFAGs with vertical orbit excursion (VFFAGs) provide a promising alternative design for the magnets in fixed-field machines. They have a vertical magnetic field component that increases with height in the vertical aperture, yielding a skew quadrupole focussing structure. The end fields of such magnets with edge angles provide an alternating gradient without the need for reverse bends, thus reducing the machine circumference. Similarly to spiral scaling horizontal FFAGs (but unlike non-scaling versions), the machine has fixed tunes and no intrinsic limitation on momentum range. Rings capable of boosting the 150mm.mrad geometric emittance beam from the ISIS proton synchrotron to 3, 5 and 12GeV using superconducting magnets are presented, the latter corresponding to 2.5MW beam power.

MOPPD020

A Model for a High-Power Scaling FFAG Ring

dynamic-aperture, lattice, extraction, proton

409

G.H. Rees, D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

High-power FFAG rings are under study to serve as drivers for neutron spallation, muon production, and accelerator-driven reactor systems. In this paper, which follows on from earlier work*, a 20 - 70 MeV model for a high-power FFAG driver is described. This model would serve as a test bed to study topics such as space charge and injection in such rings. The design incorporates a long straight to facilitate H^- charge exchange injection. The dynamic aperture is calculated in order to optimize the working point in tune space. The injection scheme is also described. A separate design for an ISIS injector, featuring a novel modification to the scaling law, was also studied.
*G.H. Rees and D.J. Kelliher, “New, high power, scaling, FFAG driver ring designs” HB2010, Morschach, September 2010, MOPD07, p. 54, http://www. JACoW.org

MOPPD024

C70 Arronax in the Hands-On Phase

target, cyclotron, proton, simulation

418

F. Poirier, S. Auduc, L. Lamouric
SUBATECH, Nantes, France
S. Girault, F. Gomez, E. Mace
Cyclotron ARRONAX, Saint-Herblain, France
C. Huet
EMN, Nantes, France

The C70 Arronax, is a high-intensity (2x375 μA) and high-energy (70 MeV) multiparticle cyclotron that started its hands-on phase in December 2010. The operating and maintenance group is accumulating experience on this machine. A review of the machine status and present possibilities in terms of beam capacities is thus presented in this paper. The status of the beamline simulations is also given.

MOPPD026

A Superconducting Ring Cyclotron for the DAEδALUS Experiment

cyclotron, extraction, proton, focusing

421

L. Calabretta
INFN/LNS, Catania, Italy
A. Calanna, D. Campo
CSFNSM, Catania, Italy
M.M. Maggiore, L.A.C. Piazza
INFN/LNL, Legnaro (PD), Italy
F. Méot
BNL, Upton, Long Island, New York, USA

Funding: Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud.
The experiment DAEδALUS*, 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 is able to accelerate a H²⁺ molecule beam up to 800 MeV/n with a peak current of 10 mA and average power higher than 1.6 MW. To simplify the design of the superconducting magnetic coils, to minimize the radial force shift and to increase the room to host the RF cavities, the previous study has been updated increasing the injection energy of the H²⁺ and also the injection energy. The updated study on the magnetic sector configuration, on the superconducting coils and the magnetic forces are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too.
* J. Alonso et al., Jun2010 e-Print: arXiv:1006.0260
** L. Calabretta, Proc. IPAC 2011, WEPS073 (2011).
*** L. Calabretta, Cyclotrons 2010, Lanzhou.

MOPPD028

Observation of Longitudinal Space Charge Effects in the Injection Beam Line of NIRS-930 Cyclotron

bunching, cyclotron, space-charge, simulation

427

S. Hojo, A. Goto, T. Honma, K. Katagiri, A. Sugiura
NIRS, Chiba-shi, Japan

Dependence of bunching efficiencies on the position of a beam buncher was measured for the AVF cyclotron at the National Institute of Radiological Sciences (NIRS) for 30 MeV proton beams with intensities up to 100 microamperes at injection. The measurement was carried out for two positions: 1.53 m and 2.33 m upstream from the inflector. For the buncher position of 2.33 m the bunching efficiency decreased, as the beam intensity increased, to about half of that at low intensities, while for 1.5 m it was constant up to 100 microamperes. The intensity distributions of extracted beam with respect to the buncher phase were also measured for the two buncher positions. The dependence of bunch width on the beam intensity is discussed by comparing the data with one-dimensional simulations on longitudinal space charge effects.

MOPPD034

Flux-coupled Stacking of Cyclotrons for a High-power ADS Fission Driver

cyclotron, cavity, focusing, target

439

A. Sattarov, S. Assadi, K.E. Badgley, J.N. Kellams, T.L. Mann, A.D. McInturff, P.M. McIntyre, N. Pogue
Texas A&M University, College Station, Texas, USA

Funding: This work is funded by grants from the State of Texas (ASE) and the Mitchell Family Foundation.
The sector magnets for an isochronous cyclotron are configured as a flux-coupled stack of apertures, each forming an independent cyclotron, separated sufficiently to accommodate independent superconducting rf cavities. The stack strategy makes it possible to deliver any amount of proton beam power consistent with the limitations of each individual cyclotron, and to deliver the aggregate power to a number of spallation targets as dictated by optimum coupling for accelerator-driven subcritical (ADS) fission and by limitations in target transfer.

MOPPD054

Effect of the 2011 Great East Japan Earthquake in the Injection and Extraction of the J-PARC 3-GeV RCS

extraction, septum, beam-transport, simulation

490

P.K. Saha, H. Harada, H. Hotchi, S.I. Meigo, N. Tani, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the injection and extraction systems play important roles for the beam injection and extraction, respectively. Unfortunately, the 2011 great east Japan earthquake had a serious impact on the ongoing schedule due to the big damage of the whole accelerator facility and the infrastructure as well. The injection and extraction including the beam transport lines magnets suffered a noticeable displacement resulting with alignment errors. As realignment of the RCS magnets can not be done in this year, then based on the post earthquake measured alignment data, we have estimated the effect as well as possible solutions on the injected and extracted beam for as usual operation. Fortunately, the simulation results shows that there would not be any serious impact on both injected as well as extracted beam with present alignment errors and thus user operation can be resume as expected. The simulation result together with some experimental results will be presented.

MOPPD057

CERN PSB-to-PS Transfer Modifications for the 2 GeV Upgrade

optics, quadrupole, dipole, septum

493

W. Bartmann, J. Borburgh, S.S. Gilardoni, B. Goddard, A. Newborough, S. Pittet, R. Steerenberg
CERN, Geneva, Switzerland
C.H. Yu
IHEP, Beijing, People's Republic of China

Within the frame of the CERN PS Booster (PSB) energy upgrade from 1.4 to 2 GeV, the PSB to PS transfer line will be adapted for pulse-to-pulse modulated operation. A modified lattice is presented including a re-design of the switching dipole between ISOLDE and PS and additional collimators to protect the PS injection septum. Optics solutions optimized for small emittance LHC beams as well as for the large emittance high-intensity beams are shown.

MOPPD058

LHC Abort Gap Cleaning Studies during Luminosity Operation

luminosity, kicker, emittance, beam-losses

496

E. Gianfelice-Wendt
Fermilab, Batavia, USA
W. Bartmann, A. Boccardi, C. Bracco, E. Bravin, B. Goddard, W. Höfle, D. Jacquet, A. Jeff, V. Kain, M. Meddahi, F. Roncarolo, J.A. Uythoven, D. Valuch
CERN, Geneva, Switzerland

The presence of significant intensities of un-bunched beam is a potentially serious issue in the LHC. Procedures using damper kickers for cleaning both Abort Gap (AG) and buckets targeted for injection, are currently in operation at flat bottom. Recent observations of relatively high population of the AG during physics runs brought up the need for AG cleaning during luminosity operation as well. In this paper the results of experimental studies performed in October 2011 are presented.

MOPPD062

Aperture Measurements in the LHC Interaction Regions

emittance, luminosity, optics, resonance

508

S. Redaelli, M.C. Alabau Pons, R.W. Assmann, R. Bruce, M. Giovannozzi, G.J. Müller, M. Pojer, J. Wenninger
CERN, Geneva, Switzerland

The aperture of the LHC interaction regions is crucial for the LHC performance because it determines the smaller β^* that can be achieved. The aperture has been measured at a maximum energy of 3.5 TeV and at different β^* values, following optimized procedure to allow safe measurements at high energy. In this paper, the results of these aperture measurements, which are used as a reference for β^* reach and crossing scheme estimates at the LHC interaction points, are presented.

MOPPD063

A 180 MeV Injection System for the ISIS Synchrotron

dipole, synchrotron, electron, simulation

511

B. Jones, D.J. Adams, M.C. Hughes, S.J.S. Jago, H. V. Smith, C.M. Warsop, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. It operates at 50 Hz accelerating 3x10¹³ protons per pulse via a 70 MeV H⁻ linac and an 800 MeV proton synchrotron, delivering a mean beam power of 0.2 MW. A favoured first step to upgrade ISIS towards the megawatt regime is replacement of the linac with a new 180 MeV injector. Studies of this upgrade, which aims to increase mean beam power up to 0.5 MW are continuing. This paper summarises designs for a new injection region including beam dynamics and related hardware.

MOPPD064

Simulation of Double Layer Carbon Stripping Foils for ISIS Injection Upgrades

simulation, radiation, scattering, proton

514

H. V. Smith, D.J. Adams, B. Jones, C.M. Warsop
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
Y. Irie, Y. Takeda
KEK, Ibaraki, Japan

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, 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, continue to be studied. This paper highlights recent results from temperature studies of double layer carbon foils, suitable for injection at 180 MeV into ISIS, using ANSYS. Experimental data from KEK was used to benchmark models and the variation of temperature as a function of foil separation was considered.

MOPPD069

Challenges for the SNS Ring Energy Upgrade

electron, kicker, septum, extraction

520

M.A. Plum, T.V. Gorlov, J.A. Holmes, T. Hunter, R.T. Roseberry, J. G. Wang
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
The Oak Ridge Spallation Neutron Source accumulator ring presently operates at a beam power of about 1 MW and a beam energy of 925 MeV. A power upgrade is planned to increase the beam energy to 1.3 GeV. For the accumulator ring this mostly involves modifications to the injection and extraction sections. A variety of modifications to the existing injection section were necessary to achieve 1 MW, and the tools developed and the lessons learned from this work are now being applied to the design of the new injection section. This paper will discuss the tools and the lessons learned, and also present the design and status of the upgrades to the accumulator ring.

MOPPD070

A SVD-based Orbit Steering Algorithm for RHIC Injection

ion, heavy-ion, proton, controls

523

C. Liu, A. Marusic, M.G. Minty, V. Ptitsyn
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The RHIC physics programs involve experiments with polarized proton and several species of ion beams. In the past, when switching between physics programs, first turn and circulating beam in RHIC was established manually by adjustments to the corrector dipoles for minimum beam loss. In this report, we introduce a new steering scheme based on an SVD algorithm which uses a single-pass orbit response matrix for first turn steering. The new scheme was implemented into the controls system and demonstrated successfully in Run-11. Establishing circulating beam using this automated approach has been shown to dramatically reduce the beam setup time.

MOPPD073

Development of Transportation System for Low Energy Electron Group

electron, solenoid, collimation, simulation

532

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

There is a time that we want to measure the electron which occurred in the accelerator in the small situation of a noise. In that case, it is one method that we transport these electrons to the place distant form the accelerator where a noise is small. In order to realize that, development of transport line for low energy electrons is required. So, we start to develop transport line using solenoid magnets. We present status of development of this transportation system.

MOPPD074

Localization of Large Angle Foil Scattering Beam Loss Caused by Multi-Turn Charge-Exchange Injection

collimation, simulation, scattering, insertion

535

S. Kato
Tohoku University, Graduate School of Science, Sendai, Japan
H. Harada, S. Hatakeyama, J. Kamiya, M. Kinsho, K. Yamamoto, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the J-PARC RCS, the significant losses were observed at the branch of H⁰ dump line and the Beam Position Monitor which was put at the downstream of the H⁰ dump branch duct. These losses were caused by the large angle scattering of the injection and circulating beam at the charge exchange foil. To realize high power operation, we have to mitigate these losses. So, we started to develop a new collimation system in the H⁰ branch duct and installed in October 2011. In order to optimize this system efficiently, we primarily focused on the relative angle of collimator block from scattering particles. We simulated behavior of particles scattered by foil and produced by collimator block and researched most optimized position and angle of the collimator block. In this process, we devised the method of angular regulation of collimator block. We present the method of angular regulation and performance of this new collimation system.

MOPPD075

Optimization of the Collimation System for the CSNS/RCS

collimation, closed-orbit, beam-losses, scattering

538

N. Wang, M.Y. Huang, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China

Beam loss induced activation of the accelerator components is one of the primary concerns in designing a high intensity machine. The uncontrolled beam loss is required to be less than 1 W/m for hands-on maintenance of the machine. A two stage collimation system is designed in the Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) to localize the beam losses in a restricted area. The parameters of the collimator are optimized in order to obtain high collimation efficiency. The final design of the collimation system is presented. The reliability of the collimation system is estimated for different working points and with closed orbit errors.

MOPPD083

Improving the Fermilab Booster Notching Efficiency, Beam Losses and Radiation Levels

booster, kicker, radiation, beam-losses

562

I.L. Rakhno, A.I. Drozhdin, N.V. Mokhov, V.I. Sidorov, I.S. Tropin
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
Currently a fast vertical 1.08-m long kicker (notcher) located in the Fermilab Booster Long-5 straight section is used to remove 3 out of 84 circulating bunches after injection to generate an abort gap. With magnetic field of 72.5 Gauss it removes only 87% of the 3-bunch intensity at 400 MeV, with 75% loss on pole tips of the focusing Booster magnets, 11% on the Long-6 collimators, and 1% in the rest of the ring. We propose to improve the notching efficiency and reduce beam loss in the Booster by using two horizontal kickers in the Long-12 section. The STRUCT calculations show that using such horizontal notchers, one can remove up to 99% of the 3-bunch intensity at 400-700 MeV, directing 96% of it to a new beam dump at the Long-13 section. This fully decouples notching and collimation. The beam dump absorbs most of the impinging proton energy in its jaws. The latter are encapsulated into an appropriate radiation shielding that reduces impact on the machine components, personnel and environment to the tolerable levels. The MARS simulations show that corresponding prompt and residual radiation levels can be reduced ten times compared to the current ones.

MOPPP031

A New Injection System for an Electron/Positron Linac

linac, electron, gun, positron

628

C. Liebig, M. Hüning, M. Schmitz
DESY, Hamburg, Germany

For the Linac II, which supplies the accelerator chain at DESY with electrons and positrons, a new injection system is planned. It is supposed to ensure reliable operation and to avoid the beam loss of about 60% before the positron converter and the associated activation. The main components are a 6 A/100 kV triode gun, buncher and a dispersive section for energy collimation. The output energy is 5 MeV. The new buncher structure is a hybrid of a standing wave and traveling wave structure and allows a compact design and good electron capture. Its main part is a traveling wave structure in 2π/3 mode, to which one capture cell is coupled in π mode. The function of the injector components, the entire injection system and the acceleration in the linac sections were optimized in simulations. In addition, the design is analysed in a test rig before final installation. Test rig and subsequent injector are equipped with extensive diagnostics. Besides the design of the injection system results of simulations and measurements on the test rig will be presented.

MOPPP051

NSLS-II Transport Line Progress

booster, linac, storage-ring, diagnostics

676

R.P. Fliller, A.T. Anderson, B. Benish, W. DeBoer, G. Ganetis, R. Heese, H.-C. Hseuh, J. Hu, M.P. Johanson, B.N. Kosciuk, D. Padrazo, K. Roy, T.V. Shaftan, O. Singh, J.L. Tuozzolo, B. Wahl, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The National Synchrotron Light Source II (NSLS-II) is a state-of-the-art 3-GeV third generation light source currently under construction at Brookhaven National Laboratory. The NSLS-II injection system consists of a 200 MeV linac, a 3-GeV booster synchrotron and associated transfer lines. The first part of the Linac to Booster Transport (LBT) line has been installed for linac commissioning. This part includes all components necessary to commission the NSLS-II linac. The second part of this transport line is undergoing installation. Initial results of hardware commissioning will be discussed. The Booster to Storage Ring (BSR) transport line underwent a design review. The first part of the BSR transport line, consisting of all components necessary to commission the booster will be installed in 2012 for booster commissioning. We report on the final design of the BSR line along with the plan to commission the booster.

MOPPP052

Booster Synchrotron for SIRIUS Light Source

booster, dipole, extraction, emittance

679

F. H. de Sá, L. Liu, A.R.D. Rodrigues
LNLS, Campinas, Brazil

A full energy 3 GeV booster for the new Brazilian Synchrotron Light Laboratory (LNLS) third generation light source, SIRIUS, is proposed. The 144 m circumference magnetic lattice consists of two super-periods of FODO cells with defocusing dipoles and focusing quadrupoles. The optics provides a low emittance beam of 38 nm.rad at 3 GeV, high horizontal betatron and zero dispersion functions at straight sections. The top-up operation requires a cycling energy ramp from 150 MeV to 3 GeV with repetition rate of 1 Hz.

MOPPP053

Failure Mode Analysis in Preparation for Top-up Injection at the Canadian Light Source (CLS)

storage-ring, dipole, kicker, simulation

682

L.O. Dallin
CLS, Saskatoon, Saskatchewan, Canada

Top-up injection involves injecting beam with beamline safety shutters open. Consequently it is extremely important that no electrons enter the beamlines where they could be a potential safety hazard to beamline personnel. To investigate the likelihood that electrons could exit the storage ring various failure mode simulations have been done. The approach is to account for all possible injection trajectories and show that these particles will be intercepted by various storage ring apertures before they reach an amplitude that is deemed unsafe. This amplitude was chosen to be 50 mm and the field roll-off of all storage ring magnets were defined to this amplitude. Failure modes invested included injection kicker failures, uncorrected misalignment errors, off-energy injection and shorted storage ring magnet coils. Errors that would render it impossible to store beam were not investigated. As some particles reached amplitudes beyond the safe limit measures have been devised to eliminate these unsafe scenarios.

MOPPP054

Study of a New Injection Scheme for the SSRF Storage Ring

kicker, storage-ring, emittance, dynamic-aperture

685

M.Z. Zhang, B.C. Jiang, L. Ouyang, Q.L. Sun, S.Q. Tian
SINAP, Shanghai, People's Republic of China

A low emittance configuration of the SSRF storage ring had been designed and commissioned. Along with reducing the emittance, the dynamic aperture decreases quickly. It doesn’t meet aperture require of the normal injection scheme anymore and the injection efficiency is lower. The pulsed multi-pole magnets give the opportunity to overcome the smaller dynamic aperture. Pulsed quadrupole and sextupole both are study for the injection scheme. With and without the orbit bump kickers are also considered in this study. The injection scheme suggestions are presented in this paper.

MOPPP056

Injection Transient Motion at PLS-II

kicker, septum, electron, linac

688

I. Hwang, T. Ha, Y.D. Joo, C. Kim, M. Kim, S.H. Kim, B.-J. Lee, E.H. Lee, S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea

PLS-II is an upgraded third generation synchrotron which includes many insertion devices with improved beam properties. Top-up operation is short time-interval injection to make roughly constant current and is essential to provide high intensity beam. When the electrons are injected to synchrotron, the stored beam is disturbed by small error of the injection system and the beam quality at the beamline can be decreased. We present this injection transient motion at PLS-II.

MOPPP057

Optimization of the Low-emittance Lattice of the APS Booster Synchrotron

booster, lattice, emittance, sextupole

690

C. Yao, V. Sajaev, N. Sereno, H. Shang
ANL, Argonne, USA

Funding: Work supported by U.S. Department of Energy, Offices of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06- CH11357.
The APS booster is a 7GeV electron synchrotron. Three lattices have been originally designed with a nominal beam emittance of 132, 109, and 92 nm, respectively. In the past we have mostly operated the booster with the 132 nm lattice because of its better stability. The lower-emittance lattices are not utilized. In early 2010 we upgraded the booster ramp correction and reduced the 360Hz current ripples of the ramp supplies. Current ramp errors have been significantly reduced. This raises our interest in running the low- emittance lattice to improve APS storage ring injection efficiency and reduce radiation losses. This report presents the optimization methods and measurement results of booster beam performance of the booster 92nm lattice.

MOPPP058

Improvements to the APS Booster Injection Controllaw Process

controls, booster, lattice, synchrotron

693

C. Yao, F. Lenkszus, H. Shang, S. Xu
ANL, Argonne, USA

Funding: Work supported by U.S. Department of Energy, Offices of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06- CH11357.
The APS booster is a 7-GeV electron synchrotron with a 0.5-second cycle time. The booster runs a set of injection control programs that corrects the injection beam trajectory based on the beam history of two BPMs. An IOC process calculates the I and Q components of beam oscillation from turn-by turn beam position samples over the first 64 turns. The booster injection control programs apply phase, energy, and transverse angle correction based on the result of the IOC processing. The initial system was installed in 2007. Since installation the system has mostly worked well for normal user operations. However, occasionally the system has yielded inconsistent results. Recently we reviewed the signal and processes involved in this system and made necessary upgrades to some components, including selection of a new set of two input BPMs, optimization of FFT parameters, and addition of an injection tune control program. These upgrades have significantly improved the effectiveness and consistency of the system. We report the findings, analysis, and results.

MOPPP060

Top-Off Mode of Operations: Setting Limits on the Extracted Beam Energy by Constraining Currents of Multiple Booster Dipole Power Supplies.

dipole, booster, extraction, lattice

696

T.V. Shaftan
BNL, Upton, Long Island, New York, USA

In preparation for top-off mode of the NSLS-II operations we have studied impact of errors in the dipole power supply current on the extracted beam energy, which has to be interlocked so to satisfy the safety requirements. The NSLS-II booster dipole circuits are combined into 3 independent PS circuits, which adds complexity to the analysis of the extracted beam energy limits.

MOPPR002

Overview of the Beam Diagnostics in the MedAustron Accelerator: Design Choices and Test Beam Commissioning

emittance, synchrotron, extraction, proton

774

F. Osmic, M. Feurstein, A. Gyorgy, A. Kerschbaum, M. Repovz, S.M. Schwarz
EBG MedAustron, Wr. Neustadt, Austria
G. Burtin
CERN, Geneva, Switzerland

The MedAustron center is a synchrotron based accelerator complex for cancer treatment and for clinical and non-clinical research with protons and light ions, currently under construction in Wiener Neustadt, Austria. The accelerator complex is based on the CERN-PIMMS study and its technical implementation by the Italian CNAO foundation in Pavia. The MedAustron beam diagnostics system is based on sixteen different monitor types (153 devices in total) and will allow measuring all relevant beam parameters from the source to the irradiation rooms. The monitors will have to cope with large intensity and energy ranges. Currently, one ion source, the low energy beam transfer line and the RFQ are being commissioned in the Injector Test Stand (ITS) at CERN. This paper gives an overview of all beam monitors foreseen for the MedAustron accelerator, elaborates some of the design choices, and reports the first beam commissioning results from the ITS.

MOPPR008

The Beam Loss Monitoring System at ELSA

extraction, electron, booster, monitoring

786

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

A new diagnostic tool to monitor beam loss in the storage ring at the Electron Stretcher Facility ELSA has been set up. It enables the investigation of causes for electron loss in real time, providing an essential tool needed to achieve the planned beam current upgrade from 30 mA to 200 mA. The monitoring system consists of 32 pin-diode based radiation detectors spread around the storage ring. Therefore, individual electron loss can be localized after each quadrupole. The readout system was designed to allow an integration of single loss events within 70 μs in order to be able to correlate these events to machine state changes. The used monitoring hardware and readout system will be detailed. Furthermore first measurements of the beam loss during injection, the fast energy ramp during acceleration and the extraction phase will be presented.

MOPPR015

Bunch-by-bunch Feedback Systems at the DELTA Storage Ring

feedback, kicker, electron, synchrotron

807

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

Funding: Work supported by BMBF (05K10PEB)
At the DELTA 1.5-GeV electron storage ring operated as a synchrotron radiation source by the TU Dortmund University, bunch-by-bunch feedback systems have been recently installed and commissioned to detect and suppress longitudinal as well as transverse multibunch instabilities. Besides that, the feedback systems are used as a diagnostics tool. Growth rates of multibunch instabilities and their dependence on the beam current have been measured. Additionally, the oscillation amplitudes of electron bunches have been studied during the injection process.

MOPPR025

The BPM DAQ System Upgrade for SuperKEKB Injector Linac

linac, electron, emittance, positron

834

M. Satoh, K. Furukawa, F. Miyahara, T. Suwada
KEK, Ibaraki, Japan
T. Kudou, S. Kusano
MELCO SC, Tsukuba, Japan

The non-destructive beam position monitor (BPM) is indispensable diagnostic tool for the stable beam operation. In the KEK Linac, approximately nineteen BPMs with the strip-line type electrodes are used for the beam orbit measurement and feedback. In addition, some of them are also used for the beam energy feedback loops. The current DAQ system consists of the fast digital oscilloscopes. A signal from each electrode is analyzed with a predetermined response function up to 50 Hz. The beam position resolution of current system is limited to about 0.5 mm because of ADC resolution. Towards SuperKEKB project, we have a plan to upgrade the BPM DAQ system since the Linac should provide the smaller emittance beam. We will report the system description of the new DAQ system and the results of performance test in detail.

MOPPR028

Upgrade Plan of BLM System of J-PARC MR

extraction, proton, ion, monitoring

837

K. Satou, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The upgrade plan of BLM system of J-PARC Main Ring synchrotron (MR) will be described. Existing proportional chamber beam loss monitors (P-BLMs) have fast signal rise time of about 100ns and high gas gain of about 2·10⁴ at the maximum. These abilities were quite advantageous for the early beam commissioning stage. On the other hand, the gas gain is degraded with increasing output current. The P-BLM is suitable for a measurement of a low level beam loss event, however, vulnerable to a measurement of an accidental beam loss event (fast loss) causing high radiation. To enhance the dynamic range of the system, 1m long Air Ionization Chambers (AICs) will be installed and operated with the P-BLM. Experiments using the real beam loss at collimator area and at the Co60 radiation facility have demonstrated the stable operations up to the radiation level activated by the maximum beam loss power of the collimator area. A new data taking system is now under development, and its performances will also be presented.

MOPPR030

Various Methods to Measure the Betatron Tune of the Synchrotoron

betatron, closed-orbit, pick-up, synchrotron

843

S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan

Generally in the synchrotron, the frequency of transverse oscillation of the bunched beam for each single turn (usually called betatron tune or just "tune") is one of fundamental controllable knobs to avoid the instability of the accelerator. In this report, it is not mentioned about the effect to the beam instability but it is focused to various methods to measure the betatron tune by using bunch-by-bunch transverse beam position. The following items will be presented, (1) least square fitting to the time-domain beam position at specific location. (2) peak finding of the frequency-domain beam position at specific location. (3) phase space analysis of the beam position at specific location.(4) frequency-domain analysis of the beam position in the normalized coordinate at many locations in the ring orbit. For the application to the real accelerator, data of the J-PARC (Japan Proton Accelerator Research Complex) will be shown.

MOPPR031

BPM Data Processing Based on EPICS Soft IOC at HLS

EPICS, brilliance, storage-ring, controls

846

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

A data analysis program has been developed and verified successfully for the new beam position monitor (BPM) system of the storage ring at Hefei Light Source (HLS). The new BPM system will be equipped with Libera Brilliance BPM processors in the upgrade project of HLS. The embedded system on Libera has completed some basic work, including data acquisition, position calculation, and EPICS IOC data output. A new record type was developed to accomplish the beam position recalculation by log-ratio method. The new position signal’s character was studied in the time and frequency domain, including distribution, RMS noise, spectrum, tune, digital filter, signal correlation, etc. Recalculation beam position showed higher sensitivity and greater linear range.

MOPPR038

Bunch by Bunch Beam Diagnostics in SSRF

damping, betatron, wakefield, diagnostics

861

Y.B. Leng, J. Chen, Z.C. Chen, Y.B. Yan, N. Zhang
SSRF, Shanghai, People's Republic of China
B.P. Wang
SINAP, Shanghai, People's Republic of China

A set of broadband beam instruments including filling pattern monitor, scope based BPM processor and streak camera has been implemented in the storage ring of SSRF. Several parameters such as charge, lifetime, transverse position, betatron tune and beam length, can be measured for individual bunch by these devices. The operation experience and measurement results will be introduced. The preliminary effort to retrieve wake field information from these measurements will be presented as well.

MOPPR051

TLS Transportline BPM Upgrade

booster, EPICS, diagnostics, storage-ring

897

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

There are seven stripline beam position monitor (BPM) installed in TLS booster to storage ring transport line. In order to provide the BPM system with better performance and functionalities, the latest generation BPM electronics Libera SinglePass had been adopted in TLS transport line for these stripline BPM. One unit had been tested in early 2011 and delivered the reliable and satisfactory results therefore extra six units had been purchased later. Currently, all of the new 7 units have replaced the past BPM electronics. The application had also been continuously developed. On the other hand, it is expected that the upgrade could enhance diagnostic functionalities for the related injection study. In this report, the injection stability and efficiency had been investigated.

MOPPR059

Modeling Space-charge and its Influence on the Measurement of Phase Space in ALICE by Tomographic Methods

space-charge, quadrupole, electron, diagnostics

918

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

Funding: STFC.
ALICE is an experimental electron accelerator designed to operate over a range of energies up to 35 MeV, and with up to 80 pC bunch charge. A dedicated tomography diagnostic section allows measurement of the transverse phase space with different beam parameters. In the low-energy, high-charge regime, space charge effects must be considered: to quantify these effects, the tracking code GPT has been used to simulate beams in the tomography diagnostic section. The results can be compared with simplified models, and with experimental measurements.

MOPPR060

Calibration of the EMMA Beam Position Monitors: Position, Charge and Accuracy

pick-up, quadrupole, simulation, diagnostics

921

I.W. Kirkman
The University of Liverpool, Liverpool, United Kingdom
J.S. Berg
BNL, Upton, Long Island, New York, USA
G. Cox
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Kalinin
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The accurate determination of transverse beam position is essential to understanding the performance of an accelerator system, and this is particularly the case with non-scaling FFAG machines such as EMMA, where, due to fundamental principles of design, the beam may deviate widely from the central beampipe axis. This paper describes the various modelling approaches taken for the three different button pickup assemblies used in EMMA, and the subsequent methods of calibration (‘mappings’) which allow beam position and charge to be deduced from the processed BPM signals. The use and validity of the modelling and mapping approach adopted is described, and the contributions to positional and bunch charge uncertainty arising from these procedures is discussed.

MOPPR061

Computing Bunch Charge, Position, and BPM Resolution in Turn-by-Turn EMMA BPMs

pick-up, EPICS, controls, quadrupole

924

A. Kalinin, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R.G. Borrell
WareWorks Ltd, Manchester, United Kingdom
G. Cox
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
I.W. Kirkman
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The NS-FFAG electron model ‘EMMA’ and its Injection and Extraction Lines are equipped with a total of 53 EPICS VME BPMs*. In the BPMs, each opposite button signal pair is time-domain-multiplexed into one channel as a pulse doublet. The recording of turn-by-turn data into the BPM memory is triggered by the bunch itself on each of its passages. For each accelerating cycle, the BPMs deliver a snapshot of a turn-by-turn trajectory measured in each of 42 cells. Additional BPMs (two pairs) are used to obtain a Poincare map. We describe the EPICS architecture, and a set of Python data processing algorithms that are used to automatically set a BPM intensity range, to eliminate an error due to tails of the doublet pulses, to calculate the bunch charge and position, and, for a set of injections, to find the BPM resolution. We use three types of button pickup mappings** that allow: to eliminate bunch charge signal dependence on offset, to get a linear offset response, and to eliminate ‘quadrupole’ signal dependence on offset as well (which is used in resolution calculation). We present beam measurement results collected in 2011 runs.
* A. Kalinin et al., Proc. of IPAC’10, MOPE068, p. 1134, (2010.
** I. Kirkman, these proceedings.

TUXA02

Upgrade Plans for the LHC Injector Complex

linac, electron, vacuum, feedback

1010

R. Garoby, H. Damerau, S.S. Gilardoni, B. Goddard, K. Hanke, A.M. Lombardi, M. Meddahi, B. Mikulec, E.N. Shaposhnikova, M. Vretenar
CERN, Geneva, Switzerland

Challenging beams with much higher brightness than today are required for the LHC to achieve its high luminosity objective after the year 2020. It is the purpose of the LHC Injectors Upgrade (LIU) Project to achieve this result, consolidating and upgrading the existing set of ageing synchrotrons (PSB, PS and SPS), and using the new linac presently in construction (Linac4). The anticipated beam characteristics are described and compared to the known limitations in the different accelerators. The foreseen solutions are outlined as well as the planning for their implementation.

Slides TUXA02 [72.367 MB]

TUYA03

Performance and Prospects of BEPCII

luminosity, coupling, optics, feedback

1030

Q. Qin
IHEP, Beijing, People's Republic of China

BEPCII, the upgrade project of Beijing Electron Positron Collider (BEPC), has been put into operation for both high energy physics experiments as well as synchrotron radiation application since its completion in 2009. The peak luminosity reaches 6.5*10³² cm^-2 s^-1 at 1.89 GeV with e⁺e⁻ collisions of each beam current 700 mA. The collider operates for dedicated synchrotron radiation mode with 250 mA electron beams at 2.5 GeV. The performance of BEPCII should be reported and the measures to upgrade its luminosity described.

Slides TUYA03 [5.529 MB]

TUPPC019

Beam Dynamics Simulations of J-PARC Main Ring for Damage Recovery from the Tohoku Earthquake in Japan and Upgrade Plan of Fast Extraction Operation

alignment, simulation, acceleration, linac

1200

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

Magnets of Japan Proton Accelerator Research Complex (J-PARC) were shaken by the Tohoku Earthquake in Japan on March 11th, 2011. The alignment of J-PARC Main Ring (MR) received 20 mm displacement horizontally and 6 mm vertically. Beam dynamics simulations were performed to estimate the effect of the displacement on closed orbit distortions and beam loss in fast extraction (FX) operation of J-PARC MR. Based on the simulation results, we concluded that re-alignment of J-PARC MR was needed to achieve high-power beam. The re-alignment of MR was finished on October 28th, 2011. We also considered the effects of the earthquake on the upstream of MR to establish our upgrade plan, which was based on beam dynamics simulations optimizing collimator balance of injection beam transport (3-50BT) and MR, and RF patterns. J-PARC MR FX operation was resumed from December 2011.

TUPPC050

Beam Transport and Storage with Cold Neutral Atoms and Molecules

sextupole, solenoid, multipole, quadrupole

1281

P.L. Walstrom, M.D. Di Rosa
LANL, Los Alamos, New Mexico, USA

Funding: US Department of Energy
Paramagnetic neutral atoms and molecules are subject to magnetic-field-gradient forces on their magnetic moments. Li atoms and CaH molecules both have an effective magnetic moment of about one Bohr magneton, and in the presence of a strong (~1 T) magnetic field, acquire a Zeeman energy of one of two values, ±μ|B|. Particles with positive (negative) energy are repelled by (attracted toward) increasing fields. Li and CaH can be laser-cooled to speeds of tens of m/s and the corresponding magnetic fields needed for transport and injection are on the order of 1 T. The stable stored state is the field-repelled state. Many concepts of accelerator physics apply to our neutral particles. The analog of charge-exchange injection into storage rings is laser-based optical pumping from a field-seeking state to a field-repelled state. The role of dipoles in charged-particle optics is played by quadrupoles in neutral particle optics, and the role of quadrupoles by sextupoles. We present our design and tracking results for a neutral atom/molecule accumulator including an injection chicane with a laser-stimulated state-flip.

TUPPC057

RHIC Spin Flipper Commissioning Results

dipole, resonance, polarization, proton

1302

M. Bai, W.C. Dawson, J. Kewisch, Y. Makdisi, P. Oddo, C. Pai, P.H. Pile, T. Roser
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The five ac dipole design of RHIC spin flipper in the Blue ring was first commissioned during the RHIC 2012 polarized proton operation. The advantage of this design is to eliminate the vertical coherent betatron oscillations outside the spin flipper*. Spin flipping efficiency was measured with both 100 GeV and 250 GeV polarized proton beams. This paper presents the latest commissioning results.
* M. Bai , T. Roser, C. Dawson, Y. Makdisi, W. Meng, F. Meot, P. Oddo, C. Pai, P. Pile, RHIC Spin Flipper New Design and Commissioning Plan, IPAC10 proceedings, IPAC 2010, Kyoto, Japan, 2010

TUPPC062

Transfer of Polarized 3He Ions in the AtR Beam Transfer Line

ion, extraction, dipole, proton

1317

N. Tsoupas, W.W. MacKay, F. Méot, T. Roser, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the US Department of Energy
In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will also facilitate the collisions of electrons with polarized 3He ions. The AGS is the last acceleration stage of ions before injection into one RHIC for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized 3He ions from AGS into one of the RHIC’s collider rings. In this paper we investigate the extraction energy of the polarized 3He ions from the AGS which will optimize the polarization of 3He ions injected into RHIC. Some of the peculiarities (interleaved horizontal and vertical bends) of the AtR line's layout may degrade this spin matching of the polarized 3He ions. We will also discuss possible simple modifications of the AtR line to accomplish a perfect “spin matching” of the injected 3He beam with that of the stable spin direction at the injection point of the RHIC ring.

TUPPC063

The AGS Synchrotron with Four Helical Magnets

resonance, betatron, optics, quadrupole

1320

N. Tsoupas, H. Huang, W.W. MacKay, T. Roser, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: *Work supported by the US Department of Energy.
The idea* of using two partial helical magnets was applied successfully to the AGS synchrotron**, to preserve the proton beam polarization. In this paper we explore in details the idea of using four helical magnets placed symmetrically in the AGS ring. This modification provides many advantages over the present setup of the AGS that uses two partial helical magnets. First, the symmetric placement of the four helical magnets allows for a better control of the AGS optics with reduced values of the beta functions especially near beam injection, second, the vertical spin direction during beam injection and extraction is closer to vertical, and third, it provides a larger “spin tune gap” for the placement of both the vertical and horizontal tunes of the AGS during acceleration, second. Although the same spin gap can be obtained with two partial helices of equal strength, the required strength of the two helices makes it impractical. In this paper we will provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and comparison of these results with the present setup of the AGS that uses two partial helical magnets***.
* T. Roser et al., Proc. EPAC04, p. 1577 (2004).
** H. Huang et al., PRL 99, 154801(2007).
*** N. Tsoupas et. al., these proceedings.

TUPPC080

Investigations of Scaling Laws of Dynamic Aperture with Time for Numerical Simulations including Weak-Strong Beam-Beam Effects

simulation, dynamic-aperture, beam-beam-effects, lattice

1359

M. Giovannozzi
CERN, Geneva, Switzerland
E. Laface
ESS, Lund, Sweden

A scaling law describing the time-dependence of the dynamic aperture, i.e., the region of phase space where stable motion occurs, was proposed in previous papers about ten years ago. It was shown that dynamic aperture has a logarithmic dependence on time, which would be suggested by some fundamental theorems of the theory of dynamical systems. So far, such a law was applied to single-particle effects only, i.e., the only source of non-linear effects was the magnetic imperfections. In this paper an attempt is made to extend the scaling law to the case of weak-strong beam-beam effects. The results of numerical simulations performed, including both non-linear magnetic imperfections and weak-strong beam-beam effects, are presented and discussed in detail.

TUPPC081

First Experimental Observations from the LHC Dynamic Aperture Experiment

dynamic-aperture, kicker, beam-losses, synchrotron

1362

M. Giovannozzi, M. Albert, G.E. Crockford, S.D. Fartoukh, W. Höfle, E.H. Maclean, A. Macpherson, L. Ponce, S. Redaelli, H. Renshall, F. Roncarolo, R.J. Steinhagen, E. Todesco, R. Tomás, W. Venturini Delsolaro
CERN, Geneva, Switzerland
R. Miyamoto
BNL, Upton, Long Island, New York, USA

Following intensive numerical simulations to compute the dynamic aperture for the LHC in the design phase, the successful beam commissioning and the ensuing beam operations opened the possibility of performing beam measurements of the dynamics aperture. In this paper the experimental set-up and the first observations based on the few experimental sessions performed will be presented and discussed in detail.

TUPPD001

The Mice Muon Beamline and Host Accelerator Beam Bump

target, proton, controls, extraction

1404

A.J. Dobbs, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
D.J. Adams
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
E. Overton, P.J. Smith
Sheffield University, Sheffield, United Kingdom

Funding: Science and Technology Facilities Council
The international Muon Ionization Cooling Experiment (MICE) is designed provide a proof of principle of the technique of ionization cooling, that is the reduction of the phase space of a muon beam via ionization energy loss in absorbers. Subsequent reacceleration is then provided by RF cavities (‘‘sustainable cooling''). Ionization cooling represents an important step toward future facilities based on stored muons beams, such as a future Neutrino Factory or Muon Collider. The MICE Muon Beam begins with the decay of pions produced by a cylindrical titanium target dipped into the circulating proton beam of the 800 MeV ISIS synchrotron at the Rutherford Appleton Laboratory, U.K. This generates a pion shower which is captured and subsequently decays producing the muon beam. A secondary effect of the MICE target is to cause an increase in the number of protons lost from the ISIS beam. It is important that this effect be minimized. An overview is presented here of the MICE Muon Beam, including the results of a study in to the effect of raising the vertical position of the ISIS beam (a ‘‘beam bump'') in the vicinity of the MICE target.

TUPPD005

Design Concept for Nu-STORM: an Initial “Very Low-Energy Neutrino Factory”

storage-ring, target, proton, factory

1413

D.V. Neuffer, A.D. Bross, S. Geer, A. Liu, M. Popovic
Fermilab, Batavia, USA
C.M. Ankenbrandt, T.J. Roberts
Muons, Inc, Batavia, USA

Funding: US DOE under contract DE-AC02-07CH11359
We present a design concept for a Nu-source from a STORage ring for Muons - NuSTORM. In this initial design a high-intensity proton beam produces ~5 GeV pions that provide muons that are captured using “stochastic injection” within a ~3.6 GeV racetrack storage ring. In “stochastic injection”, the ~53 GeV pion beam is transported from the target into the storage ring, dispersion-matched into a long straight section. (Circulating and injection orbits are separated by momentum.) Decays within that straight section provide muons that are within the ~2 GeV/c ring momentum acceptance and are stored for the muon lifetime of ~1000 turns. Muon (and pion) decays in the long straight sections provide neutrino beams that can be used for precision measurements of neutrino interactions, and neutrino oscillations or disappearance at L/E=~1 m/MeV. The facility is described and variations are discussed.

TUPPD020

An EMMA Racetrack

dipole, quadrupole, extraction, electron

1452

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
H.L. Owen
UMAN, Manchester, United Kingdom

EMMA (Electron Machine for Many Applications) is the world’s first 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. Alternative methods of injection and extraction into the EMMA ring are explored together with their feasibility and implications. The option of developing nested racetracks to achieve a particular desired energy is also explored.

TUPPD044

Conceptual Gas Jet as a Stripping Target for Charge Exchange Injection

target, ion, laser, proton

1500

V.G. Dudnikov, C.M. Ankenbrandt
Muons, Inc, Batavia, USA

Stripping targets for charge exchange injection now uses thin carbon or Al2O3 foils. During long time injection for high intense beam accumulation by low current injection a foil life time can be compromised by overheating and alternative stripping targets need be developed. A pulsed supersonic gas jet was used as a stripping target in first realization of charge exchange injection with H⁻ ion energy 1.5 MeV and stationary gas jets are used as internal targets in experiments with super high vacuum. A stripper target thickness is proportional to the injection energy and for energy 1GeV should be ~0.3 mg/cm² of carbon. The pulsed gas target with such thickness acceptable for long time charge exchange injection can be produced with using of heavy hydrocarbon molecules used in the diffusion or booster vacuum pumps. Formation of the pulsed gas jet stripping targets will be considered.

TUPPD057

High Charge Low Emittance RF Gun for SuperKEKB

gun, cathode, emittance, laser

1533

T. Natsui, Y. Ogawa, M. Yoshida, X. Zhou
KEK, Ibaraki, Japan

We are developing a new RF gun for SuperKEKB. We are upgrading KEKB to SuperKEKB now. High charge low emittance electron and positron beams are required for SuperKEKB. We will generate 7.0 GeV electron beam at 5 nC 20 mm-mrad by J-linac. In this linac, a photo cathode S-band RF gun will be used as the electron beam source. For this reason, we are developing an advanced RF gun. Now, we are testing a Disk and Washer (DAW) type RF gun. Its photo cathode material is LaB6. Normally, LaB6 is used as a thermionic cathode, but it is suitable for　long-life photo cathode operation. This gun has a strong focusing field at the cathode and the acceleration field distribution also has a focusing effect. We will obtain 3.2 MeV beam energy with the gun. The design of RF gun and experimental results will be shown.

TUPPD061

High-Power RF Test of an RF-Gun for PAL-XFEL

gun, laser, emittance, electron

1539

J.H. Hong, J.H. Han, H.-S. Kang, C. Kim, S.H. Kim, C.-K. Min, S.S. Park, S.J. Park, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea
M.S. Chae, I.S. Ko, Y.W. Parc
POSTECH, Pohang, Kyungbuk, Republic of Korea

A photocathode RF-gun for the X-ray free electron laser (XFEL) at the Pohang Accelerator Laboratory (PAL) has been fabricated and tested at PAL. This RF-gun is based on a 1.6-cell cavity with dual-feed waveguide ports and two pumping ports. The RF gun was designed by PAL and POSTECH. The RF-gun has been successfully tested with a cathode electric field gradient up to 126MV/m at a repetition rate of 30 Hz. This paper reports the recent results on the beam test of the RF-gun with high power RF at the gun test facility. We present and discuss the measurements of the basic beam parameters such as charge, energy, energy spread, and transverse emittance.

TUPPD065

An Electron Gun Test Stand to Prepare for the MAX IV Project

gun, cathode, coupling, linac

1551

S. Werin, E. Elafifi, M. Eriksson, D. Kumbaro, F. Lindau, S. Thorin
MAX-lab, Lund, Sweden
E. Mansten
Lund University, Division of Atomic Physics, Lund, Sweden

The MAX IV facility, currently under construction, will include a 3 GeV linac injector with two RF guns providing beams for the two operations modes: ring injection and the Short Pulse Facility. The ring injection will be done by a thermionic 3 GHz RF gun developing from the current MAX-lab RF gun. The SPF gun will be a laser driven photo cathode 3 GHz RF gun based on the 1.6 cell BNL/SLAC type. The guns will be operated with short (0.7 us) RF pulses from a SLED system. A test stand to fine tune the operation of the two different systems has been assembled at the MAX IV laboratory (former MAX-lab). The experience in RF commissioning and initial measurements of energy, charge and quantum efficiency will be reported and the extension of the test stand for full emittance characterization will be outlined.

TUPPD077

SPEAR3 Booster RF System Upgrade: Performance Requirements and Evaluation of Resources

booster, klystron, cavity, linac

1578

S. Park, W.J. Corbett, R.O. Hettel, J.F. Schmerge, J.J. Sebek, J.W. Wang
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy Contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences.
The SPEAR2 accelerator system originally had 3 RF stations (2 for storage ring, 1 Booster) operating at 358.5 MHz. SPEAR3 now operates at 476.3 MHz with PEP-II type RF system, while the Booster RF frequency remains unchanged. For top-off operation, the Booster injects single 3.0 GeV electron bunches into SPEAR3 at 10 Hz every 5 minutes to replenish lost charge. Due to the frequency mismatch between SPEAR3 and the Booster, only one SPEAR3 bucket can injected per shot limiting injection rate and overall system flexibility. The aging high-power RF subsystems of the Booster pose a reliability issue as well. In order to remove these constraints, studies are underway to replace the Booster RF system using the PEP-II type RF system as a baseline. The new Booster RF system will be tuned to 475.036 MHz, and phase-locked to the SPEAR3 RF system. The project calls for ramping the Booster cavity gap voltage to 0.80 MV at 10 Hz, each with a 40 ms acceleration interval. With very low beam loading and low average RF power, there are many subsystems that can be operationally simplified. In this paper we present the results of analysis leading to a new Booster RF system.

TUPPP001

Beam Based Measurements with Superconducting Wigglers at the Canadian Light Source with Applications to Nonlinear Beam Dynamics

wiggler, dynamic-aperture, optics, multipole

1599

W.A. Wurtz, L.O. Dallin, M.J. Sigrist
CLS, Saskatoon, Saskatchewan, Canada

The Canadian Light Source (CLS) employs two superconducting wigglers for the production of hard x-rays. These wigglers cause a large decrease in injection efficiency. While such a decrease is not unexpected due to the large distortion to the linear optics, a correction to the linear optics does not restore injection efficiency. This inability to restore injection is not predicted by a kickmap model of the wiggler. We performed beam based measurements to construct a phenomenological, nonlinear model of the wiggler. Particle tracking with this wiggler model shows that the reduction in dynamic aperture is due to the amplitude dependent tune shift crossing a resonance, even with the linear optics corrected. Moving the tunes allows us to avoid this resonance and measurements at these tunes show that injection efficiency is not greatly affected by the wigglers.

TUPPP004

Low-alpha Operation for the SOLEIL Storage Ring

optics, coupling, radiation, photon

1608

M.-A. Tordeux, J. Barros, A. Bence, P. Brunelle, N. Hubert, M. Labat, P. Lebasque, A. Nadji, L.S. Nadolski, J.-P. Pollina
SOLEIL, Gif-sur-Yvette, France
C. Evain
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France

The low momentum compaction factor (alpha) operation has been recently established on the SOLEIL Storage Ring. Both time resolved X-ray and THz radiation user communities are taking benefit from a hybrid filling pattern with a 4.7 ps RMS bunch length. At a value of 1.7 10^-5 (nominal alpha /25) and a current per bunch of 65 μA, stable THz radiation is produced in the range of 8 - 20 cm^-1 (measurements and comparison with Coherent Synchrotron Radiation (CSR) modeling are reported elsewhere*, **). Several low-alpha optics have been investigated and the optics presented at IPAC’11 has been selected for the operation. This paper presents the comprehensive experimental characterization of this optics. Specificities of the low-alpha operation, driven by the very demanding user experiments, are reviewed: closed orbit stability issues, extremely tight injected current step when refilling which implies a specific Linac tuning, low current diagnostics optimization, short bunch measurements, insertion devices effect on the CSR characteristics and radiation safety aspects justified by beam losses at injection.
* C. Evain, A. Loulergue et al., this conference.
** E. Roussel et al., this conference.

TUPPP016

Recent Development of PF Ring and PF-AR

undulator, polarization, linac, vacuum

1641

Y. Tanimoto, T. Aoto, S. Asaoka, K. Endo, K. Haga, K. Harada, T. Honda, 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, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto
KEK, Ibaraki, Japan
H. Takaki
ISSP/SRL, Chiba, Japan

After the earthquake of March 11, two light sources of KEK, PF ring and PF-AR, have recovered the regular operation from October, 2011. We installed tandem variably-polarized undulators at PF ring in 2009. Recently, the orbit switching system has been completed with sufficient feed-forward orbit compensation at 10-Hz. PF ring is usually operated at 450 mA with a top-up injection using the pulsed sextupole magnet instead of the conventional kicker magnets. The transverse and longitudinal instabilities are suppressed by a digital feedback system using the iGp signal processor. In the longitudinal direction, we observed unstable quadrupole mode oscillation which could not be controlled by the feedback system. We had applied the phase modulation of the main RF cavity to stabilize the quadrupole oscillation before. Old-type RF-shielded gate valves damaged by the earthquake were removed from the ring during the summer maintenance. In the operation after autumn, the quadrupole oscillation can be cured by dividing the bunch train of partial-filling. Without the phase modulation, the effective brightness of SR beam has been improved especially at beam lines of finite dispersion function.

TUPPP018

Design and Commissioning of the Very Low Emittance Optics in the SSRF Storage Ring

emittance, optics, storage-ring, lattice

1647

S.Q. Tian, J. Chen, B.C. Jiang, Y.B. Leng, H.H. Li, L.Y. Yu, M.Z. Zhang, W.Z. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

In synchrotron radiation light sources, there are continuous efforts to lower the storage ring emittance and thus increase its photon beam brightness. The lowest effective emittance of SSRF is found by a systematic method. Results of design and commissioning of this kind of optics are presented, of which the beam emittance is smaller than the nominal one by 1 nm.rad. The measured beam parameters agree well with the design ones.

TUPPP025

Resurrection of RESOLVE at NSRRC Prepared for the First Turn Beam Steering of the TPS Commissioning

storage-ring, controls, quadrupole, kicker

1665

H.-P. Chang, H.H. Chen, P.C. Chiu, P.J. Chou, K.T. Hsu, S.J. Huang, Y.-C. Liu, F.H. Tseng
NSRRC, Hsinchu, Taiwan

MATLAB based high level application software prepared for the 3GeV Taiwan Photon Source has been built and tested on the 1.5GeV Taiwan Light Source continuously. The RESOLVE program is surveyed and resurrected at NSRRC to support and help the first turn beam steering in the coming commissioning of the TPS accelerator complex. Due to the RESOLVE’s history, it contributed a lot in the past commissioning of SLC at SLAC National Accelerator Laboratory, we believe it may give help although most of the first turn beam steering of current light source machines may pass smoothly with well machine construction. In order to make the revised RESOLVE working, not only the compiling problem but also some memory bugs have been fixed, the updated RESOLVE now can be run on PC/Linux and Mac/OSX computer systems. We are trying to apply and test it on the TLS SR with the turn-by-turn digital BPM system. Some exercises of the error finding in beam steering of the off-axis injection beam are performed for presentation.

TUPPP026

RF Rescue Option for TPS Linac

electron, linac, bunching, booster

1668

K.L. Tsai, H.-P. Chang, C.-T. Chen, C.-S. Fann, K.T. Hsu, S.Y. Hsu, K.-K. Lin, H.M. Shih
NSRRC, Hsinchu, Taiwan
K. Dunkel, C. Piel
RI Research Instruments GmbH, Bergisch Gladbach, Germany

The 150 MeV linac of Taiwan Photon Source was commissioned in June 2011. It consists of 90 keV electron source, bunching system and three S-band accelerating sections driven by three high-power klystrons. The rf system is equipped with rescue option such that the rf power from second klystron can be split and fed into both accelerating section 1 and 2. The rescue operation will be needed in the event of a failure occurred at the first klystron. In the report, the rescue capability will be illustrated and the test results will also be discussed.

TUPPR030

Thermo-mechanical Analysis of the CLIC Post-Linac Energy Collimators

linac, simulation, collimation, betatron

1882

J. Resta-López
IFIC, Valencia, Spain
J.L. Fernández-Hernando
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A. Latina
CERN, Geneva, Switzerland

Funding: FPA2010-21456-C02-01
The post-linac energy collimation system of the Compact Linear Collider (CLIC) has been designed for passive protection of the Beam Delivery System (BDS) against mis-steered beams due to failure modes in the main linac. In this paper, a thermo-mechanical analysis of the CLIC energy collimators is presented. This study is based on simulations using the codes FLUKA and ANSYS when an entire bunch train hit the collimators. Different failure mode scenarios in the main linac are considered. Moreover, we discuss the results for different collimator materials. The aim is to improve the collimator design in order to make a reliable and robust design so that it survives without damage from the impact of a full bunch train in case of likely events generating energy errors.

TUPPR034

Beam-based Alignment in CTF3 Test Beam Line

quadrupole, alignment, feedback, beam-losses

1894

G. Sterbini, S. Döbert, R.L. Lillestøl, E. Marín, D. Schulte
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

The CLIC linear collider is based on the two beams acceleration scheme. During acceleration, the drive beam suffers a large increase in its energy spread. In order to efficiently transport such a beam, beam-based alignment techniques together with tight pre-alignment tolerances are crucial. A beam-based steering campaign has been conducted at the Test Beam Line of the CLIC Test Facility to evaluate the performance of several algorithms. In the following we present and discuss the obtained results.

TUPPR035

A Comparative Study for the CLIC Drive Beam Decelerator Optics

optics, quadrupole, alignment, lattice

1897

G. Sterbini, D. Schulte
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

The baseline for the CLIC drive beam decelerators optics consists of a 2-m-long FODO cell. This solution was adopted to have strong focusing in order to mitigate the effect of the PETS wakefields and to minimize the drive beam envelope. Taking into account the most recent PETS design, we compare the performance of the baseline FODO cell with a proposal that consider twice longer FODO cell. Despite of the expected cost in term of performance, the reduction of the complexity of the system due to the halving of the number of quadrupoles can be beneficial for the overall optimization of the decelerator design.

TUPPR054

Internal H⁰/H⁻ Dump for the Proton Synchrotron Booster Injection at CERN

vacuum, booster, linac, radiation

1942

M. Delonca, C. Maglioni, A.A. Patapenka, A. Sarrió Martínez
CERN, Geneva, Switzerland

In the frame of the LHC Injectors Upgrade Project at CERN (LIU), the new 160MeV H⁻ Linac4 will inject into the four existing PS Booster rings after the conversion of H⁻ into H⁺ in a stripping foil. Given a limited stripping efficiency and possible foil failures, a certain percentage of the beam is foreseen to remain partially (H⁰) or completely (H⁻) unstripped. An internal dump installed into the chicane magnet to stop these unstripped beams is therefore required. This paper presents the conceptual design of the internal dump, reviewing loading assumptions, design constraints, limitations and integration studies. Power evacuation through the thermal contact between the core and the external active cooling is addressed and, finally, results from the numerical thermo-mechanical analyses are reported.

TUPPR068

The Achromatic Telescopic Squeezing Scheme: Basic Principles and First Demonstration at the LHC

optics, sextupole, insertion, quadrupole

1978

S.D. Fartoukh, R. De Maria, B. Goddard, W. Höfle, M. Lamont, G.J. Müller, L. Ponce, S. Redaelli, R.J. Steinhagen, M. Strzelczyk, R. Tomás, G. Vanbavinckhove, J. Wenninger
CERN, Geneva, Switzerland
R. Miyamoto
ESS, Lund, Sweden

The Achromatic Telescopic Squeezing (ATS) scheme [1] is a novel squeezing mechanism enabling the production of very low β^* in circular colliders. The basic principles of the ATS scheme will be reviewed together with its strong justification for the High-Luminosity LHC Project. In this context, a few dedicated beam experiments were meticulously prepared and took place at the LHC in 2011. The results obtained will be highlighted, demonstrating already the potential of the ATS scheme for any upgrade project relying on a strong reduction of β^*.
[1] S. Fartoukh, "An Achromatic Telescopic Squeezing (ATS) Scheme For The LHC Upgrade," IPAC'11, WEPC037, p. 2088 (2001).

TUPPR087

Status of NSCL Cyclotron Gas Stopper

ion, cyclotron, extraction, emittance

2029

N.S. Joshi, G. Bollen, M. Brodeur, D.J. Morrissey, S. Schwarz
NSCL, East Lansing, Michigan, USA

A gas-filled reverse cyclotron for the thermalization of energetic beams is under construction at NSCL/MSU. Rare isotopes produced via projectile fragmentation after in-flight separation will be injected into the device and converted into low-energy beams through buffer gas interactions as they spiral towards the center of the device. The extracted thermal beams will be used for low energy experiments such as precision mass measurements with traps or laser spectroscopy, and further transport for reacceleration. Detailed calculations have been performed to optimize the magnetic field design as well as the transport and stopping of ions inside the gas. An RF-carpet will be used to transport the thermal ions to the axial extraction point. The calculations indicate that the cyclotron gas stopper will be much more efficient for the thermalization of light and medium mass ions compared to linear gas cells. In this contribution we will discuss simulations of the overall performance and acceptance of machine, the beam matching calculations to the fragment separator emittance, and the construction status.

TUPPR088

Baseline Design of the SuperB Factory Injection System

linac, positron, electron, emittance

2032

S. Guiducci, A. Bacci, M.E. Biagini, R. Boni, M. Boscolo, D. Pellegrini, M.A. Preger, P. Raimondi, A.R. Rossi, M. Zobov
INFN/LNF, Frascati (Roma), Italy
M.A. Baylac
LPSC, Grenoble, France
J. Brossard, S. Cavalier, O. Dadoun, T. Demma, P. Lepercq, E. Ngo Mandag, C. Rimbault, A. Variola
LAL, Orsay, France
J.T. Seeman
SLAC, Menlo Park, California, USA
D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia

The injection complex of the SuperB, B-factory project of INFN consists of a polarized electron gun, a positron production system, electron and positron linac sections, a positron damping ring and the transfer lines connecting these systems and the collider main rings. To keep the ultra high luminosity nearly constant, continuous injection of 4 GeV electrons and 7 GeV positrons in both Low Energy Ring (LER) and High Energy Ring (HER) is necessary. In this paper we describe the baseline design and the beam dynamics studies performed to evaluate the system performance.

TUPPR089

Design Study of Beam Injection for SuperKEKB Main Ring

septum, synchrotron, optics, emittance

2035

T. Mori, N. Iida, M. Kikuchi, T. Mimashi, Y. Sakamoto, H. Sugimoto, S. Takasaki, M. Tawada
KEK, Ibaraki, Japan

The SuperKEKB project is in progress toward the initial physics run in the year 2015. It assumes the nano-beam scheme, in which the emittance of the colliding beams is ε=4.6 nm. The emittance of the injected beam is ε=1.46 nm. To achieve such a low emittance, it is vitally important to preserve the emittance during the transport of the beam from the linac to the main ring. One of the most difficult parts is the injection system. We are considering the synchrotron injection for the electron-line to avoid a beam blowup in the ring after injection, which is caused by a beam-beam interaction with the stored beam. The optics study for electron injection and the current R&D status for the septum magnet will be reported in this paper.

TUPPR090

Analysis of Ferrite Heating of the LHC Injection Kickers and Proposals for Future Reduction of Temperature

kicker, vacuum, impedance, coupling

2038

M.J. Barnes, L. Ducimetière, N. Garrel, B. Goddard, V. Mertens, W.J.M. Weterings
CERN, Geneva, Switzerland

The two LHC injection kicker magnet (MKI) systems produce a kick of 1.3 T-m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. A beam screen, consisting of a ceramic tube with conductors on the inner wall, is placed in the aperture of the magnets. The conductors provide a path for the image current of the, high intensity, LHC beam and screen the ferrite against wake fields. The conductors initially used gave adequately low beam coupling impedance however inter-conductor discharges occurred during pulsing of the magnet; hence an alternative design was implemented to meet the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time and good high voltage behaviour. During 2011 the LHC has been operated with high intensity beam, coasting for many hours at a time, resulting in heating of both the ferrite yoke and beam impedance reduction ferrites, of the MKIs. This paper presents an analysis of thermal measurement data and an extrapolation of the heating for future operation; in addition means are discussed for reducing ferrite heating and improving cooling.

TUPPR091

Status of the 160 MeV H⁻ Injection into the CERN PSB

emittance, vacuum, simulation, proton

2041

W.J.M. Weterings, B. Balhan, E. Benedetto, J. Borburgh, C. Bracco, C. Carli, B. Goddard, K. Hanke, B. Mikulec, A. Newborough, R. Noulibos, J. Tan
CERN, Geneva, Switzerland

The 160 MeV H⁻ beam from the LINAC4 will be injected into the 4 superimposed rings of the PS Booster (PSB) with an new H⁻ charge-exchange injection system. This entails a massive upgrade of the injection region. The hardware requirements and constraints, the performance specifications and the design of the H⁻ injection region are described.

TUPPR092

Transient Beam Losses in the LHC Injection Kickers from Micron Scale Dust Particles

kicker, beam-losses, vacuum, electron

2044

B. Goddard, P. Adraktas, T. Baer, M.J. Barnes, F. Cerutti, A. Ferrari, N. Garrel, A.H.J. Gerardin, M. Guinchard, A. Lechner, A. Masi, V. Mertens, R. Morón Ballester, S. Redaelli, J.A. Uythoven, V. Vlachoudis, F. Zimmermann
CERN, Geneva, Switzerland

Transient beam losses on a time scale of a few ms have been observed in the LHC injection kickers, occurring mainly shortly after beam injection with a strong correlation in time to the kicker pulsing. The beam losses, which have at times affected LHC availability, are attributed to micron scale ceramic dust particles detached from the alumina beam pipe and accelerated into the beam. The beam related observations are described, together with laboratory measurements of beam pipe contamination and kicker vibration, simulations of electric field in the beam pipe and the basic dynamic model. Energy deposition simulations modelling the beam losses are presented and compared to measurement. Extrapolations to future LHC operation at higher intensities and energies are made, and prospects for mitigation are discussed.

TUPPR093

Sources and Solutions for LHC Transfer Line Stability Issues

extraction, kicker, septum, controls

2047

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

The LHC is filled through two 3km transfer lines from the last pre-injector, the SPS. Safe injection into the LHC requires stable trajectories in the transfer lines. During the LHC proton operations 2011 instabilities were observed. In particular shot-by-shot and bunch-by-bunch variations cause difficulties for steering of the beam and can potentially cause high beam losses at injection. The causes of these instabilities have been studied and will be presented in this paper. Based on the studies solutions will be proposed and finally the effects of the solutions will be studied.

TUPPR094

SPS Transverse Beam Scraping and LHC Injection Losses

emittance, luminosity, proton, controls

2050

L.N. Drosdal, W. Bartmann, C. Bracco, K. Cornelis, B. Goddard, V. Kain, M. Meddahi, E. Veyrunes
CERN, Geneva, Switzerland

Machine protection sets strict requirements for the quality of the injected beam, in particular in the transverse plane. Losses at aperture restrictions and protection elements have to be kept at a minimum. Particles in the beam tails are lost at the tight transfer line collimators and can trigger the LHC beam abort system. These particles have to be removed by scrapers in the vertical and horizontal plane in the SPS. Scraping has become vital for high intensity LHC operation. This paper shows the dependence of injection quality on the SPS scraping and discusses an improved scraper setting up strategy for better reproducibility with the current scraper system.

TUPPR096

Angular Alignment of the LHC Injection Protection Stopper

alignment, kicker, proton, beam-losses

2056

C. Bracco, R.W. Assmann, W. Bartmann, B. Goddard, V. Kain, J.A. Uythoven
CERN, Geneva, Switzerland

Machine safety depends critically on the correct setup of the protection elements. One of the injection protection collimators is constituted by exceptionally long jaws (4 m). For this element, an angular offset of the jaws could affect significantly the measured beam size and, as a consequence, the correct setup with respect to the beam. Dedicated studies and cross-calibrations have been performed to quantify the effect of tilts and offsets on the setup of this collimator and to check the provided passive protection.

TUPPR098

Comparison of LHC Collimator Beam-Based Alignment Centers to BPM-Interpolated Centers

alignment, hadron, collimation, collider

2062

G. Valentino, N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta
R.W. Assmann, R. Bruce, G.J. Müller, S. Redaelli, A. Rossi, G. Valentino
CERN, Geneva, Switzerland
L. Lari
IFIC, Valencia, Spain

The beam centers at the Large Hadron Collider collimators are determined by beam-based alignment, where both jaws of a collimator are moved in separately until a loss spike is detected on a Beam Loss Monitor downstream. Orbit drifts of more than a few hundred micrometers cannot be tolerated, as they would reduce the efficiency of the collimation system. Beam Position Monitors (BPMs) are installed at various locations around the LHC ring, and a linear interpolation of the orbit can be obtained at the collimator positions. In this paper, the results obtained from beam-based alignment are compared with the orbit interpolated from the BPM data throughout the 2011 LHC proton run. The stability of the orbit determined by collimator alignment during the run is evaluated.

WEYA03

Overview of B-Factories

emittance, sextupole, quadrupole, collider

2086

M.E. Biagini
INFN/LNF, Frascati (Roma), Italy

An overview of the two recently approved high luminosity B-Factories, the SuperB in Italy and the SuperKEKB in Japan, will be presented. The main design features to reach the very high luminosity requested and a status of progress in design and construction will be given.

Slides WEYA03 [6.151 MB]

WEOAA01

Injected Beam Imaging at SPEAR 3 with a Digital Optic Mask

synchrotron, storage-ring, target, quadrupole

2116

H.D. Zhang, R.B. Fiorito, A.G. Shkvarunets
UMD, College Park, Maryland, USA
W.J. Corbett, A.S. Fisher, K. Tian
SLAC, Menlo Park, California, USA

Funding: *This work is partially funded by the Office of Naval Research and the DOD Joint Technology Office.
At SPEAR3, the light source operates in top-up injection mode with 273nC charge circulating in the storage ring (350mA). Each individual injection pulse contains only 40pC, or a contrast ration of 1:6800. In order to monitor injected beam dynamics during User operations, it is desirable to optically image the injected charge distribution on a turn-by-turn basis in the presence of the bright stored beam. The measurement is made by re-imaging visible synchrotron radiation onto a 1024x768 pixel Digital-Micro-Array mirror device (DMD) which is used to 'mask' light from the central stored beam while observing the weak injected beam signal on an intensified, fast-gated CCD camera. Complex beam dynamics are observed after only a few 10's of turns around the synchrotron. In this paper we report on the DMD optical configuration, masking considerations, measurement timing and initial tests imaging the injected beam in the presence of stored beam.

Slides WEOAA01 [1.874 MB]

WEOAA03

Development of the Beam Halo Monitor in the J-PARC 3-GeV RCS

extraction, electron, beam-losses, gun

2122

M. Yoshimoto, N. Hayashi, H. Hotchi, M. Kinsho, S.I. Meigo, K. Okabe, P.K. Saha, K. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Transverse beam halo is one of the most important beam parameters due to limit the performance of the high intensity beam accelerator. Therefore the transverse beam halo measurement is required to increase the beam power of the J-PARC 3-GeV RCS. Transverse halo monitors, which are horizontal and vertical scanning aluminum plates type, has been installed in the extraction beam line. But the residual secondary electrons hindered the beam halo diagnostic. Thus we develop the new beam halo monitor with vibrating wire monitor.

Slides WEOAA03 [6.701 MB]

WEOAB01

New Results from the EMMA Experiment

acceleration, resonance, betatron, electron

2134

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C.S. Edmonds, K.M. Hock, M.G. Ibison, I.W. Kirkman
The University of Liverpool, Liverpool, United Kingdom
J.M. Garland, H.L. Owen
UMAN, Manchester, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After demonstration of acceleration in the serpentine channel in April 2011, the beam study with EMMA continues to explore the large transverse and longitudinal acceptance and effects of integer tune crossing with slower rate on the betatron amplitude. Together with a comparison of detailed models based on measured field maps and the experimental mapping of the machine by relating the initial and final phase space coordinates. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.

Slides WEOAB01 [2.120 MB]

WEEPPB002

Plasma Acceleration Experiment at SPARC_LAB with External Injection

plasma, electron, laser, acceleration

2169

L. Serafini, A. Bacci
Istituto Nazionale di Fisica Nucleare, Milano, Italy
M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, A.R. Rossi, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
C. Maroli, V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
A. Mostacci
URLS, Rome, Italy
P. Tomassini
Università degli Studi di Milano, Milano, Italy

At the SPARC-LAB facility of INFN-LNF we are installing two transport lines for ultra-short electron bunches and an ultra-intense laser pulses, generated by the SPARC photo-injector and by the FLAME laser in a synchronized fashion at the tens of fs level, to co-propagate inside a hydrogen filled glass capillary, in order to perform acceleration of the electron bunch by a plasma wave driven by the laser pulse. The main aim of this experiment is to demonstrate that a high brightness electron beam can be accelerated by a plasma wave without any significant degradation of its quality. A 10 pC electron bunch, 10 fs long is produced by SPARC and transported to injection into the capillary, which is 100 micron wide, at a gas density around 5*10¹⁷ ne/cm³ . The laser pulse, 25 fs long, focused down to 30 microns into the capillary is injected ahead of the bunch, drives a weakly non-linear plasma wave with wavelength of about 120 microns. A proper phasing of the two pulses allows acceleration of electrons from the injection energy of 150 MeV up to about 1 GeV for a 10 cm long capillary. Installation of the beam lines is foreseen by the end of 2012 and first tests starting in mid 2013.

WEEPPB014

The Magnetic Model of the LHC during the 3.5 TeV Run

quadrupole, dipole, controls, optics

2194

E. Todesco, N. Aquilina, M. Giovannozzi, M. Lamont, F. Schmidt, R.J. Steinhagen, M. Strzelczyk, R. Tomás
CERN, Geneva, Switzerland
N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta

The magnetic model of the LHC is based on a fit of the magnetic measurements through equations that model the field components (geometric, saturation, persistent) at different currents. In this paper we will review the main results related to the magnetic model during the run of the LHC in 2010-2011: with a top energy of 3.5 TeV, all components of the model but the saturation are visible. We first give an estimate of the reproducibility of the main components and multipolar errors as they can be deduced from beam measurements, i.e. orbit, tune, chromaticity, beta beating and coupling. We then review the main results relative to the decay at injection plateau, dependence on powering history, and snapback at the beginning of the ramp for both tune and chromaticity. We discuss the precision obtained in tracking the magnets during the ramp, where the persistent current components gradually disappear. We conclude by presenting the behaviour of the quadrupoles model during the squeeze. A list of the major changes implemented during the operation together with what are considered as the main open issues is given.

WEPPC059

A Two-stage Injection-locked Magnetron for Accelerators with Superconducting Cavities

linac, simulation, cavity, controls

2348

G.M. Kazakevich, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer
Muons, Inc, Batavia, USA
B. Chase, S. Nagaitsev, R.J. Pasquinelli, N. Solyak, V. Tupikov, D. Wolff, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Supported in part by SBIR Grant 4743 11SC06261
A concept for a two-stage injection-locked CW magnetron intended to drive Superconducting Cavities (SC) for intensity-frontier accelerators has been proposed. The concept is based on a theoretical model that considers a magnetron as a forced oscillator; the model has been experimentally verified with a 2.5 MW pulsed magnetron. The two-stage CW magnetron can be used as a RF power source for Fermilab’s Project-X to feed separately each of the SC of the 8 GeV pulsed linac. For Project-X the 1.3 GHz two-stage magnetron with output power of 20-25 kW and expected output/input power ratio of about 35-40 dB would operate in a quasi-CW mode with a pulse duration ≤ 10 ms and repetition rate of 10 Hz. The magnetrons for both stages should be based on the commercial prototypes to decrease the cost of the system. An experimental model of the two-stage CW S-band magnetron with peak power of 1 kW, with pulse duration of 1-10 ms, has been developed and built for study. A description of the theoretical and experimental models, simulations, and experimental results are presented and discussed in this work.

WEPPC060

A High-power 650 MHz CW Magnetron Transmitter for Intensity Frontier Superconducting Accelerators

controls, proton, LLRF, linac

2351

G.M. Kazakevich, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer
Muons, Inc, Batavia, USA
B. Chase, S. Nagaitsev, R.J. Pasquinelli, V.P. Yakovlev
Fermilab, Batavia, USA
T.A. Treado
CPI, Beverley, Massachusetts, USA

A concept of a 650 MHz CW magnetron transmitter with fast control in phase and power, based on two-stage injection-locked CW magnetrons, has been proposed to drive Superconducting Cavities (SC) for intensity-frontier accelerators. The concept is based on a theoretical model considering a magnetron as a forced oscillator and experimentally verified with a 2.5 MW pulsed magnetron. To fulfill fast control of phase and output power requirements of SC accelerators, both two-stage injection-locked CW magnetrons are combined with a 3-dB hybrid. Fast control in output power is achieved by varying the input phase of one of the magnetrons. For output power up to 250 kW we expect the output/input power ratio to be about 35 to 40 dB in CW or quasi-CW mode with long pulse duration. All magnetrons of the transmitter should be based on commercially available models to decrease the cost of the system. An experimental model using 1 kW, CW, S-band, injection-locked magnetrons with a 3-dB hybrid combiner has been developed and built for study. A description of the model, simulations, and experimental results are presented and discussed in this work.

WEPPC063

Superconducting RF Cavity for High-current Cyclotrons

cavity, cyclotron, focusing, extraction

2354

N. Pogue, P.M. McIntyre, A. Sattarov
Texas A&M University, College Station, Texas, USA

Funding: This work is supported by grants from the State of Texas (ASE) and the Mitchell Family Foundation.
A novel superconducting cavity is presented for applications in cyclotrons. The cavity is in effect an extrusion of a 2-D double-quarter-wave structure, in which the ends of the extrusion are wrapped around and joined so that the cavity has no end perturbations. Power is applied to a linear array of input coupling loops, so that rf sheet current is launched in a laminar flow that matches the power coupled to the orbits of the cyclotron. Each loop is driven by an independent solid-state rf source. A strategy is presented for using to advantage the independent control of phase and amplitude to suppress transient phenomena. Longitudinal modes can be strongly suppressed. These provisions are of importance to suppress phenomena that can limit beam current.

WEPPD015

Saturation Behaviour of the LHC NEG Coated Beam Pipes

vacuum, simulation, site, insertion

2525

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

In the CERN Large Hadron Collider (LHC), about 6 km of the UHV beam pipe are at room temperature and serve as experimental or utility insertions. TiZrV non-evaporable getter (NEG) coating is used to maintain the design pressure during beam operation. Molecular desorption due to dynamic effects is stimulated during protons operation at high intensity. This phenomenon produces an important gas load from the vacuum chamber walls which could lead to a partial or total saturation of the NEG coating. To keep the design vacuum performances and to schedule technical interventions for NEG re-activation, it is necessary to take in account all these aspects and to regularly evaluate the saturation level of the NEG coating. Experimental studies in a typical LHC vacuum sector were conducted in order to identify the best method to assess the saturation level of the beam pipe. Partial saturation of the NEG was performed and the effects in the variations of pressure reading, effective pumping speed, transmission and capture probability are analysed. Finally, based on these results, a detailed analysis of the NEG coating saturation level of some area of the LHC is presented and analysed.

WEPPD018

LHC Beam Vacuum During 2011 Machine Operation

vacuum, electron, kicker, proton

2534

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

During the year 2011 the LHC operated for 682 fills, meaning 247 days and 2 hours of stable beam in total. From 368 bunches per beam at 150 ns bunch spacing circulating in the ring in December 2010, the 2011 proton physic ended with 1380 bunches per beam circulating with 50 ns bunch spacing. The machine performances increased in parallel with the vacuum improvement thanks to a well performed scrubbing run in April 2011 and a continuous conditioning of the beam pipes while the machine was running. The 2011 LHC operation ended with one month of ions physic runs. During the machine operation various phenomena of beam - vacuum interaction were detected, analyzed and solved. This paper describes the pressure behavior along the machine layout and mainly in specific components position like TDI and MKI. The “pressure spike” phenomena near the experiment CMS and in some Dipole 1 (D1) regions are discussed. Finally, results obtained during the 25 ns machine developments are presented.

WEPPD047

Sequencer Design of Timing System for the Taiwan Photon Source

controls, booster, gun, EPICS

2621

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

The timing system of the Taiwan Photon Source is used to distribute trigger signals and synchronously clocks to all the equipment of the machine which need them. The timing system basically works by sending event codes from one event generator (EVG) through tree structured, bidirectional optical fiber network to many event receivers. To accommodate various operation and injection scenarios of the TPS storage ring and booster synchrotron and LINAC, timing sequencer design and control is crucial. The sequencer (event code) is stored at sequence RAM of the EVG module. In order to manage sequence RAM of EVG, the timing sequence control is considered to use Matlab scripts embedded in the timing master EPICS IOC. The timing sequencer design will be summarized in this paper.

WEPPD050

Upgrade of the RF Reference Distribution System for 400 MeV LINAC at J-PARC

linac, controls, acceleration, klystron

2630

K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono
KEK, Ibaraki, Japan
F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan

In J-PARC, the accelerator systems are controlled using the 12 MHz master clock in center control building. In the present J-PARC Linac, the negative hydrogen is accelerated by 181 MeV using the RFQ, DTLs, and SDTLs which have the resonance frequency of 324 MHz. The low-level radio frequency (LLRF) system is based on the reference signal of 312 MHz (LO) synchronized with the master clock. We are planning to upgrade Linac by the accelerated energy to 400 MeV by the installation of ACS cavities with the resonance frequency of 972 MHz. Then, not only 312 MHz but also 960 MHz reference signals are necessary. Therefore, a new RF reference signal oscillator was installed at J-PARC LINAC. The phase noise of the output signal in this module was measured by the signal source analyzer. The jitter of the output signal, which was estimated from the integration of phase noise from 10 Hz to 1 MHz, becomes about 40 fs and was two order smaller than that of the old system (about 1700 fs) by the installation of new oscillator and the optimization of the path of the master clock. It can be expected to improve the operating ratio in J-PARC LINAC.

WEPPD064

Quick Recovery of the KEK e⁻/e⁺ Injector Linac from the Great East Japan Earthquake

linac, vacuum, positron, electron

2669

A. Enomoto
KEK, Ibaraki, Japan

The KEK e⁻/e⁺ injector linac is under operation for the KEK Photon Factory (PF) storage ring and Photon Factory - Advanced Ring (PF-AR). And the linac has just started the upgrade for the SuperKEKB project. On March 11, the linac suffered great damage from the Great East Japan Earthquake. Due to an extraordinary strong vibration, many bellows of vacuum pipes were violently torn and the entire linac vacuum was exposed to the atmosphere. Without electricity, highly humid air entered the inside of accelerator structures. Some people supposed the linac would not be recovered within a year. However, it resumed operation after only two months. We report the memorable disaster and how we recovered the linac so quickly.

WEPPD071

The FLUKA LineBuilder and Element DataBase: Tools for Building Complex Models of Accelerator Beam Lines

optics, simulation, insertion, proton

2687

A. Mereghetti
UMAN, Manchester, United Kingdom
V. Boccone, F. Cerutti, R. Versaci, V. Vlachoudis
CERN, Geneva, Switzerland

Extended FLUKA models of accelerator beam lines can be extremely complex: heavy to manipulate, poorly versatile and prone to mismatched positioning. We developed a framework capable of creating the FLUKA model of an arbitrary portion of a given accelerator, starting from the optics configuration and a few other information provided by the user. The framework includes a builder (LineBuilder), an element database and a series of configuration and analysis scripts. The LineBuilder is a Python program aimed at dynamically assembling complex FLUKA models of accelerator beam lines: positions, magnetic fields and scorings are automatically set up, and geometry details such as apertures of collimators, tilting and misalignment of elements, beam pipes and tunnel geometries can be entered at user's will. The element database (FEDB) is a collection of detailed FLUKA geometry models of machine elements. This framework has been widely used for recent LHC and SPS beam-machine interaction studies at CERN, and led to a drastic reduction in the time otherwise required to rework old machine models, and to a coherent and traceable description of the inputs used for all the simulations.

WEPPP017

Recent Results at the SPARC_LAB Facility

laser, electron, plasma, photon

2758

M. Ferrario, D. Alesini, M.P. Anania, M. Bellaveglia, R. Boni, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, A. Esposito, A. Gallo, C. Gatti, G. Gatti, A. Ghigo, T. Levato, E. Pace, L. Pellegrino, R. Pompili, A.R. Rossi, B. Spataro, P. Tomassini, C. Vaccarezza, F. Villa
INFN/LNF, Frascati (Roma), Italy
A. Bacci, C. De Martinis, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
G. Dattoli, E. Di Palma, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, I.P. Spassovsky, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
D. Di Giovenale
INFN-Roma II, Roma, Italy
U. Dosselli
INFN, Roma, Italy
R. Faccini
INFN-Roma, Roma, Italy
R. Fedele
Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli, Italy
M. Gambaccini
INFN-Ferrara, Ferrara, Italy
D. Giulietti
UNIPI, Pisa, Italy
L.A. Gizzi, L. Labate
CNR/IPP, Pisa, Italy
P. Londrillo
INFN-Bologna, Bologna, Italy
S. Lupi
Università di Roma I La Sapienza, Roma, Italy
A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy
G. Passaleva
INFN-FI, Sesto Fiorentino, Italy
V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
J.V. Rau
ISM-CNR, Rome, Italy
G. Turchetti
Bologna University, Bologna, Italy

A new facility named SPARC_LAB (Sources for Plasma Accelerators and Radiation Compton with Lasers and Beams) has been recently launched at the INFN National Labs in Frascati, merging the potentialities of the old projects SPARC and PLASMONX. The SPARC project, a collaboration among INFN, ENEA and CNR, is now completed, hosting a 150 MeV high brightness electron beam injector which feeds a 12 meters long undulator. Observation of FEL radiation in the SASE, Seeded and HHG modes has been performed from 500 nm down to 40 nm wevelength. A second beam line has been also installed to drive a narrow band THz radiation source. In parallel to that, INFN decided to host a 300 TW laser that will be linked to the linac and devoted to explore laser-matter interaction, in particular with regard to laser-plasma acceleration in the self injection and external injection modes, (the PLASMONX experiments). The facility will be also used for particle driven plasma acceleration experiments (the COMB experiment). A Thomson scattering experiment coupling the electron bunch to the high-power laser to generate coherent monochromatic X-ray radiation is also in the commissioning phase.

WEPPP018

A New Beam Injection Scheme for a Compact Low-energy Storage Ring

kicker, damping, storage-ring, acceleration

2761

Y. Honda
KEK, Ibaraki, Japan

A very compact storage ring at low energy has an unique application such as Compton X-ray source. Scheme for efficient injection is an issue for such a compact storage ring. Utilizing a phase-shift in the non-relativistic energy region, a new idea for accumulating the incoming bunch on an already circulating bunch without any kicker or orbit bump has been presented. Its applicable parameter range will be presented.

WEPPP019

Designing of Photonic Crystal Accelerator for Radiation Biology

laser, electron, vacuum, acceleration

2763

K. Koyama, Y. Matsumura
University of Tokyo, Tokyo, Japan
A. Aimidula, M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
T. Natsui, M. Yoshida
KEK, Ibaraki, Japan

Funding: This work was performed as part of the Global COE Program (Nuclear Education and Research Initiative, MEXT, Japan.
A photonic crystal accelerator with a combination of a fiber laser is under development in order to apply it to the radiation biology. In order to investigate fundamental biological processes in a cell, a DNA is precisely shot by an electron bunch with an in situ observation of a radiation interaction using a microscope. Required beam diameter, bunch length, and beam energy are nanometer, attosecond, and 100 keV to 1 MeV, respectively. A photonic crystal or dielectric laser accelerator energized by a fiber laser is suitable for producing such a fine beam with a palm top device. A preliminary estimation shows that 200 keV electron bunch is available from a 0.8-mm-long accelerator and a few cm electron gun, which is driven by a few μJ, 5-ps laser pulse. We are developing a fiber laser in order to drive the photonic crystal accelerator. The Yb-fiber oscillator delivers mode-locked pulse train of ≈5 nJ/pulse at the repetition frequency of 62.5 MHz. The output pulse will be increased to several μJ by adopting a fiber amplifier

WEPPP062

Characterization and Stabilization of Multi-Bunch Instabilities at the ANKA Storage Ring

feedback, kicker, storage-ring, controls

2849

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

ANKA is a 2.5 GeV storage ring for synchrotron radiation. Up to 200 mA are accumulated at 0.5 GeV and then ramped to 2.5 GeV. In the past storage ring operation suffered from vertical multi-bunch instabilities. These could partially be cured by increased chromaticity, a large gap in the filling structure and by keeping the beam longitudinally unstable. A vertical digital bunch-by-bunch system from ITECH has been installed that allows an operation of the storage ring without exciting the longitudinal modes. In addition, the system allows analyzing multi-bunch instabilities both transverse and longitudinal and their dependence from cavity temperature, filling structure and chromaticity. This paper reports on our experience operating this system and presents an investigation of multi-bunch modes in the ANKA storage ring.

WEPPP083

Near Real-time Response Matrix Calibration for 10-Hz GOFB

feedback, dipole, damping, quadrupole

2903

C. Liu, R.L. Hulsart, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The 10-Hz global orbit feedback, for damping the trajectory perturbation (~10 Hz) due to the vibrations of the triplets, is operational for injection and store in RHIC. The operation of the system has been performed using transfer functions between the beam position monitors and correctors obtained from the online optics model and a correction algorithm based on singular value decomposition (SVD). Calibration of the transfer functions by measuring the beam position oscillations while modulating the dedicated correctors has been carried out. The feedback results with model matrix and measured matrix will be compared.

WEPPP085

Study on the Realignment Plan for J-PARC 3 GeV RCS after the Tohoku Earthquake in Japan

extraction, quadrupole, survey, alignment

2909

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

J-PARC 3GeV RCS suffered the big damage to its building and cooling and electric facilities by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. After the earthquake, RCS magnets were measured to confirm the state of accelerator beam line. As a result, it was found out that there was an alignment error of several millimeters in both horizontal and vertical directions that caused a deformation in the J-PARC 3GeV RCS tunnel. In this paper, we report the survey result in the accelerator tunnel after the earthquake and the realignment plan for J-PARC 3GeV RCS.

WEPPR005

Study of Electron Cloud Instability in Fermilab Main Injector

electron, simulation, proton, damping

2943

K. Ohmi
KEK, Ibaraki, Japan
R.M. Zwaska
Fermilab, Batavia, USA

Electron cloud has been observed in Fermilab main injector. Electron signal is enhanced near the transition. The slippage factor which suppress instabilities approach to zero at the transition. Instabilities must be most serious near the transition. The instability caused by the electron cloud is an important issue for high intensity operation and the future toward Project-X. Simulations of electron cloud instability near the transition is presented.

WEPPR006

Serpentine Acceleration in Scaling FFAG

acceleration, proton, closed-orbit, betatron

2946

E. Yamakawa, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, T. Uesugi
Kyoto University, Research Reactor Institute, Osaka, Japan
K. Okabe, I. Sakai
University of Fukui, Faculty of Engineering, Fukui, Japan

A serpentine acceleration in scaling FFAG accelerator is examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is derived analytically. Experiment to demonstrate a serpentine acceleration in scaling FFAG is done.

WEPPR007

Simulation Calculation of Longitudinal Beam Distribution in J-PARC MR

beam-loading, acceleration, simulation, extraction

2949

K. Hara, T. Koseki, C. Ohmori
KEK, Tokai, Ibaraki, Japan
Y. Sato
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC accelerator complex consists of 3 accelerators, a linear accelerator, a rapid cycle synchrotron (RCS) and a Main Ring (MR) synchrotron. Simulation calculation of longitudinal beam distribution in J-PARC Main Ring has been performed. The effect that RF voltage pattern, space charge, and beam loading gave was examined.

WEPPR018

Beam Experiments towards High-intensity Beams in RHIC

proton, vacuum, cryogenics, radiation

2979

C. Montag, L. A. Ahrens, M. Blaskiewicz, J.M. Brennan, K.A. Drees, W. Fischer, T. Hayes, H. Huang, K. Mernick, G. Robert-Demolaize, K.S. Smith, R. Than, P. Thieberger, K. Yip, K. Zeno, S.Y. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Proton bunch intensities in RHIC will be increased from 2*10¹¹ to 3*10¹¹ protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results will be presented.

WEPPR038

Independent Component Analysis (ICA) Applied to Long Bunch Beams in the Los Alamos Proton Storage Ring

betatron, linac, extraction, coupling

3018

J.S. Kolski, R.J. Macek, R.C. McCrady, X. Pang
LANL, Los Alamos, New Mexico, USA

Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis (PCA), which is the BSS foundation of the well known model independent analysis (MIA), ICA is more robust to noise, coupling, and nonlinearity. ICA of turn-by-turn beam position data has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch and discuss the source signals identified as betatron motion and longitudinal beam structure.

WEPPR058

The Vertical Impedance Distribution Measurement Using Response Matrix Method at BEPCII BPR

impedance, kicker, feedback, betatron

3057

Y. Wei, D. Ji
IHEP, Beijing, People's Republic of China

Funding: Work supported by the Chinese National Foundation of Natural Sciences, contract 111100512108.
In the last run of BEPCII, the single bunch current is limited to about 8mA by the beam-beam effect. To obtain the design luminosity, larger number of bunches are necessary. But higher total current may be limited by the collective effects. A good understanding of the transverse impedance distribution around the BEPCII storage ring is required. Response matrix method has been applied successfully in BEPCII to fit the quadrupole errors and restore the optics. We can also calculate the variation of betatron phase advance around the ring with different single bunch current using the response matrix method and the transverse impedance distribution is thus deduced. In this paper, the first measurement of transverse impedance in BEPCII is presented.

WEPPR065

Electromagnetic Simulations of the Impedance of the LHC Injection Protection Collimator

simulation, impedance, vacuum, wakefield

3075

B. Salvant, V. Baglin, B. Goddard, A. Grudiev, E. Métral, M.A. Timmins
CERN, Geneva, Switzerland

During the 2011 LHC run, significant vacuum and temperature increase were observed at the location of the LHC injection protection collimators (TDI) during the physics fills. Besides, measurements of the LHC transverse tune shift while changing the TDI gap showed that the impedance of the TDI was significantly higher than the LHC impedance model prediction based on multilayer infinite length theory. This contribution details the electromagnetic simulations performed with a full 3D model of the TDI to obtain both longitudinal and transverse impedances and their comparison with measured observables.

WEPPR069

Measurements and Simulations of Transverse Coupled-Bunch Instability Rise Times in the LHC

simulation, octupole, feedback, impedance

3087

N. Mounet, R. Alemany-Fernandez, W. Höfle, D. Jacquet, V. Kain, E. Métral, L. Ponce, S. Redaelli, G. Rumolo, R. Suykerbuyk, D. Valuch
CERN, Geneva, Switzerland

In the current configuration of the LHC, multibunch instabilities due to the beam-coupling impedance would be in principle a critical limitation if they were not damped by the transverse feedback. For the future operation of the machine, in particular at higher bunch intensities and/or higher number of bunches, one needs to make sure the coupled-bunch instability rise times are still manageable by the feedback system. Therefore, in May 2011 experiments were performed to measure those rise times and compare them with the results obtained from the LHC impedance model and the HEADTAIL wake fields simulation code. At injection energy, agreement turns out to be very good, while a larger discrepancy appears at top energy.

WEPPR071

Evaluation of the Beam Coupling Impedance of New Beam Screen Designs for the LHC Injection Kicker Magnets

impedance, kicker, coupling, simulation

3093

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

During the 2011 run of the LHC there was a measured temperature increase in the LHC Injection Kicker Magnets (LHC-MKI) during operation with 50ns bunch spacing. This was suspected to be due to increased beam-induced heating of the magnet due to beam impedance. Due to concerns about future heating with the increased total intensity to nominal and ultimate luminosities a review of the impedance reduction techniques within the magnet was required. A number of new beam screen designs are proposed and their impedance evaluated. Heating estimates are also given with a particular attention paid to future intensity upgrades to ultimate and HL-LHC parameters.

WEPPR072

Increasing Instability Thresholds in the SPS by Lowering Transition Energy

optics, emittance, extraction, coupling

3096

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

A new optics for the SPS with lower transition energy was tested experimentally during 2010-2011, showing a significant increase of the single bunch instability thresholds at injection, due to the 3-fold increase of the slip factor. This paper summarizes the series of performed machine studies for different LHC bunch structures and intensities. In particular, the search of the TMCI threshold in the new optics is presented. Observations on the longitudinal multi-bunch stability are compared between the nominal and the low-transition optics. Finally, optics variants with higher vertical tunes are discussed, which can allow to further increase the TMCI and vertical instability thresholds by reducing the vertical beta function.

WEPPR075

Monitoring the Progress of LHC Electron-Cloud Scrubbing by Benchmarking Simulations and Pressure-Rise Observations

electron, simulation, vacuum, dipole

3105

C.O. Domínguez, G. Arduini, E. Métral, G. Rumolo, F. Zimmermann
CERN, Geneva, Switzerland
G. Iadarola
Naples University Federico II, Science and Technology Pole, Napoli, Italy

Electron bombardment of a surface has been proven to reduce drastically the secondary electron yield of a material. This technique, known as scrubbing, is the ultimate solution to decrease the negative effects of an electron cloud build-up in any particle accelerator operating with intense beams. Its effectiveness has been already observed at the LHC. Since at the LHC no in-situ secondary-yield measurements are available, it has been necessary to develop a method to infer different key beam-pipe surface parameters by benchmarking simulations and pressure-rise observations. The method developed allows us to monitor the scrubbing process in order to decide on the most appropriate strategies for machine operation. In this paper we present the latest results of applying this method to the LHC in the fall of 2011 and early 2012, including data for the nominal bunch spacing of 25 ns.

WEPPR082

The Collective Effects of Long Straight Sections (LSSs) in the Advanced Photon Source Upgrade

impedance, undulator, storage-ring, collective-effects

3120

Y.-C. Chae, L.H. Morrison
ANL, Argonne, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357.
The Advanced Photon Source is a 7-GeV hard x-ray synchrotron light source. The APS Upgrade specifies additional beamlines delivering higher brightness and flux as well as for the short-pulse x-ray (SPX). In order to fulfill these demands we plan to provide long straight sections (LSS), for which the total length of the insertion devices is increased to 7.7m. The long straight section also helps in implementing the SPX scheme without removing insertion devices. However, the impedance of the LSS may reduce the single-bunch current of 16 mA per bunch delivered to the users during hybrid fill. We estimate the effect of LSS impedance on the bunched beam current and propose an impedance optimization of the undulator chamber with a small gap.

WEPPR085

Observation of Instabilities of Coherent Transverse Ocillations in the Fermilab Booster

coupling, booster, damping, space-charge

3129

Y. Alexahin, N. Eddy, E. Gianfelice-Wendt, V.A. Lebedev, W.L. Marsh, W. Pellico, A.K. Triplett
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The Fermilab Booster - built more than 40 years ago - operates well above the design proton beam intensity of 4.e12 ppp. Still, the Fermilab neutrino experiments call for even higher intensity of 5.5·10¹² ppp. A multitude of intensity related effects must be overcome in order to meet this goal including suppression of coherent dipole instabilities of transverse oscillations which manifest themselves as a sudden drop in the beam current. In this report we present the results of observation of these instabilities at different tune, coupling and chromaticity settings and discuss possible cures.

WEPPR090

A 4.2 GS/s Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback

controls, feedback, kicker, acceleration

3144

J.D. Fox, J.J. Olsen, C.H. Rivetta, I.I. Rivetta, O. Turgut, S. Uemura
SLAC, Menlo Park, California, USA
W. Höfle, U. Wehrle
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP).
A 4.2 GS/s beam excitation system with accelerator synchronization and power stages is described. The system is capable of playing unique samples (32 samples/bunch) for 15,000 turns on selected bunch(es) in the SPS in synchronism with the injection and acceleration cycle. The purpose of the system is to excite internal modes of single-bunch vertical motion, and study the bunch dynamics in the presence of developing Electron cloud or TMCI effects. The system includes a synchronized master oscillator, SPS timing functions, an FPGA based arbitrary waveform generator, 4.2 GS/sec. D/A system and four 80W 20 -1000 MHz amplifiers driving a tapered stripline pickup/kicker. A software GUI allows specification of various modulation signals and selection of bunches and turns to excite, while a remote control interface allows simple control/monitoring of the RF power stages located in the tunnel. Excitation signals developed to excite head-tail and other modes of vertical motion are illustrated. The successful use of this system for SPS MD measurements in August and November 2011 is a vital proof-of-principle for wideband feedback using similar functions to correct the beam motion.

THYB03

Collective Effects in the LHC and its Injector Complex

emittance, luminosity, linac, impedance

3218

E. Métral
CERN, Geneva, Switzerland

Operation during 4-8 hours at a constant luminosity of five times the nominal one (with “leveling”) is required for the CERN HL-(High Luminosity)-LHC project to be able to reach integrated luminosities of ~ 250 fb-1 per year and ~ 3 ab-1 twelve years after the upgrade. This means that the potential peak luminosity should be at least two times larger than the leveled one, i.e. a factor more than ten compared to the nominal case is contemplated. Even though the LHC had a bold beginning, reaching one third of the nominal peak luminosity at the end of the 2011 run, a factor more than thirty remains to be gained, which will be achieved only if all the collective effects are deeply understood and mastered both in the LHC and its injectors. The observations made during the 2010-2011 runs are first reviewed and compared to predictions to try and identify possible bottlenecks. The lessons learned and the possible solutions and/or mitigation measures to implement in the HL-LHC and the LHC Injectors Upgrade (LIU) projects are then discussed.

Slides THYB03 [34.295 MB]

THEPPB005

Study on the Injection Optimization and Transverse Coupling for CSNS/RCS

emittance, beam-losses, collimation, coupling

3240

M.Y. Huang, J. Qiu, S. Wang, S.Y. Xu
IHEP, Beijing, People's Republic of China

The injection system of the China Spallation Neutron Source uses H⁻ stripping and phase space painting method to fill large ring acceptance with the linac beam of small emittance. The emittance evolution, beam losses, and collimation efficiency during the injection procedures for different injection parameters, such as the injection emittances, starting injection time, twiss parameters and momentum spread, were studied, and then the optimized injection parameters was obtained. In addition, the phase space painting scheme which also affect the emittance evolution and beam losses were simulated and the optimization range of phase space painting were obtained. There will be wobble in the power supply of the injection bumps, and the wobble effects were presented. In order to study the transverse coupling, the injection procedures for different betatron tunes and momentum spreads were studied.

THPPC030

Multi-physics Analysis of the Fermilab Booster RF Cavity

cavity, booster, proton, extraction

3347

M.H. Awida, M.S. Champion, T.N. Khabiboulline, V.A. Lebedev, J. Reid, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE
After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

THPPD012

Measurement of Injection System of AC Septum Magnets for TPS Storage Ring

septum, storage-ring, shielding, vacuum

3521

F.-Y. Lin, C.-H. Chang, C.-S. Fann, C.-S. Hwang, C.S. Yang
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) is a 3 GeV third generation light source and will be operated in top-up injection mode. The leakage field of the septum magnet will dominate the injection performance. The septum magnets, parts of injection system, consist of AC and DC current mode magnets. The AC septum magnet were designed and constructed by NSRRC. In order to verify the magnetic field quality and the leakage field distribution, the search coil probe and the printed circuit technology for long coil probe measurement systems are developed and implemented for magnetic field measurement. This paper will describe the magnetic field measurement system, the magnetic field mapping results and the field shielding performance of AC septum magnet.

THPPD025

Expected and Measured Behaviour of the Tune in the LHC Operation at 3.5 TeV

quadrupole, dipole, feedback, betatron

3554

N. Aquilina
CERN, Geneva, Switzerland

The tune of the Large Hadron Collider depends on the strength of the quadrupole magnets, the b2 component in the main dipoles plus the b3 component in the main dipoles and the sextupolar correctors via feed down in case of systematic misalignment. The magnetic model of the machine, based on a fit of magnetic measurements, has an intrinsic precision which can be estimated in a few units. During the first years of operation of the LHC, tune has been routinely measured and corrected through a feedback system. In this paper we reconstruct from the beam measurements and the settings of the feedback loop the evolution of tune during injection, ramp, and squeeze. This gives the obtained precision of the magnetic model of the machine with respect to quadrupolar and sextupolar components. At the injection plateau there is an unexpected large decay whose origin is not understood: we present the data, with the time constants and the dependence on the previous cycles, and compare to the magnetic measurements. During the ramp the tune drifts by about 0.05: this precision is related to the precision in tracking the quadrupolar field in the machine.

THPPD026

Splice Resistance Measurements in the LHC Main Superconducting Magnet Circuits by the New Quench Protection System

dipole, monitoring, background, controls

3557

Z. Charifoulline, K. Dahlerup-Petersen, R. Denz, A.P. Siemko, J. Steckert
CERN, Geneva, Switzerland

The interconnections between the LHC main magnets are made of soldered joints (splices) of two superconducting cables stabilized by a copper bus bar. After the 2008 LHC incident, caused by a defective interconnection, a new layer of high resolution magnet circuit quench protection (nQPS) has been developed and integrated with the existing systems. It allowed mapping of the resistances of all superconducting splices during the 2009 commissioning campaign. Since April 2010, when the LHC was successfully restarted at 3.5TeV, every bus bar interconnection is constantly monitored by the nQPS electronics. The acquired data are saved to the LHC Logging Database. The paper will briefly describe the data analysis method and will present the results from the two years of resistance measurements. Although no splice was found with resistance higher than 3.3nOhm and no significant degradation in time was observed so far, the monitoring of splices will stay active till the end of LHC 3.5TeV run. The detected outliers will be repaired during the Splice Consolidation Campaign in 2013-2014.

THPPD038

Measurements of the Persistent Current Decay and Snapback Effect in Nb3Sn Accelerator Prototype Magnets at Fermilab

dipole, quadrupole, sextupole, multipole

3593

G. Velev, G. Chlachidze, J. DiMarco, V. Kashikhin
Fermilab, Batavia, USA

In recent years, Fermilab has been performing an intensive R&D program on Nb3Sn accelerator magnets. This program has included dipole and quadrupole magnets for different programs and projects, including LARP and VLHC. A systematic study of the persistent current decay and snapback effect in the fields of these magnets was executed at the Fermilab Magnet Test Facility. The decay and snapback were measured under a range of conditions including variations of the current ramp parameters and flattop and injection plateau durations. This study has mostly focused on the dynamic behavior of the normal sextupole and dodecapole components in dipole and quadrupole magnets respectively. The paper summarizes the recent measurements and presents a comparison with previously measured NbTi magnets.

THPPD039

Magnetic Analysis of a Single-Aperture 11T Nb3Sn Demonstrator Dipole for LHC Upgrades

dipole, simulation, sextupole, coupling

3596

B. Auchmann, M. Karppinen
CERN, Geneva, Switzerland
V. Kashikhin, A.V. Zlobin
Fermilab, Batavia, USA

Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
The planned upgrade of the LHC collimation system foresees additional collimators to be installed in the dispersion suppressor areas around points 2, 3, and 7. The necessary longitudinal space for the collimators could be provided by replacing some 8.33-T 15-m-long NbTi LHC main dipoles with shorter 11-T Nb3Sn dipoles compatible with the LHC lattice and main systems. To demonstrate this possibility, in 2011 Fermilab and CERN started a joint R&D program with the goal of building a 5.5-m-long twin-aperture dipole prototype suitable for installation in the LHC by 2014. The first step of this program is the development of a 2-m-long single-aperture demonstration dipole with the nominal field of 11 T at the LHC nominal current of ~11.85 kA and 60-mm bore with ~20% margin. This paper presents the results of magnetic analysis of the single-aperture Nb3Sn demonstrator dipole for the LHC collimation system upgrade.

THPPD051

New Power Supply of the Injection Bump Magnet for Upgrading the Injection Energy in the J-PARC 3-GeV RCS

power-supply, superconductivity, linac, proton

3626

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

With the energy upgrading of LINAC (Linear accelerator) to 400 MeV in the J-PARC (Japan Proton Accelerator Research Complex), a new power supply of the injection bump magnet has been designed for the 3-GeV RCS (Rapid Cycling Synchrotron). The new power supply is composed with the capacitor bank which has function to form the output current pattern. This power supply is a commutation strategy using the electrical charge and discharge of the capacitor, and the frequency of the switch that becomes the source of the noise is a little. Comparing to the conventional switching-type power supply, this power supply is switched only twice for the pattern formation. Thus, the ripple due to the switching can be expected to be much lower. The 1/16 scale model was manufactured and the characteristics was evaluated. This paper summarizes the design parameter and the experimental result of the new power supply.

THPPD052

Operation and Current Status of Injection, Extraction, Kicker Magnet and the Power Supply for J-PARC 3 GeV RCS

kicker, impedance, extraction, power-supply

3629

M. Watanabe, N. Hayashi, Y. Shobuda, K. Suganuma, T. Takayanagi, T. Togashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

3-GeV RCS (Rapid Cycling Synchrotron) at High Intensity Proton Accelerator Facility (J-PARC) have started for 24-hour operation with repetition rate of 25 pps in February, 2009. Kicker power supply system which uses thyratrons switches is used for extraction of the proton beam. There were many troubles for unstable operation of the thyratrons just after beam commissioning started. Recently, however, the operations were improved and the failure rate was reduced to approximately 0.1 % in October 2010. After the earthquake on March 11, 2011, the injection and extraction magnets, power supplies, the cables and the bus-duct have been checked. Insulation resistance test, impedance test were performed. Reflected wave measurements by the low-level and high-power pulse of the kicker magnets were performed. Visual checks by a fiber endoscope were also performed in the kicker magnets. The results of the measurements and the checks were all not in the problem.

THPPD067

Performance of Kicker Pulsers for TPS Project

kicker, power-supply, storage-ring, booster

3665

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

A set of kicker power suppliers has been designed and fabricated for storage ring beam injection of the Taiwan Photon Source (TPS) project. In order to fulfill the requirements, the performance of the designed units has been bench tested and the results are examined. The matching in four pulsers, the pulse-to-pulse stability and the time jitter are specified according to the beam injection requirements. The engineering evaluation and the measurement results are briefly discussed.

THPPD069

Adjustable Pulse Duration Fast Kicker for the CRYRING Storage Ring

kicker, extraction, high-voltage, controls

3671

J.-P. Lavieville, P. Lebasque
SOLEIL, Gif-sur-Yvette, France
W. Beeckman, O. Cosson
Sigmaphi, Vannes, France

The CRYRING storage ring of the Manne Siegbahn Laboratory (MSL, Stockholm) shall be moved to become part of FLAIR accelerators complex in Darmstadt to be used for deceleration of antiprotons and charged ions. That needs an upgrade to adapt it to the full energy range (30MeV – 0.13 MeV) of its future exploitation. SIGMAPHI, in close collaboration with SOLEIL light Source, is in charge of new fast injection and extraction magnets kickers and their pulsed power supplies. The injection will be done at maximum energy (30 MeV) while the extraction need to cover the full energy range (30 MeV – 0.13 MeV) that requires a continuous adjustment capability on the pulse duration and on the deviation amplitude. The development made specifically for the CRYRING kickers is based on a new design involving two different pulsed power supplies, each one managing either the fast rise time or the current flat top. Using solid state switches allows adapting simultaneously the pulse duration and its amplitude. This contribution presents the specific scheme and the development of a kicker system working up to 20 kV with pulse duration from 1.62 μs to 16.3 μs with transient times less than 300 ns.

THPPD075

Design and Measurements of a Fast High-voltage Pulse Generator for the MedAustron Low Energy Transfer Line Fast Deflector

high-voltage, synchrotron, power-supply, simulation

3689

T. Fowler, M.J. Barnes, T. Kramer, F. Müller, T. Stadlbauer
CERN, Geneva, Switzerland

MedAustron, a centre for ion-therapy and research, will comprise an accelerator facility based on a synchrotron for the delivery of protons and light ions for cancer treatment. The Low Energy Beam Transfer line (LEBT) to the synchrotron contains an electrostatic fast deflector (EFE) which, when energized, deviates the continuous beam arriving from the ion source onto a Faraday Cup: the specified voltage is ±3.5 kV. De-energizing the EFE for variable pulse durations from 500 ns up to d.c. allows beam passage for multi-turn injection into the synchrotron. To maintain beam quality in the synchrotron, the EFE pulse generator requires rise and fall times of less than 300 ns between 90 % of peak voltage and a ±1 V level. To achieve this, a pulsed power supply (PKF), with high voltage MOSFET switches connected in a push-pull configuration, will be mounted in close proximity to the deflector itself. A fast, large dynamic range monitoring circuit will verify switching to the ±1 V level and subsequent flat bottom pulse quality. A prototype will be installed in the injector test stand in 2012; this paper presents the design and first measurements of the PKF and its monitoring circuit.

THPPD083

Analysis of Kicker Noise Induced Beam Emittance Growth

kicker, emittance, high-voltage, monitoring

3710

W. Zhang, L. A. Ahrens, I. Blackler, M. Blaskiewicz, J.M. Brennan, W. Fischer, H. Hahn, H. Huang, N.A. Kling, M. Lafky, G.J. Marr, K. Mernick, J.-L. Mi, M.G. Minty, C. Naylor, T. Roser, J. Sandberg, T.C. Shrey, B. Van Kuik, A. Zelenski
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Over the last few years, physicists have suspected the presence of noise acting on the RHIC beams observable as occasional emittance growth at high beam energies. While the noise was sporadic in the past, it became more persistent during the run-11 setup period. An investigation diagnosed the source as originating from the RHIC abort kicker system. Once identified the issue was quickly resolved. We report in this paper the investigation result, circuit analysis, measured and simulated waveforms, solutions, and future plans.

THPPD085

Research and Development of RHIC Injection Kicker Upgrade with Nano Second FID Pulse Generator

kicker, high-voltage, monitoring, pulsed-power

3716

W. Zhang, W. Fischer, H. Hahn, C.J. Liaw, C. Pai, J. Sandberg, J.E. Tuozzolo
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Our recent effort to test a 50 kV, 1 kA, 50 ns pulse width, 10 ns pulse rise time FID pulse generator with 250 ft transmission cable, resistive load, and existing RHIC injection kicker magnet has produced unparalleled result. This is the very first attempt to drive a high strength fast kicker magnet with a nanosecond high pulsed power (50 MVA) generator for large accelerator and colliders. The technology is impressive. We report here the result and future plan of RHIC Injection kicker upgrade.

THPPP001

High Intensity Intermediate Charge State Heavy Ions in Synchrotrons

ion, septum, emittance, heavy-ion

3719

P.J. Spiller, U. Blell, L.H.J. Bozyk, H. Reich-Sprenger, J. Stadlmann
GSI, Darmstadt, Germany
Y. El-Hayek
FIAS, Frankfurt am Main, Germany

In order to reach the desired FAIR intensities for heavy ions, 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 machine design. After partially completing the upgrade program of SIS18, the number of intermediate charge state heavy ions accelerated to the FAIR booster energy of 200 MeV/u, could be increased by a factor of 70. The specific challenge for the SIS18 and SIS100 booster operation is the high cross section for ionization of the intermediate charge state heavy ions, in combination with gas desorption processes and the dynamic vacuum pressure. The achieved progress in minimizing the ionization beam loss underlines that the chosen technical strategies described in this report are appropriate. The latest intensity records and results from the machine development programs are presented.

THPPP004

Design and Test of Injection Kicker Magnets for the JPARC Main Ring

kicker, impedance, coupling, proton

3728

K. Fan, S. Fukuoka, K. Ishii, H. Matsumoto, H. Someya, T. Sugimoto, T. Toyama
KEK, Ibaraki, Japan

The present injection kicker magnets of the JPARC main ring consists of three transmission type kickers. To overcome the operational problems, four lumped inductance kicker magnets have been developed for the simplicity and the high reliability. The tight requirements on the rise and fall time create difficulties for the new design. Magnetic field measurements, coupling impedance measurements and have been carried out. The measurement results show that the new kicker magnets can satisfy the requirements of beam injection.

THPPP010

LHC Orbit Correction Reproducibility and Related Machine Protection

controls, feedback, status, luminosity

3746

K. Fuchsberger, T. Baer, R. Schmidt, J. Wenninger
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) has an unprecedented nominal stored beam energy of up to 362 MJ per beam. In order to ensure an adequate machine protection by the collimation system, a high reproducibility of the beam position at collimators and special elements like the final focus quadrupoles is essential. This is realized by a combination of manual orbit corrections, feed forward and real time feedback. In order to protect the LHC against inconsistent orbit corrections, which could put the machine in a vulnerable state, a novel software-based interlock system for orbit corrector currents was developed. In this paper, the principle of the new interlock system is described and the reproducibility of the LHC orbit correction is discussed against the background of this system.

THPPP012

Performance of the CERN Heavy Ion Production Complex

ion, target, proton, luminosity

3752

D. Manglunki, M. E. Angoletta, H. Bartosik, G. Bellodi, A. Blas, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, K. Cornelis, H. Damerau, I. Efthymiopoulos, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, S. Maury, M. O'Neil, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger
CERN, Geneva, Switzerland

The second LHC ion run took place at 1.38 A TeV/c per beam in autumn 2011; more than 100 inverse microbarns was accumulated by each of the experiments. In addition, the LHC injector chain delivered primary Pb and secondary Be ion beams to fixed target experiments in the North Area. This paper presents the current performance of the heavy ion production complex, and prospects to further improve it in the near future.

THPPP014

Design Parameters of a High-Power Proton Synchrotron for Neutrino Beams at Cern

proton, linac, space-charge, synchrotron

3755

Y. Papaphilippou, M. Benedikt, I. Efthymiopoulos, F. Gerigk, R. Steerenberg
CERN, Geneva, Switzerland

Design studies have been initiated at CERN for exploring the prospects of future high-power proton beams for producing neutrinos within the LAGUNA-LBNO project. These studies include a possible increase of the SPS beam power from 500kW to 700kW for a new conventional neutrino beam line based on the CNGS technology, and at a second stage a 2~MW High-Power Proton Synchrotron (HP-PS) using the Low Power Superconducting Proton Linac (LP-SPL) as injector. A low energy 5GeV-4MW neutrino super-beam alternative based on a high-power version of SPL is also considered. This paper concentrates on the HP-PS by exploring the parameter space and constraints regarding beam characteristics, machine hardware and layout, for reaching the 2~MW average beam power.

THPPP018

Operation of the LHC at High Luminosity and High Stored Energy

luminosity, vacuum, emittance, radiation

3767

J. Wenninger, R. Alemany-Fernandez, G. Arduini, R.W. Assmann, B.J. Holzer, E.B. Holzer, V. Kain, M. Lamont, A. Macpherson, G. Papotti, M. Pojer, L. Ponce, S. Redaelli, M. Solfaroli Camillocci, J.A. Uythoven, W. Venturini Delsolaro
CERN, Geneva, Switzerland

In 2011 the operation of the Large Hadron Collider LHC entered its first year of high luminosity production at a beam energy of 3.5 TeV. In the first months of 2011 the number of bunches was progressively increased to 1380, followed by a reduction of the transverse emittance, an increase of the bunch population and a reduction of the betatron function at the collision points. The performance improvements steps that were accumulated in 2011 eventually brought the peak luminosity to 3.6·10³³ cm^-2s⁻¹. The integrated luminosity delivered to each of the high luminosity experiments amounted to 5.6 fb-1, a factor of 5 above the initial target defined in 2010. The operational experience with high intensity and high luminosity at the LHC will be presented here, together with the issues that had to be tackled on the road to high intensity and luminosity.

THPPP021

6 Batch Injection and Slipped Beam Tune Measurements in Fermilab’s Main Injector

booster, proton, coupling, target

3776

D.J. Scott, D. Capista, I. Kourbanis, K. Seiya, M.-J. Yang
Fermilab, Batavia, USA

During Nova operations it is planned to run the Fermilab Recycler in a 12 batch slip stacking mode. In preparation for this, measurements of the tune during a six batch injection and then as the beam is slipped by changing the RF frequency, but without a 7th injection, have been carried out in the Main Injector. The coherent tune shifts due to the changing beam intensity were measured and compared well with the theoretically expected tune shift. The tune shifts due to changing RF frequency, required for slip stacking, also compare well with the linear theory, although some nonlinear affects are apparent at large frequency changes. These results give us confidence that the expected tunes shifts during 12 batch slip stacking Recycler operations can be accommodated.

THPPP023

Momentum Cogging at the Fermilab Booster

booster, dipole, controls, extraction

3782

K. Seiya, C.C. Drennan, W. Pellico, A.K. Triplett, A.M. Waller
Fermilab, Batavia, USA

The Fermilab booster has an intensity upgrade plan called the Proton Improvement plan (PIP). The flux throughput goal is 2·10¹⁷ protons/hour which is almost double the current operation at 1.10¹⁷ protons/hour. The beam loss in the machine is going to be an issue. The booster accelerates beam from 400 MeV to 8GeV and extracts to The Main Injector (MI). Cogging is the process that synchronizes the extraction kicker gap to the MI by changing radial position of the beam during the cycle. The gap creation occurs at about 700MeV which is 6msec into the cycle. The variation of the revolution frequency from cycle to cycle is larger at lower energy and it is hard to control by changing the radial position because of aperture limitations. Momentum cogging is able to move the gap creation earlier by using dipole correctors and radial position feedback, and controlling the revolution frequency and radial position at the same time. The new cogging is going to save energy loss and aperture. The progress of the momentum cogging system development is going to be discussed in this paper.

THPPP024

Alignment and Aperture Scan at the Fermilab Booster

booster, alignment, proton, lattice

3785

K. Seiya, J.R. Lackey, W.L. Marsh, W. Pellico, D.A. Still, A.K. Triplett, A.M. Waller
Fermilab, Batavia, USA

The Fermilab booster has an intensity upgrade plan called the Proton Improvement plan (PIP). The flux throughput goal is 2·10¹⁷ protons/hour, which is almost double the current operation at 1.10¹⁷ protons/hour. The beam loss in the machine is going to be the source of issues. The booster accelerates beam from 400 MeV to 8 GeV and extracts to the Main Injector. Several percent of the beam is lost within 3 msec after the injection. The aperture at injection energy was measured and compared with the survey data. The magnets are going to be realigned in March 2012 in order to increase the aperture. The beam studies, analysis of the scan and alignment data, and the result of the magnet moves will be discussed in this paper.

THPPP026

Experimental Effects of Orbit on Polarization Loss in RHIC

resonance, polarization, acceleration, proton

3788

V.H. Ranjbar
Tech-X, Boulder, Colorado, USA
M. Bai, H. Huang, A. Marusic, M.G. Minty, V. Ptitsyn
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We are performing several experiments during the RHIC ramp to better understand the impact of orbit errors on the polarization at our current working point. These will be conducted by exciting specified orbit harmonics during the final two large intrinsic resonance crossing in RHIC during the 250 GeV polarized proton ramp. The resultant polarization response will then be measured.

THPPP030

Near Integer Tune for Polarization Preservation in the AGS

optics, polarization, acceleration, resonance

3797

N. Tsoupas, L. A. Ahrens, M. Bai, K.A. Brown, J.W. Glenn, H. Huang, W.W. MacKay, T. Roser, V. Schoefer, K. Zeno
BNL, Upton, Long Island, New York, USA

Funding: *Work supported by the US Department of Energy.
The high energy (T=250 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the beam. In order to preserve the polarization of the proton beam, during the acceleration in the AGS, which is the pre-injector to RHIC, two partial helical magnets* have been installed in AGS. In order to minimize the loss of the beam polarization due to the various intrinsic spin resonances occurring during the proton acceleration, we constrain the value of the vertical tune to be higher than 8.97. With the AGS running at near integer tune the perturbations caused by the partial helical magnets is large resulting in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have introduced compensation quads** in AGS. In this paper we present the beam optics of the AGS which ameliorates this effect of the partial helices.
* H. Huang, et al., Proc. EPAC06, p. 273, (2006).
** N. Tsoupas et al., Proc. PAC07, p. 3723 (2007).

THPPP070

Comparison of the Residual Doses Before and After Resumption of User Operation in J-PARC RCS

alignment, target, scattering, neutron

3901

K. Yamamoto, H. Harada, S. Hatakeyama, N. Hayashi, H. Hotchi, M. Kinsho, R. Saeki, P.K. Saha, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

J-PARC Facilities were damaged by East Japan Earthquake in March 2011, but All Facirities resumed a beam operation from December 2012. In this paper, we report and compare the beam loss distribution and the residual doses before and after resumption of user operation in J-PARC RCS.

THPPP079

Status of J-PARC Main Ring After Recovery from the Great East Japan Earthquake Damage

extraction, kicker, proton, status

3915

T. Koseki
KEK, Ibaraki, Japan

The J-PARC facility was heavily damaged by the Great East Japan Earthquake on March 11, 2011. For the Main Ring synchrotron (MR), a few tens of cracks were found in the tunnel and many of them leaked groundwater. Displacements of magnet positions after the earthquake were larger than ±15 mm in horizontal and ±5 mm in vertical. Re-alignment of all the magnets and monitors in the MR were carried out in the autumn 2011. Accelerator study and users operation are plan to resume in December 2011 and January 2012, respectively. During the long shutdown period from March to December of 2011, we made work not only for the recovery from the earthquake damages but also for improvements to increase beam power as follows; replacement of injection kickers, upgrade of the ring collimator section, installation of a new collimator system in the slow extraction sections, two rf-systems, four skew-quadrupoles and three octupoles. In this paper, the recovery work and the improvements made in the shutdown periods are reported. Status of high power beam operation after the long shutdown is also presented in details.

THPPP080

Beam Halo Reduction in the J-PARC 3-GeV RCS

emittance, bunching, extraction, linac

3918

H. Hotchi, H. Harada, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie, T. Koseki, Y. Sato, M.J. Shirakata
KEK, Ibaraki, Japan
K. Satou
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC RCS (3-GeV rapid cycling synchrotron) has two functions as a proton driver to the MLF (Materials and life science facility) and an injector to the MR (50-GeV main ring synchrotron). One of important issues in the current RCS bam tuning is to suppress the beam halo formation, which is essential especially to reduce the beam loss at the MR. In this paper, we present beam study results on the formation mechanism and reduction of the beam halo in the RCS.

THPPP081

Status of Injection Energy Upgrade for J-PARC RCS

power-supply, impedance, quadrupole, kicker

3921

N. Hayashi, H. Harada, H. Hotchi, J. Kamiya, P.K. Saha, Y. Shobuda, T. Takayanagi, N. Tani, M. Watanabe, Y. Watanabe, K. Yamamoto, M. Yamamoto, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The injection energy upgrade for J-PARC RCS is planed in 2013. This includes the power supplies upgrade of injection pulsed magnet system, suppression for leakage field, quadrupole correction magnets, reduction of kicker impedance effect and improvements of beam diagnostic instrumentation. The paper reports the present status.

THPPP082

RF Feedforward System for Beam Loading Compensation in the J-PARC MR

impedance, cavity, beam-loading, proton

3924

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

For acceleration of high intensity proton beams in the J-PARC MR, beam loading compensation is important. In the MA-loaded RF cavity in the MR, which has a Q-value in the order of 20, the wake voltage consists of the accelerating harmonic (h=9) and the neighbor harmonics (h=8, 10). We employ the RF feedforward method for the beam loading compensation, like in the J-PARC RCS, in which the impedance seen by the beam is greatly reduced by the feedforward. The full-digital feedforward system developed for the MR has a similar architecture to that of the RCS. The system compensates the beam loading of the important three harmonics (h=8, 9, 10). We present the structure of the RF feedforward system. Also, we report the preliminary results of the beam tests.

THPPP083

Status of J-PARC 3 GeV RCS

extraction, beam-losses, beam-transport, vacuum

3927

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

J-PARC RCS have delivered beam progressively since 2008. The RCS ramped up the beam power, and delivered beam of 300kW equivalent and 220kW to MR and MLF, respectively, before the earthquake disaster. The RCS was heavily affected by the last Great East Japan Earthquake. At the RCS, the circulating road went wavy and the yard area for electricity and cooling water devices was heavily distorted. We have investigated damages of each device and also have tried to restore beam operation. From middle of December last year we could start beam test and also would start to deliver beam to MR and MLF for user operation from this January. We have been performed not only recovery works but also improvement of the RCS for realizing high power stable operation with low beam losses. I report status of beam operation and near future plan for the RCS.

THPPP088

Beam Loss Studies of the ISIS Synchrotron Using ORBIT

simulation, acceleration, synchrotron, emittance

3942

D.J. Adams
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
I.S.K. Gardner, B. Jones, B.G. Pine, A. Seville, H. V. Smith, C.M. Warsop, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS synchrotron forms part of the accelerator chain for the Spallation Neutron Source at RAL, UK. The synchrotron is an 800 MeV, 50Hz , RCS accelerating ~2.8·10¹³ protons per cycle. Beam loss is localized in two super periods of the ring using a system of collimators. The injection and acceleration processes, vacuum vessels and collimation systems have been modeled using the particle tracking code ORBIT. This paper presents simulation results in comparison to measurements of longitudinal profiles and beam loss.

THPPP097

Diagnostic Pulse for Single-particle-like Beam Position Measurements During Accumulation/Production Mode in the Los Alamos Proton Storage Ring

diagnostics, linac, betatron, LLRF

3960

J.S. Kolski, S.A. Baily, E. Björklund, G.O. Bolme, M.J. Hall, S. Kwon, M.P. Martinez, M.S. Prokop, F.E. Shelley, P.A. Torrez
LANL, Los Alamos, New Mexico, USA

Beam position monitors (BPMs) are the primary diagnostic in the Los Alamos Proton Storage Ring (PSR). Injecting one turn, the transverse motion is approximated as a single particle with initial betatron position and angle (x0 and x0'). With single-turn injection, we fit the betatron tune, closed orbit (CO), and injection offset (x0 and x0' at the injection point) to the turn-by-turn beam position. In production mode, we accumulate multiple turns, the transverse phase space fills after 5 injections (horizontal and vertical fractional betatron tunes ~0.2) resulting in no coherent betatron motion, and only the CO may be measured. The injection offset, which determines the accumulated beam size and is very sensitive to steering upstream of the ring, is not measurable in production mode. We describe our approach and ongoing efforts to measure the injection offset during production mode by injecting a ‘‘diagnostic'' pulse ~50 us after the accumulated beam is extracted. We also study the effects of increasing the linac RF gate length to accommodate the diagnostic pulse on the production beam position, transverse size, and loss.

THPPR013

Beam Transport in Alternative Lattices at the University of Maryland Electron Ring (UMER)

lattice, quadrupole, focusing, betatron

3993

S. Bernal, B.L. Beaudoin, M. Cornacchia, R.A. Kishek, D.F. Sutter
UMD, College Park, Maryland, USA

Funding: This work is funded by the US Dept. of Energy Offices of High Energy Physics and High Energy Density Physics, and by the US Dept. of Defense Office of Naval Research and Joint Technology Office.
We discuss the motivation, general procedure and results of first experiments of beam transport with two alternative focusing schemes at UMER, a low-energy (10 keV), high-current (1-100 mA) electron storage ring. The new ring optics simplifies injection and RMS envelope matching, and gives us a larger number of beam position monitors (BPMs) per (un-depressed) betatron wavelength, all of which are desirable conditions for better orbit control. Furthermore, one of the new optics schemes is more symmetrical than the standard one, facilitating e.g. the implementation of quadrupole scans for betatron resonance studies. The alternative lattices also allow us to expand significantly on the tune parameter space available for the study of space-charge dominated beam transport.

THPPR024

Upgrade of Radiation Monitoring System at SSRF for Top-up Operation

radiation, monitoring, controls, neutron

4014

X. Xia, J. Chen, J.J. Lv, W. Shen, T. Wan, W.F. Wu, X.J. Xu, H. Zhao
SINAP, Shanghai, People's Republic of China

The radiation monitoring system (RMS) at Shanghai Synchrotron Radiation Facility, SSRF, is required to upgrade to have dose interlock functions for top-up operation as an important safety issue. This paper describes the basic requirements, design criteria, signal network, and functions of the upgraded radiation monitoring system. Both the prompt dose rate and the accumulative dose alarm were archived for the safety issue after the upgrade. The reliability and stability of the upgraded RMS are in testing for getting operation permission from authority for radiation safety issue.

THPPR026

Automated Phase Optimization for the HDSM at MAMI

synchrotron, linac, microtron, acceleration

4020

M. Dehn
IKP, Mainz, Germany

Funding: This work has been supported by CRC 443 of the Deutsche Forschungsgemeinschaft.
The Harmonic Double Sided Microtron (HDSM) at Mainz University is a very reliable stage of the 1.6 GeV CW microtron cascade MAMI. Nevertheless setting up and operating the machine depends largely upon an appropriate adjustment of the RF systems. To assist the MAMI operators, a new approach basing on the analysis of the synchrotron oscillation has been developed and enables the optimization of the RF phases of the linacs for the given RF amplitudes.

THPPR034

Safety Interlock Implementation of Top-up Operation in the SSRF Control System

controls, storage-ring, booster, linac

4044

L.R. Shen, G.H. Chen, J.F. Chen, W.D. Fang
SINAP, Shanghai, People's Republic of China

The SSRF has performed two years stable operation on decay mode. In order to realize the Top-up operation, the upgrade of control system has been carried out for Top-up trial run. Control system sets up the operation mode control center and accomplishes the upgrading of the MPS system. According to the requirements of the physical design, control system accomplished the design and implementation of the interface for interoperate with PPS system, beam diagnosis system and power supply system and set up the interlocks of the radiation dose, energy, injection efficiency, beam current and beam life in Top-up mode. The kernel of top-up operation safety interlock system is based on hardware interlock system and also provides software interlocking as auxiliary. In the meantime, the reliability of software interlock has been improved.

THPPR039

Controlled Transverse Blow-Up of High-energy Proton Beams for Aperture Measurements and Loss Maps

emittance, feedback, resonance, proton

4059

W. Höfle, R.W. Assmann, S. Redaelli, R. Schmidt, D. Valuch, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

A technique was developed to blow-up transversely in a controlled way high energy proton beams in the LHC. The technique is based on band limited white noise excitation that is injected into the transverse damper feedback loop. The injected signal can be gated to selectively blow-up individual trains of bunches. The speed of transverse blow-up can be precisely controlled. This opens the possibility to perform safely and efficiently aperture measurements and loss maps with high intensity bunch trains well above stored beam energies that are considered to be safe. In particular, lengthy procedures for measurements at top energy, otherwise requiring multiple fills of individual bunches, can be avoided. In this paper, the method is presented and results from beam measurements are discussed and compared with alternative blow-up methods.

THPPR040

First Operational Experience with the LHC Machine Protection System when Operating with Beam Energies Beyond the 100 MJ Range

luminosity, monitoring, feedback, interlocks

4062

M. Zerlauth, R.W. Assmann, B. Dehning, M. Ferro-Luzzi, B. Goddard, M. Lamont, R. Schmidt, A.P. Siemko, J.A. Uythoven, J. Wenninger
CERN, Geneva, Switzerland

The LHC made a remarkable progress in luminosity production during 2011 operation. This was made possible by a progressive increase of beam intensities by more than 5 orders of magnitude, reaching stored beam energies beyond 100MJ at the end of the year. The correct functioning of the machine protection systems was vital during initial operation and even more when approaching nominal beam parameters, where an uncontrolled loss of a small fraction of the beam is already sufficient to damage accelerator equipment or the large experimental detectors The machine protection system depends on the interplay of many different elements: beam dumping system, beam interlocks, beam instrumentation, equipment monitoring, collimators and absorbers, etc. The strategy applied during 2011 to allow for an efficient but yet safe increase of the beam intensities is presented along with the associated risks and drawbacks of a too aggressive approach. The experience gained with the key systems will be discussed along with possibilities to further enhance machine availability whilst maintaining the current level of safety.

THPPR064

MW-class 800 MeV/n H²⁺ SC-Cyclotron for ADC application, Design Study and Goals

cyclotron, extraction, target, closed-orbit

4121

F. Méot, T. Roser, W.-T. Weng
BNL, Upton, Long Island, New York, USA
L. Calabretta
INFN/LNS, Catania, Italy
A. Calanna
CSFNSM, Catania, Italy

A megawatt class isochronous cyclotron is a potential candidate for accelerator driven systems, as in the subcritical-fission molten-salt reactor application. A scheme for a 800 MeV/nucleon cyclotron accelerating molecular H₂⁺ has been derived from on-going proton driver design studies for neutrino beam production. The present paper reports on beam dynamics studies regarding that cyclotron, exploiting its superconducting coil magnetic sector OPERA field map. These studies are aimed at assessing lattice properties as accelerated orbit, phase oscillations, tunes, beam envelopes and other resonance effects.