IPAC2013 - List of Keywords (multipole)

Paper	Title	Other Keywords	Page
MOODB102	Multiple Function Magnet Systems for MAX IV	dipole, quadrupole, octupole, sextupole	34
	F. Bødker, C.E. Hansen, N. Hauge, E.K. Krauthammer, D. Kristoffersen, G. Nielsen, C.W.O. Ostenfeld, C.G. Pedersen Danfysik A/S, Taastrup, Denmark
	Danfysik is currently producing 60 up to 3.3 m long magnet systems consisting of up to 12 multipole magnets integrated into each of the yokes for the bending achromats of the MAX IV 3 GeV storage ring and 12 similar systems for the MAX IV 1.5 GeV storage ring. Each magnet yoke contains combined function soft-end dipole and quadrupole elements which are machined out of one single iron block at tolerances of ± 0.02 mm. In addition, separate, higher order multipole magnets are kinematically mounted into the yokes. The integration of many magnetic elements into single yoke structures enables a compact, low emittance storage ring design. The dipole and quadrupole magnetic elements are magnetically field mapped with high precision on a 3D hall probe measuring bench. Higher order multipoles are measured on a slow rotating coil system developed for that purpose. Much effort has been put into automation in order to quickly perform the very comprehensive measurement program each girder will through.
	Slides MOODB102 [2.701 MB]

MOPWA035	Beam Loss Studies for the CERN PS Booster using FLUKA	injection, booster, beam-losses, extraction	744
	S. Damjanovic, B. Dehning, B. Mikulec, M. Sapinski CERN, Geneva, Switzerland
	In view of future upgrade plans, the beam loss monitor (BLM) coverage of the PS Booster (PSB) rings was reviewed. The response of two types of monitors, LHC-IC and LHC-LIC, has been studied with FLUKA at LINAC4 injection and PSB extraction energies. The goal of this study was to find out whether the current beam loss monitor coverage of two monitors at a certain location per PSB section was adapted to potential beam losses associated with a future Linac4 injection. The outcome of this study was a proposal to double the number of beam loss monitors in the PSB section by using a combination of horizontally oriented LHC-IC and LHC-LIC type monitors.

MOPWO001	Moment Method Beam Dynamics Code Development: Extended for Radio Frequency Quadrupole Simulations	rfq, simulation, quadrupole, radio-frequency	879
	T. Roggen, H. De Gersem, B. Masschaele KU Leuven, Kortrijk, Belgium W. Ackermann, S. Franke, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: This research is funded by grant “KUL 3E100118” “Electromagnetic Field Simulation for Future Particle Accelerators”, project FP7-Euratom No. 269565 and the Belgian Nuclear Research Centre (SCK•CEN). A Radio Frequency Quadrupole (RFQ) enables acceleration of a continuous low-velocity hadron beam, combining velocity independent electric focusing and adiabatic bunching, resulting in high-current compact bunches with nearly 100% capture and transmission efficiency. With virtually no post-construction tuning capabilities, an RFQ design phase requires all transient parameters (machining tolerances, thermo-mechanical deformation factors). This allows the determination of acceptable tolerances on input and output beam characteristics, of major importance in beam availability and beam trip prevention, and makes fast beam dynamics simulation codes incorporating RFQs indispensable. This article presents the implementation and validation of an RFQ beam line element into V-Code, a moment method beam dynamics simulation code. V-Code time integrates the Vlasov equation for an initial particle distribution represented by a discrete set of characteristic moments, accounting for all exerting internal and external forces. V-Code delivers highly accurate beam dynamics results with precision and efficiency advantages in terms of average or rms beam dimensions, projected emittances or total energy.

MOPWO027	Improved TEAPOT Method and Tracking with Thick Quadrupoles for the LHC and its Upgrade	quadrupole, optics, lattice, insertion	945
	H. Burkhardt, R. De Maria, M. Giovannozzi, T. Risselada CERN, Geneva, Switzerland
	The comparison between tracking with thick and thin lens models for the LHC have been studied. A widely-used method to generate thin models is based on the TEAPOT slicing, which, in the original implementation is limited in the number of slices. In this paper an improved method is presented, which overcomes some of the limitations of the original TEAPOT. The performance is analysed and the impact on numerical simulation of the dynamic aperture is evaluated, both for the LHC and its upgrade, HL-LHC.

MOPWO028	Recent Developments and Future Plans for SixTrack	simulation, collimation, ion, HOM	948
	R. De Maria, R. Bruce, R. Calaga, L. Deniau, M. Fjellstrom, M. Giovannozzi, L. Lari, Y.I. Levinsen, E. McIntosh, A. Mereghetti, D. Pastor Sinuela, S. Redaelli, H. Renshall, A. Rossi, F. Schmidt, R. Tomás, V. Vlachoudis CERN, Geneva, Switzerland R. Appleby, D.R. Brett UMAN, Manchester, United Kingdom D. Banfi, J. Barranco EPFL, Lausanne, Switzerland B. Dalena CEA/IRFU, Gif-sur-Yvette, France L. Lari IFIC, Valencia, Spain V. Previtali Fermilab, Batavia, USA G. Robert-Demolaize BNL, Upton, Long Island, New York, USA
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. SixTrack is a symplectic 6D tracking code routinely used to simulate single particle trajectories in high energy circular machines like the LHC and RHIC. The paper presents the developments recently implemented and those foreseen for extending the physics models: exact Hamiltonian, different ions and charge states, RF multipoles, non-linear fringe fields, Taylor maps, e-lenses, ion scattering. Moreover new functionalities are also added like variable number of tracked particles, time dependent strengths, GPU computations with a refactoring of the core structure. The developments will benefit studies on the LHC and SPS, for collimation efficiency, ion operations, failure scenarios and HL-LHC design.

MOPWO074	A Novel Differential Algebraic Adaptive Fast Multipole Method	target, simulation	1055
	S. Abeyratne, B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA B. Erdelyi, S.L. Manikonda ANL, Argonne, USA
	The direct pairwise calculation of the potential/electric field created by a very large number of particles is computationally impracticable since it requires long run time and a large amount of memory. The Fast Multipole Method (FMM) is a fast algorithm which scales linearly with the number of particles and it enables highly accurate evaluation of the potentials and fields among the large number of particles using less memory compared to the direct evaluation. The FMM has two main forms, non-adaptive and adaptive. The former is suitable for uniform distributions while the latter is more efficient for non-uniform distributions typically encountered in beam physics. This paper presents an implementation of a novel 3D adaptive FMM algorithm and some results obtained from simulations performed with non-uniform particle distributions.

TUPFI076	First RHIC Collider Test Operation at 2.5GeV Beam Energy	ion, dipole, injection, luminosity	1523
	C. Montag, L. A. Ahrens, M. Bai, J. Beebe-Wang, I. Blackler, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, W. Fischer, C.J. Gardner, X. Gu, M. Harvey, T. Hayes, L.T. Hoff, H. Huang, R.L. Hulsart, J.S. Laster, C. Liu, Y. Luo, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, S. Nemesure, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, J.E. Tuozzolo, M. Wilinski, A. Zaltsman, K. Zeno, W. 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. To search for the critical point in the QCD phase diagram, RHIC needs to operate at a set of low gold beam energies between 2.5 and 20 GeV per nucleon. During run 12, first successful collider operation at the lowest energy of 2.5 GeV per nucleon was achieved. We present the challenges and achieved results, and discuss possible future upgrades and improvements.

TUPWA064	Suppression of Halo Formation in FODO Focusing Channel with Nonlinear Focusing	quadrupole, focusing, space-charge, emittance	1850
	Y.K. Batygin, A. Scheinker LANL, Los Alamos, New Mexico, USA
	Averaging method was applied to analyze focusing properties of a quadrupole FODO channel with inserted multipole lenses. General expression for averaged focusing potential is obtained as a function of position of multipole lenses with respect to FODO quadrupole lenses. Obtained results were applied to the problem of intense beam transport in combined FODO structure. Numerical and analytical treatments of high-brightness beam dynamics with suppressed space-charge induced halo formation are presented.

TUPWO046	The ESS Linac Simulator: A First Benchmark with TraceWin	space-charge, linac, simulation, cavity	1970
	E. Laface, M. Eshraqi, R. Miyamoto ESS, Lund, Sweden
	The ESS Linac Simulator, ELS, will be the core of the online model used in the normal operations of the ESS linac. ESS Linac Simulator will operate through the eXtensible Accelerator Language, XAL, in order to provide an effective interface capable to simulate and predict the beam dynamics of the accelerator. The ELS is capable of simulating the dynamics of the beam envelope in both transverse and longitudinal planes in real time. In order to validate the effectiveness of the physics implemented, the ELS calculations are here benchmarked with TraceWin: the simulation code used for the design of the accelerator.

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

WEPWA055	Multipole and End-field Shimming Results of EPU46 at the TPS	quadrupole, undulator, polarization, electron	2244
	T.Y. Chung, C.-H. Chang, J. Chen, J.C. Huang, C.-S. Hwang, J.C. Jan, F.-Y. Lin NSRRC, Hsinchu, Taiwan
	Multipole error and the first and second integrals of EPU46 require shimming to fulfill the tolerance requirements of beam dynamics. In this paper, we describe the field correction, including central-field and end-field shimming procedures, and the results for EPU46 at TPS. End-pole shimming for the first and second integrals serve to adjust the beam trajectory, and magic fingers to decrease the multipole error. For the active multipole shimming for undulators of type Apple II, a trim-long-coil array is used to compensate for multipole error. This scheme efficiently eliminates a phase-dependent skew quadrupole error.

WEPWO045	RF Multipolar Characterization of the Latest LHC Deflecting Cavities	cavity, dipole, luminosity, extraction	2402
	M. Navarro-Tapia, R. Calaga, A. Grudiev CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. Deflecting cavity geometries considered for the Large Hadron Collider (LHC)crab scheme lack axial symmetry resulting in non-zero higher-order components of the deflecting field. A formalism to express the higher-order multipoles was developed and applied on previous cavity designs to characterize their influence on the beam stability. In this paper, the radio frequency (RF) multipoles are numerically estimated for the latest cavity geometries and compared to the older versions. A sensitivity study is carried to understand the numerical error levels and define mechanical tolerances.

WEPWO047	A Double Quarter-Wave Deflecting Cavity for the LHC	cavity, HOM, higher-order-mode, simulation	2408
	R. Calaga CERN, Geneva, Switzerland S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404 An asymmetric quarter wave deflecting cavity at 400 MHz for crab crossing in the LHC was already proposed in 2011. Due to improved cancellation of on-axis longitudinal field and the higher order components of the deflecting field, a symmetric version is now considered as the baseline for the quarter wave geometry. Relevant RF properties of the symmetric cavity are compared to the original asymmetric cavity. Some aspects of input coupler design, higher order modes, multipacting and frequency tuning are also addressed.

WEPWO079	Superconducting Single-spoke Cavities for High-velocity Applications	cavity, electron, higher-order-mode, linac	2480
	C.S. Hopper, J.R. Delayen, R.G. Olave ODU, Norfolk, Virginia, USA
	Spoke cavities have been investigated for particle acceleration in the high-velocity regime. As part of these efforts, single-spoke cavities for particles traveling at the speed of light are being designed and built for proof-of-principle demonstration. We report here on the results of electromagnetic properties, design optimization, multipacting analysis, field non-linearities and higher order mode spectrum for a single-spoke cavity operating at 325 MHz.

WEPWO080	Compact Superconducting RF-dipole Cavity Designs for Deflecting and Crabbing Applications	dipole, cavity, HOM, higher-order-mode	2483
	S.U. De Silva, A. Castilla, J.R. Delayen ODU, Norfolk, Virginia, USA A. Castilla DCI-UG, León, Mexico
	Over the years the superconducting parallel-bar design has evolved into an rf-dipole cavity with improved properties. The new rf-dipole design is considered for number of deflecting and crabbing applications. Some of those applications are the 499 MHz rf separator system for the Jefferson Lab 12 GeV upgrade, 400 MHz crabbing cavity system for the proposed LHC high luminosity upgrade, and 750 MHz crabbing cavity for the medium energy electron-ion collider in Jefferson Lab. In this paper we present the optimized rf design in terms of rf performance including rf properties, higher order mode properties, multipacting, multipole expansion for the above mentioned applications.

WEPEA015	Possibility Study of High Repetition Rate Operation of JPARC Main Ring	sextupole, injection, quadrupole, space-charge	2528
	K. Fan, S. Igarashi, K. Ishii, T. Koseki, M. Uota KEK, Ibaraki, Japan
	The original design of JPARC main ring is to provide high beam power of 750 kW with machine repetition rate of 0.3 Hz. However, the severe space charge effects at low injection energy limit the beam intensity. In order to raise the beam power to the design limit, one logical way is to increase the repetition rate. However, the resulting eddy current in the laminations and pipes may impair the field quality of all magnets. In addition, the activation of beam pipe becomes severer in high beam power operation. Titanium beam pipe is proposed to replace the stainless steel pipe to reduce the activation and decrease the decay time. However, titanium has lower resistivity, severer eddy current effects are expected. The studies investigate the eddy current effects on field quality of the main dipole, quadrupole and sextupole magnets.

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

WEPEA045	Specifications of the Field Quality at Injection Energy of the New Magnets for the HL-LHC Upgrade Project	injection, dynamic-aperture, simulation, optics	2603
	R. De Maria, S.D. Fartoukh, M. Giovannozzi CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The HL-LHC project relies on new magnet designs and technologies to achieve very small β^* values. In particular, Nb3Sn magnets show large allowed multipole imperfections at low current. These field errors may have a non-negligible impact on the dynamic aperture and beam life time in the HL-LHC, also because of the smaller-than-nominal β^* values foreseen IR1 and IR5 at injection energy, which aims at decreasing the dynamic range of the squeeze and therefore contributing to optimize the turn around time. The paper describes an analysis of the machine performance based on analytical estimates and tracking simulations with the goal of providing field quality specifications for the new magnets.

WEPEA047	Dynamic Aperture Performance for Different Collision Optics Scenarios for the LHC Luminosity Upgrade	optics, luminosity, dynamic-aperture, injection	2609
	M. Giovannozzi, R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland A. Chancé, B. Dalena, J. Payet CEA/IRFU, Gif-sur-Yvette, France K.M. Hock, M. Korostelev, A. Wolski The University of Liverpool, Liverpool, United Kingdom J. Resta-López IFIC, Valencia, Spain
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The ATS[1] optics solution for the HL-LHC offers the possibility of different collision optics, with a β^* as small as 10 cm in both transverse planes, or with a β^* aspect ratio of up to 4 pushing β^* to even smaller value (5cm) in the parallel separation plane while relaxing it (20 cm) in the crossing plane. The latter configuration features two possible options for alternated orientations of the crossing plane in the two high luminosity insertions, both considered in this study. In this paper we study the impact of few selected field imperfection models of the new magnets foreseen for the upgrade through tracking simulations and scaling laws. [1] S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA048	Specification of a System of Correctors for the Triplets and Separation Dipoles of the LHC Upgrade	dipole, simulation, optics, insertion	2612
	M. Giovannozzi, R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The luminosity upgrade of the LHC aims at reducing β^* from 55 cm to 15 cm or beyond. This can be achieved by the ATS* scheme and means of new large aperture superconducting triplet (IT) quadrupoles (150 mm), preferably using the Nb3Sn technology in order to keep the gradient reasonably high (140 T/m). The field quality requires careful specification in order to ensure a large enough dynamic aperture. In this context, dedicated corrector magnets are foreseen to provide semi-local corrections of specific multipole components and find the best possible compromise between the demand and what can be realistically achieved by the magnet manufacturer. In this paper the layout and main parameters of the IT corrector package are presented together with the correction strategy. Moreover, the foreseen performance is discussed in detail. * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA076	Comparison of Taylor Maps with Radio Frequency Multipoles in a Thin Lens 6D Tracking Code	cavity, luminosity, collider, hadron	2687
	D.R. Brett, R. Appleby UMAN, Manchester, United Kingdom J. Barranco, R. De Maria, R. Tomás CERN, Geneva, Switzerland
	Funding: HiLumi LHC Design Study is part of the High Luminosity LHC project and is part funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. SixTrack is a general purpose 6D thin lens tracking code used for dynamic aperture studies. In the high luminosity LHC upgrade it is proposed that crab cavities are used to enhance the luminosity. In this study, for the current proposed optics, we consider the use of RF multipoles and Taylor maps as methods to simulate crab cavity elements in the lattice.

THPFI017	Development of Harmonic Field Measurement System with Higher Resolution ADC	background, dipole, quadrupole, focusing	3330
	R. Kitahara, Y. Fuwa, Y. Iwashita, Y. Nasu Kyoto ICR, Uji, Kyoto, Japan
	Quadrupole magnets for ILC final focus should be enough strong with the limitation on the external radius, while the vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few m downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for the purpose, which is under investigation. The precise magnetic harmonic field measurement system is also under development for adjusting each magnet ring and evaluation of the assembled singlet. A rotating magnet system and a rotating coil system are prepared for the former and the latter purposes, respectively. Both systems have 24-bit ADC's for higher resolution. For the rotation coil, a flexible print circuit sheet, where a pair of one turn coils is printed on, is glued on a quartz rod. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. The two digitized signals are integrated digitally.

THPME011	Magnetic Field Design of the BAPS High Precision Quadrupole Magnet	quadrupole, storage-ring, photon, vacuum	3531
	Y.S. Zhu, F.S. Chen, W. Kang, X.J. Sun IHEP, Beijing, People's Republic of China
	The Beijing Advanced Photon Source (BAPS) is a high performance light source planned to be constructed in China. High precision small aperture quadrupole magnets are required in the BAPS storage ring, which needs extremely high mechanical accuracy. Instead of the conventional manufacture method, the coils are comprised of several U-shaped solid copper sheets. So two-piece structure of the iron core can be adopted to reduce assembly error and improve the poles symmetry. Design considerations, 2D and 3D magnetic field calculations are presented in detail, and the needed mechanical precision is estimated according to the error field analysis.

THPME012	Measuring the Direction of Permanent Magnet Easy Axis by Helmholtz Coil	quadrupole, permanent-magnet, DTL, linac	3534
	X.Y. Jia, S.X. Zheng TUB, Beijing, People's Republic of China
	Permanent magnets for quadrupole focusing was used in drift-tube linac of the Compact Pulsed Hadron Sources(CPHS) in Tsinghua university. In order to ensure the accuracy of the quadrupole field can meet the design requirement, we need measure the strength and direction of remanence and choose the suit magnet. This paper proposed an easy way to get the direction of permanent magnet easy axis by Helmholtz coil without knowing the angle between magnet and the axis of the coil: the magnet rotational angle data was measured by rotary encoder and encoder would send trigger signal every turn at the same direction. First we started to record data when trigger signal was appeared. Then measured the magnet in three perpendicular directions (x,y,z). Last, caculated the remanence in three directions. We had measured some magnet by the new method and obtained satisfactory results.

THPME021	Application of Magnetic Field Integral Measurement of Magnet Module to Research Alterable Gap Undulator	controls, undulator, quadrupole, synchrotron	3549
	H.F. Wang, W. Zhang, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	A set of magnetic measurement system and a suitable magnetic field optimization method for an In-Vacuum Undulator (IVU) with alterable gaps have been developed. The method is based on assembling orders and directions of all magnet modules for correcting rms optical phase error, electron trajectory and multipole components of the IVU. Magnetic field distributions on axis and off axis of every magnet block module are measured. Then the appropriate magnetic block modules will be chosen from measured magnet modules according to a sorting algorithm and assemble them to two inner girders of an IVU. This paper will describe a magnetic field measurement system, magnetic field optimization method and optimized results of an IVU with a period of 20 mm.

THPME023	A NEW HARMONIC COIL BENCH AT SINAP FOR THE ALS COMBINED FUNCTION SEXTUPOLE MAGNETS	dipole, sextupole, controls, quadrupole	3552
	J.D. Zhang, H.W. Du, L. Yin, Q.G. Zhou SINAP, Shanghai, People's Republic of China N. Li, A. Madur LBNL, Berkeley, California, USA
	A new harmonic coil bench has been developed at Shanghai Institute of Applied Physics (SINAP) to measure the ALS combined function sextupole magnets. The measurement system has been designed with the aim to perform precise, fast and reliable measurements of series of magnets. It determines the strength, and the multipole content of the field as well as the magnetic axis for precise positioning of alignment targets on top of the multipoles. The multipole, while supported on a marble platform, can be moved with regard to the rotating coil using multi-dimensional adjustment plate. The resolution of the movement is read out by micrometer with a few μm resolutions. This article introduces the measurement system constitutes.

THPME037	Magnetic Field Character of TPS Booster Magnets	quadrupole, sextupole, dipole, booster	3594
	J.C. Jan, C.-H. Chang, H.-H. Chen, Y.L. Chu, M.-H. Huang, C.-S. Hwang, C.Y. Kuo, F.-Y. Lin, C.S. Yang, Y.T. Yu NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is a 3-GeV synchrotron radiation facility operated in top-up injection mode. The booster ring of TPS shares the same tunnel, concentric with the storage ring. The lattice of the booster is a 24-cell DBA of circumference 496.8 m. The energy of the electron beam is ramped from 150 MeV to 3 GeV at repetition rate 3 Hz in the booster ring. The trajectory of the electron beam is controlled with complicated combined-function magnets including combined dipole magnet, combined quadrupole magnet, pure quadrupole magnet, sextupole magnet and corrector magnet. The measurement and performance of these magnets are discussed in this letter.

THPME041	Configurable Field Magnets for a Proton Beam Dynamics R&D Ring	dipole, injection, proton, space-charge	3603
	S.J. Brooks STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Magnets with many independently-powered coils can provide nearly arbitrary combinations of multipoles up to a certain order. This paper gives examples of field quality in such an "omni-magnet", which is normal-conducting and simulated with Poisson. Since the magnets also have quite large apertures they may be used to make a general-purpose FFAG and synchrotron test ring for beam dynamics studies. This could use the 3MeV H⁻ beam from the RAL proton Front End Test Stand (FETS) and outline ring parameters are given for that situation.

THPME046	A Summary of the Quality of the ALS Combined Function Sextupole Magnets	sextupole, dipole, quadrupole, controls	3615
	N. Li, A. Madur LBNL, Berkeley, California, USA C. Chen, H.J. Hu, J. Jin, Y.M. Wen, L. Yin, J.D. Zhang, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231. A total of 51 combined function magnets is required to upgrade the Advanced Light Source (ALS) Storage Ring at LBNL. These magnets will provide 4 types of magnetic fields: sextupole, horizontal and vertical dipoles, and skew quadrupole and will enable an emittance reduction and upgrade of the beam quality in the ALS ring. A relatively new procedure using EDM cut poles after core assembly that was first used by Buckley System Ltd, NZ was adopted during the production of these magnets. Also, a new 3D CAD modeling was used for the coil design. A total of 57 magnets (including prototypes and spare magnets) were built by the Shanghai Institute of Applied Physics (SINAP) in China. These magnets have achieved extraordinarily high pole profile accuracies and exhibit excellent coil performance characteristics: resistances and water flows reached a high degree of consistency. Consequently, the system errors of the magnetic field of these magnets all meet the LBNL specifications. This paper will summarize the mechanical quality and magnetic field properties of these magnets. The interrelationship between the qualities of coil and the magnet field will be described as well.

THPME052	Analysis of the NSLS-II Magnet Measurement Data	dipole, quadrupole, sextupole, storage-ring	3624
	W. Guo, A.K. Jain, S.K. Sharma, J. Skaritka, C.J. Spataro BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 NSLS-II is a third generation 3GeV light source that is under-construction at the Brookhaven National Laboratory. The 30-DBA-cell storage ring will provide micron size beam resulting from the 1nm emittance. Recently the last magnet was received and the completion of girder installation in the tunnel is foreseeable in a few months. In this paper we will briefly review the physics considerations for the magnet specifications, the major field quality related issues that arose during the fabrication process. Our emphasis will be on the statistical analysis of the magnet measurement results and comparison with the design tolerances.

THPWO024	PROGRESS ON DTL DESIGN FOR ESS	DTL, linac, emittance, simulation	3815
	M. Comunian, F. Grespan, A. Pisent, C. Roncolato INFN/LNL, Legnaro (PD), Italy R. De Prisco ESS, Lund, Sweden P. Mereu INFN-Torino, Torino, Italy
	In the European Spallation Source (ESS) accelerator, the Drift Tube Linac (DTL) will accelerate a proton beam of 50 mA pulse peak current from 3 to ~80 MeV. In this paper the engineering design of DTL tanks with the beam dynamics errors studies and the RF design are shown.

Paper

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MOODB102

Multiple Function Magnet Systems for MAX IV

dipole, quadrupole, octupole, sextupole

34

F. Bødker, C.E. Hansen, N. Hauge, E.K. Krauthammer, D. Kristoffersen, G. Nielsen, C.W.O. Ostenfeld, C.G. Pedersen
Danfysik A/S, Taastrup, Denmark

Danfysik is currently producing 60 up to 3.3 m long magnet systems consisting of up to 12 multipole magnets integrated into each of the yokes for the bending achromats of the MAX IV 3 GeV storage ring and 12 similar systems for the MAX IV 1.5 GeV storage ring. Each magnet yoke contains combined function soft-end dipole and quadrupole elements which are machined out of one single iron block at tolerances of ± 0.02 mm. In addition, separate, higher order multipole magnets are kinematically mounted into the yokes. The integration of many magnetic elements into single yoke structures enables a compact, low emittance storage ring design. The dipole and quadrupole magnetic elements are magnetically field mapped with high precision on a 3D hall probe measuring bench. Higher order multipoles are measured on a slow rotating coil system developed for that purpose. Much effort has been put into automation in order to quickly perform the very comprehensive measurement program each girder will through.

Slides MOODB102 [2.701 MB]

MOPWA035

Beam Loss Studies for the CERN PS Booster using FLUKA

injection, booster, beam-losses, extraction

744

S. Damjanovic, B. Dehning, B. Mikulec, M. Sapinski
CERN, Geneva, Switzerland

In view of future upgrade plans, the beam loss monitor (BLM) coverage of the PS Booster (PSB) rings was reviewed. The response of two types of monitors, LHC-IC and LHC-LIC, has been studied with FLUKA at LINAC4 injection and PSB extraction energies. The goal of this study was to find out whether the current beam loss monitor coverage of two monitors at a certain location per PSB section was adapted to potential beam losses associated with a future Linac4 injection. The outcome of this study was a proposal to double the number of beam loss monitors in the PSB section by using a combination of horizontally oriented LHC-IC and LHC-LIC type monitors.

MOPWO001

Moment Method Beam Dynamics Code Development: Extended for Radio Frequency Quadrupole Simulations

rfq, simulation, quadrupole, radio-frequency

879

T. Roggen, H. De Gersem, B. Masschaele
KU Leuven, Kortrijk, Belgium
W. Ackermann, S. Franke, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: This research is funded by grant “KUL 3E100118” “Electromagnetic Field Simulation for Future Particle Accelerators”, project FP7-Euratom No. 269565 and the Belgian Nuclear Research Centre (SCK•CEN).
A Radio Frequency Quadrupole (RFQ) enables acceleration of a continuous low-velocity hadron beam, combining velocity independent electric focusing and adiabatic bunching, resulting in high-current compact bunches with nearly 100% capture and transmission efficiency. With virtually no post-construction tuning capabilities, an RFQ design phase requires all transient parameters (machining tolerances, thermo-mechanical deformation factors). This allows the determination of acceptable tolerances on input and output beam characteristics, of major importance in beam availability and beam trip prevention, and makes fast beam dynamics simulation codes incorporating RFQs indispensable. This article presents the implementation and validation of an RFQ beam line element into V-Code, a moment method beam dynamics simulation code. V-Code time integrates the Vlasov equation for an initial particle distribution represented by a discrete set of characteristic moments, accounting for all exerting internal and external forces. V-Code delivers highly accurate beam dynamics results with precision and efficiency advantages in terms of average or rms beam dimensions, projected emittances or total energy.

MOPWO027

Improved TEAPOT Method and Tracking with Thick Quadrupoles for the LHC and its Upgrade

quadrupole, optics, lattice, insertion

945

H. Burkhardt, R. De Maria, M. Giovannozzi, T. Risselada
CERN, Geneva, Switzerland

The comparison between tracking with thick and thin lens models for the LHC have been studied. A widely-used method to generate thin models is based on the TEAPOT slicing, which, in the original implementation is limited in the number of slices. In this paper an improved method is presented, which overcomes some of the limitations of the original TEAPOT. The performance is analysed and the impact on numerical simulation of the dynamic aperture is evaluated, both for the LHC and its upgrade, HL-LHC.

MOPWO028

Recent Developments and Future Plans for SixTrack

simulation, collimation, ion, HOM

948

R. De Maria, R. Bruce, R. Calaga, L. Deniau, M. Fjellstrom, M. Giovannozzi, L. Lari, Y.I. Levinsen, E. McIntosh, A. Mereghetti, D. Pastor Sinuela, S. Redaelli, H. Renshall, A. Rossi, F. Schmidt, R. Tomás, V. Vlachoudis
CERN, Geneva, Switzerland
R. Appleby, D.R. Brett
UMAN, Manchester, United Kingdom
D. Banfi, J. Barranco
EPFL, Lausanne, Switzerland
B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
L. Lari
IFIC, Valencia, Spain
V. Previtali
Fermilab, Batavia, USA
G. Robert-Demolaize
BNL, Upton, Long Island, New York, USA

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
SixTrack is a symplectic 6D tracking code routinely used to simulate single particle trajectories in high energy circular machines like the LHC and RHIC. The paper presents the developments recently implemented and those foreseen for extending the physics models: exact Hamiltonian, different ions and charge states, RF multipoles, non-linear fringe fields, Taylor maps, e-lenses, ion scattering. Moreover new functionalities are also added like variable number of tracked particles, time dependent strengths, GPU computations with a refactoring of the core structure. The developments will benefit studies on the LHC and SPS, for collimation efficiency, ion operations, failure scenarios and HL-LHC design.

MOPWO074

A Novel Differential Algebraic Adaptive Fast Multipole Method

target, simulation

1055

S. Abeyratne, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA
B. Erdelyi, S.L. Manikonda
ANL, Argonne, USA

The direct pairwise calculation of the potential/electric field created by a very large number of particles is computationally impracticable since it requires long run time and a large amount of memory. The Fast Multipole Method (FMM) is a fast algorithm which scales linearly with the number of particles and it enables highly accurate evaluation of the potentials and fields among the large number of particles using less memory compared to the direct evaluation. The FMM has two main forms, non-adaptive and adaptive. The former is suitable for uniform distributions while the latter is more efficient for non-uniform distributions typically encountered in beam physics. This paper presents an implementation of a novel 3D adaptive FMM algorithm and some results obtained from simulations performed with non-uniform particle distributions.

TUPFI076

First RHIC Collider Test Operation at 2.5GeV Beam Energy

ion, dipole, injection, luminosity

1523

C. Montag, L. A. Ahrens, M. Bai, J. Beebe-Wang, I. Blackler, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, W. Fischer, C.J. Gardner, X. Gu, M. Harvey, T. Hayes, L.T. Hoff, H. Huang, R.L. Hulsart, J.S. Laster, C. Liu, Y. Luo, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, S. Nemesure, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, J.E. Tuozzolo, M. Wilinski, A. Zaltsman, K. Zeno, W. 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.
To search for the critical point in the QCD phase diagram, RHIC needs to operate at a set of low gold beam energies between 2.5 and 20 GeV per nucleon. During run 12, first successful collider operation at the lowest energy of 2.5 GeV per nucleon was achieved. We present the challenges and achieved results, and discuss possible future upgrades and improvements.

TUPWA064

Suppression of Halo Formation in FODO Focusing Channel with Nonlinear Focusing

quadrupole, focusing, space-charge, emittance

1850

Y.K. Batygin, A. Scheinker
LANL, Los Alamos, New Mexico, USA

Averaging method was applied to analyze focusing properties of a quadrupole FODO channel with inserted multipole lenses. General expression for averaged focusing potential is obtained as a function of position of multipole lenses with respect to FODO quadrupole lenses. Obtained results were applied to the problem of intense beam transport in combined FODO structure. Numerical and analytical treatments of high-brightness beam dynamics with suppressed space-charge induced halo formation are presented.

TUPWO046

The ESS Linac Simulator: A First Benchmark with TraceWin

space-charge, linac, simulation, cavity

1970

E. Laface, M. Eshraqi, R. Miyamoto
ESS, Lund, Sweden

The ESS Linac Simulator, ELS, will be the core of the online model used in the normal operations of the ESS linac. ESS Linac Simulator will operate through the eXtensible Accelerator Language, XAL, in order to provide an effective interface capable to simulate and predict the beam dynamics of the accelerator. The ELS is capable of simulating the dynamics of the beam envelope in both transverse and longitudinal planes in real time. In order to validate the effectiveness of the physics implemented, the ELS calculations are here benchmarked with TraceWin: the simulation code used for the design of the accelerator.

WEPWA033

The Magnetic Performance of Two Undulators for HLS

undulator, polarization, electron, vacuum

2202

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

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

WEPWA055

Multipole and End-field Shimming Results of EPU46 at the TPS

quadrupole, undulator, polarization, electron

2244

T.Y. Chung, C.-H. Chang, J. Chen, J.C. Huang, C.-S. Hwang, J.C. Jan, F.-Y. Lin
NSRRC, Hsinchu, Taiwan

Multipole error and the first and second integrals of EPU46 require shimming to fulfill the tolerance requirements of beam dynamics. In this paper, we describe the field correction, including central-field and end-field shimming procedures, and the results for EPU46 at TPS. End-pole shimming for the first and second integrals serve to adjust the beam trajectory, and magic fingers to decrease the multipole error. For the active multipole shimming for undulators of type Apple II, a trim-long-coil array is used to compensate for multipole error. This scheme efficiently eliminates a phase-dependent skew quadrupole error.

WEPWO045

RF Multipolar Characterization of the Latest LHC Deflecting Cavities

cavity, dipole, luminosity, extraction

2402

M. Navarro-Tapia, R. Calaga, A. Grudiev
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
Deflecting cavity geometries considered for the Large Hadron Collider (LHC)crab scheme lack axial symmetry resulting in non-zero higher-order components of the deflecting field. A formalism to express the higher-order multipoles was developed and applied on previous cavity designs to characterize their influence on the beam stability. In this paper, the radio frequency (RF) multipoles are numerically estimated for the latest cavity geometries and compared to the older versions. A sensitivity study is carried to understand the numerical error levels and define mechanical tolerances.

WEPWO047

A Double Quarter-Wave Deflecting Cavity for the LHC

cavity, HOM, higher-order-mode, simulation

2408

R. Calaga
CERN, Geneva, Switzerland
S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA

Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
An asymmetric quarter wave deflecting cavity at 400 MHz for crab crossing in the LHC was already proposed in 2011. Due to improved cancellation of on-axis longitudinal field and the higher order components of the deflecting field, a symmetric version is now considered as the baseline for the quarter wave geometry. Relevant RF properties of the symmetric cavity are compared to the original asymmetric cavity. Some aspects of input coupler design, higher order modes, multipacting and frequency tuning are also addressed.

WEPWO079

Superconducting Single-spoke Cavities for High-velocity Applications

cavity, electron, higher-order-mode, linac

2480

C.S. Hopper, J.R. Delayen, R.G. Olave
ODU, Norfolk, Virginia, USA

Spoke cavities have been investigated for particle acceleration in the high-velocity regime. As part of these efforts, single-spoke cavities for particles traveling at the speed of light are being designed and built for proof-of-principle demonstration. We report here on the results of electromagnetic properties, design optimization, multipacting analysis, field non-linearities and higher order mode spectrum for a single-spoke cavity operating at 325 MHz.

WEPWO080

Compact Superconducting RF-dipole Cavity Designs for Deflecting and Crabbing Applications

dipole, cavity, HOM, higher-order-mode

2483

S.U. De Silva, A. Castilla, J.R. Delayen
ODU, Norfolk, Virginia, USA
A. Castilla
DCI-UG, León, Mexico

Over the years the superconducting parallel-bar design has evolved into an rf-dipole cavity with improved properties. The new rf-dipole design is considered for number of deflecting and crabbing applications. Some of those applications are the 499 MHz rf separator system for the Jefferson Lab 12 GeV upgrade, 400 MHz crabbing cavity system for the proposed LHC high luminosity upgrade, and 750 MHz crabbing cavity for the medium energy electron-ion collider in Jefferson Lab. In this paper we present the optimized rf design in terms of rf performance including rf properties, higher order mode properties, multipacting, multipole expansion for the above mentioned applications.

WEPEA015

Possibility Study of High Repetition Rate Operation of JPARC Main Ring

sextupole, injection, quadrupole, space-charge

2528

K. Fan, S. Igarashi, K. Ishii, T. Koseki, M. Uota
KEK, Ibaraki, Japan

The original design of JPARC main ring is to provide high beam power of 750 kW with machine repetition rate of 0.3 Hz. However, the severe space charge effects at low injection energy limit the beam intensity. In order to raise the beam power to the design limit, one logical way is to increase the repetition rate. However, the resulting eddy current in the laminations and pipes may impair the field quality of all magnets. In addition, the activation of beam pipe becomes severer in high beam power operation. Titanium beam pipe is proposed to replace the stainless steel pipe to reduce the activation and decrease the decay time. However, titanium has lower resistivity, severer eddy current effects are expected. The studies investigate the eddy current effects on field quality of the main dipole, quadrupole and sextupole magnets.

WEPEA021

Influence of the Vacuum Chamber Limitation on Dynamic Aperture Calculations

dynamic-aperture, vacuum, resonance, optics

2543

M. Attal
SESAME, Allan, Jordan

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

WEPEA045

Specifications of the Field Quality at Injection Energy of the New Magnets for the HL-LHC Upgrade Project

injection, dynamic-aperture, simulation, optics

2603

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

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The HL-LHC project relies on new magnet designs and technologies to achieve very small β^* values. In particular, Nb3Sn magnets show large allowed multipole imperfections at low current. These field errors may have a non-negligible impact on the dynamic aperture and beam life time in the HL-LHC, also because of the smaller-than-nominal β^* values foreseen IR1 and IR5 at injection energy, which aims at decreasing the dynamic range of the squeeze and therefore contributing to optimize the turn around time. The paper describes an analysis of the machine performance based on analytical estimates and tracking simulations with the goal of providing field quality specifications for the new magnets.

WEPEA047

Dynamic Aperture Performance for Different Collision Optics Scenarios for the LHC Luminosity Upgrade

optics, luminosity, dynamic-aperture, injection

2609

M. Giovannozzi, R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland
A. Chancé, B. Dalena, J. Payet
CEA/IRFU, Gif-sur-Yvette, France
K.M. Hock, M. Korostelev, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The ATS[1] optics solution for the HL-LHC offers the possibility of different collision optics, with a β^* as small as 10 cm in both transverse planes, or with a β^* aspect ratio of up to 4 pushing β^* to even smaller value (5cm) in the parallel separation plane while relaxing it (20 cm) in the crossing plane. The latter configuration features two possible options for alternated orientations of the crossing plane in the two high luminosity insertions, both considered in this study. In this paper we study the impact of few selected field imperfection models of the new magnets foreseen for the upgrade through tracking simulations and scaling laws.
[1] S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA048

Specification of a System of Correctors for the Triplets and Separation Dipoles of the LHC Upgrade

dipole, simulation, optics, insertion

2612

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

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The luminosity upgrade of the LHC aims at reducing β^* from 55 cm to 15 cm or beyond. This can be achieved by the ATS* scheme and means of new large aperture superconducting triplet (IT) quadrupoles (150 mm), preferably using the Nb3Sn technology in order to keep the gradient reasonably high (140 T/m). The field quality requires careful specification in order to ensure a large enough dynamic aperture. In this context, dedicated corrector magnets are foreseen to provide semi-local corrections of specific multipole components and find the best possible compromise between the demand and what can be realistically achieved by the magnet manufacturer. In this paper the layout and main parameters of the IT corrector package are presented together with the correction strategy. Moreover, the foreseen performance is discussed in detail.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA076

Comparison of Taylor Maps with Radio Frequency Multipoles in a Thin Lens 6D Tracking Code

cavity, luminosity, collider, hadron

2687

D.R. Brett, R. Appleby
UMAN, Manchester, United Kingdom
J. Barranco, R. De Maria, R. Tomás
CERN, Geneva, Switzerland

Funding: HiLumi LHC Design Study is part of the High Luminosity LHC project and is part funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
SixTrack is a general purpose 6D thin lens tracking code used for dynamic aperture studies. In the high luminosity LHC upgrade it is proposed that crab cavities are used to enhance the luminosity. In this study, for the current proposed optics, we consider the use of RF multipoles and Taylor maps as methods to simulate crab cavity elements in the lattice.

THPFI017

Development of Harmonic Field Measurement System with Higher Resolution ADC

background, dipole, quadrupole, focusing

3330

R. Kitahara, Y. Fuwa, Y. Iwashita, Y. Nasu
Kyoto ICR, Uji, Kyoto, Japan

Quadrupole magnets for ILC final focus should be enough strong with the limitation on the external radius, while the vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few m downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for the purpose, which is under investigation. The precise magnetic harmonic field measurement system is also under development for adjusting each magnet ring and evaluation of the assembled singlet. A rotating magnet system and a rotating coil system are prepared for the former and the latter purposes, respectively. Both systems have 24-bit ADC's for higher resolution. For the rotation coil, a flexible print circuit sheet, where a pair of one turn coils is printed on, is glued on a quartz rod. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. The two digitized signals are integrated digitally.

THPME011

Magnetic Field Design of the BAPS High Precision Quadrupole Magnet

quadrupole, storage-ring, photon, vacuum

3531

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

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

THPME012

Measuring the Direction of Permanent Magnet Easy Axis by Helmholtz Coil

quadrupole, permanent-magnet, DTL, linac

3534

X.Y. Jia, S.X. Zheng
TUB, Beijing, People's Republic of China

Permanent magnets for quadrupole focusing was used in drift-tube linac of the Compact Pulsed Hadron Sources(CPHS) in Tsinghua university. In order to ensure the accuracy of the quadrupole field can meet the design requirement, we need measure the strength and direction of remanence and choose the suit magnet. This paper proposed an easy way to get the direction of permanent magnet easy axis by Helmholtz coil without knowing the angle between magnet and the axis of the coil: the magnet rotational angle data was measured by rotary encoder and encoder would send trigger signal every turn at the same direction. First we started to record data when trigger signal was appeared. Then measured the magnet in three perpendicular directions (x,y,z). Last, caculated the remanence in three directions. We had measured some magnet by the new method and obtained satisfactory results.

THPME021

Application of Magnetic Field Integral Measurement of Magnet Module to Research Alterable Gap Undulator

controls, undulator, quadrupole, synchrotron

3549

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

A set of magnetic measurement system and a suitable magnetic field optimization method for an In-Vacuum Undulator (IVU) with alterable gaps have been developed. The method is based on assembling orders and directions of all magnet modules for correcting rms optical phase error, electron trajectory and multipole components of the IVU. Magnetic field distributions on axis and off axis of every magnet block module are measured. Then the appropriate magnetic block modules will be chosen from measured magnet modules according to a sorting algorithm and assemble them to two inner girders of an IVU. This paper will describe a magnetic field measurement system, magnetic field optimization method and optimized results of an IVU with a period of 20 mm.

THPME023

A NEW HARMONIC COIL BENCH AT SINAP FOR THE ALS COMBINED FUNCTION SEXTUPOLE MAGNETS

dipole, sextupole, controls, quadrupole

3552

J.D. Zhang, H.W. Du, L. Yin, Q.G. Zhou
SINAP, Shanghai, People's Republic of China
N. Li, A. Madur
LBNL, Berkeley, California, USA

A new harmonic coil bench has been developed at Shanghai Institute of Applied Physics (SINAP) to measure the ALS combined function sextupole magnets. The measurement system has been designed with the aim to perform precise, fast and reliable measurements of series of magnets. It determines the strength, and the multipole content of the field as well as the magnetic axis for precise positioning of alignment targets on top of the multipoles. The multipole, while supported on a marble platform, can be moved with regard to the rotating coil using multi-dimensional adjustment plate. The resolution of the movement is read out by micrometer with a few μm resolutions. This article introduces the measurement system constitutes.

THPME037

Magnetic Field Character of TPS Booster Magnets

quadrupole, sextupole, dipole, booster

3594

J.C. Jan, C.-H. Chang, H.-H. Chen, Y.L. Chu, M.-H. Huang, C.-S. Hwang, C.Y. Kuo, F.-Y. Lin, C.S. Yang, Y.T. Yu
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is a 3-GeV synchrotron radiation facility operated in top-up injection mode. The booster ring of TPS shares the same tunnel, concentric with the storage ring. The lattice of the booster is a 24-cell DBA of circumference 496.8 m. The energy of the electron beam is ramped from 150 MeV to 3 GeV at repetition rate 3 Hz in the booster ring. The trajectory of the electron beam is controlled with complicated combined-function magnets including combined dipole magnet, combined quadrupole magnet, pure quadrupole magnet, sextupole magnet and corrector magnet. The measurement and performance of these magnets are discussed in this letter.

THPME041

Configurable Field Magnets for a Proton Beam Dynamics R&D Ring

dipole, injection, proton, space-charge

3603

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

Magnets with many independently-powered coils can provide nearly arbitrary combinations of multipoles up to a certain order. This paper gives examples of field quality in such an "omni-magnet", which is normal-conducting and simulated with Poisson. Since the magnets also have quite large apertures they may be used to make a general-purpose FFAG and synchrotron test ring for beam dynamics studies. This could use the 3MeV H⁻ beam from the RAL proton Front End Test Stand (FETS) and outline ring parameters are given for that situation.

THPME046

A Summary of the Quality of the ALS Combined Function Sextupole Magnets

sextupole, dipole, quadrupole, controls

3615

N. Li, A. Madur
LBNL, Berkeley, California, USA
C. Chen, H.J. Hu, J. Jin, Y.M. Wen, L. Yin, J.D. Zhang, Q.G. Zhou
SINAP, Shanghai, People's Republic of China

Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231.
A total of 51 combined function magnets is required to upgrade the Advanced Light Source (ALS) Storage Ring at LBNL. These magnets will provide 4 types of magnetic fields: sextupole, horizontal and vertical dipoles, and skew quadrupole and will enable an emittance reduction and upgrade of the beam quality in the ALS ring. A relatively new procedure using EDM cut poles after core assembly that was first used by Buckley System Ltd, NZ was adopted during the production of these magnets. Also, a new 3D CAD modeling was used for the coil design. A total of 57 magnets (including prototypes and spare magnets) were built by the Shanghai Institute of Applied Physics (SINAP) in China. These magnets have achieved extraordinarily high pole profile accuracies and exhibit excellent coil performance characteristics: resistances and water flows reached a high degree of consistency. Consequently, the system errors of the magnetic field of these magnets all meet the LBNL specifications. This paper will summarize the mechanical quality and magnetic field properties of these magnets. The interrelationship between the qualities of coil and the magnet field will be described as well.

THPME052

Analysis of the NSLS-II Magnet Measurement Data

dipole, quadrupole, sextupole, storage-ring

3624

W. Guo, A.K. Jain, S.K. Sharma, J. Skaritka, C.J. Spataro
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
NSLS-II is a third generation 3GeV light source that is under-construction at the Brookhaven National Laboratory. The 30-DBA-cell storage ring will provide micron size beam resulting from the 1nm emittance. Recently the last magnet was received and the completion of girder installation in the tunnel is foreseeable in a few months. In this paper we will briefly review the physics considerations for the magnet specifications, the major field quality related issues that arose during the fabrication process. Our emphasis will be on the statistical analysis of the magnet measurement results and comparison with the design tolerances.

THPWO024

PROGRESS ON DTL DESIGN FOR ESS

DTL, linac, emittance, simulation

3815

M. Comunian, F. Grespan, A. Pisent, C. Roncolato
INFN/LNL, Legnaro (PD), Italy
R. De Prisco
ESS, Lund, Sweden
P. Mereu
INFN-Torino, Torino, Italy

In the European Spallation Source (ESS) accelerator, the Drift Tube Linac (DTL) will accelerate a proton beam of 50 mA pulse peak current from 3 to ~80 MeV. In this paper the engineering design of DTL tanks with the beam dynamics errors studies and the RF design are shown.