IPAC2011 - List of Keywords (dipole)

Paper	Title	Other Keywords	Page
MOPC021	Design of a Choke-mode Damped Accelerating Structure for CLIC Main Linac	damping, impedance, wakefield, HOM	113
	J. Shi, A. Grudiev, W. Wuensch CERN, Geneva, Switzerland H. Chen, W.-H. Huang, C.-X. Tang, H. Zha TUB, Beijing, People's Republic of China
	Choke-mode damped accelerating structures are being studied as an alternative to the CLIC baseline structure by a CERN-Tsinghua collaboration. Choke-mode structures hold the potential for much lower levels of pulsed surface heating and, since milling is not needed, reduced cost. Structures with radial choke attached are simulated in Gdfidl to investigate the damping of the transverse wake. The first pass-band of the dipole modes is well damped, while the higher order dipole modes are possible to be reflected by the choke. Therefore, the geometry of the choke is tuned to minimize the reflection of these higher order dipoles. Based on this damping scheme, an accelerating structure with the same iris dimensions as the nominal CLIC design but with choke-mode damping has been designed. A prototype structure will be manufactured and high power tested in the near future.

MOPC024	Construction Status of the CPHS RFQ at Tsinghua University	rfq, quadrupole, cavity, vacuum	122
	Q.Z. Xing, Y.J. Bai, J.C. Cai, C. Cheng, L. Du, T. Du, X. Guan, Q. Qiang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China J.H. Billen TechSource, Santa Fe, New Mexico, USA W.Q. Guan, Y. He, J. Li NUCTECH, Beijing, People's Republic of China J. Stovall CERN, Geneva, Switzerland L.M. Young AES, Medford, NY, USA
	Funding: Work supported by the “985 Project” of the Ministry of Education of China. We present, in this paper, the construction status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The 3-meter-long RFQ will deliver 3 MeV protons to the downstream Drift Tube Linac (DTL) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. The RFQ has been mechanically separated into three sections. A ball-end mill, instead of a forming cutter, is adopted to machine the vane tip due to its varying radius of curvature. The precision of the numerically controlled milling machine has been verified by machining test pieces of aluminum and copper. Fine machining of the vanes was completed in July, 2011. The pre-braze tuning was completed at the beginning of this August.

MOPC040	The Measurement of Transversal Shunt Impedance of RF Deflector	cavity, impedance, simulation, emittance	163
	A.Yu. Smirnov, M.V. Lalayan, N.P. Sobenin MEPhI, Moscow, Russia A.A. Zavadtsev Nano, Moscow, Russia
	This paper presents the results of transverse shunt impedance measurement performed using field perturbation technique and comparison with numerical MWS simulations. The structure under test is the S-band 3-cell deflecting cavity. The mentioned cavity operates with a dipole TM11-like mode with a phase shift of 120 deg per cell. The analyses were carried out with use of two types of perturbing beads: dielectric beads and metallic rings. The latter type perturbs the on-axis magnetic field much stronger than the electric field, which allows us calculating transversal shunt impedance using on-axis EM fields values.

MOPC044	Design of the Radiofrequency Quadrupole Coldmodel for the ESS-BILBAO Linear Accelerator	rfq, quadrupole, simulation, radio-frequency	175
	A. Velez, I. Bustinduy, N. Garmendia, O. Gonzalez, J.L. Munoz, D. de Cos ESS Bilbao, Bilbao, Spain F.J. Bermejo Bilbao, Faculty of Science and Technology, Bilbao, Spain V. Etxebarria, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	This work will present the design of the ESS-Bilbao LINAC RFQ cold model. The process goes through the electromagnetic design of the cavity by properly setting the resonant quadrupole and dipole modes, as well as the resonance frequency. The prototype includes the vane modulation designed to accelerate a 75 mA proton beam from 75 keV to 3 MeV, with an operating frequency of 352.2 MHz. To this end, electromagnetic and electrostatic simulations have been performed by means of the commercial software COMSOL. Furthemore, results for the three components of the electrical field distribution will be presented and compared to those calculated by evaluating the 8-term multipole expansion.

MOPC061	Simulations to Flatten the Field of the FETS RFQ	rfq, simulation, cavity, quadrupole	223
	S.R. Lawrie, A.P. Letchford STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom J.K. Pozimski, P. Savage Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	A high performance Radio Frequency Quadrupole (RFQ) is the next major component to be installed on the Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) in the UK. The beam dynamics, RF, thermal and mechanical designs of the RFQ are almost complete and so the copper has recently been purchased with a view to start cutting metal near Summer-time. This report summarizes the simulation work performed to ensure the RF design is sound. This includes performance studies of the end-wall dipole suppression fingers, tuning the frequency of the input and output vane end regions and implementing a simple solution to remove modulation induced field tilt.

MOPC096	Design and Fabrication of a 5-Cell High Current Superconducting Cavity	cavity, HOM, simulation, quadrupole	301
	Y.M. Li, K.X. Liu, S.W. Quan, F. Zhu PKU/IHIP, Beijing, People's Republic of China R. Nassiri ANL, Argonne, USA
	Funding: National High Technology Research and Development program 863 (2009AA03Z206) Energy recovery linacs (ERL) is promising to achieve high average current with superior beam quality. The key component for accelerating such high current beams is the superconducting radio frequency (SRF) cavity. The design of a 1.3 GHz 5-cell high current superconducting cavity has been carried out under the cooperation between Peking University (PKU) and Argonne National Laboratory (ANL). RF properties, damping of the HOMs, multipacting and mechanical features of this cavity have been discussed and the final design is presented.

MOPC106	Study of the Variation of Transverse Voltage in the 4 Rod Crab Cavity for LHC	cavity, luminosity, simulation, HOM	322
	B.D.S. Hall, P.K. Ambattu, G. Burt, C. Lingwood Cockcroft Institute, Lancaster University, Lancaster, United Kingdom P. Goudket, C. Hill STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The planned high luminosity upgrade to LHC will utilise crab cavities to rotate the beam in order to increase the luminosity in the presence of a finite crossing angle. A compact design is required in order for the cavities to fit between opposing beam-lines. In this paper we discuss we discuss one option for the LHC crab cavity based on a 4 rod TEM deflecting cavity. Due to the large transverse size of the LHC beam the cavity is required to have a large aperture while maintaining a constant transverse voltage across the aperture. The cavity has been optimised to minimise the variation of the transverse voltage while keeping the peak surface electric and magnetic fields low for a given kick. This is achieved while fitting within the strict design space of the LHC. The variation of deflecting voltage across the aperture has been studied numerically and compared with numerical and analytical estimates of other deflecting cavity types. Performance measurements an aluminium prototype of this cavity are presented and compared to the simulated design.

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

MOPS030	Beam Dynamics of the FRANZ Bunch Compressor using Realistic Fields with a Focus on the Rebuncher Cavities	cavity, linac, simulation, focusing	667
	D. Noll, L.P. Chau, M. Droba, O. Meusel, H. Podlech, U. Ratzinger, C. Wiesner IAP, Frankfurt am Main, Germany
	Funding: Work supported by HIC for FAIR. The ARMADILLO bunch compressor currently being designed at IAP is capable of reaching a longitudinal pulse compression ratio of 45 for proton beams of 150 mA at 2 MeV. It will provide one nanosecond proton pulses with a peak current of 7.7 A. The system guides nine linacμbunches deflected by a 5 MHz rf kicker and uses four dipole magnets - two homogeneous and two with field gradients - to merge them on the target. For longitudinal focusing and an energy variation of ±200 keV two multitrack rf cavities are included. ARMADILLO will be installed at the end of the Frankfurt Neutron Source FRANZ making use of the unique 250 kHz time structure. This contribution will provide an overview of the layout of the system as well as recent advances in component design and beam dynamics of the compressor.

MOPS033	Beam Dynamics Studies on the 100 MeV/100 kW Electron Linear Accelerator for NSC KIPT Neutron Source	linac, electron, gun, simulation	673
	S. Pei, Y.L. Chi, M. Hou, W.B. Liu, G. Pei, S.H. Wang, Z.S. Zhou IHEP Beijing, Beijing, People's Republic of China N. Aizatsky, I.M. Karnaukhov, V.A. Kushnir, V. Mitrochenco, A.Y. Zelinsky NSC/KIPT, Kharkov, Ukraine
	We designed one 100MeV/100kW electron linear accelerator for NSC KIPT, which will be used to drive a neutron source on the base of subcritical assembly. Beam dynamics studies has been conducted to reach the design requirement (E=100MeV, P=100kW, dE/E<1% for 99% particles). In this paper, we will present the progress of the design and dynamics simulation results. For high intensity and long beam pulse linear accelerators, BBU effect is one big issue; special care has been taken in the accelerating structure design. To satisfy the energy spread requirement at the linac exit, the particles with large energy difference from the synchronous particle should be eliminated at low energy stage to ease the design of the collimation system and radiation shielding. A dispersion free chicane with 4 bending magnets is introduced at the downstream of the 1st accelerating section; the unwanted particles will be collimated there.

MOPS047	Studies of Transverse Single-pass Beam Breakup in E-Linac	HOM, cavity, linac, emittance	706
	D. Kaltchev, R.A. Baartman, Y.-C. Chao, P. Kolb, S.R. Koscielniak, L. Merminga, A.K. Mitra, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Time-domain simulations of single-pass transverse beam-breakup (BBU) effects in E-linac are described. We use dipole-HOM parameters for the 9-cell cavity obtained with Particle Studio to evaluate the rms bunch orbit offsets at linac exit. Finding the multi-bunch orbit contribution to machine emittance as a function of the average beam current allows to evaluate the performance of two cavity models for two different modes of machine operation.

MOPS053	Electron Cloud Effects in Coasting Heavy-ion Beams*	electron, simulation, ion, accumulation	724
	F.B. Petrov, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany O. Boine-Frankenheim GSI, Darmstadt, Germany
	Funding: Work supported by BMBF under contract 06DA9022I. During slow extraction of intense ion beams electron clouds (EC) can accumulate in the circulating coasting beam and reduce the extraction efficiency. This is a concern for the existing SIS-18 heavy ion synchrotron at GSI and for the projected SIS-100 as part of the FAIR project. For medium energy heavy-ion beams the production of electrons from residual gas ionization is very effective. The electron density is limited due to Coulomb scattering by the beam ions. Above a threshold beam intensity the two-stream instability and the resulting coherent beam oscillations limit the electron density. Below this threshold the electron cloud can lead to observable deformations of the Schottky side-bands. To avoid EC build-up one can introduce a gap in the beam using barrier rf bucket. The reduction of the build-up efficiency caused by the gap is studied in details based on the solution of the Hill's equation for electrons. Finally we estimate the saturation level for the electron cloud density.

MOPS056	An Analytical Formula of the Electron Cloud Linear Map Coefficient in a Strong Dipole	electron, vacuum, simulation, storage-ring	733
	T. Demma INFN/LNF, Frascati (Roma), Italy S. Petracca, A. Stabile U. Sannio, Benevento, Italy G. Rumolo CERN, Geneva, Switzerland
	Electron cloud effects have been indentified as one of the most serious bottleneck for reaching design performances in presently running and proposed future storage rings. The analysis of these effects is usually performed with very time consuming simulation codes. An alternative analytic approach, based on a cubic map model for the bunch-to-bunch evolution of the electron cloud density, could be useful to determine regions in parameters space compatible with safe machine operations. In this communication we derive a simple approximate formula relating the quadratic coefficient in the electron cloud density map to the parameters relevant for the electron cloud evolution in a strong vertical magnetic field. Results are compared with simulations with particular reference to the LHC dipoles.

MOPS084	Status of Electron Cloud Dynamics Measurements at CESRTA*	electron, betatron, damping, feedback	799
	M.G. Billing, G. Dugan, M.J. Forster, D.L. Kreinick, R.E. Meller, M.A. Palmer, G. Ramirez, M.C. Rendina, N.T. Rider, J.P. Sikora, K.G. Sonnad, H.A. Williams CLASSE, Ithaca, New York, USA J.Y. Chu CMU, Pittsburgh, Pennsylvania, USA J.W. Flanagan KEK, Ibaraki, Japan R. Holtzapple, M. Randazzo CalPoly, San Luis Obispo, California, USA
	Funding: Supported by US National Science Foundation (PHY-0734867) & Dept. of Energy (DE-FC02-08ER41538) The study of electron cloud-related instabilities for the CESR-TA project permits the observation of the interaction of the electron cloud with the stored beam under a variety of accelerator conditions. These measurements are undertaken utilizing automatic and semi-automatic techniques for three basic observations: the measurement of tune shifts of individual bunches along a train, the detection of the coherent self-excited spectrum for each bunch within a train and the pulsed excitation of either the betatron dipole or head-tail mode for each individual bunch within the train, followed by the observation of the damping of its coherent motion. These techniques are employed to study the electron cloud-related interactions in a number of conditions, such as trains of bunches with low emittance and spaced by as little as 4 nsec between bunches. We report on the most recent observations and results.

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

MOPS091	Study of Electron Cloud for MEIC	electron, simulation, emittance, luminosity	817
	S. Ahmed, J.D. Dolph, G.A. Krafft, T. Satogata, B.C. Yunn JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The Medium Energy Electron Ion Collider (MEIC) at Jefferson Lab has been envisioned as a future high energy particle accelerator beyond the 12 GeV upgrade of the existing Continuous Electron Beam Accelerator Facility (CEBAF). Synchrotron radiation from the closely spaced proton bunches in MEIC can generate photoelectrons inside the vacuum chamber and cause secondary emission due to multipacting in the presence of beam's electric field. This phenomenon can lead to fast build up of electron density, known as electron cloud effect – resulting into beam instability coupled to multi-bunches in addition to a single bunch. For MEIC, the estimated threshold value of the electron-cloud density is approximately 5 x 10¹² m-3. In this paper, we would like to report the self-consistent simulation studies of electron cloud formation for MEIC. The code has been benchmarked against the published data of electron cloud effects observed in LHC. Our first simulations predict increase of electron clouds with the increase of repetition rate. The detailed simulations are under progress and will be reported.

MOPZ001	MuSIC, the World's Highest Intensity DC Muon Beam using a Pion Capture System	proton, solenoid, target, simulation	820
	A. Sato, Y. Kuno, H. Sakamoto Osaka University, Osaka, Japan S. Cook, R.T.P. D'Arcy UCL, London, United Kingdom M. Fukuda, K. Hatanaka RCNP, Osaka, Japan Y. Hino, N.H. Tran, N.M. Truong Osaka University, Graduate School of Science, Osaka, Japan Y. Mori KURRI, Osaka, Japan T. Ogitsu, A. Yamamoto, M.Y. Yoshida KEK, Tokai, Ibaraki, Japan
	MuSIC is a project to provide the world's highest-intensity muon beam with continuous time structure at Research Center of Nuclear Physics (RCNP) of Osaka University, Japan. A pion capture system using a superconducting solenoid magnet and a part of superconducting muon transport solenoid channel have been build in 2010. The highest muon production efficiency was demonstrated by the beam test carried out in February 2011. The result concludes that the MuSIC can provide more than 10⁹ muons/sec using a 400 W proton beam. The pion capture system is one of very important technologies for future muon programs such as muon to electron conversion searches, neutrino factories, and a muon collider. The MuSIC built the first pion capture system and demonstrate its potential to provide an intense muon beam. The construction on the entire beam channel of the MuSIC will be finished in five years. We plan to carry out not only an experiment to search the lepton flavor violating process but also other experiments for muon science and their applications using the intense muon beam at RCNP.

MOPZ002	MICE Beamline	emittance, solenoid, beam-losses, target	823
	Y. Karadzhov DPNC, Genève, Switzerland
	The muon ionization cooling experiment (MICE) is under development at the Rutherford Appleton Laboratory (UK). The goal of the experiment is to build a section of a muon cooling channel that can demonstrate the principle of Ionization cooling over a range of emittances and momenta. The MICE beam line must generate several matched muon beams with different momenta and optical parameters at the entrance of the cooling channel. This is done exploiting a titanium target dipping into the ISIS proton beam, a 5T superconducting pion decay solenoid, two dipole magnets and a mechanism for inflation of the initial emittance called diffuser. First measurements of muon rates and beam emittance performed using two TOF hodoscopes detectors will be presented.

MOPZ006	Main Magnets Design Studies for the Non-scaling Fixed Field Alternating Gradient Accelerator for a Final Acceleration Stage of the Neutrino Factory	quadrupole, factory, focusing, acceleration	829
	J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom M. Aslaninejad, C. Bonţoiu, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	The International Design Study of the Neutrino Factory (IDS-NF) aims to design the next generation facility for the precision neutrino oscillation searches. The non scaling Fixed Field Alternating Gradient Accelerator was prosed for the final muon beam acceleration in order to reduce the cost of the final acceleration. The superconducting magnet design based on the independent multipole coils approach using the ROXIE code is presented. The feasibility of the magnet construction together with the quench limitations are discussed.

MOPZ031	Multipass Muon RLA Return Arcs based on Linear Combined-function Magnets	linac, quadrupole, optics, lattice	868
	V.S. Morozov, S.A. Bogacz, Y. Roblin JLAB, Newport News, Virginia, USA K.B. Beard Muons, Inc, Batavia, USA
	Funding: Supported in part by US DOE STTR Grant DE-FG02-08ER86351. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Recirculating Linear Accelerators (RLA) are an efficient way of accelerating short-lived muons to the multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper we present a design of a two-pass RLA return arc based on linear combined function magnets, in which both charge muons with momenta different by a factor of two are transported through the same string of magnets. The arc is composed of 60°-bending symmetric super cells allowing for a simple arc geometry closing. By adjusting the dipole and quadrupole components of the combined-function magnets, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both muon momenta. Such a design provides a greater compactness than, for instance, an FFAG lattice with its regular alternating bends and is expected to possess a large dynamic aperture characteristic of linear-field lattices.

MOPZ037	Extension of the 3-spectrometer Beam Transport Line for the KAOS Spectrometer at MAMI and Recent Status of MAMI	target, electron, beam-transport, status	880
	R.G. Heine, M. Dehn, K.-H. Kaiser, H.-J. Kreidel, U.L. Ludwig-Mertin IKP, Mainz, Germany
	Funding: Work supported by DFG (CRC443) and the German Federal State of Rhineland-Palatinate The institute for nuclear physics (KPH) at Mainz University is operating a 1.6 GeV c.w. microtron cascade (MAMI) for nuclear physics research. One of the vast experimental activities is electron scattering. A 3-spectrometer setup is used for cross-section measurements of hadron knock-out and meson production. The KAOS spectrometer magnet of GSI is installed there in parallel to detect particles from (e,e'K)reactions under small forward angles. So the primary electron beam has to transit the spectrometer and after this it has to hit the existing beam dump. Because of the existing experimental setup, this must be realised by deflecting the beam before the target that is rotated to be in line with the KAOS spectrometer's inlet. This paper will deal with the basic concept of a flexible beam transport line (BTL) magnet chicane for different KAOS forward angles, while keeping the forward beam direction for the 3-spectrometer setup untouched. A survey concept for assembly and adjustment of the BTL will be introduced, that is also useful for future adjustments of the target mount after target change. Results of the BTL commissioning and a general MAMI status will be presented as well.

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

TUXA01	Status and Challenges of the China Spallation Neutron Source	linac, DTL, power-supply, rfq	889
	S. Fu, H. Chen, Y.W. Chen, Y.L. Chi, H. Dong, L. Dong, S.X. Fang, K.X. Huang, W. Kang, J. Li, L. Ma, H.F. Ouyang, H. Qu, H. Sun, J. Tang, C.H. Wang, Q.B. Wang, S. Wang, T.G. Xu, Z.X. Xu, X. Yin, C. Zhang, J. Zhang IHEP Beijing, Beijing, People's Republic of China
	The accelerator complex of China Spallation Neutron Source (CSNS) mainly consists of an H⁻ linac of 80 MeV and a rapid-cycling synchrotron of 1.6 GeV. It operates at 25 Hz repetition rate with an initial proton beam power of 100 kW and is upgradeable to 500kW. The project will start construction in the middle of 2011 with a construction period of 6.5 years. The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges. This paper presents the current status of CSNS project and summarizes the technology development during the past several years.
	Slides TUXA01 [3.444 MB]

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

TUPC015	Comparative Wakefield Analysis of a First Prototype of a DDS Structure for CLIC Main Linac	wakefield, simulation, impedance, damping	1024
	A. D'Elia, A. Grudiev, V.F. Khan, W. Wuensch CERN, Geneva, Switzerland R.M. Jones UMAN, Manchester, United Kingdom
	A Damped Detuned Structure (DDS) for CLIC main linac has been proposed as an alternative to the present baseline design which is based on heavy damping. A first prototype, CLIC_DDS_A, for high power tests has been already designed and is under construction. It is also foreseen to design a further prototype, CLIC_DDS_B, to test both the wakefield suppression and high power performances. Wakefield calculations for DDS are, in the early design stage, based on single infinitely periodic cells. Though cell-to-cell interaction is taken into account to calculate the wakefields, it is important to study full structure properties using computational tools. In particular this is fundamental for defining the input parameters for the HOM coupler that is crucial for the performances of DDS. In the following a full analysis of wakefields and impedances based on simulations conducted with finite difference based electromagnetic computer code GdfidL will be presented.

TUPC019	Beam-based Alignment of CLIC Drive Beam Decelerator using Girders Movers	quadrupole, alignment, simulation, extraction	1036
	G. Sterbini, D. Schulte CERN, Geneva, Switzerland
	The CLIC drive beams will provide the rf power to accelerate the colliding beams: in order to reach the design performance, an efficient transport of the drive beam has to be ensured in spite of its challenging energy spread and large current intensity. As shown in previous studies, the specifications can be met by coupling a convenient optics design with the state-of-the-art of pre-alignment and beam-based alignment techniques. In this paper we consider a novel beam-based alignment scheme that does not require quadrupole movers or dipole correctors but uses the motors already foreseen for the pre-alignment system. This implies potential savings in terms of complexity and cost at the expense of the alignment flexibility: the performance, limitations and sensitivity to pre-alignment tolerances of this method are discussed.

TUPC026	Status of the Crab Cavity Design for the CLIC	cavity, damping, wakefield, coupling	1054
	P.K. Ambattu, G. Burt, A.C. Dexter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom V.A. Dolgashev SLAC, Menlo Park, California, USA A. Grudiev CERN, Geneva, Switzerland R.M. Jones UMAN, Manchester, United Kingdom P.A. McIntosh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	RF design of a crab cavity (2π/3, 11.9942 GHz) for the Compact Linear Collide (CLIC) is presented. As part of the UK-CLIC collaboration, CERN is building two copper prototypes, designed by Lancaster University / Cockcroft Institute. The first prototype to be made will be a 12 cell undamped cavity and the second will be waveguide damped cavity. The RF test at CERN will help characterisation of the dipole mode with X-band RF pulses of 15 MW peak power and pulse length of ~242 ns. Since the cavity frequency and phase advance per cell are identical to those of the CLIC main linac, the first prototype could exploit CERN’s X-band cavity characterisation facilities. A fully damped cavity will be required for the actual machine in order to meet the luminosity specs. The damped prototype will use an identical coupler type as the undamped one, but the cells will have damping waveguides with / without dielectric material.

TUPC045	Recirculating Electron Linacs (REL) for LHeC and eRHIC	electron, linac, lattice, proton	1099
	D. Trbojevic, J. Beebe-Wang, Y. Hao, D. Kayran, V. Litvinenko, V. Ptitsyn, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy. We present a design of a CW Electron Recovery Linacs (ERL) for future electron hadron colliders eRHIC and LHeC. In eRHIC, a six-pass ERL would be installed in the existing tunnel of the present Relativistic Heavy Ion Collider (RHIC). The 5-30 GeV polarized electrons will collide with RHIC’s 50-250 (325) GeV polarized protons or 20-100 (130) GeV/u heavy ions. In LHeC a 3-pass 60 GeV CW ERL will produce polarized electrons for collisions with 7 TeV protons. After collision, electron beam energy is recovered and electrons are dumped at low energy. Two superconducting linacs are located in the two straight sections in both ERLs. The multiple arcs are made of Flexible Momentum Compaction lattice (FMC) allowing adjustable momentum compaction for electrons with different energies. The multiple arcs, placed above each other, are matched to the two linac’s straight sections with splitters and combiners.

TUPC046	Alignment Tolerances for Vertical Emittance	emittance, quadrupole, lattice, closed-orbit	1102
	K.P. Wootton, R.P. Rassool, G. Taylor The University of Melbourne, Melbourne, Australia M.J. Boland, R.T. Dowd, G. LeBlanc, Y.E. Tan ASCo, Clayton, Victoria, Australia Y. Papaphilippou CERN, Geneva, Switzerland
	Alignment tolerances for the CLIC main damping ring magnetic lattice elements are presented. Tolerances are defined by the design equilibrium vertical emittance of 1 pm rad. The sensitivity of the uncorrected lattice to magnet misalignments is presented. Misalignments considered included quadrupole vertical offsets and rolls, sextupole vertical offsets, and main dipole rolls. Seeded simulations were conducted in MAD-X, and compared with expectation values calculated from theory. The lattice was found to be sensitive to betatron coupling as a result of sextupole vertical offsets in the arcs. Alignment tolerances, BPM and corrector requirements are presented also. For the same misalignment types, the equilibrium emittance of the corrected lattice is simulated. These are compared with expectation values calculated from theory. The vertical alignment tolerance of arc sextupoles is again demanding.

TUPC049	Optics considerations for the Delay Loop in the CLIC Damping Rings Complex	quadrupole, emittance, optics, damping	1108
	P. Zisopoulos, F. Antoniou, H. Bartosik, Y. Papaphilippou CERN, Geneva, Switzerland
	For the recombination of the two trains coming from the CLIC damping rings, a delay loop will be used in order to obtain the nominal 0.5~ns bunch spacing. The optics design of the loop is based upon an isochronous ring, in order to preserve the longitudinal beam distribution. Analytical expressions for achieving isochronous conditions in high order for Theoretical Minimum Emittance cells are obtained. A parametrisation of the quadrupole settings for achieving these conditions is presented, along with general considerations regarding the choice of bending magnet characteristics.

TUPC077	Investigations on High Sensitive Sensor Cavity for Longitudinal and Transversal Schottky for the CR at FAIR	cavity, coupling, resonance, simulation	1180
	M. Hansli, A. Angelovski, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany W. Ackermann, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany P. Hülsmann GSI, Darmstadt, Germany
	Funding: Funded by the Federal Ministry of Education and Research (BMBF): 06DA90351 For the Collector Ring (CR) at the FAIR (Facility for Antiproton and Ion Research) accelerator complex a sensitive Schottky sensor is required. The CR covers different modes of operation, like pre-cooling of antiprotons at 3 GeV, pre-cooling of rare isotope beams at 740 MeV/u and an isochronous mode for mass measurements. For longitudinal Schottky measurements the concept of a resonant cavity had been introduced [Hansli2011]. Due to limited space inside the ring, the integration of transversal Schottky analysis into this cavity is desired. In this paper the demands and required changes to implement also transversal Schottky measurements are discussed. An analysis of the expected signal characteristics featuring equivalent circuit is shown, as well as numerical full wave simulations of the cavity. * M. Hansli, A. Penirschke, R. Jakoby, W. Kaufmann, W. Ackermann, T. Weiland, "Conceptual Design of a High Sensitive Versatile Schottky Sensor for the Collector Ring at FAIR", DIPAC2011.

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

TUPC111	Design of Cavity Beam Monitor at HLS	cavity, quadrupole, emittance, gun	1278
	Q. Luo, Q.K. Jia, B.G. Sun, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work supported by the Natural Science Foundation of China, National “985 Project”, China Postdoctoral Science Foundation and “the Fundamental Research Funds for the Central Universities” X-FEL requires precious control of beam position and transverse emittance. Non-destructive on-line beam diagnostic methods are required. During the upgrading of HLS a high brightness injector based on photocathode RF electron gun, which can also be used to study FEL, is installed. The cavity beam monitor system designed for the HLS photocathode RF electron gun consists of a cavity beam position monitor and a beam quadrupole moment monitor system. The cavity beam position monitor uses a re-entrant position cavity tuned to TM110 mode as position cavity and cut-through waveguides to suppress the monopole signal. Cold test results showed that position resolution of prototype BPM is better than 3 μm. Beam quadrupole moment monitor system consists of a square pill-box quadrupole moment cavity, a cylindrical pill-box reference cavity, a waveguide coupling network and a superheterodyne receiver used as front-end signal processing system. The whole system works at 5.712 GHz. Strength of quadrupole magnets is adjust to construct a matrix which can be used to work out beam parameters.

TUPC118	Test Results on Beam Position Resolution for Low-Q IP-BPM at KEK-ATF2	cavity, feedback, alignment, collider	1293
	S.W. Jang, A. Heo, J.G. Hwang, E.-S. Kim, H.-S. Kim Kyungpook National University, Daegu, Republic of Korea H.K. Park CHEP, Daegu, Republic of Korea
	We have performed the beam tests on the beam position resolution for the Low-Q IP-BPM (Interaction Point-Beam Position Monitor) at ATF2 which is an accelerator test facility for the International Linear Collider. The main goals of KEK-ATF2 are to achieve beam size of 37 nm and beam resolution of nano-meter for beam stabilization. Resolution tests for the Low-Q IP-BPM were performed with KEK BPM doublet in Jan. 2011. We got the results of beam position resolution 70 nm during the experimental periods and will present the detailed experimental procedures and results.

TUPC119	A Comprehensive Study of Nanometer Resolution of the IPBPM at ATF2*	cavity, simulation, coupling, extraction	1296
	Y.I. Kim, H. Park Kyungpook National University, Daegu, Republic of Korea S.T. Boogert Royal Holloway, University of London, Surrey, United Kingdom J.C. Frisch, D.J. McCormick, J. Nelson, T.J. Smith, G.R. White, M. Woodley SLAC, Menlo Park, California, USA Y. Honda, R. Sugahara, T. Tauchi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Funding: Work supported in part by Department of Energy Contract DE-AC02-76SF00515. High-resolution beam position monitors (IPBPMs) have been developed in order to measure the electron beam position at the focus point of ATF2 to a few nanometers in the vertical plane. To date, the IPBPM system has operated in test mode with a highest demonstrated resolution of 8.7 nm in the ATF extraction line during 2008. After expected noise source calculations there still remains 7.9 nm of noise of unexplained origin. We summarize the experimental work on the IPBPM system since this measurement and outline the possible origins of these sources. We then present a study plan to be performed at the ATF2 facility designed to identify and to improve the resolution performance and comment on the expected ultimate resolution of this system.

TUPC161	Cavity Beam Position Monitor System for ATF2	cavity, quadrupole, EPICS, extraction	1410
	S.T. Boogert, R. Ainsworth, G.E. Boorman, S. Molloy Royal Holloway, University of London, Surrey, United Kingdom A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan F.J. Cullinan, N.Y. Joshi, A. Lyapin JAI, Egham, Surrey, United Kingdom J.C. Frisch, D.J. McCormick, J. Nelson, T.J. Smith, G.R. White SLAC, Menlo Park, California, USA A. Heo, E.-S. Kim, Y.I. Kim KNU, Deagu, Republic of Korea
	The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 41 high resolution C and S band resonant cavity beam position monitors (BPM) with associated mixer electronics and digitizers. In addition 4 high resolution BPMs have been recently installed at the interaction point, we briefly describe the first operational experience of these cavities in the ATF2 beam-line. The current status of the overall BPM system is also described, with a focus on operational techniques and performance.

TUPO006	Design of a Dispersive Beam Transport Line for the JETI Laser Wakefield Accelerators	undulator, radiation, electron, quadrupole	1455
	C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, P. Peiffer KIT, Karlsruhe, Germany M. Kaluza, M. Nicolai IOQ, Jena, Germany R. Rossmanith Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	Laser wakeﬁeld accelerators (LWFA) emit electrons with energies of a few 100 MeV at very short bunch lengths while having a compact design. However, electron bunches from LWFA show a larger energy spread than those of conventional accelerators. This is a challenge when using these bunches e.g. to generate radiation in an undulator. A possible strategy to cope with that is to spectrally disperse the bunch and match the resulting spatial distribution with a spatially varying undulator ﬁeld amplitude. For realizing the dispersion a pair of dipole magnets is used. The electrons leaving this dipole chicane have to meet certain requirements imposed by the undulator: In the deﬂection plane the beam has to be collimated and its energy distribution must match the undulator ﬁeld. In the other transversal plane the beam has to be focussed on the center of the undulator keeping the value of the beta function small. To include this in the compact design of the setup, a combination of specially designed quadrupole and sextupole magnets is employed. In this contribution the design of the setup and the results of the particle tracking through this chicane are presented.

TUPO033	Emittance Minimization by Courant-Snyder Parameter Scan in Merger Section at the Compact Energy Recovery Linear Accelerator.	emittance, space-charge, betatron, SRF	1506
	J.G. Hwang Kyungpook National University, Daegu, Republic of Korea E.-S. Kim KNU, Deagu, Republic of Korea T. Miyajima KEK, Tsukuba, Japan
	The project of compact-Energy Recovery Linac(c-ERL) at Photon Factory in KEK is a test facility for the 5 GeV ERL, which is one of the candidates of next generation light source. It consists of injector system, merger section, main SRF section, return arc, long straight section and beam dump. The injector system produces beams with a low-energy of 5 MeV and low-emittance less than 1 mm-mrad. It causes the large emittance growth by space charge force in merger section, which consists of two rectangular type dipole magnets and one sector type magnet. Dispersion also causes the displacement of bunch sllice on horizontal plane. The displacement of bunch slice is laid on the kick angle induced by space charge force. Also, each slice has the orientation of the phase ellipse on horizontal phase space. Therefore, the emittance growth due to the displacement of bunch sllice induced by space charge force in the horizontal phase space can be minimized by matching the displacement to the orientation of the phase ellipse at the exit of merger. We present the results of the emittance minimization performed by mathcing of the angle of the phase ellipse by scan of CS (Courant-Snyder) parameter.

TUPS019	Synchrotron Radiation in the LHC Vacuum System	photon, vacuum, radiation, proton	1563
	V. Baglin, G. Bregliozzi, J.M. Jimenez, G. Lanza CERN, Geneva, Switzerland
	CERN is currently operating the Large Hadron Collider (LHC) with 3.5 TeV per beam. At this energy level, when the protons trajectory is bent, the protons emit synchrotron radiation (SR) with a critical energy of 5.5 eV. Under operation, SR induced molecular desorption is routinely observed in the LHC arcs, long straight sections and experiments. This contribution recalls the SR parameters over the LHC ring for the present and nominal beam parameters. Vacuum observations during energy ramp, after accumulation of dose and along the LHC ring are discussed. Expected pressure profiles and long term behaviours of vacuum levels will be also addressed.

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

TUPS028	Performance of Carbon Coating for Mitigation of Electron Cloud in the SPS	electron, vacuum, insertion, extraction	1590
	C. Yin Vallgren, P. Chiggiato, P. Costa Pinto, H. Neupert, G. Rumolo, E.N. Shaposhnikova, M. Taborelli CERN, Geneva, Switzerland
	Amorphous carbon (a-C) coatings have been tested in electron cloud monitors (ECM) in the Super Proton Synchrotron (SPS) and have shown for LHC type beams a reduction of the EC current by a factor 10⁴ compared to stainless steel (SS). This performance has been maintained for more than 2 years under SPS operation conditions. Secondary electron yield (SEY) laboratory data confirm that after 1 year of SPS operation, the coating maintains a SEY below 1. The compatibility of coexisting SS and a-C surfaces has been studied in an ECM having coated and uncoated areas. The results show no degradation of the properties of the a-C areas. The performance of diamond like carbon (DLC) coating has also been studied. DLC shows a less effective reduction of the EC current than a-C, but conditioning is faster than for SS. Three a-C coated dipoles were inserted in the SPS. However, even with no EC detected, the dynamic pressure rise is similar to the one observed in the SS reference dipoles. Measurement in a new ECM equipped with clearing electrodes to verify the relation between pressure signals and intensity of the EC, as well as an improvement of the diagnostics in the dipoles are in progress.

TUPS039	Reduction of Magnetic Interference on the Position Sensors of the LHC Collimators	shielding, simulation, radiation	1623
	A. Masi, M. Lamberti, R. Losito, M. Martino CERN, Geneva, Switzerland
	The jaws of the LHC collimators have to be positioned with respect to the beam with an accuracy of 20 μm. On some collimators, installed in the LHC transfer lines from SPS, huge reading errors of several tens of micrometers have been observed on the Linear Variable Differential Transformer (LVDT) positioning sensors in synchronization with the variable magnetic field produced by the feed cables of the pulsed resistive dipoles of the transfer line. In this paper we introduce and describe in detail the problem, the model developed using FLUXTM for the simulation of the magnetic flux density generated by the current cables in the complex environment of an LHC transfer line, and the magnetic shielding we designed and implemented. Finally, we compare the results of simulations with experimental measurements taken during on-line pulsed magnets test campaigns.

TUPS093	Automatic Measurement System for Electrical Verification of the LHC Superconducting Circuits	pick-up, high-voltage, instrumentation, superconducting-magnet	1756
	A. Kotarba, M. Bednarek, P. Jurkiewicz, J. Ludwin, M. Talach IFJ-PAN, Kraków, Poland R. Mompo CERN, Geneva, Switzerland
	In the LHC machine, superconducting magnet circuits are used on a very large scale. The circuits, more than 1600, are all equipped with a complex set of instrumentation required for safe operation and diagnostics. The length of many circuits exceed 3 km. Due to risks of accidental damages during transport and assembly or misconnection of the circuits’ auxiliary components, it is necessary to perform an Electrical Quality Assurance (ELQA) campaign after every major intervention on a circuit and also after each thermal cycle of the machine. In order to be able to perform reliable tests on a circuit within a short time frame, a highly extensible automated mobile test system was designed and built. Four of these instruments were successfully used during the Hardware Commissioning phases of the LHC. This paper describes the hardware solutions used in the test system.

TUPS094	Girder and Support System for PLS-II Project	multipole, storage-ring, alignment, quadrupole	1759
	H.-G. Lee, H.S. Han, J.Y. Huang, Y.-G. Jung, D.E. Kim, S.N. Kim, S.H. Nam, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) is planning to upgrade the Pohang Light Source (PLS) which is a 3rd generation light source operating since 1995. We have designed a new steel magnet girder using new schemes to achieve long-term mechanical stability, vibration suppression and precision adjusting system. Each half cell of girder is composed of three pieces, two multipole magnet girder(MMG) and one dipole magnet girder(DMG). The storage ring girders consist of 48 multipole magnet girders and 24 dipole magnet girders. The new girder systems have been fabricated and tested. Recently the girders have been installing and testing the moving mechanism in the storage ring. In this report, the design consideration for the PLSII girder and support systems are reported.

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

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

TUPZ039	Modelling of the AGS Using Zgoubi - Status	multipole, quadrupole, simulation, resonance	1897
	F. Méot, L. A. Ahrens, Y. Dutheil, J.W. Glenn, H. Huang, T. Roser, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Models of the Alternating Gradient Synchrotron, based on stepwise ray-tracing methods using both mathematical modelling or ﬁeld maps so to represent the optical elements, including the siberian snakes, are being developed based on stepwise ray-tracing numerical tools. The topic is introduced in earlier PAC and IPAC publications, a status is given here.

WEPC002	RF Separator and Septum Layout Concepts for Simultaneous Beams to RIB and FEL Users at ARIEL	septum, linac, FEL, electron	1998
	Y.-C. Chao, C. Gong, S.R. Koscielniak TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	A ½ MW capable CW electron linac is being designed and constructed at TRIUMF in support of the existing Rare Isotope Beam program. In the simplest configuration, the beam makes a single pass through three cryomodules to the RIB production targets. However, after the construction of a recirculation path, beam could make a second pass through two cryomodules with the RF phase advance adjusted to give energy recovery. Here it is proposed to time-interleave two bunch trains, and via an RF separator and septum, to direct one single-pass train to RIB production and the second train through the energy recovery ring that contains an IR FEL. It is also the intention, in single user mode, to use the ring as an energy doubler. This paper describes the RF separation scheme and options for the extraction optics that satisfy the requirements of “simultaneous” beams to two users.

WEPC006	Upgrade Plans on the Superconducting Electron Accelerator S-DALINAC	recirculation, linac, electron, extraction	2010
	M. Kleinmann, R. Eichhorn, F. Hug, N. Pietralla TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by DFG through SFB 634 The S-DALINAC is a superconducting recirculating electron accelerator with maximum design energy of 130 MeV operating in cw at 3 GHz. Even so the gradients of the superconducting cavities are well above design, their design quality factor of 3*10⁹ have not been reached so far, leading to higher heat transfer into the liquid helium than expected. Due to the limited cooling power of the cryo-plant being 120 W, the final energy achievable in cw operation is around 85 MeV, currently. In order to provide a cw beam with the designed final energy in the future, the installation of an additional recirculation path is projected. We will report on the beam-line and the magnet design for the new recirculation path. In addition, we will present the layout of two proposed scraper-systems which will be used to remove the halo of the electron beam allowing high precision coincidence experiments with very low background for nuclear physics in the future.

WEPC024	LOCO in the ALBA Storage Ring	quadrupole, optics, coupling, storage-ring	2055
	G. Benedetti, D. Einfeld, Z. Martí, M. Muñoz CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3 GeV 3rd generation light source which achieved first stored beam in February 2011, and will be commissioned during 2011. The ring comprises of 112 independent quadrupoles grouped in 14 families and 32 combined gradient dipoles powered in series. This paper reviews the process of recovering the design lattice and the symmetry of the machine, and the effects on orbit and lifetime. The main tool employ for this has been the LOCO implementation provided in the Matlab MiddleLayer. First results shows that the main effect on the symmetry is the difference between bending magnets. As this effect can not be compensated locally at present at the bendings, a global optics correction using all the quadrupoles is used.

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

WEPC029	Accuracy of the LHC Optics Measurement based on AC Dipoles	optics, simulation, quadrupole, focusing	2064
	R. Miyamoto, R. Calaga BNL, Upton, Long Island, New York, USA R. Tomás, G. Vanbavinckhove CERN, Geneva, Switzerland
	Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP). The tight tolerances in the LHC requires optics measurement with very good accuracy. Therefore, AC dipoles are employed as the primary devices to measure the LHC optics. The accuracy of the measurement is mainly determined by the length of the coherent signal, signal-to-noise ratio of the measurement, and the data processing to effectively suppress the noise. This paper presents numerical and experimental studies of how these factors affect the accuracy of the LHC optics measurement using the AC dipoles.

WEPC030	Measurement of Coupling Resonance Driving Terms in the LHC with AC Dipoles	kicker, optics, quadrupole, resonance	2067
	R. Miyamoto, R. Calaga BNL, Upton, Long Island, New York, USA M. Aiba PSI, Villigen, Switzerland R. Tomás, G. Vanbavinckhove CERN, Geneva, Switzerland
	Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP). Transverse betatron coupling in the LHC is measured from Fourier analysis of turn-by-turn beam oscillations excited by AC dipoles. The use of the AC dipole for optics measurements induces a small systematic error which can be corrected with an appropriate data interpretation. An algorithm to apply this correction to the measurement of the coupling resonance driving terms is developed for the first time. This paper will review this new algorithm and present results of its application to the LHC.

WEPC031	Optics Corrections at RHIC	optics, betatron, proton, quadrupole	2070
	G. Vanbavinckhove CERN, Geneva, Switzerland M. Bai, G. Robert-Demolaize BNL, Upton, Long Island, New York, USA
	Excessive beta-beat, deviation of measured beta function from the calculated beta functions based on an model, in high energy colliders can lead to large deviation of beta function at collision point as well as other adverse effects. The segment-by-segment technique was successfully demonstrated in the LHC operation for reducing the beta-beat. It was then applied to RHIC polarized proton operation in 2011. This paper reports the experimental results of optics correction at RHIC. Future plan is also presented.

WEPC048	Calibrating Transport Lines using LOCO Techniques	quadrupole, optics, simulation, focusing	2118
	Y. Roblin JLAB, Newport News, Virginia, USA
	Funding: Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 With the 12GeV upgrade underway at CEBAF, there is a need to recharacterize the beamlines after the modifications made to it to accommodate running at higher energies. We present a linear perturbation approach to calibrating the optics model of transport lines. This method is adapted from the LOCO method in use for storage rings. We consider the effect of quadrupole errors, dipole construction errors as well as beam position monitors and correctors calibrations. The ideal model is expanded to first order in Taylor series of the quadrupole errors. A set of difference orbits obtained by exciting the correctors along the beamline is taken, yielding the measured response matrix. An iterative procedure is invoked and the quadrupole errors as well as beam position monitors and corrector calibration factors are obtained. Here we present details of the method and results of first measurements at CEBAF in early 2011 Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes

WEPC055	Beam Orbit and Power Converter Stability at the CR	emittance, power-supply, antiproton, closed-orbit	2139
	A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck, H. Weick GSI, Darmstadt, Germany
	For the isochronous mode operation of the CR with reference to have good properties of the mass measurements we study the sources of the beam orbit fluctuation and as consequence power converter requirements for the CR operated at BR=13 Tm. This papaer presents a summary of the different factors causing beam orbit variation, which leads to reduction of the mass measurements precision. The requirements to the power converters have been addressed.

WEPC058	Field Properties of the ESR Magnets and their Influence on Beam Optics	quadrupole, betatron, sextupole, simulation	2148
	O.E. Gorda, C. Dimopoulou, A. Dolinskii, S.A. Litvinov, F. Nolden, M. Steck GSI, Darmstadt, Germany
	Machine experiments at the experimental storage ring (ESR) demonstrated that the ring acceptance is strongly restricted by field errors. Higher-order field harmonics of the dipole and quadrupole magnets have been calculated and then used in particle tracking simulations in order to find out the dynamic aperture of the ESR. To benchmark the results of numerical calculations, betatron tune measurements have been performed with a uranium beam at the energy of 400 MeV/u. The results of the magnetic field simulations for the ESR magnets and a comparison between the measured and calculated tune behavioгr are presented.

WEPC059	Optimization of the Sextupole Scheme and Compensation of the Time-Dependent Field Errors during Slow Extraction from the Superconducting Synchrotron SIS300	extraction, sextupole, lattice, resonance	2151
	A. Saa Hernandez, P.J. Spiller GSI, Darmstadt, Germany U. Ratzinger IAP, Frankfurt am Main, Germany
	The SIS300 synchrotron, planned for the new Facility for Antiproton and Ion Research (FAIR) at GSI-Darmstadt, will become the first superconducting synchrotron worldwide using cos(θ) magnets for resonant slow extraction. A multi-objective optimization algorithm has been developed for the design of the non-linear magnet scheme. The optimization algorithm makes use of the analytical model for the slow extraction from Kobayashi, the analytical description of the resonance excitation and amplitude-dependent tune-shift from Bengtsson, and corrects the chromaticity in order to fulfill the Hardt condition. As a result, the placement of the chromatic and harmonic sextupole magnets in SIS300, the number of sextupole families and the gradients of these families have been optimized for a high efficiency slow extraction. The algorithm accounts also for the sextupole errors on the dipole magnets, compensating its effects. Furthermore, optimized time-dependent settings for the sextupole magnets are generated to compensate the persistent current decay occurring at slow extraction. Tolerances for the magnets are set for the limits where the compensation is no longer valid.

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

WEPC061	ENC Interaction Region Separation Dipoles	solenoid, electron, sextupole, multipole	2157
	P. Schnizer, E.S. Fischer GSI, Darmstadt, Germany K. Aulenbacher IKP, Mainz, Germany
	The Electron Nucleon Collider (ENC) is proposed as an upgrade of the High Energy Storage Ringe of the FAIR. The beams are separated by two dipoles, mounted closely to the intraction point; surrounded by the detectors. Hence these magnetsmust provide sufficient field quality but be slim to be transparaent to the secondary particles. Further these must be air coil magnets due to the detector solenoid field of 2T. We present the 3D optimised magnet next to a first design of the mechanical restraint structure and a concise description for the field distortion leaking into the detector.

WEPC067	The Spin Aberration of Polarized Beam in Electrostatic Rings	cavity, simulation, emittance, lattice	2175
	Y. Senichev, A. Lehrach, R. Maier, D. Zyuzin FZJ, Jülich, Germany
	For a beam with nonzero transverse emittance and momentum spread passing through an electric field, for example an electric focusing lens or deflector, the orientation of a spin vector becomes a function of 6D initial phase coordinates that leads to spin aberrations. We investigate this process analytically and numerically.

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

WEPC085	Multipole Fringe Fields	multipole, quadrupole	2211
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom M.J. de Loos, S.B. van der Geer Pulsar Physics, Eindhoven, The Netherlands
	When creating an initial model of an accelerator, one usually has to resort to a hard edge model for the quadrupoles and higher order multipoles at the start of the project. Ordinarily, it is not until much later on that one has a field map for the given multipoles. This can be rather inconvenient when one is dealing with particularly thin elements or elements which are rather close together in a beamline as the hard edge model may be inadequate for the level of precision desired. For example, in the EMMA project, the two types of quadrupoles used are so close together that they are usually described by a single field map or via hard edge models. The first method has the desired accuracy but was not available at the start of the project and the second is known to be a rough approximation. In this paper, an analytic expression is derived and presented for fringe fields for a multipole of any order with a view to applying it to cases like EMMA.

WEPC088	Embedding Finite Element Results for Accelerator Components in a Moment Approach Beam Dynamics Code*	quadrupole, simulation, electron, sextupole	2217
	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''. A moment based beam dynamics code has particular advantages, i.e. accuracy and efficiency, over macro-particle tracking and full particle-in-cell (PIC) codes respectively. Instead of embedding analytical descriptions of the accelerator components in the beam dynamics model, it is proposed to insert a surrogate model obtained from the finite element model of individual accelerator components. We apply the V-Code, which accepts moments up to the sixth order and accounts for space charge effects. We construct and calculate finite element and finite difference time domain models using the CST Studio Suite 2011 software package. An interface is implemented using VBA and MATLAB. As an example of the accuracy of this cascadic simulation approach, we compare the beam dynamics of an S-DALINAC quadrupole obtained by directly tracking particles to the calculated fields with the results for the cascadic approach with the V-Code. This work was performed during a three month research visit at the Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Darmstadt, Germany.

WEPC100	Simulation of the Single Bunch Instability due to the Electron Cloud Effect by Tracking with a Pre-computed 2D Wake Matrix*	electron, simulation, single-bunch, positron	2247
	A. Markoviḱ, G. Pöplau, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Supported by DFG Contract Nr. RI 814/20-1. The passage of a positron bunch through an initially homogeneous electron cloud (e-cloud) changes the distribution of the e-cloud in a way that the concentration of electrons in the proximity of the beam axis grows rapidly. The electrons are primarily moving in the transverse plane and are very sensitive on the beam centroid position in that plane. Thus the transverse kick of the e-cloud on the tail particles depends on the centroid position of the head particles of the same bunch. A PIC simulation of the interaction of a positron beam with an e-cloud yields the wake kick from the electrons on the tail particles for a certain offset in the transverse centroid position of the head parts of the bunch. With such a pre-computed 2D wake matrix, for a certain e-cloud density, we investigate the stability of a single bunch by tracking it through the linear optics of the storage ring while at each turn applying the kick from the e-cloud. We examine the positron bunch stability of KEKB-LER and PETRAIII for a certain electron cloud density.

WEPC125	Higher Order Modes in Coupled Cavities of the FLASH Module ACC39	cavity, simulation, HOM, diagnostics	2301
	R.M. Jones, I.R.R. Shinton UMAN, Manchester, United Kingdom Z. Li SLAC, Menlo Park, California, USA
	We analyse the higher order modes (HOMs) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.

WEPC159	A Python Tracking Code and GUI for Control Room Operations	controls, lattice, storage-ring, status	2358
	M.T. Heron, J. Rowland Diamond, Oxfordshire, United Kingdom
	Considerable use has been made in recent years of accelerator physics modelling and online tools under Matlab. These have demonstrated the benefits of operating in a rich integrated environment and further given good portability across projects and operating systems. As a possible alternative to Matlab, Diamond has been evaluating options based on Python. Python together with the Numpy libraries and Qt Graphics provides an environment which offers a lot of the functionality of Matlab. This paper presents these developments, which include a tracking code, symplectic integrator, twiss and response matrix together with a GUI interface.

WEPC175	FLUKA Studies of the Asynchronous Beam Dump Effects on LHC Point 6	proton, insertion, simulation, quadrupole	2397
	R. Versaci, V. Boccone, B. Goddard, A. Mereghetti, R. Schmidt, V. Vlachoudis CERN, Geneva, Switzerland
	The LHC is a record-breaking machine for beam energy and intensity. An intense effort has therefore been deployed in simulating critical operational scenarios of energy deposition. FLUKA is the most widely used code for this kind of simulations at CERN because of the high reliability of its results and the ease to custom detailed simulations all along hundreds of meters of beam line. We have investigated the effects of an asynchronous beam dump on the LHC Point 6 where, beams with a stored energy of 360 MJ, can instantaneously release up to a few J cm^-3 in the cryogenic magnets which have a quench limit of the order of the mJ cm^-3. In the present paper we will briefly introduce FLUKA, describe the simulation approach, and discuss the evaluated maximum energy release onto the superconducting magnets during an asynchronous beam dump. We will then analyse the shielding provided by collimators installed in the area and discuss safety limits for the operation of the LHC.

WEPC176	Beam Loss Monitoring and Machine Protection System Design and Application for the ALICE Test Accelerator at Daresbury Laboratory	beam-losses, monitoring, radiation, simulation	2400
	S.R. Buckley, J.-L. Fernández-Hernando STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	ALICE is a demonstrator accelerator system which has been designed and built at Daresbury Laboratory. The heart of this facility is an ERL accelerator and a powerful multi-terrawatt laser. It serves as an advanced test facility for novel accelerator and photon science applications. Beam loss monitoring and machine protection systems are vital areas for the successful operation of ALICE. These systems are required, both for efficient machine set up and for hardware protection during operation. This paper gives an overview of the system design, commissioning details and a summary of the systems’ effectiveness as a diagnostic tool.

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

WEPO003	The FERMI@Elettra Magnets	quadrupole, gun, electron, FEL	2409
	D. Castronovo, R. Fabris, G.L. Loda, D. Zangrando ELETTRA, Basovizza, Italy
	FERMI@Elettra is a single-pass FEL user-facility located next to the third generation synchrotron radiation facility ELETTRA in Trieste, Italy. The linear accelerator contains more than 200 magnets. This paper reports on the design, construction, magnetic measurement and installation.

WEPO014	Magnetic Design of Quadrupoles for the Medium and High Energy Beam Transport line of the LIPAC Accelerator	quadrupole, coupling, beam-transport, simulation	2424
	C. Oliver, B. Brañas, A. Ibarra, I. Podadera, F. Toral CIEMAT, Madrid, Spain
	Funding: Work partially supported by Spanish Ministry of Science and Innovation under project AIC10-A-000441 and ENE2009-11230. The LIPAC accelerator will be a 9 MeV, 125 mA cw deuteron accelerator which will verify the validity of the design of the future IFMIF accelerator. A Medium Energy Beam Transport line (MEBT) is necessary to handle the high current beam from the RFQ to the Superconducting RF accelerating cavities (SRF) whereas a High Energy Beam Transport line (HEBT) is used to match the beam from the SRF to the beam dump. The high space charge and beam power determine the beam dynamics in both transport lines. As a consequence, magnets with strong fields in a reduced space are required. Along the transport beamlines, there are different types of quadrupoles with steerers and a dipole. Special care is devoted to maximize the integrated fields in the available space. Both 2-D and 3-D magnetic calculations are used to optimize coil configurations. Magnetic performance and cost, both of magnet and power supply, have been taken into account for final choice. In this paper, the design of the resistive quadrupoles of the MEBT and HEBT of the LIPAC accelerator is presented.

WEPO015	MAX IV 3 GeV Storage Ring Prototype Magnet	storage-ring, simulation, magnet-design, lattice	2427
	M.A.G. Johansson, L.-J. Lindgren MAX-lab, Lund, Sweden B. Anderberg AMACC, Uppsala, Sweden
	The MAX IV facility, currently under construction, will consist of a 3 GeV storage ring, a 1.5 GeV storage ring, and a full energy injector/SPF/FEL driver. The magnet design for the 3 GeV storage ring is conceptually identical to the MAX III storage ring magnets, with all magnet elements within each cell machined into one solid iron block. A prototype of a matching cell magnet block has been manufactured and mechanical and magnetic field measurements have been performed.

WEPO016	Design of the MAX IV/Solaris 1.5 GeV Storage Ring Magnets	lattice, ion, storage-ring, simulation	2430
	M.A.G. Johansson MAX-lab, Lund, Sweden
	The MAX IV facility, currently under construction in Lund, Sweden, will consist of a 3 GeV storage ring, a 1.5 GeV storage ring, and a full energy injector/SPF/FEL driver. The Solaris facility, which will be built in Krakow, Poland, will use an identical 1.5 GeV storage ring, injected at 500 MeV. The magnet design for the 1.5 GeV storage ring is conceptually identical to the MAX III and the MAX IV 3 GeV storage ring magnets, with several magnet elements machined into one solid iron block. Detailed design has been done in Opera3D, with a model of the full magnet block being set up and simulated, and iterated against the lattice design.

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

WEPO021	Quadrupole Magnet with an Integrated Dipole Steering Element for the ISIS Beam Transport Line	quadrupole, target, beam-transport, proton	2445
	S.J.S. Jago, J. Shih, S.F.S. Tomlinson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S.M. Gurov BINP SB RAS, Novosibirsk, Russia
	A refurbishment of beam transport line to the original ISIS target station at the Rutherford Appleton Laboratory has recently been completed. This work involved a slight change to the optics in the area, which included the requirement for extra steering capabilities. Due to the space constraints in the region, a quadrupole magnet with an integrated dipole steering element was developed. The steering dipole consists of four saddle shaped coils situated within the bore of the quadrupole magnet providing a maximum steering angle of 2.5mrad. This paper outlines the magnetic and mechanical design of the steering element.

WEPO022	Tightening the Tolerance Budget of Core Fabrication to Achieve Higher Magnet Performance	sextupole, vacuum, quadrupole, scattering	2448
	N. Li, A. Madur LBNL, Berkeley, California, USA J. Jin 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. Traditionally, laminated cores of AC magnets have been always built by the laminations that are produced by a punching die. There are 5 links in the tolerance chain when a magnet core is built by this procedure: 1. Error of punching die; 2. Error of lamination punching; 3. Error of half core stacking; 4. Error of core assembly; and 5. Error of magnet re-assembling during the installation in the accelerator. As time goes on, the Lattice physicists call for more and more ever higher magnet performance, which makes the required magnet field quality almost impossible achieve by traditional core fabrication procedures. It is the goal of this paper to describe a relatively new procedure that was first used by Buckley System Ltd, NZ and is being used at SINAP, China for ALS combined function sextupole core fabrication. The advantage of this new procedure and the fabrication issues related to this procedure will be described in this paper.

WEPO024	Design and Operation Parameters of the Superconducting Main Magnets for the SIS100 Accelerator of FAIR	quadrupole, sextupole, multipole, ion	2451
	E.S. Fischer, E. Floch, J. Macavei, P. Schnizer GSI, Darmstadt, Germany P.G. Akishin JINR, Dubna, Moscow Region, Russia A. Mierau TEMF, TU Darmstadt, Darmstadt, Germany
	SIS100, the worlds second large scale synchrotron for ion research, will use superferric magnets. The dipoles are of the window frame type, whose aperture was chosen as an optimum balance between the achievable field quality and AC losses at cryogenic temperatures. Analogous design optimisation was done for the quadrupole and corrector magnets as well. We present the design of the main magnets, estimate their operation parameters and define the crucial aspects to be experimentally analysed before series production, e.g. precise magnetic end field optimisation.

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

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

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

WEPS011	Application of Orbit Response Matrix Method at CSNS/RCS	closed-orbit, lattice, alignment, simulation	2505
	Y.W. An, S. Wang IHEP Beijing, Beijing, People's Republic of China
	The China Spallation Neutron Source(CSNS) consists of a low energy linac and a high energy Rapid Cycling Synchrotron(RCS). RCS accumulates 80MeV beam and accelerates to 1.6GeV with 25Hz repetition rate and the average extraction beam power is 100kW. For controlling beam loss, the closed orbit should be adjusted as flexible as possible. The orbit response matrix(ORM) method is applied to correct the closed orbit distortion in RCS. The simulation study was made by using the code Linear Optics from Closed Orbit(LOCO) for CSNS/RCS, and the results of simulation study are presented.

WEPS029	Innovative Superconducting Non Scaling Fixed Field Alternating Gradient Isocentric Gantry for Carbon Cancer Therapy*	focusing, ion, radiation, proton	2544
	D. Trbojevic BNL, Upton, Long Island, New York, USA V.S. Morozov JLAB, Newport News, Virginia, USA
	Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy. Numbers of proton/carbon cancer therapy facilities in recent years is rising fast due to a clear advantage with respect to the other radiation therapy treatments. Cost of the ion cancer therapy is dominated by the delivery systems. An update on a design of the carbon and proton isocentric gantries is presented, using the non-scaling alternating gradient fixed field magnets (NS-FFAG). Size and weight of these magnets much smaller than any other magnets used today in cancer therapy treatment. The weight of the transport elements of the carbon isocentric gantry is estimated to be 1.5 tons to be compared to the 130 tons weight of the top-notch Heidelberg facility gantry. For the transport elements of the proton, the permanent magnet isocentric gantry is 500 kg.

WEPS037	RF Design of a 325 MHz 4-ROD RFQ	rfq, simulation, linac, quadrupole	2568
	B. Koubek, A. Schempp, J.S. Schmidt IAP, Frankfurt am Main, Germany L. Groening GSI, Darmstadt, Germany
	Usually 4-ROD Radio Frequency Quadrupoles (RFQ) are built for frequencies up to 216 MHz. For higher frequencies 4-VANE structures are more common. The advantages of 4-Rod structures, the greater flexibility for tuning and being more comfortable for maintenance, are motivating the development of a 4-Rod RFQ for higher frequencies than 216 MHz. In particular a 325 MHz RFQ with an output energy of 3 MeV is needed for the proton linac for the FAIR project of GSI. This paper reports about the design studies and the latest developments of this RFQ.

WEPS092	High Energy Beam Line Design of the 600MeV, 4 mA Proton Linac for the MYRRHA Facility	target, vacuum, proton, linac	2721
	H. Saugnac IPN, Orsay, France
	The general goal of the CDT project is to design a FAst Spectrum Transmutation Experimental Facility (FASTEF) able to demonstrate efficient transmutation and associated technology through a system working in subcritical and/or critical mode. A superconducting LINAC, part of the MYRRHA facility, will produce a 600 MeV, 4 mA proton beam and transport it to the spalation target located inside the reactor core. On this paper we focus on the final beam line design and describe optic simulations, beam instrumentation, integration inside the reactor building, mechanical and vacuum aspects as well as a preliminary design of the 2.4 MW beam dump located at the end of the accelerator tunnel.

WEPZ008	Experimental Plans to Explore Dielectric Wakefield Acceleration in the THz Regime	wakefield, acceleration, simulation, electron	2781
	F. Lemery, D. Mihalcea, P. Piot Northern Illinois University, DeKalb, Illinois, USA C. Behrens, E. Elsen, K. Flöttmann, C. Gerth, G. Kube, B. Schmidt DESY, Hamburg, Germany J. Osterhoff LBNL, Berkeley, California, USA P. Stoltz Tech-X, Boulder, Colorado, USA
	Funding: This work was supported by the Defense Threat Reduction Agency, Basic Research Award \# HDTRA1-10^-1-0051, to Northern Illinois University Dielectric wakefield accelerators have shown great promise toward high-gradient acceleration. We investigate tow experiments in preparation to explore the performance of cylindrically-symmetric and slab-shaped dielectric-loaded waveguides. The planned experiments at Fermilab and DESY will use unique pulse shaping capabilities offered at these facilities. The superconducting test accelerator at FNAL will ultimately provide flat beams with variable current profiles needed for enhancing the transformer ratio. The FLASH facility at DESY recently demonstrated the generation of a ramped round beam current profile that will enable us to explore the performance of cylindrically-symmetric structures. Finally both of these facilities incorporate superconducting linear accelerator that could generate bunch trains with closely spaced bunches thereby opening the exploration of dynamical effects in dielectric wakefield accelerators. We present the planned layout and simulated experimental performances.

WEPZ013	Design Status of LHeC Linac-Ring Interaction Region	proton, electron, quadrupole, optics	2796
	R. Tomás, J.L. Abelleira, S. Russenschuck, F. Zimmermann CERN, Geneva, Switzerland N.R. Bernard UCLA, Los Angeles, California, USA
	The ECFA-CERN-NuPECC design study for a Large Hadron electron Collider (LHeC) based on the LHC, considers two options, using a ring accelerator like LEP on top of the LHC or adding a recirculating energy-recovery linac tangential to the LHC. In order to obtain the required luminosity with an e^- beam from a linac, with average lepton beam current limited to a few mA, reaching the smallest possible proton beam size is essential. Another constraint is imposed by the need to separate e^- and p beams after the collision without losing too much luminosity from a crossing angle. A further constraint is that the ep collision should occur simultaneously to pp collisions at other LHC interaction points such that the second LHC proton beam must be accommodated in the interaction region too. We present a conceptual layout using detector-integrated combination-separation dipoles and challenging Nb3Sn technology quadrupoles for focusing the colliding proton beam and providing a low-field “hole” to accommodate both the non-colliding proton beam and the lepton beam, and the optics for all three beams. We discuss synchrotron radiation fluxes and the chromatic correction for the lepton final focus.

THOBA03	Dual AC Dipole Excitation for the Measurement of Magnetic Multipole Strength from Beam Position Monitor Data*	sextupole, kicker, simulation, lattice	2865
	M. Spata, G.A. Krafft JLAB, Newport News, Virginia, USA
	Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a technique for characterizing the nonlinear fields of the beam transport system. Two air-core dipole magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the electron beam. Fourier decomposition of beam position monitor data was then used to measure the amplitude of these frequencies at different positions along the beamline. For a purely linear transport system one expects to find solely the frequencies that were applied to the dipoles with amplitudes that depend on the phase advance of the lattice. In the presence of nonlinear fields one expects to also find harmonics of the driving frequencies that depend on the order of the nonlinearity. The technique was calibrated using one of the sextupole magnets in a CEBAF beamline and then applied to a dipole to measure the sextupole and octupole strength of the magnet. A comparison is made between the beam-based measurements, results from TOSCA and data from our Magnet Measurement Facility.
	Slides THOBA03 [6.193 MB]

THOAB03	Commissioning of the Ion Beam Gantry at HIT	ion, proton, heavy-ion, quadrupole	2874
	M. Galonska, R. Cee, Th. Haberer, K. Höppner, A. Peters, S. Scheloske, T. Winkelmann HIT, Heidelberg, Germany
	The Heidelberg Ion Beam Therapy Facility (HIT) is the first dedicated proton and carbon cancer therapy facility in Europe. It uses a full 3D intensity controlled raster scanning dose delivering method. The ion energy ranges from ca. 50 to 430 MeV/u corresponding to ion penetration depths of 20 to 300 mm in water. The HIT facility comprises the only heavy ion gantry worldwide designed for the beam transport of beams demanding a magnetic rigidity from 1 to 6.6 Tm. The gantry rotation of 360° enables beam scanning patient treatment from arbitrary directions. The libraries of carbon and proton pencil beams at the gantry are now offered with the whole variety of ion beam properties, i.e. 255 energy steps, 4 beam foci, 360°, and 10 intensities (10⁶-1010/spill). The beam has to be adjusted only for a fraction of possible combinations of energy, focus, and gantry angle. These are taken as base points for a calculation of an overall number of about 37,000 different set values per ion type, and one intensity step according to the data supply model. This paper gives an outline on the practical concepts and results of adjusting the required beam properties independent of the gantry angle.
	Slides THOAB03 [4.526 MB]

THPPA00	Study of Beam Diagnostics with Trapped Modes in Third Harmonic Superconducting Cavities at FLASH	cavity, HOM, simulation, electron	2891
	P. Zhang DESY, Hamburg, Germany P. Zhang UMAN, Manchester, United Kingdom
	Contribution selected for EPS-AG Prize d). Off-axis beams passing through an accelerating cavity excite dipole modes among other higher order modes (HOMs). These modes have linear dependence on the transverse beam offset from the cavity axis. Therefore they can be used to monitor the beam position within the cavity. The fifth dipole passband of the third harmonic superconducting cavities at FLASH has modes trapped within each cavity and do not propagate through the adjacent beam pipes, while most other cavity modes do. This could enable the beam position measurement in individual cavities. This paper investigates the possibility to use the fifth dipole band for beam alignment in the third harmonic cavity module. Simulations and measurements both with and without beam-excitations are presented. Various analysis methods are used and compared. A good correlation of HOM signals to the beam position is observed.
	Slides THPPA00 [2.740 MB]

THPPA01	EPS-AG Sacherer Prize: Beam Optics Developments for SPS, RHIC, LHC, CLIC and ATF2	resonance, sextupole, optics, extraction	2894
	R. Tomás CERN, Geneva, Switzerland
	Highlights of linear and nonlinear optics studies are presented from various accelerators. At the LHC, optics correction is of critical importance to guarantee safe beam operation. Preparation for LHC optics measurements and corrections has been a major activity during the last decade. In particular, SPS and RHIC have served as excellent research and development machines to test new techniques and instrumentation, such as the measurement of resonance driving terms with and without AC dipoles. Together with a meticulous field quality specification, a careful installation strategy and an elaborate magnet model, these efforts have paid off in the LHC, where a record low beta-beating for hadron colliders below 10% has been achieved. Looking further into the future, the performance of the Final Focus System (FFS) is of critical importance for a future linear collider like CLIC, since it determines the IP beam spot sizes. The large chromatic aberrations required the development of novel non-linear optimization methods. Such techniques have successfully increased the CLIC design luminosity by 70% and an experimental test has been proposed for ATF2 to halve the design IP beam spot sizes.
	Slides THPPA01 [1.514 MB]

THPC003	Installation of the ASTRID2 Synchrotron Light Source	extraction, kicker, cavity, vacuum	2909
	J.S. Nielsen, N. Hertel, S.P. Møller ISA, Aarhus, Denmark
	ASTRID2 is the new 10 nm UV and soft x-ray light source being built at Aarhus University, to replace the aging source ASTRID. ASTRID2 is now in the middle of its installation. An update of the design will be presented. Almost all components have now been acquired and received. Several choices and solutions of hardware will be described, and future commissioning plans outlined. Commissioning is expected to take place in the winter 2011/2012.

THPC012	Mitigating the Pertubations Caused by U 180 at the Metrology Light Source	undulator, quadrupole, optics, focusing	2930
	P.O. Schmid, D.B. Engel, J. Feikes, M. Ries, G. Wüstefeld HZB, Berlin, Germany
	The Metrology Light Source is equipped with an electromagnetic undulator with a period length of 180 mm. User requests demand operation of this undulator in a wide energy range from 100 MeV through 629 MeV for user and dedicated low alpha modes. Mitigating the pertubations caused by the undulator to an acceptable level for all user requests, requires each quadrupole in the lattice to be powered individually. To what extend this recently implemented capability allows the restoration of the main properties of the machine optics for various settings of the undulator is presented in this document.

THPC023	Third Generation Light Source Project in Iran	booster, emittance, lattice, radiation	2954
	J. Rahighi, E. Salimi, R. safian IPM, Tehran, Iran M. Jafarzadeh, Kh.S. Sarhadi ILSF, Tehran, Iran
	The Institute for Research in Fundamental Sciences (IPM) is in charge of the establishing the Iranian Light Synchrotron Source Facility (ILSF). This facility will be a 3rd generation 3 GeV storage ring with a circumference of roughly 300 m. The injector will consist of a 150 MeV Linac and a full energy booster synchrotron. The storage ring has a four-fold symmetry with 4 long (7.88m), 16 medium (4.0 m) and 12 short (2.8 m) straight sections. Within the medium straight section there are mini beta values in order to get an optimized flux density for the users. The emittance is in the range of 3 nmrad. The booster synchrotron has a circumference of roughly 192 m with an emittance of roughly 31 nmrad. It is a separated function machine in order to have the maximum flexibility. For both machine it is foreseen to use a 500 MHZ RF-system with normal conducting cavities. The machine will be build in an international collaboration, in which the main components have to be supplied from international market. The conceptual design report should be finished in 2012, the commissioning of the machine is expected to be in 2020.

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

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

THPC059	Recent Improvements to the Lattices for the MAX IV Storage Rings	storage-ring, lattice, injection, optics	3029
	S.C. Leemann MAX-lab, Lund, Sweden
	Construction of the MAX IV facility started early this year. The facility will include two storage rings for the production of synchrotron radiation. The 3 GeV ring will house insertion devices for the production of x-rays while the 1.5 GeV ring will serve UV and IR users. Recently, the lattices for the storage rings in the MAX IV facility were updated. In the 3 GeV storage ring the vertical beam size in the long straights has been reduced. The lattice of the 1.5 GeV storage ring has been updated to take into account first results from detailed magnet and vacuum system designs. Additionally, a new injection method to facilitate commissioning of the storage rings has been studied. This paper summarizes the changes made in the lattices and the effect of these modifications.

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

THPC067	Tolerance Studies of the Max-IV Linac	linac, quadrupole, emittance, sextupole	3047
	P.H. Williams STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom D. Angal-Kalinin, J.K. Jones, P.H. Williams Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Eriksson, S. Thorin, S. Werin MAX-lab, Lund, Sweden
	The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF) and an FEL (in phase 2). We briefly describe the layout, optics and bunch compression / linearization scheme of the linac. We then investigate the robustness of the design to element errors.

THPC068	CSR and THz Emission Measurements at the Diamond Light Source	radiation, electron, bunching, vacuum	3050
	R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas Diamond, Oxfordshire, United Kingdom I.P.S. Martin JAI, Oxford, United Kingdom
	After the successful implementation of the low alpha optics at Diamond we have started a characterisation of coherent THz emission with the aim of classifying the rich phenomenology of stable and bursting emission and to devise the best operational mode for potential THz users. In conjunction with the Diamond IR beamline B22, THz spectral data were acquired simultaneously with Schottky diode signals in the mm-wave region of the spectrum. We also report the results of comparison with numerical simulations made with the aim of reproducing the measured THz emission spectra and gaining further understanding on the mechanisms of the instability.

THPC071	Study of the Possibility of Implementing a Superbend in the Diamond Light Source	vacuum, radiation, magnet-design, photon	3059
	R.P. Walker, N.P. Hammond, J. Kay, S.P. Mhaskar, B. Singh Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	We report on recent studies of the feasibility and impact of replacing one of the regular 1.4 T bending magnets in Diamond with a normal conducting 3 T "Superbend" in order to enhance the hard X-ray output for a possible future beamline. We describe the preliminary magnet design, the engineering implications and the effect on beam dynamics, including the additional constraints that arise from implementing a superbend in a DBA lattice, as compared to the more common application in a TBA lattice.

THPC075	Lattice Design for PEP-X Ultimate Storage Ring Light Source	emittance, wiggler, lattice, dynamic-aperture	3068
	Y. Nosochkov, K.L.F. Bane, Y. Cai, R.O. Hettel, M.-H. Wang SLAC, Menlo Park, California, USA
	Funding: Work supported by the Department of Energy Contract DE-AC02-76SF00515. SLAC expertise in designing and operating high current storage rings and the availability of the 2.2-km PEP-II tunnel present an opportunity for building a next generation light source – PEP-X – that would replace the SPEAR3 storage ring in the future. The "baseline" design for PEP-X, with 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. As a next step in the study, a so-called "ultimate" PEP-X lattice having another order of magnitude reduction in emittance from the baseline design has been investigated. The beam emittance approaches the diffraction limited photon emittance for multi-keV photons, providing near maximum photon brightness and high coherence. In this design, the ring arcs contain seven-bend achromat cells yielding 29 pm-rad natural emittance and up to 9 insertion device straights per arc. Another factor of two emittance reduction is achieved with an 89.3-m damping wiggler installed in one of the six long straights. Details of the lattice design, the sextupole correction scheme, dynamic aperture simulations, and calculation of the intra-beam scattering effect and Touschek lifetime at a nominal 200-mA current are presented.

THPO001	Design Power Supply Considerations to Compensate Booster Power Supply Effects on the SOLEIL Storage Ring	booster, power-supply, storage-ring, controls	3335
	J.-P. Lavieville, R. Ben El Fekih, S. Bobault, D. Muller, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	Top-up injection mode has been routinely in operation since March 2009 for various bunch filling patterns at Synchrotron SOLEIL. The electron beam stored current is maintained within 1%. At each injection the 3 Hz booster power supplies are ramped up and down over 10 seconds every 3 minutes in average. During this time DC and AC perturbations are observed on the storage ring horizontal closed orbit. Typically, the beamline source points can be shifted up to 10^-20 μm and the amplitude of the 3Hz frequency is multiplied by a factor 9. The origin of these perturbations lies in the imperfect compensation of the magnet currents circulating along the booster ring located inside the storage ring. To compensate these disturbances, a wire loop was installed in the booster cable tray fed by an in-house developed power supply. Its output current is driven by direct measurement of the main currents of the booster dipole, quadrupole, sextupole power supplies with a proper amplitude and phase shift. This paper presents the determination of the compensation needs according to beam measurements, the original design and the performance reached when this power supply is acting.

THPO005	A Dipole Power Supply Based on Multi-lever Inverter Technique	power-supply, controls, status, ion	3343
	Y.X. Chen, D.Q. Gao, Y.Z. Huang, R.K. Wang, H.B. Yan IMP, Lanzhou, People's Republic of China
	By applying multi-lever inverter technique to ion accelerator power supply, it can provide steady current in wide range, increase the power supply’s equivalent output frequency, then further promote power supply’s response capability and reduce the output ripple current. This article firstly by giving a detailed introduction of composite and basic working process of dipole power supply which also applied the technique mentioned above, interpret the working principle of multi-lever inverter, and illustrate its advantages. However, applying this technique will make controller more complicated, which need to be overcome by digital regulator technique. And meanwhile digital regulator technique can improve the power supply's performance. The second part of this article briefly introduces the overall scheme of digital regulator. And at last, this article illustrate the dipole power supply meet to design target and make some improvement by using the practical results to prove that applying multi-level inverter technique into accelerator power supply is practicable and beneficial.

THPO020	TPS Digital Corrector Magnet Power Converter based on FPGA	feedback, controls, booster, quadrupole	3382
	Y.D. Li, Y.-C. Chien, K.-B. Liu NSRRC, Hsinchu, Taiwan
	This thesis presents the design and implementation of a FPGA-based fully digital-controlled programmable power supply.

THPO022	Risk Assessment of the Chopper Dipole Kicker Magnets for the MedAustron Facility	controls, power-supply, kicker, radiation	3388
	T. Kramer, T. Stadlbauer EBG MedAustron, Wr. Neustadt, Austria M.J. Barnes, M. Benedikt, T. Fowler CERN, Geneva, Switzerland
	The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and ions for both cancer therapy and research. Different types of kicker magnets will be used in the facility, including fast beam chopper dipoles: these allow the beam to be switched on and off for routine operational reasons or in case of emergency. One of the main requirements for the beam chopper system is reliability. A criticality analysis, to chart the probability of failure modes against the severity of their consequences of the fault, has been carried out for the chopper dipole system. This “Failure Mode, Effects, and Criticality Analysis” (FMECA), has been used to highlight failure modes with relatively high probability and severity of consequences: conservative ratings of critical components and appropriate redundancy, together with measurements and interlocks, have been used to reduce the probability and criticality of faults. This paper presents the results of the FMECA.

THPS002	Progress of the 2 MeV Electron Cooler Development for COSY-Jülich/HESR	electron, solenoid, high-voltage, proton	3427
	J. Dietrich, V. Kamerdzhiev FZJ, Jülich, Germany M.I. Bryzgunov, A.D. Goncharov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva, D.N. Skorobogatov BINP SB RAS, Novosibirsk, Russia
	The 2 MeV electron cooling system for COSY-Jülich was proposed to further boost the luminosity even in presence of strong heating effects of high-density internal targets. The project is funded since mid 2009. The design and construction of the cooler is accomplished in cooperation with the Budker Institute of Nuclear Physics in Novosibirsk, Russia. The 2 MeV cooler is also well suited in the start up phase of the High Energy Storage Ring (HESR) at FAIR in Darmstadt. It can be used for beam cooling at injection energy and is intended to test new features of the high energy electron cooler for HESR. The infrastructure necessary for the operation of the cooler in the COSY ring (radiation shielding, cabling, water cooling etc.) is established. The electron beam commissioning at BINP Novosibirsk is scheduled to start at May of 2011. First results are reported. Final commissioning at COSY-Jülich is planned for the end of 2011.

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

THPS058	Third Integer Resonance Slow Extraction Using RFKO at High Space Charge.	extraction, resonance, betatron, space-charge	3559
	V.P. Nagaslaev, J.F. Amundson, J.A. Johnstone, C.S. Park, S.J. Werkema Fermilab, Batavia, USA
	A proposal to search for direct mu->e conversion at Fermilab requires slow, resonant extraction of an intense proton beam. Large space charge forces will present challenges, partly due to the substantial betatron tune spread. The main challenges will be maintaining a uniform spill shape and moderate losses at the septum. We propose to use "radio frequency knockout" (RFKO) for fine tuning the extraction. Strategies for the RFKO method will be discussed here in the context of the mu->e experiment. Feasibility of this method has been demonstrated using simulations.

THPS074	Design of Superconducting Rotating-gantry for Heavy-ion Therapy	quadrupole, superconducting-magnet, ion, heavy-ion	3601
	Y. Iwata, T. Furukawa, A. I. Itano, K. Mizushima, K. Noda, T. Shirai NIRS, Chiba-shi, Japan N. Amemiya KUEE, Kyoto, Japan T. Obana NIFS, Gifu, Japan T. Ogitsu KEK, Ibaraki, Japan T. Tosaka, I. Watanabe Toshiba, Tokyo, Japan M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Tumor therapy using energetic carbon ions, as provided by the HIMAC, has been performed since June 1994, and more than 5000 patients were treated until now. With the successful clinical results, we constructed a new treatment facility. The new facility has three treatment rooms; two of them have both horizontal and vertical fixed-irradiation-ports, and the other has a rotating-gantry-port. For all the ports, a scanning-irradiation method is applied. The fixed-irradiation-ports were constructed and commissioned, and we are now designing the rotating gantry. This isocentric rotating-gantry can transport heavy ions having 430 MeV/u to the isocenter with irradiation angles of 0-360 degrees. For the magnets, combined-function superconducting-magnets will be employed. The use of the superconducting magnets allowed us to design the compact gantry; the length and radius of the gantry would be approximately 12m and 5m, which are comparable to those of the existing proton gantries. A part of the superconducting magnets will be constructed within this fiscal year. The design of the rotating gantry, including the beam optics as well as details of the superconducting magnets, will be presented.

THPS081	Design Choices of the MedAustron Nozzles and Proton Gantry based on Modeling of Particle Scattering	scattering, proton, vacuum, optics	3621
	M. Palm CERN, Geneva, Switzerland M. Benedikt, A. Fabich EBG MedAustron, Wr. Neustadt, Austria M. Palm ATI, Wien, Austria
	MedAustron, the Austrian hadron therapy center is currently under construction. Irradiations will be performed using active scanning with a proton or carbon ion pencil beam which is subject to scattering in vacuum windows, beam monitors and air gap. For applications where sharp lateral beam penumbras are required in order to spare critical organs from unwanted dose, scattering should be minimal. A semi-empirical scattering model has been established to evaluate beam size growth at the patient due to upstream scattering. Major design choices for proton gantry and nozzle based on the scattering calculations are presented.

THPZ007	Lattice Design of Low Emittance and Low Beta Function at Collision Point for SuperKEKB	emittance, dynamic-aperture, luminosity, lattice	3693
	Y. Ohnishi, H. Koiso, A. Morita, K. Oide, H. Sugimoto KEK, Ibaraki, Japan
	Extremely low beta function at the interaction point(IP) and low emittance are necessary to achieve the design luminosity of 8x10³5 cm^-2 s^-1 for a SuperKEKB project. The low emittance with a large Piwinski angle makes this possible with longer bunch longitudinally compared with the vertical beta function at IP. We call this Nano-beam scheme. In this scheme, a beam-beam parameter is realized to be less than 0.09 for the design luminosity. The lattice features, chromaticity corrections, and dynamic aperture are discussed in this article.

THPZ014	LHeC Lattice Design	optics, lattice, insertion, electron	3714
	M. Fitterer, O.S. Brüning, H. Burkhardt, B.J. Holzer, J.M. Jowett, K.H. Meß, T. Risselada CERN, Geneva, Switzerland M. Klein The University of Liverpool, Liverpool, United Kingdom A.-S. Müller KIT, Karlsruhe, Germany
	The Large Hadron Electron Collider (LHeC) aims at lepton-proton and lepton-nucleus collisions with centre of mass energies of 1-2 TeV at ep luminosities in excess of 10³3 cm^-2 s^-1. We present here a lattice design for the electron ring option, which meets the design parameters and also the constraints imposed by the integration of the new electron ring in the LHC tunnel.

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MOPC021

Design of a Choke-mode Damped Accelerating Structure for CLIC Main Linac

damping, impedance, wakefield, HOM

113

J. Shi, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland
H. Chen, W.-H. Huang, C.-X. Tang, H. Zha
TUB, Beijing, People's Republic of China

Choke-mode damped accelerating structures are being studied as an alternative to the CLIC baseline structure by a CERN-Tsinghua collaboration. Choke-mode structures hold the potential for much lower levels of pulsed surface heating and, since milling is not needed, reduced cost. Structures with radial choke attached are simulated in Gdfidl to investigate the damping of the transverse wake. The first pass-band of the dipole modes is well damped, while the higher order dipole modes are possible to be reflected by the choke. Therefore, the geometry of the choke is tuned to minimize the reflection of these higher order dipoles. Based on this damping scheme, an accelerating structure with the same iris dimensions as the nominal CLIC design but with choke-mode damping has been designed. A prototype structure will be manufactured and high power tested in the near future.

MOPC024

Construction Status of the CPHS RFQ at Tsinghua University

rfq, quadrupole, cavity, vacuum

122

Q.Z. Xing, Y.J. Bai, J.C. Cai, C. Cheng, L. Du, T. Du, X. Guan, Q. Qiang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
J.H. Billen
TechSource, Santa Fe, New Mexico, USA
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
J. Stovall
CERN, Geneva, Switzerland
L.M. Young
AES, Medford, NY, USA

Funding: Work supported by the “985 Project” of the Ministry of Education of China.
We present, in this paper, the construction status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The 3-meter-long RFQ will deliver 3 MeV protons to the downstream Drift Tube Linac (DTL) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. The RFQ has been mechanically separated into three sections. A ball-end mill, instead of a forming cutter, is adopted to machine the vane tip due to its varying radius of curvature. The precision of the numerically controlled milling machine has been verified by machining test pieces of aluminum and copper. Fine machining of the vanes was completed in July, 2011. The pre-braze tuning was completed at the beginning of this August.

MOPC040

The Measurement of Transversal Shunt Impedance of RF Deflector

cavity, impedance, simulation, emittance

163

A.Yu. Smirnov, M.V. Lalayan, N.P. Sobenin
MEPhI, Moscow, Russia
A.A. Zavadtsev
Nano, Moscow, Russia

This paper presents the results of transverse shunt impedance measurement performed using field perturbation technique and comparison with numerical MWS simulations. The structure under test is the S-band 3-cell deflecting cavity. The mentioned cavity operates with a dipole TM11-like mode with a phase shift of 120 deg per cell. The analyses were carried out with use of two types of perturbing beads: dielectric beads and metallic rings. The latter type perturbs the on-axis magnetic field much stronger than the electric field, which allows us calculating transversal shunt impedance using on-axis EM fields values.

MOPC044

Design of the Radiofrequency Quadrupole Coldmodel for the ESS-BILBAO Linear Accelerator

rfq, quadrupole, simulation, radio-frequency

175

A. Velez, I. Bustinduy, N. Garmendia, O. Gonzalez, J.L. Munoz, D. de Cos
ESS Bilbao, Bilbao, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
V. Etxebarria, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

This work will present the design of the ESS-Bilbao LINAC RFQ cold model. The process goes through the electromagnetic design of the cavity by properly setting the resonant quadrupole and dipole modes, as well as the resonance frequency. The prototype includes the vane modulation designed to accelerate a 75 mA proton beam from 75 keV to 3 MeV, with an operating frequency of 352.2 MHz. To this end, electromagnetic and electrostatic simulations have been performed by means of the commercial software COMSOL. Furthemore, results for the three components of the electrical field distribution will be presented and compared to those calculated by evaluating the 8-term multipole expansion.

MOPC061

Simulations to Flatten the Field of the FETS RFQ

rfq, simulation, cavity, quadrupole

223

S.R. Lawrie, A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

A high performance Radio Frequency Quadrupole (RFQ) is the next major component to be installed on the Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) in the UK. The beam dynamics, RF, thermal and mechanical designs of the RFQ are almost complete and so the copper has recently been purchased with a view to start cutting metal near Summer-time. This report summarizes the simulation work performed to ensure the RF design is sound. This includes performance studies of the end-wall dipole suppression fingers, tuning the frequency of the input and output vane end regions and implementing a simple solution to remove modulation induced field tilt.

MOPC096

Design and Fabrication of a 5-Cell High Current Superconducting Cavity

cavity, HOM, simulation, quadrupole

301

Y.M. Li, K.X. Liu, S.W. Quan, F. Zhu
PKU/IHIP, Beijing, People's Republic of China
R. Nassiri
ANL, Argonne, USA

Funding: National High Technology Research and Development program 863 (2009AA03Z206)
Energy recovery linacs (ERL) is promising to achieve high average current with superior beam quality. The key component for accelerating such high current beams is the superconducting radio frequency (SRF) cavity. The design of a 1.3 GHz 5-cell high current superconducting cavity has been carried out under the cooperation between Peking University (PKU) and Argonne National Laboratory (ANL). RF properties, damping of the HOMs, multipacting and mechanical features of this cavity have been discussed and the final design is presented.

MOPC106

Study of the Variation of Transverse Voltage in the 4 Rod Crab Cavity for LHC

cavity, luminosity, simulation, HOM

322

B.D.S. Hall, P.K. Ambattu, G. Burt, C. Lingwood
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
P. Goudket, C. Hill
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The planned high luminosity upgrade to LHC will utilise crab cavities to rotate the beam in order to increase the luminosity in the presence of a finite crossing angle. A compact design is required in order for the cavities to fit between opposing beam-lines. In this paper we discuss we discuss one option for the LHC crab cavity based on a 4 rod TEM deflecting cavity. Due to the large transverse size of the LHC beam the cavity is required to have a large aperture while maintaining a constant transverse voltage across the aperture. The cavity has been optimised to minimise the variation of the transverse voltage while keeping the peak surface electric and magnetic fields low for a given kick. This is achieved while fitting within the strict design space of the LHC. The variation of deflecting voltage across the aperture has been studied numerically and compared with numerical and analytical estimates of other deflecting cavity types. Performance measurements an aluminium prototype of this cavity are presented and compared to the simulated design.

MOPO039

B-train Performances at CNAO

feedback, synchrotron, power-supply, extraction

568

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

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

MOPS030

Beam Dynamics of the FRANZ Bunch Compressor using Realistic Fields with a Focus on the Rebuncher Cavities

cavity, linac, simulation, focusing

667

D. Noll, L.P. Chau, M. Droba, O. Meusel, H. Podlech, U. Ratzinger, C. Wiesner
IAP, Frankfurt am Main, Germany

Funding: Work supported by HIC for FAIR.
The ARMADILLO bunch compressor currently being designed at IAP is capable of reaching a longitudinal pulse compression ratio of 45 for proton beams of 150 mA at 2 MeV. It will provide one nanosecond proton pulses with a peak current of 7.7 A. The system guides nine linacμbunches deflected by a 5 MHz rf kicker and uses four dipole magnets - two homogeneous and two with field gradients - to merge them on the target. For longitudinal focusing and an energy variation of ±200 keV two multitrack rf cavities are included. ARMADILLO will be installed at the end of the Frankfurt Neutron Source FRANZ making use of the unique 250 kHz time structure. This contribution will provide an overview of the layout of the system as well as recent advances in component design and beam dynamics of the compressor.

MOPS033

Beam Dynamics Studies on the 100 MeV/100 kW Electron Linear Accelerator for NSC KIPT Neutron Source

linac, electron, gun, simulation

673

S. Pei, Y.L. Chi, M. Hou, W.B. Liu, G. Pei, S.H. Wang, Z.S. Zhou
IHEP Beijing, Beijing, People's Republic of China
N. Aizatsky, I.M. Karnaukhov, V.A. Kushnir, V. Mitrochenco, A.Y. Zelinsky
NSC/KIPT, Kharkov, Ukraine

We designed one 100MeV/100kW electron linear accelerator for NSC KIPT, which will be used to drive a neutron source on the base of subcritical assembly. Beam dynamics studies has been conducted to reach the design requirement (E=100MeV, P=100kW, dE/E<1% for 99% particles). In this paper, we will present the progress of the design and dynamics simulation results. For high intensity and long beam pulse linear accelerators, BBU effect is one big issue; special care has been taken in the accelerating structure design. To satisfy the energy spread requirement at the linac exit, the particles with large energy difference from the synchronous particle should be eliminated at low energy stage to ease the design of the collimation system and radiation shielding. A dispersion free chicane with 4 bending magnets is introduced at the downstream of the 1st accelerating section; the unwanted particles will be collimated there.

MOPS047

Studies of Transverse Single-pass Beam Breakup in E-Linac

HOM, cavity, linac, emittance

706

D. Kaltchev, R.A. Baartman, Y.-C. Chao, P. Kolb, S.R. Koscielniak, L. Merminga, A.K. Mitra, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Time-domain simulations of single-pass transverse beam-breakup (BBU) effects in E-linac are described. We use dipole-HOM parameters for the 9-cell cavity obtained with Particle Studio to evaluate the rms bunch orbit offsets at linac exit. Finding the multi-bunch orbit contribution to machine emittance as a function of the average beam current allows to evaluate the performance of two cavity models for two different modes of machine operation.

MOPS053

Electron Cloud Effects in Coasting Heavy-ion Beams*

electron, simulation, ion, accumulation

724

F.B. Petrov, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim
GSI, Darmstadt, Germany

Funding: Work supported by BMBF under contract 06DA9022I.
During slow extraction of intense ion beams electron clouds (EC) can accumulate in the circulating coasting beam and reduce the extraction efficiency. This is a concern for the existing SIS-18 heavy ion synchrotron at GSI and for the projected SIS-100 as part of the FAIR project. For medium energy heavy-ion beams the production of electrons from residual gas ionization is very effective. The electron density is limited due to Coulomb scattering by the beam ions. Above a threshold beam intensity the two-stream instability and the resulting coherent beam oscillations limit the electron density. Below this threshold the electron cloud can lead to observable deformations of the Schottky side-bands. To avoid EC build-up one can introduce a gap in the beam using barrier rf bucket. The reduction of the build-up efficiency caused by the gap is studied in details based on the solution of the Hill's equation for electrons. Finally we estimate the saturation level for the electron cloud density.

MOPS056

An Analytical Formula of the Electron Cloud Linear Map Coefficient in a Strong Dipole

electron, vacuum, simulation, storage-ring

733

T. Demma
INFN/LNF, Frascati (Roma), Italy
S. Petracca, A. Stabile
U. Sannio, Benevento, Italy
G. Rumolo
CERN, Geneva, Switzerland

Electron cloud effects have been indentified as one of the most serious bottleneck for reaching design performances in presently running and proposed future storage rings. The analysis of these effects is usually performed with very time consuming simulation codes. An alternative analytic approach, based on a cubic map model for the bunch-to-bunch evolution of the electron cloud density, could be useful to determine regions in parameters space compatible with safe machine operations. In this communication we derive a simple approximate formula relating the quadratic coefficient in the electron cloud density map to the parameters relevant for the electron cloud evolution in a strong vertical magnetic field. Results are compared with simulations with particular reference to the LHC dipoles.

MOPS084

Status of Electron Cloud Dynamics Measurements at CESRTA*

electron, betatron, damping, feedback

799

M.G. Billing, G. Dugan, M.J. Forster, D.L. Kreinick, R.E. Meller, M.A. Palmer, G. Ramirez, M.C. Rendina, N.T. Rider, J.P. Sikora, K.G. Sonnad, H.A. Williams
CLASSE, Ithaca, New York, USA
J.Y. Chu
CMU, Pittsburgh, Pennsylvania, USA
J.W. Flanagan
KEK, Ibaraki, Japan
R. Holtzapple, M. Randazzo
CalPoly, San Luis Obispo, California, USA

Funding: Supported by US National Science Foundation (PHY-0734867) & Dept. of Energy (DE-FC02-08ER41538)
The study of electron cloud-related instabilities for the CESR-TA project permits the observation of the interaction of the electron cloud with the stored beam under a variety of accelerator conditions. These measurements are undertaken utilizing automatic and semi-automatic techniques for three basic observations: the measurement of tune shifts of individual bunches along a train, the detection of the coherent self-excited spectrum for each bunch within a train and the pulsed excitation of either the betatron dipole or head-tail mode for each individual bunch within the train, followed by the observation of the damping of its coherent motion. These techniques are employed to study the electron cloud-related interactions in a number of conditions, such as trains of bunches with low emittance and spaced by as little as 4 nsec between bunches. We report on the most recent observations and results.

MOPS085

Wakefield Calculations for the LCLS in Multibunch Operation*

linac, injection, HOM, FEL

802

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

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

MOPS091

Study of Electron Cloud for MEIC

electron, simulation, emittance, luminosity

817

S. Ahmed, J.D. Dolph, G.A. Krafft, T. Satogata, B.C. Yunn
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The Medium Energy Electron Ion Collider (MEIC) at Jefferson Lab has been envisioned as a future high energy particle accelerator beyond the 12 GeV upgrade of the existing Continuous Electron Beam Accelerator Facility (CEBAF). Synchrotron radiation from the closely spaced proton bunches in MEIC can generate photoelectrons inside the vacuum chamber and cause secondary emission due to multipacting in the presence of beam's electric field. This phenomenon can lead to fast build up of electron density, known as electron cloud effect – resulting into beam instability coupled to multi-bunches in addition to a single bunch. For MEIC, the estimated threshold value of the electron-cloud density is approximately 5 x 10¹² m-3. In this paper, we would like to report the self-consistent simulation studies of electron cloud formation for MEIC. The code has been benchmarked against the published data of electron cloud effects observed in LHC. Our first simulations predict increase of electron clouds with the increase of repetition rate. The detailed simulations are under progress and will be reported.

MOPZ001

MuSIC, the World's Highest Intensity DC Muon Beam using a Pion Capture System

proton, solenoid, target, simulation

820

A. Sato, Y. Kuno, H. Sakamoto
Osaka University, Osaka, Japan
S. Cook, R.T.P. D'Arcy
UCL, London, United Kingdom
M. Fukuda, K. Hatanaka
RCNP, Osaka, Japan
Y. Hino, N.H. Tran, N.M. Truong
Osaka University, Graduate School of Science, Osaka, Japan
Y. Mori
KURRI, Osaka, Japan
T. Ogitsu, A. Yamamoto, M.Y. Yoshida
KEK, Tokai, Ibaraki, Japan

MuSIC is a project to provide the world's highest-intensity muon beam with continuous time structure at Research Center of Nuclear Physics (RCNP) of Osaka University, Japan. A pion capture system using a superconducting solenoid magnet and a part of superconducting muon transport solenoid channel have been build in 2010. The highest muon production efficiency was demonstrated by the beam test carried out in February 2011. The result concludes that the MuSIC can provide more than 10⁹ muons/sec using a 400 W proton beam. The pion capture system is one of very important technologies for future muon programs such as muon to electron conversion searches, neutrino factories, and a muon collider. The MuSIC built the first pion capture system and demonstrate its potential to provide an intense muon beam. The construction on the entire beam channel of the MuSIC will be finished in five years. We plan to carry out not only an experiment to search the lepton flavor violating process but also other experiments for muon science and their applications using the intense muon beam at RCNP.

MOPZ002

MICE Beamline

emittance, solenoid, beam-losses, target

823

Y. Karadzhov
DPNC, Genève, Switzerland

The muon ionization cooling experiment (MICE) is under development at the Rutherford Appleton Laboratory (UK). The goal of the experiment is to build a section of a muon cooling channel that can demonstrate the principle of Ionization cooling over a range of emittances and momenta. The MICE beam line must generate several matched muon beams with different momenta and optical parameters at the entrance of the cooling channel. This is done exploiting a titanium target dipping into the ISIS proton beam, a 5T superconducting pion decay solenoid, two dipole magnets and a mechanism for inflation of the initial emittance called diffuser. First measurements of muon rates and beam emittance performed using two TOF hodoscopes detectors will be presented.

MOPZ006

Main Magnets Design Studies for the Non-scaling Fixed Field Alternating Gradient Accelerator for a Final Acceleration Stage of the Neutrino Factory

quadrupole, factory, focusing, acceleration

829

J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
M. Aslaninejad, C. Bonţoiu, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The International Design Study of the Neutrino Factory (IDS-NF) aims to design the next generation facility for the precision neutrino oscillation searches. The non scaling Fixed Field Alternating Gradient Accelerator was prosed for the final muon beam acceleration in order to reduce the cost of the final acceleration. The superconducting magnet design based on the independent multipole coils approach using the ROXIE code is presented. The feasibility of the magnet construction together with the quench limitations are discussed.

MOPZ031

Multipass Muon RLA Return Arcs based on Linear Combined-function Magnets

linac, quadrupole, optics, lattice

868

V.S. Morozov, S.A. Bogacz, Y. Roblin
JLAB, Newport News, Virginia, USA
K.B. Beard
Muons, Inc, Batavia, USA

Funding: Supported in part by US DOE STTR Grant DE-FG02-08ER86351. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Recirculating Linear Accelerators (RLA) are an efficient way of accelerating short-lived muons to the multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper we present a design of a two-pass RLA return arc based on linear combined function magnets, in which both charge muons with momenta different by a factor of two are transported through the same string of magnets. The arc is composed of 60°-bending symmetric super cells allowing for a simple arc geometry closing. By adjusting the dipole and quadrupole components of the combined-function magnets, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both muon momenta. Such a design provides a greater compactness than, for instance, an FFAG lattice with its regular alternating bends and is expected to possess a large dynamic aperture characteristic of linear-field lattices.

MOPZ037

Extension of the 3-spectrometer Beam Transport Line for the KAOS Spectrometer at MAMI and Recent Status of MAMI

target, electron, beam-transport, status

880

R.G. Heine, M. Dehn, K.-H. Kaiser, H.-J. Kreidel, U.L. Ludwig-Mertin
IKP, Mainz, Germany

Funding: Work supported by DFG (CRC443) and the German Federal State of Rhineland-Palatinate
The institute for nuclear physics (KPH) at Mainz University is operating a 1.6 GeV c.w. microtron cascade (MAMI) for nuclear physics research. One of the vast experimental activities is electron scattering. A 3-spectrometer setup is used for cross-section measurements of hadron knock-out and meson production. The KAOS spectrometer magnet of GSI is installed there in parallel to detect particles from (e,e'K)reactions under small forward angles. So the primary electron beam has to transit the spectrometer and after this it has to hit the existing beam dump. Because of the existing experimental setup, this must be realised by deflecting the beam before the target that is rotated to be in line with the KAOS spectrometer's inlet. This paper will deal with the basic concept of a flexible beam transport line (BTL) magnet chicane for different KAOS forward angles, while keeping the forward beam direction for the 3-spectrometer setup untouched. A survey concept for assembly and adjustment of the BTL will be introduced, that is also useful for future adjustments of the target mount after target change. Results of the BTL commissioning and a general MAMI status will be presented as well.

MOPZ038

EMMA Injection and Extraction

injection, extraction, septum, kicker

883

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

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

TUXA01

Status and Challenges of the China Spallation Neutron Source

linac, DTL, power-supply, rfq

889

S. Fu, H. Chen, Y.W. Chen, Y.L. Chi, H. Dong, L. Dong, S.X. Fang, K.X. Huang, W. Kang, J. Li, L. Ma, H.F. Ouyang, H. Qu, H. Sun, J. Tang, C.H. Wang, Q.B. Wang, S. Wang, T.G. Xu, Z.X. Xu, X. Yin, C. Zhang, J. Zhang
IHEP Beijing, Beijing, People's Republic of China

The accelerator complex of China Spallation Neutron Source (CSNS) mainly consists of an H⁻ linac of 80 MeV and a rapid-cycling synchrotron of 1.6 GeV. It operates at 25 Hz repetition rate with an initial proton beam power of 100 kW and is upgradeable to 500kW. The project will start construction in the middle of 2011 with a construction period of 6.5 years. The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges. This paper presents the current status of CSNS project and summarizes the technology development during the past several years.

Slides TUXA01 [3.444 MB]

TUODA02

Status of Sirius – a New Brazilian Synchrotron Light Source

emittance, permanent-magnet, lattice, synchrotron

931

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

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

Slides TUODA02 [2.434 MB]

TUPC015

Comparative Wakefield Analysis of a First Prototype of a DDS Structure for CLIC Main Linac

wakefield, simulation, impedance, damping

1024

A. D'Elia, A. Grudiev, V.F. Khan, W. Wuensch
CERN, Geneva, Switzerland
R.M. Jones
UMAN, Manchester, United Kingdom

A Damped Detuned Structure (DDS) for CLIC main linac has been proposed as an alternative to the present baseline design which is based on heavy damping. A first prototype, CLIC_DDS_A, for high power tests has been already designed and is under construction. It is also foreseen to design a further prototype, CLIC_DDS_B, to test both the wakefield suppression and high power performances. Wakefield calculations for DDS are, in the early design stage, based on single infinitely periodic cells. Though cell-to-cell interaction is taken into account to calculate the wakefields, it is important to study full structure properties using computational tools. In particular this is fundamental for defining the input parameters for the HOM coupler that is crucial for the performances of DDS. In the following a full analysis of wakefields and impedances based on simulations conducted with finite difference based electromagnetic computer code GdfidL will be presented.

TUPC019

Beam-based Alignment of CLIC Drive Beam Decelerator using Girders Movers

quadrupole, alignment, simulation, extraction

1036

G. Sterbini, D. Schulte
CERN, Geneva, Switzerland

The CLIC drive beams will provide the rf power to accelerate the colliding beams: in order to reach the design performance, an efficient transport of the drive beam has to be ensured in spite of its challenging energy spread and large current intensity. As shown in previous studies, the specifications can be met by coupling a convenient optics design with the state-of-the-art of pre-alignment and beam-based alignment techniques. In this paper we consider a novel beam-based alignment scheme that does not require quadrupole movers or dipole correctors but uses the motors already foreseen for the pre-alignment system. This implies potential savings in terms of complexity and cost at the expense of the alignment flexibility: the performance, limitations and sensitivity to pre-alignment tolerances of this method are discussed.

TUPC026

Status of the Crab Cavity Design for the CLIC

cavity, damping, wakefield, coupling

1054

P.K. Ambattu, G. Burt, A.C. Dexter
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
V.A. Dolgashev
SLAC, Menlo Park, California, USA
A. Grudiev
CERN, Geneva, Switzerland
R.M. Jones
UMAN, Manchester, United Kingdom
P.A. McIntosh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

RF design of a crab cavity (2π/3, 11.9942 GHz) for the Compact Linear Collide (CLIC) is presented. As part of the UK-CLIC collaboration, CERN is building two copper prototypes, designed by Lancaster University / Cockcroft Institute. The first prototype to be made will be a 12 cell undamped cavity and the second will be waveguide damped cavity. The RF test at CERN will help characterisation of the dipole mode with X-band RF pulses of 15 MW peak power and pulse length of ~242 ns. Since the cavity frequency and phase advance per cell are identical to those of the CLIC main linac, the first prototype could exploit CERN’s X-band cavity characterisation facilities. A fully damped cavity will be required for the actual machine in order to meet the luminosity specs. The damped prototype will use an identical coupler type as the undamped one, but the cells will have damping waveguides with / without dielectric material.

TUPC045

Recirculating Electron Linacs (REL) for LHeC and eRHIC

electron, linac, lattice, proton

1099

D. Trbojevic, J. Beebe-Wang, Y. Hao, D. Kayran, V. Litvinenko, V. Ptitsyn, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy.
We present a design of a CW Electron Recovery Linacs (ERL) for future electron hadron colliders eRHIC and LHeC. In eRHIC, a six-pass ERL would be installed in the existing tunnel of the present Relativistic Heavy Ion Collider (RHIC). The 5-30 GeV polarized electrons will collide with RHIC’s 50-250 (325) GeV polarized protons or 20-100 (130) GeV/u heavy ions. In LHeC a 3-pass 60 GeV CW ERL will produce polarized electrons for collisions with 7 TeV protons. After collision, electron beam energy is recovered and electrons are dumped at low energy. Two superconducting linacs are located in the two straight sections in both ERLs. The multiple arcs are made of Flexible Momentum Compaction lattice (FMC) allowing adjustable momentum compaction for electrons with different energies. The multiple arcs, placed above each other, are matched to the two linac’s straight sections with splitters and combiners.

TUPC046

Alignment Tolerances for Vertical Emittance

emittance, quadrupole, lattice, closed-orbit

1102

K.P. Wootton, R.P. Rassool, G. Taylor
The University of Melbourne, Melbourne, Australia
M.J. Boland, R.T. Dowd, G. LeBlanc, Y.E. Tan
ASCo, Clayton, Victoria, Australia
Y. Papaphilippou
CERN, Geneva, Switzerland

Alignment tolerances for the CLIC main damping ring magnetic lattice elements are presented. Tolerances are defined by the design equilibrium vertical emittance of 1 pm rad. The sensitivity of the uncorrected lattice to magnet misalignments is presented. Misalignments considered included quadrupole vertical offsets and rolls, sextupole vertical offsets, and main dipole rolls. Seeded simulations were conducted in MAD-X, and compared with expectation values calculated from theory. The lattice was found to be sensitive to betatron coupling as a result of sextupole vertical offsets in the arcs. Alignment tolerances, BPM and corrector requirements are presented also. For the same misalignment types, the equilibrium emittance of the corrected lattice is simulated. These are compared with expectation values calculated from theory. The vertical alignment tolerance of arc sextupoles is again demanding.

TUPC049

Optics considerations for the Delay Loop in the CLIC Damping Rings Complex

quadrupole, emittance, optics, damping

1108

P. Zisopoulos, F. Antoniou, H. Bartosik, Y. Papaphilippou
CERN, Geneva, Switzerland

For the recombination of the two trains coming from the CLIC damping rings, a delay loop will be used in order to obtain the nominal 0.5~ns bunch spacing. The optics design of the loop is based upon an isochronous ring, in order to preserve the longitudinal beam distribution. Analytical expressions for achieving isochronous conditions in high order for Theoretical Minimum Emittance cells are obtained. A parametrisation of the quadrupole settings for achieving these conditions is presented, along with general considerations regarding the choice of bending magnet characteristics.

TUPC077

Investigations on High Sensitive Sensor Cavity for Longitudinal and Transversal Schottky for the CR at FAIR

cavity, coupling, resonance, simulation

1180

M. Hansli, A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
W. Ackermann, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany
P. Hülsmann
GSI, Darmstadt, Germany

Funding: Funded by the Federal Ministry of Education and Research (BMBF): 06DA90351
For the Collector Ring (CR) at the FAIR (Facility for Antiproton and Ion Research) accelerator complex a sensitive Schottky sensor is required. The CR covers different modes of operation, like pre-cooling of antiprotons at 3 GeV, pre-cooling of rare isotope beams at 740 MeV/u and an isochronous mode for mass measurements. For longitudinal Schottky measurements the concept of a resonant cavity had been introduced [Hansli2011]. Due to limited space inside the ring, the integration of transversal Schottky analysis into this cavity is desired. In this paper the demands and required changes to implement also transversal Schottky measurements are discussed. An analysis of the expected signal characteristics featuring equivalent circuit is shown, as well as numerical full wave simulations of the cavity.
* M. Hansli, A. Penirschke, R. Jakoby, W. Kaufmann, W. Ackermann, T. Weiland, "Conceptual Design of a High Sensitive Versatile Schottky Sensor for the Collector Ring at FAIR", DIPAC2011.

TUPC095

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

kicker, injection, quadrupole, emittance

1230

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

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

TUPC111

Design of Cavity Beam Monitor at HLS

cavity, quadrupole, emittance, gun

1278

Q. Luo, Q.K. Jia, B.G. Sun, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by the Natural Science Foundation of China, National “985 Project”, China Postdoctoral Science Foundation and “the Fundamental Research Funds for the Central Universities”
X-FEL requires precious control of beam position and transverse emittance. Non-destructive on-line beam diagnostic methods are required. During the upgrading of HLS a high brightness injector based on photocathode RF electron gun, which can also be used to study FEL, is installed. The cavity beam monitor system designed for the HLS photocathode RF electron gun consists of a cavity beam position monitor and a beam quadrupole moment monitor system. The cavity beam position monitor uses a re-entrant position cavity tuned to TM110 mode as position cavity and cut-through waveguides to suppress the monopole signal. Cold test results showed that position resolution of prototype BPM is better than 3 μm. Beam quadrupole moment monitor system consists of a square pill-box quadrupole moment cavity, a cylindrical pill-box reference cavity, a waveguide coupling network and a superheterodyne receiver used as front-end signal processing system. The whole system works at 5.712 GHz. Strength of quadrupole magnets is adjust to construct a matrix which can be used to work out beam parameters.

TUPC118

Test Results on Beam Position Resolution for Low-Q IP-BPM at KEK-ATF2

cavity, feedback, alignment, collider

1293

S.W. Jang, A. Heo, J.G. Hwang, E.-S. Kim, H.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
H.K. Park
CHEP, Daegu, Republic of Korea

We have performed the beam tests on the beam position resolution for the Low-Q IP-BPM (Interaction Point-Beam Position Monitor) at ATF2 which is an accelerator test facility for the International Linear Collider. The main goals of KEK-ATF2 are to achieve beam size of 37 nm and beam resolution of nano-meter for beam stabilization. Resolution tests for the Low-Q IP-BPM were performed with KEK BPM doublet in Jan. 2011. We got the results of beam position resolution 70 nm during the experimental periods and will present the detailed experimental procedures and results.

TUPC119

A Comprehensive Study of Nanometer Resolution of the IPBPM at ATF2*

cavity, simulation, coupling, extraction

1296

Y.I. Kim, H. Park
Kyungpook National University, Daegu, Republic of Korea
S.T. Boogert
Royal Holloway, University of London, Surrey, United Kingdom
J.C. Frisch, D.J. McCormick, J. Nelson, T.J. Smith, G.R. White, M. Woodley
SLAC, Menlo Park, California, USA
Y. Honda, R. Sugahara, T. Tauchi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Funding: Work supported in part by Department of Energy Contract DE-AC02-76SF00515.
High-resolution beam position monitors (IPBPMs) have been developed in order to measure the electron beam position at the focus point of ATF2 to a few nanometers in the vertical plane. To date, the IPBPM system has operated in test mode with a highest demonstrated resolution of 8.7 nm in the ATF extraction line during 2008. After expected noise source calculations there still remains 7.9 nm of noise of unexplained origin. We summarize the experimental work on the IPBPM system since this measurement and outline the possible origins of these sources. We then present a study plan to be performed at the ATF2 facility designed to identify and to improve the resolution performance and comment on the expected ultimate resolution of this system.

TUPC161

Cavity Beam Position Monitor System for ATF2

cavity, quadrupole, EPICS, extraction

1410

S.T. Boogert, R. Ainsworth, G.E. Boorman, S. Molloy
Royal Holloway, University of London, Surrey, United Kingdom
A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
F.J. Cullinan, N.Y. Joshi, A. Lyapin
JAI, Egham, Surrey, United Kingdom
J.C. Frisch, D.J. McCormick, J. Nelson, T.J. Smith, G.R. White
SLAC, Menlo Park, California, USA
A. Heo, E.-S. Kim, Y.I. Kim
KNU, Deagu, Republic of Korea

The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 41 high resolution C and S band resonant cavity beam position monitors (BPM) with associated mixer electronics and digitizers. In addition 4 high resolution BPMs have been recently installed at the interaction point, we briefly describe the first operational experience of these cavities in the ATF2 beam-line. The current status of the overall BPM system is also described, with a focus on operational techniques and performance.

TUPO006

Design of a Dispersive Beam Transport Line for the JETI Laser Wakefield Accelerators

undulator, radiation, electron, quadrupole

1455

C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, P. Peiffer
KIT, Karlsruhe, Germany
M. Kaluza, M. Nicolai
IOQ, Jena, Germany
R. Rossmanith
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

Laser wakeﬁeld accelerators (LWFA) emit electrons with energies of a few 100 MeV at very short bunch lengths while having a compact design. However, electron bunches from LWFA show a larger energy spread than those of conventional accelerators. This is a challenge when using these bunches e.g. to generate radiation in an undulator. A possible strategy to cope with that is to spectrally disperse the bunch and match the resulting spatial distribution with a spatially varying undulator ﬁeld amplitude. For realizing the dispersion a pair of dipole magnets is used. The electrons leaving this dipole chicane have to meet certain requirements imposed by the undulator: In the deﬂection plane the beam has to be collimated and its energy distribution must match the undulator ﬁeld. In the other transversal plane the beam has to be focussed on the center of the undulator keeping the value of the beta function small. To include this in the compact design of the setup, a combination of specially designed quadrupole and sextupole magnets is employed. In this contribution the design of the setup and the results of the particle tracking through this chicane are presented.

TUPO033

Emittance Minimization by Courant-Snyder Parameter Scan in Merger Section at the Compact Energy Recovery Linear Accelerator.

emittance, space-charge, betatron, SRF

1506

J.G. Hwang
Kyungpook National University, Daegu, Republic of Korea
E.-S. Kim
KNU, Deagu, Republic of Korea
T. Miyajima
KEK, Tsukuba, Japan

The project of compact-Energy Recovery Linac(c-ERL) at Photon Factory in KEK is a test facility for the 5 GeV ERL, which is one of the candidates of next generation light source. It consists of injector system, merger section, main SRF section, return arc, long straight section and beam dump. The injector system produces beams with a low-energy of 5 MeV and low-emittance less than 1 mm-mrad. It causes the large emittance growth by space charge force in merger section, which consists of two rectangular type dipole magnets and one sector type magnet. Dispersion also causes the displacement of bunch sllice on horizontal plane. The displacement of bunch slice is laid on the kick angle induced by space charge force. Also, each slice has the orientation of the phase ellipse on horizontal phase space. Therefore, the emittance growth due to the displacement of bunch sllice induced by space charge force in the horizontal phase space can be minimized by matching the displacement to the orientation of the phase ellipse at the exit of merger. We present the results of the emittance minimization performed by mathcing of the angle of the phase ellipse by scan of CS (Courant-Snyder) parameter.

TUPS019

Synchrotron Radiation in the LHC Vacuum System

photon, vacuum, radiation, proton

1563

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

CERN is currently operating the Large Hadron Collider (LHC) with 3.5 TeV per beam. At this energy level, when the protons trajectory is bent, the protons emit synchrotron radiation (SR) with a critical energy of 5.5 eV. Under operation, SR induced molecular desorption is routinely observed in the LHC arcs, long straight sections and experiments. This contribution recalls the SR parameters over the LHC ring for the present and nominal beam parameters. Vacuum observations during energy ramp, after accumulation of dose and along the LHC ring are discussed. Expected pressure profiles and long term behaviours of vacuum levels will be also addressed.

TUPS022

MedAustron Beam Vacuum System : From sources to Patient Treatment Rooms

vacuum, synchrotron, instrumentation, ion

1572

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

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

TUPS028

Performance of Carbon Coating for Mitigation of Electron Cloud in the SPS

electron, vacuum, insertion, extraction

1590

C. Yin Vallgren, P. Chiggiato, P. Costa Pinto, H. Neupert, G. Rumolo, E.N. Shaposhnikova, M. Taborelli
CERN, Geneva, Switzerland

Amorphous carbon (a-C) coatings have been tested in electron cloud monitors (ECM) in the Super Proton Synchrotron (SPS) and have shown for LHC type beams a reduction of the EC current by a factor 10⁴ compared to stainless steel (SS). This performance has been maintained for more than 2 years under SPS operation conditions. Secondary electron yield (SEY) laboratory data confirm that after 1 year of SPS operation, the coating maintains a SEY below 1. The compatibility of coexisting SS and a-C surfaces has been studied in an ECM having coated and uncoated areas. The results show no degradation of the properties of the a-C areas. The performance of diamond like carbon (DLC) coating has also been studied. DLC shows a less effective reduction of the EC current than a-C, but conditioning is faster than for SS. Three a-C coated dipoles were inserted in the SPS. However, even with no EC detected, the dynamic pressure rise is similar to the one observed in the SS reference dipoles. Measurement in a new ECM equipped with clearing electrodes to verify the relation between pressure signals and intensity of the EC, as well as an improvement of the diagnostics in the dipoles are in progress.

TUPS039

Reduction of Magnetic Interference on the Position Sensors of the LHC Collimators

shielding, simulation, radiation

1623

A. Masi, M. Lamberti, R. Losito, M. Martino
CERN, Geneva, Switzerland

The jaws of the LHC collimators have to be positioned with respect to the beam with an accuracy of 20 μm. On some collimators, installed in the LHC transfer lines from SPS, huge reading errors of several tens of micrometers have been observed on the Linear Variable Differential Transformer (LVDT) positioning sensors in synchronization with the variable magnetic field produced by the feed cables of the pulsed resistive dipoles of the transfer line. In this paper we introduce and describe in detail the problem, the model developed using FLUXTM for the simulation of the magnetic flux density generated by the current cables in the complex environment of an LHC transfer line, and the magnetic shielding we designed and implemented. Finally, we compare the results of simulations with experimental measurements taken during on-line pulsed magnets test campaigns.

TUPS093

Automatic Measurement System for Electrical Verification of the LHC Superconducting Circuits

pick-up, high-voltage, instrumentation, superconducting-magnet

1756

A. Kotarba, M. Bednarek, P. Jurkiewicz, J. Ludwin, M. Talach
IFJ-PAN, Kraków, Poland
R. Mompo
CERN, Geneva, Switzerland

In the LHC machine, superconducting magnet circuits are used on a very large scale. The circuits, more than 1600, are all equipped with a complex set of instrumentation required for safe operation and diagnostics. The length of many circuits exceed 3 km. Due to risks of accidental damages during transport and assembly or misconnection of the circuits’ auxiliary components, it is necessary to perform an Electrical Quality Assurance (ELQA) campaign after every major intervention on a circuit and also after each thermal cycle of the machine. In order to be able to perform reliable tests on a circuit within a short time frame, a highly extensible automated mobile test system was designed and built. Four of these instruments were successfully used during the Hardware Commissioning phases of the LHC. This paper describes the hardware solutions used in the test system.

TUPS094

Girder and Support System for PLS-II Project

multipole, storage-ring, alignment, quadrupole

1759

H.-G. Lee, H.S. Han, J.Y. Huang, Y.-G. Jung, D.E. Kim, S.N. Kim, S.H. Nam, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) is planning to upgrade the Pohang Light Source (PLS) which is a 3rd generation light source operating since 1995. We have designed a new steel magnet girder using new schemes to achieve long-term mechanical stability, vibration suppression and precision adjusting system. Each half cell of girder is composed of three pieces, two multipole magnet girder(MMG) and one dipole magnet girder(DMG). The storage ring girders consist of 48 multipole magnet girders and 24 dipole magnet girders. The new girder systems have been fabricated and tested. Recently the girders have been installing and testing the moving mechanism in the storage ring. In this report, the design consideration for the PLSII girder and support systems are reported.

TUPZ003

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

electron, simulation, vacuum, injection

1801

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

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

TUPZ021

The SPS Beam Quality Monitor, from Design to Operation

injection, extraction, quadrupole, luminosity

1849

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

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

TUPZ039

Modelling of the AGS Using Zgoubi - Status

multipole, quadrupole, simulation, resonance

1897

F. Méot, L. A. Ahrens, Y. Dutheil, J.W. Glenn, H. Huang, T. Roser, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Models of the Alternating Gradient Synchrotron, based on stepwise ray-tracing methods using both mathematical modelling or ﬁeld maps so to represent the optical elements, including the siberian snakes, are being developed based on stepwise ray-tracing numerical tools. The topic is introduced in earlier PAC and IPAC publications, a status is given here.

WEPC002

RF Separator and Septum Layout Concepts for Simultaneous Beams to RIB and FEL Users at ARIEL

septum, linac, FEL, electron

1998

Y.-C. Chao, C. Gong, S.R. Koscielniak
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

A ½ MW capable CW electron linac is being designed and constructed at TRIUMF in support of the existing Rare Isotope Beam program. In the simplest configuration, the beam makes a single pass through three cryomodules to the RIB production targets. However, after the construction of a recirculation path, beam could make a second pass through two cryomodules with the RF phase advance adjusted to give energy recovery. Here it is proposed to time-interleave two bunch trains, and via an RF separator and septum, to direct one single-pass train to RIB production and the second train through the energy recovery ring that contains an IR FEL. It is also the intention, in single user mode, to use the ring as an energy doubler. This paper describes the RF separation scheme and options for the extraction optics that satisfy the requirements of “simultaneous” beams to two users.

WEPC006

Upgrade Plans on the Superconducting Electron Accelerator S-DALINAC

recirculation, linac, electron, extraction

2010

M. Kleinmann, R. Eichhorn, F. Hug, N. Pietralla
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by DFG through SFB 634
The S-DALINAC is a superconducting recirculating electron accelerator with maximum design energy of 130 MeV operating in cw at 3 GHz. Even so the gradients of the superconducting cavities are well above design, their design quality factor of 3*10⁹ have not been reached so far, leading to higher heat transfer into the liquid helium than expected. Due to the limited cooling power of the cryo-plant being 120 W, the final energy achievable in cw operation is around 85 MeV, currently. In order to provide a cw beam with the designed final energy in the future, the installation of an additional recirculation path is projected. We will report on the beam-line and the magnet design for the new recirculation path. In addition, we will present the layout of two proposed scraper-systems which will be used to remove the halo of the electron beam allowing high precision coincidence experiments with very low background for nuclear physics in the future.

WEPC024

LOCO in the ALBA Storage Ring

quadrupole, optics, coupling, storage-ring

2055

G. Benedetti, D. Einfeld, Z. Martí, M. Muñoz
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3 GeV 3rd generation light source which achieved first stored beam in February 2011, and will be commissioned during 2011. The ring comprises of 112 independent quadrupoles grouped in 14 families and 32 combined gradient dipoles powered in series. This paper reviews the process of recovering the design lattice and the symmetry of the machine, and the effects on orbit and lifetime. The main tool employ for this has been the LOCO implementation provided in the Matlab MiddleLayer. First results shows that the main effect on the symmetry is the difference between bending magnets. As this effect can not be compensated locally at present at the bendings, a global optics correction using all the quadrupoles is used.

WEPC025

Modeling Results of the ALBA Booster

booster, emittance, injection, quadrupole

2058

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

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

WEPC029

Accuracy of the LHC Optics Measurement based on AC Dipoles

optics, simulation, quadrupole, focusing

2064

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

Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
The tight tolerances in the LHC requires optics measurement with very good accuracy. Therefore, AC dipoles are employed as the primary devices to measure the LHC optics. The accuracy of the measurement is mainly determined by the length of the coherent signal, signal-to-noise ratio of the measurement, and the data processing to effectively suppress the noise. This paper presents numerical and experimental studies of how these factors affect the accuracy of the LHC optics measurement using the AC dipoles.

WEPC030

Measurement of Coupling Resonance Driving Terms in the LHC with AC Dipoles

kicker, optics, quadrupole, resonance

2067

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

Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
Transverse betatron coupling in the LHC is measured from Fourier analysis of turn-by-turn beam oscillations excited by AC dipoles. The use of the AC dipole for optics measurements induces a small systematic error which can be corrected with an appropriate data interpretation. An algorithm to apply this correction to the measurement of the coupling resonance driving terms is developed for the first time. This paper will review this new algorithm and present results of its application to the LHC.

WEPC031

Optics Corrections at RHIC

optics, betatron, proton, quadrupole

2070

G. Vanbavinckhove
CERN, Geneva, Switzerland
M. Bai, G. Robert-Demolaize
BNL, Upton, Long Island, New York, USA

Excessive beta-beat, deviation of measured beta function from the calculated beta functions based on an model, in high energy colliders can lead to large deviation of beta function at collision point as well as other adverse effects. The segment-by-segment technique was successfully demonstrated in the LHC operation for reducing the beta-beat. It was then applied to RHIC polarized proton operation in 2011. This paper reports the experimental results of optics correction at RHIC. Future plan is also presented.

WEPC048

Calibrating Transport Lines using LOCO Techniques

quadrupole, optics, simulation, focusing

2118

Y. Roblin
JLAB, Newport News, Virginia, USA

Funding: Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
With the 12GeV upgrade underway at CEBAF, there is a need to recharacterize the beamlines after the modifications made to it to accommodate running at higher energies. We present a linear perturbation approach to calibrating the optics model of transport lines. This method is adapted from the LOCO method in use for storage rings. We consider the effect of quadrupole errors, dipole construction errors as well as beam position monitors and correctors calibrations. The ideal model is expanded to first order in Taylor series of the quadrupole errors. A set of difference orbits obtained by exciting the correctors along the beamline is taken, yielding the measured response matrix. An iterative procedure is invoked and the quadrupole errors as well as beam position monitors and corrector calibration factors are obtained. Here we present details of the method and results of first measurements at CEBAF in early 2011 Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes

WEPC055

Beam Orbit and Power Converter Stability at the CR

emittance, power-supply, antiproton, closed-orbit

2139

A. Dolinskii, C. Dimopoulou, O.E. Gorda, S.A. Litvinov, F. Nolden, M. Steck, H. Weick
GSI, Darmstadt, Germany

For the isochronous mode operation of the CR with reference to have good properties of the mass measurements we study the sources of the beam orbit fluctuation and as consequence power converter requirements for the CR operated at BR=13 Tm. This papaer presents a summary of the different factors causing beam orbit variation, which leads to reduction of the mass measurements precision. The requirements to the power converters have been addressed.

WEPC058

Field Properties of the ESR Magnets and their Influence on Beam Optics

quadrupole, betatron, sextupole, simulation

2148

O.E. Gorda, C. Dimopoulou, A. Dolinskii, S.A. Litvinov, F. Nolden, M. Steck
GSI, Darmstadt, Germany

Machine experiments at the experimental storage ring (ESR) demonstrated that the ring acceptance is strongly restricted by field errors. Higher-order field harmonics of the dipole and quadrupole magnets have been calculated and then used in particle tracking simulations in order to find out the dynamic aperture of the ESR. To benchmark the results of numerical calculations, betatron tune measurements have been performed with a uranium beam at the energy of 400 MeV/u. The results of the magnetic field simulations for the ESR magnets and a comparison between the measured and calculated tune behavioгr are presented.

WEPC059

Optimization of the Sextupole Scheme and Compensation of the Time-Dependent Field Errors during Slow Extraction from the Superconducting Synchrotron SIS300

extraction, sextupole, lattice, resonance

2151

A. Saa Hernandez, P.J. Spiller
GSI, Darmstadt, Germany
U. Ratzinger
IAP, Frankfurt am Main, Germany

The SIS300 synchrotron, planned for the new Facility for Antiproton and Ion Research (FAIR) at GSI-Darmstadt, will become the first superconducting synchrotron worldwide using cos(θ) magnets for resonant slow extraction. A multi-objective optimization algorithm has been developed for the design of the non-linear magnet scheme. The optimization algorithm makes use of the analytical model for the slow extraction from Kobayashi, the analytical description of the resonance excitation and amplitude-dependent tune-shift from Bengtsson, and corrects the chromaticity in order to fulfill the Hardt condition. As a result, the placement of the chromatic and harmonic sextupole magnets in SIS300, the number of sextupole families and the gradients of these families have been optimized for a high efficiency slow extraction. The algorithm accounts also for the sextupole errors on the dipole magnets, compensating its effects. Furthermore, optimized time-dependent settings for the sextupole magnets are generated to compensate the persistent current decay occurring at slow extraction. Tolerances for the magnets are set for the limits where the compensation is no longer valid.

WEPC060

Magnetic Field Description in Curved Accelerator Magnets using Local Toroidal Multipoles

multipole, antiproton, synchrotron, quadrupole

2154

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

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

WEPC061

ENC Interaction Region Separation Dipoles

solenoid, electron, sextupole, multipole

2157

P. Schnizer, E.S. Fischer
GSI, Darmstadt, Germany
K. Aulenbacher
IKP, Mainz, Germany

The Electron Nucleon Collider (ENC) is proposed as an upgrade of the High Energy Storage Ringe of the FAIR. The beams are separated by two dipoles, mounted closely to the intraction point; surrounded by the detectors. Hence these magnetsmust provide sufficient field quality but be slim to be transparaent to the secondary particles. Further these must be air coil magnets due to the detector solenoid field of 2T. We present the 3D optimised magnet next to a first design of the mechanical restraint structure and a concise description for the field distortion leaking into the detector.

WEPC067

The Spin Aberration of Polarized Beam in Electrostatic Rings

cavity, simulation, emittance, lattice

2175

Y. Senichev, A. Lehrach, R. Maier, D. Zyuzin
FZJ, Jülich, Germany

For a beam with nonzero transverse emittance and momentum spread passing through an electric field, for example an electric focusing lens or deflector, the orientation of a spin vector becomes a function of 6D initial phase coordinates that leads to spin aberrations. We investigate this process analytically and numerically.

WEPC078

Non-linear Chromaticity Studies of the LHC at Injection

octupole, injection, optics, emittance

2199

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

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

WEPC085

Multipole Fringe Fields

multipole, quadrupole

2211

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
M.J. de Loos, S.B. van der Geer
Pulsar Physics, Eindhoven, The Netherlands

When creating an initial model of an accelerator, one usually has to resort to a hard edge model for the quadrupoles and higher order multipoles at the start of the project. Ordinarily, it is not until much later on that one has a field map for the given multipoles. This can be rather inconvenient when one is dealing with particularly thin elements or elements which are rather close together in a beamline as the hard edge model may be inadequate for the level of precision desired. For example, in the EMMA project, the two types of quadrupoles used are so close together that they are usually described by a single field map or via hard edge models. The first method has the desired accuracy but was not available at the start of the project and the second is known to be a rough approximation. In this paper, an analytic expression is derived and presented for fringe fields for a multipole of any order with a view to applying it to cases like EMMA.

WEPC088

Embedding Finite Element Results for Accelerator Components in a Moment Approach Beam Dynamics Code*

quadrupole, simulation, electron, sextupole

2217

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''.
A moment based beam dynamics code has particular advantages, i.e. accuracy and efficiency, over macro-particle tracking and full particle-in-cell (PIC) codes respectively. Instead of embedding analytical descriptions of the accelerator components in the beam dynamics model, it is proposed to insert a surrogate model obtained from the finite element model of individual accelerator components. We apply the V-Code, which accepts moments up to the sixth order and accounts for space charge effects. We construct and calculate finite element and finite difference time domain models using the CST Studio Suite 2011 software package. An interface is implemented using VBA and MATLAB. As an example of the accuracy of this cascadic simulation approach, we compare the beam dynamics of an S-DALINAC quadrupole obtained by directly tracking particles to the calculated fields with the results for the cascadic approach with the V-Code.
This work was performed during a three month research visit at the Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Darmstadt, Germany.

WEPC100

Simulation of the Single Bunch Instability due to the Electron Cloud Effect by Tracking with a Pre-computed 2D Wake Matrix*

electron, simulation, single-bunch, positron

2247

A. Markoviḱ, G. Pöplau, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: Supported by DFG Contract Nr. RI 814/20-1.
The passage of a positron bunch through an initially homogeneous electron cloud (e-cloud) changes the distribution of the e-cloud in a way that the concentration of electrons in the proximity of the beam axis grows rapidly. The electrons are primarily moving in the transverse plane and are very sensitive on the beam centroid position in that plane. Thus the transverse kick of the e-cloud on the tail particles depends on the centroid position of the head particles of the same bunch. A PIC simulation of the interaction of a positron beam with an e-cloud yields the wake kick from the electrons on the tail particles for a certain offset in the transverse centroid position of the head parts of the bunch. With such a pre-computed 2D wake matrix, for a certain e-cloud density, we investigate the stability of a single bunch by tracking it through the linear optics of the storage ring while at each turn applying the kick from the e-cloud. We examine the positron bunch stability of KEKB-LER and PETRAIII for a certain electron cloud density.

WEPC125

Higher Order Modes in Coupled Cavities of the FLASH Module ACC39

cavity, simulation, HOM, diagnostics

2301

R.M. Jones, I.R.R. Shinton
UMAN, Manchester, United Kingdom
Z. Li
SLAC, Menlo Park, California, USA

We analyse the higher order modes (HOMs) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and ACE3P) and globalised scattering matrix calculations are used to investigate the modes in these cavities. This study is primarily focused on the dipole component of the multiband expansion of the wakefield, with the emphasis being on the development of a HOM-based BPM system for ACC39. Coupled inter-cavity modes are simulated together with a limited band of trapped modes.

WEPC159

A Python Tracking Code and GUI for Control Room Operations

controls, lattice, storage-ring, status

2358

M.T. Heron, J. Rowland
Diamond, Oxfordshire, United Kingdom

Considerable use has been made in recent years of accelerator physics modelling and online tools under Matlab. These have demonstrated the benefits of operating in a rich integrated environment and further given good portability across projects and operating systems. As a possible alternative to Matlab, Diamond has been evaluating options based on Python. Python together with the Numpy libraries and Qt Graphics provides an environment which offers a lot of the functionality of Matlab. This paper presents these developments, which include a tracking code, symplectic integrator, twiss and response matrix together with a GUI interface.

WEPC175

FLUKA Studies of the Asynchronous Beam Dump Effects on LHC Point 6

proton, insertion, simulation, quadrupole

2397

R. Versaci, V. Boccone, B. Goddard, A. Mereghetti, R. Schmidt, V. Vlachoudis
CERN, Geneva, Switzerland

The LHC is a record-breaking machine for beam energy and intensity. An intense effort has therefore been deployed in simulating critical operational scenarios of energy deposition. FLUKA is the most widely used code for this kind of simulations at CERN because of the high reliability of its results and the ease to custom detailed simulations all along hundreds of meters of beam line. We have investigated the effects of an asynchronous beam dump on the LHC Point 6 where, beams with a stored energy of 360 MJ, can instantaneously release up to a few J cm^-3 in the cryogenic magnets which have a quench limit of the order of the mJ cm^-3. In the present paper we will briefly introduce FLUKA, describe the simulation approach, and discuss the evaluated maximum energy release onto the superconducting magnets during an asynchronous beam dump. We will then analyse the shielding provided by collimators installed in the area and discuss safety limits for the operation of the LHC.

WEPC176

Beam Loss Monitoring and Machine Protection System Design and Application for the ALICE Test Accelerator at Daresbury Laboratory

beam-losses, monitoring, radiation, simulation

2400

S.R. Buckley, J.-L. Fernández-Hernando
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

ALICE is a demonstrator accelerator system which has been designed and built at Daresbury Laboratory. The heart of this facility is an ERL accelerator and a powerful multi-terrawatt laser. It serves as an advanced test facility for novel accelerator and photon science applications. Beam loss monitoring and machine protection systems are vital areas for the successful operation of ALICE. These systems are required, both for efficient machine set up and for hardware protection during operation. This paper gives an overview of the system design, commissioning details and a summary of the systems’ effectiveness as a diagnostic tool.

WEPO001

Design and Optimization of the MedAustron Synchrotron Main Dipoles

simulation, synchrotron, ion, quadrupole

2406

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

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

WEPO003

The FERMI@Elettra Magnets

quadrupole, gun, electron, FEL

2409

D. Castronovo, R. Fabris, G.L. Loda, D. Zangrando
ELETTRA, Basovizza, Italy

FERMI@Elettra is a single-pass FEL user-facility located next to the third generation synchrotron radiation facility ELETTRA in Trieste, Italy. The linear accelerator contains more than 200 magnets. This paper reports on the design, construction, magnetic measurement and installation.

WEPO014

Magnetic Design of Quadrupoles for the Medium and High Energy Beam Transport line of the LIPAC Accelerator

quadrupole, coupling, beam-transport, simulation

2424

C. Oliver, B. Brañas, A. Ibarra, I. Podadera, F. Toral
CIEMAT, Madrid, Spain

Funding: Work partially supported by Spanish Ministry of Science and Innovation under project AIC10-A-000441 and ENE2009-11230.
The LIPAC accelerator will be a 9 MeV, 125 mA cw deuteron accelerator which will verify the validity of the design of the future IFMIF accelerator. A Medium Energy Beam Transport line (MEBT) is necessary to handle the high current beam from the RFQ to the Superconducting RF accelerating cavities (SRF) whereas a High Energy Beam Transport line (HEBT) is used to match the beam from the SRF to the beam dump. The high space charge and beam power determine the beam dynamics in both transport lines. As a consequence, magnets with strong fields in a reduced space are required. Along the transport beamlines, there are different types of quadrupoles with steerers and a dipole. Special care is devoted to maximize the integrated fields in the available space. Both 2-D and 3-D magnetic calculations are used to optimize coil configurations. Magnetic performance and cost, both of magnet and power supply, have been taken into account for final choice. In this paper, the design of the resistive quadrupoles of the MEBT and HEBT of the LIPAC accelerator is presented.

WEPO015

MAX IV 3 GeV Storage Ring Prototype Magnet

storage-ring, simulation, magnet-design, lattice

2427

M.A.G. Johansson, L.-J. Lindgren
MAX-lab, Lund, Sweden
B. Anderberg
AMACC, Uppsala, Sweden

The MAX IV facility, currently under construction, will consist of a 3 GeV storage ring, a 1.5 GeV storage ring, and a full energy injector/SPF/FEL driver. The magnet design for the 3 GeV storage ring is conceptually identical to the MAX III storage ring magnets, with all magnet elements within each cell machined into one solid iron block. A prototype of a matching cell magnet block has been manufactured and mechanical and magnetic field measurements have been performed.

WEPO016

Design of the MAX IV/Solaris 1.5 GeV Storage Ring Magnets

lattice, ion, storage-ring, simulation

2430

M.A.G. Johansson
MAX-lab, Lund, Sweden

The MAX IV facility, currently under construction in Lund, Sweden, will consist of a 3 GeV storage ring, a 1.5 GeV storage ring, and a full energy injector/SPF/FEL driver. The Solaris facility, which will be built in Krakow, Poland, will use an identical 1.5 GeV storage ring, injected at 500 MeV. The magnet design for the 1.5 GeV storage ring is conceptually identical to the MAX III and the MAX IV 3 GeV storage ring magnets, with several magnet elements machined into one solid iron block. Detailed design has been done in Opera3D, with a model of the full magnet block being set up and simulated, and iterated against the lattice design.

WEPO019

Magnetic Model of the CERN Proton Synchrotron Main Magnetic Unit

focusing, multipole, synchrotron, proton

2439

M. Juchno
EPFL, Lausanne, Switzerland

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

WEPO021

Quadrupole Magnet with an Integrated Dipole Steering Element for the ISIS Beam Transport Line

quadrupole, target, beam-transport, proton

2445

S.J.S. Jago, J. Shih, S.F.S. Tomlinson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.M. Gurov
BINP SB RAS, Novosibirsk, Russia

A refurbishment of beam transport line to the original ISIS target station at the Rutherford Appleton Laboratory has recently been completed. This work involved a slight change to the optics in the area, which included the requirement for extra steering capabilities. Due to the space constraints in the region, a quadrupole magnet with an integrated dipole steering element was developed. The steering dipole consists of four saddle shaped coils situated within the bore of the quadrupole magnet providing a maximum steering angle of 2.5mrad. This paper outlines the magnetic and mechanical design of the steering element.

WEPO022

Tightening the Tolerance Budget of Core Fabrication to Achieve Higher Magnet Performance

sextupole, vacuum, quadrupole, scattering

2448

N. Li, A. Madur
LBNL, Berkeley, California, USA
J. Jin
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.
Traditionally, laminated cores of AC magnets have been always built by the laminations that are produced by a punching die. There are 5 links in the tolerance chain when a magnet core is built by this procedure: 1. Error of punching die; 2. Error of lamination punching; 3. Error of half core stacking; 4. Error of core assembly; and 5. Error of magnet re-assembling during the installation in the accelerator. As time goes on, the Lattice physicists call for more and more ever higher magnet performance, which makes the required magnet field quality almost impossible achieve by traditional core fabrication procedures. It is the goal of this paper to describe a relatively new procedure that was first used by Buckley System Ltd, NZ and is being used at SINAP, China for ALS combined function sextupole core fabrication. The advantage of this new procedure and the fabrication issues related to this procedure will be described in this paper.

WEPO024

Design and Operation Parameters of the Superconducting Main Magnets for the SIS100 Accelerator of FAIR

quadrupole, sextupole, multipole, ion

2451

E.S. Fischer, E. Floch, J. Macavei, P. Schnizer
GSI, Darmstadt, Germany
P.G. Akishin
JINR, Dubna, Moscow Region, Russia
A. Mierau
TEMF, TU Darmstadt, Darmstadt, Germany

SIS100, the worlds second large scale synchrotron for ion research, will use superferric magnets. The dipoles are of the window frame type, whose aperture was chosen as an optimum balance between the achievable field quality and AC losses at cryogenic temperatures. Analogous design optimisation was done for the quadrupole and corrector magnets as well. We present the design of the main magnets, estimate their operation parameters and define the crucial aspects to be experimentally analysed before series production, e.g. precise magnetic end field optimisation.

WEPO028

Design of HTS Sector Magnets for the RCNP New Injector Cyclotron

cyclotron, injection, neutron, cavity

2460

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

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

WEPO031

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

injection, quadrupole, optics, sextupole

2466

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

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

WEPS001

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

injection, lattice, ion, dynamic-aperture

2478

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

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

WEPS011

Application of Orbit Response Matrix Method at CSNS/RCS

closed-orbit, lattice, alignment, simulation

2505

Y.W. An, S. Wang
IHEP Beijing, Beijing, People's Republic of China

The China Spallation Neutron Source(CSNS) consists of a low energy linac and a high energy Rapid Cycling Synchrotron(RCS). RCS accumulates 80MeV beam and accelerates to 1.6GeV with 25Hz repetition rate and the average extraction beam power is 100kW. For controlling beam loss, the closed orbit should be adjusted as flexible as possible. The orbit response matrix(ORM) method is applied to correct the closed orbit distortion in RCS. The simulation study was made by using the code Linear Optics from Closed Orbit(LOCO) for CSNS/RCS, and the results of simulation study are presented.

WEPS029

Innovative Superconducting Non Scaling Fixed Field Alternating Gradient Isocentric Gantry for Carbon Cancer Therapy*

focusing, ion, radiation, proton

2544

D. Trbojevic
BNL, Upton, Long Island, New York, USA
V.S. Morozov
JLAB, Newport News, Virginia, USA

Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy.
Numbers of proton/carbon cancer therapy facilities in recent years is rising fast due to a clear advantage with respect to the other radiation therapy treatments. Cost of the ion cancer therapy is dominated by the delivery systems. An update on a design of the carbon and proton isocentric gantries is presented, using the non-scaling alternating gradient fixed field magnets (NS-FFAG). Size and weight of these magnets much smaller than any other magnets used today in cancer therapy treatment. The weight of the transport elements of the carbon isocentric gantry is estimated to be 1.5 tons to be compared to the 130 tons weight of the top-notch Heidelberg facility gantry. For the transport elements of the proton, the permanent magnet isocentric gantry is 500 kg.

WEPS037

RF Design of a 325 MHz 4-ROD RFQ

rfq, simulation, linac, quadrupole

2568

B. Koubek, A. Schempp, J.S. Schmidt
IAP, Frankfurt am Main, Germany
L. Groening
GSI, Darmstadt, Germany

Usually 4-ROD Radio Frequency Quadrupoles (RFQ) are built for frequencies up to 216 MHz. For higher frequencies 4-VANE structures are more common. The advantages of 4-Rod structures, the greater flexibility for tuning and being more comfortable for maintenance, are motivating the development of a 4-Rod RFQ for higher frequencies than 216 MHz. In particular a 325 MHz RFQ with an output energy of 3 MeV is needed for the proton linac for the FAIR project of GSI. This paper reports about the design studies and the latest developments of this RFQ.

WEPS092

High Energy Beam Line Design of the 600MeV, 4 mA Proton Linac for the MYRRHA Facility

target, vacuum, proton, linac

2721

H. Saugnac
IPN, Orsay, France

The general goal of the CDT project is to design a FAst Spectrum Transmutation Experimental Facility (FASTEF) able to demonstrate efficient transmutation and associated technology through a system working in subcritical and/or critical mode. A superconducting LINAC, part of the MYRRHA facility, will produce a 600 MeV, 4 mA proton beam and transport it to the spalation target located inside the reactor core. On this paper we focus on the final beam line design and describe optic simulations, beam instrumentation, integration inside the reactor building, mechanical and vacuum aspects as well as a preliminary design of the 2.4 MW beam dump located at the end of the accelerator tunnel.

WEPZ008

Experimental Plans to Explore Dielectric Wakefield Acceleration in the THz Regime

wakefield, acceleration, simulation, electron

2781

F. Lemery, D. Mihalcea, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
C. Behrens, E. Elsen, K. Flöttmann, C. Gerth, G. Kube, B. Schmidt
DESY, Hamburg, Germany
J. Osterhoff
LBNL, Berkeley, California, USA
P. Stoltz
Tech-X, Boulder, Colorado, USA

Funding: This work was supported by the Defense Threat Reduction Agency, Basic Research Award \# HDTRA1-10^-1-0051, to Northern Illinois University
Dielectric wakefield accelerators have shown great promise toward high-gradient acceleration. We investigate tow experiments in preparation to explore the performance of cylindrically-symmetric and slab-shaped dielectric-loaded waveguides. The planned experiments at Fermilab and DESY will use unique pulse shaping capabilities offered at these facilities. The superconducting test accelerator at FNAL will ultimately provide flat beams with variable current profiles needed for enhancing the transformer ratio. The FLASH facility at DESY recently demonstrated the generation of a ramped round beam current profile that will enable us to explore the performance of cylindrically-symmetric structures. Finally both of these facilities incorporate superconducting linear accelerator that could generate bunch trains with closely spaced bunches thereby opening the exploration of dynamical effects in dielectric wakefield accelerators. We present the planned layout and simulated experimental performances.

WEPZ013

Design Status of LHeC Linac-Ring Interaction Region

proton, electron, quadrupole, optics

2796

R. Tomás, J.L. Abelleira, S. Russenschuck, F. Zimmermann
CERN, Geneva, Switzerland
N.R. Bernard
UCLA, Los Angeles, California, USA

The ECFA-CERN-NuPECC design study for a Large Hadron electron Collider (LHeC) based on the LHC, considers two options, using a ring accelerator like LEP on top of the LHC or adding a recirculating energy-recovery linac tangential to the LHC. In order to obtain the required luminosity with an e^- beam from a linac, with average lepton beam current limited to a few mA, reaching the smallest possible proton beam size is essential. Another constraint is imposed by the need to separate e^- and p beams after the collision without losing too much luminosity from a crossing angle. A further constraint is that the ep collision should occur simultaneously to pp collisions at other LHC interaction points such that the second LHC proton beam must be accommodated in the interaction region too. We present a conceptual layout using detector-integrated combination-separation dipoles and challenging Nb3Sn technology quadrupoles for focusing the colliding proton beam and providing a low-field “hole” to accommodate both the non-colliding proton beam and the lepton beam, and the optics for all three beams. We discuss synchrotron radiation fluxes and the chromatic correction for the lepton final focus.

THOBA03

Dual AC Dipole Excitation for the Measurement of Magnetic Multipole Strength from Beam Position Monitor Data*

sextupole, kicker, simulation, lattice

2865

M. Spata, G.A. Krafft
JLAB, Newport News, Virginia, USA

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a technique for characterizing the nonlinear fields of the beam transport system. Two air-core dipole magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the electron beam. Fourier decomposition of beam position monitor data was then used to measure the amplitude of these frequencies at different positions along the beamline. For a purely linear transport system one expects to find solely the frequencies that were applied to the dipoles with amplitudes that depend on the phase advance of the lattice. In the presence of nonlinear fields one expects to also find harmonics of the driving frequencies that depend on the order of the nonlinearity. The technique was calibrated using one of the sextupole magnets in a CEBAF beamline and then applied to a dipole to measure the sextupole and octupole strength of the magnet. A comparison is made between the beam-based measurements, results from TOSCA and data from our Magnet Measurement Facility.

Slides THOBA03 [6.193 MB]

THOAB03

Commissioning of the Ion Beam Gantry at HIT

ion, proton, heavy-ion, quadrupole

2874

M. Galonska, R. Cee, Th. Haberer, K. Höppner, A. Peters, S. Scheloske, T. Winkelmann
HIT, Heidelberg, Germany

The Heidelberg Ion Beam Therapy Facility (HIT) is the first dedicated proton and carbon cancer therapy facility in Europe. It uses a full 3D intensity controlled raster scanning dose delivering method. The ion energy ranges from ca. 50 to 430 MeV/u corresponding to ion penetration depths of 20 to 300 mm in water. The HIT facility comprises the only heavy ion gantry worldwide designed for the beam transport of beams demanding a magnetic rigidity from 1 to 6.6 Tm. The gantry rotation of 360° enables beam scanning patient treatment from arbitrary directions. The libraries of carbon and proton pencil beams at the gantry are now offered with the whole variety of ion beam properties, i.e. 255 energy steps, 4 beam foci, 360°, and 10 intensities (10⁶-1010/spill). The beam has to be adjusted only for a fraction of possible combinations of energy, focus, and gantry angle. These are taken as base points for a calculation of an overall number of about 37,000 different set values per ion type, and one intensity step according to the data supply model. This paper gives an outline on the practical concepts and results of adjusting the required beam properties independent of the gantry angle.

Slides THOAB03 [4.526 MB]

THPPA00

Study of Beam Diagnostics with Trapped Modes in Third Harmonic Superconducting Cavities at FLASH

cavity, HOM, simulation, electron

2891

P. Zhang
DESY, Hamburg, Germany
P. Zhang
UMAN, Manchester, United Kingdom

Contribution selected for EPS-AG Prize d). Off-axis beams passing through an accelerating cavity excite dipole modes among other higher order modes (HOMs). These modes have linear dependence on the transverse beam offset from the cavity axis. Therefore they can be used to monitor the beam position within the cavity. The fifth dipole passband of the third harmonic superconducting cavities at FLASH has modes trapped within each cavity and do not propagate through the adjacent beam pipes, while most other cavity modes do. This could enable the beam position measurement in individual cavities. This paper investigates the possibility to use the fifth dipole band for beam alignment in the third harmonic cavity module. Simulations and measurements both with and without beam-excitations are presented. Various analysis methods are used and compared. A good correlation of HOM signals to the beam position is observed.

Slides THPPA00 [2.740 MB]

THPPA01

EPS-AG Sacherer Prize: Beam Optics Developments for SPS, RHIC, LHC, CLIC and ATF2

resonance, sextupole, optics, extraction

2894

R. Tomás
CERN, Geneva, Switzerland

Highlights of linear and nonlinear optics studies are presented from various accelerators. At the LHC, optics correction is of critical importance to guarantee safe beam operation. Preparation for LHC optics measurements and corrections has been a major activity during the last decade. In particular, SPS and RHIC have served as excellent research and development machines to test new techniques and instrumentation, such as the measurement of resonance driving terms with and without AC dipoles. Together with a meticulous field quality specification, a careful installation strategy and an elaborate magnet model, these efforts have paid off in the LHC, where a record low beta-beating for hadron colliders below 10% has been achieved. Looking further into the future, the performance of the Final Focus System (FFS) is of critical importance for a future linear collider like CLIC, since it determines the IP beam spot sizes. The large chromatic aberrations required the development of novel non-linear optimization methods. Such techniques have successfully increased the CLIC design luminosity by 70% and an experimental test has been proposed for ATF2 to halve the design IP beam spot sizes.

Slides THPPA01 [1.514 MB]

THPC003

Installation of the ASTRID2 Synchrotron Light Source

extraction, kicker, cavity, vacuum

2909

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

ASTRID2 is the new 10 nm UV and soft x-ray light source being built at Aarhus University, to replace the aging source ASTRID. ASTRID2 is now in the middle of its installation. An update of the design will be presented. Almost all components have now been acquired and received. Several choices and solutions of hardware will be described, and future commissioning plans outlined. Commissioning is expected to take place in the winter 2011/2012.

THPC012

Mitigating the Pertubations Caused by U 180 at the Metrology Light Source

undulator, quadrupole, optics, focusing

2930

P.O. Schmid, D.B. Engel, J. Feikes, M. Ries, G. Wüstefeld
HZB, Berlin, Germany

The Metrology Light Source is equipped with an electromagnetic undulator with a period length of 180 mm. User requests demand operation of this undulator in a wide energy range from 100 MeV through 629 MeV for user and dedicated low alpha modes. Mitigating the pertubations caused by the undulator to an acceptable level for all user requests, requires each quadrupole in the lattice to be powered individually. To what extend this recently implemented capability allows the restoration of the main properties of the machine optics for various settings of the undulator is presented in this document.

THPC023

Third Generation Light Source Project in Iran

booster, emittance, lattice, radiation

2954

J. Rahighi, E. Salimi, R. safian
IPM, Tehran, Iran
M. Jafarzadeh, Kh.S. Sarhadi
ILSF, Tehran, Iran

The Institute for Research in Fundamental Sciences (IPM) is in charge of the establishing the Iranian Light Synchrotron Source Facility (ILSF). This facility will be a 3rd generation 3 GeV storage ring with a circumference of roughly 300 m. The injector will consist of a 150 MeV Linac and a full energy booster synchrotron. The storage ring has a four-fold symmetry with 4 long (7.88m), 16 medium (4.0 m) and 12 short (2.8 m) straight sections. Within the medium straight section there are mini beta values in order to get an optimized flux density for the users. The emittance is in the range of 3 nmrad. The booster synchrotron has a circumference of roughly 192 m with an emittance of roughly 31 nmrad. It is a separated function machine in order to have the maximum flexibility. For both machine it is foreseen to use a 500 MHZ RF-system with normal conducting cavities. The machine will be build in an international collaboration, in which the main components have to be supplied from international market. The conceptual design report should be finished in 2012, the commissioning of the machine is expected to be in 2020.

THPC024

Lattice Candidates for the ILSF Storage Ring

storage-ring, lattice, emittance, synchrotron

2957

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

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

THPC025

Booster Design for ILSF

booster, synchrotron, storage-ring, electron

2960

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

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

THPC059

Recent Improvements to the Lattices for the MAX IV Storage Rings

storage-ring, lattice, injection, optics

3029

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

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

THPC063

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

storage-ring, power-supply, vacuum, synchrotron

3038

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

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

THPC067

Tolerance Studies of the Max-IV Linac

linac, quadrupole, emittance, sextupole

3047

P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
D. Angal-Kalinin, J.K. Jones, P.H. Williams
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Eriksson, S. Thorin, S. Werin
MAX-lab, Lund, Sweden

The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF) and an FEL (in phase 2). We briefly describe the layout, optics and bunch compression / linearization scheme of the linac. We then investigate the robustness of the design to element errors.

THPC068

CSR and THz Emission Measurements at the Diamond Light Source

radiation, electron, bunching, vacuum

3050

R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas
Diamond, Oxfordshire, United Kingdom
I.P.S. Martin
JAI, Oxford, United Kingdom

After the successful implementation of the low alpha optics at Diamond we have started a characterisation of coherent THz emission with the aim of classifying the rich phenomenology of stable and bursting emission and to devise the best operational mode for potential THz users. In conjunction with the Diamond IR beamline B22, THz spectral data were acquired simultaneously with Schottky diode signals in the mm-wave region of the spectrum. We also report the results of comparison with numerical simulations made with the aim of reproducing the measured THz emission spectra and gaining further understanding on the mechanisms of the instability.

THPC071

Study of the Possibility of Implementing a Superbend in the Diamond Light Source

vacuum, radiation, magnet-design, photon

3059

R.P. Walker, N.P. Hammond, J. Kay, S.P. Mhaskar, B. Singh
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

We report on recent studies of the feasibility and impact of replacing one of the regular 1.4 T bending magnets in Diamond with a normal conducting 3 T "Superbend" in order to enhance the hard X-ray output for a possible future beamline. We describe the preliminary magnet design, the engineering implications and the effect on beam dynamics, including the additional constraints that arise from implementing a superbend in a DBA lattice, as compared to the more common application in a TBA lattice.

THPC075

Lattice Design for PEP-X Ultimate Storage Ring Light Source

emittance, wiggler, lattice, dynamic-aperture

3068

Y. Nosochkov, K.L.F. Bane, Y. Cai, R.O. Hettel, M.-H. Wang
SLAC, Menlo Park, California, USA

Funding: Work supported by the Department of Energy Contract DE-AC02-76SF00515.
SLAC expertise in designing and operating high current storage rings and the availability of the 2.2-km PEP-II tunnel present an opportunity for building a next generation light source – PEP-X – that would replace the SPEAR3 storage ring in the future. The "baseline" design for PEP-X, with 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. As a next step in the study, a so-called "ultimate" PEP-X lattice having another order of magnitude reduction in emittance from the baseline design has been investigated. The beam emittance approaches the diffraction limited photon emittance for multi-keV photons, providing near maximum photon brightness and high coherence. In this design, the ring arcs contain seven-bend achromat cells yielding 29 pm-rad natural emittance and up to 9 insertion device straights per arc. Another factor of two emittance reduction is achieved with an 89.3-m damping wiggler installed in one of the six long straights. Details of the lattice design, the sextupole correction scheme, dynamic aperture simulations, and calculation of the intra-beam scattering effect and Touschek lifetime at a nominal 200-mA current are presented.

THPO001

Design Power Supply Considerations to Compensate Booster Power Supply Effects on the SOLEIL Storage Ring

booster, power-supply, storage-ring, controls

3335

J.-P. Lavieville, R. Ben El Fekih, S. Bobault, D. Muller, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

Top-up injection mode has been routinely in operation since March 2009 for various bunch filling patterns at Synchrotron SOLEIL. The electron beam stored current is maintained within 1%. At each injection the 3 Hz booster power supplies are ramped up and down over 10 seconds every 3 minutes in average. During this time DC and AC perturbations are observed on the storage ring horizontal closed orbit. Typically, the beamline source points can be shifted up to 10^-20 μm and the amplitude of the 3Hz frequency is multiplied by a factor 9. The origin of these perturbations lies in the imperfect compensation of the magnet currents circulating along the booster ring located inside the storage ring. To compensate these disturbances, a wire loop was installed in the booster cable tray fed by an in-house developed power supply. Its output current is driven by direct measurement of the main currents of the booster dipole, quadrupole, sextupole power supplies with a proper amplitude and phase shift. This paper presents the determination of the compensation needs according to beam measurements, the original design and the performance reached when this power supply is acting.

THPO005

A Dipole Power Supply Based on Multi-lever Inverter Technique

power-supply, controls, status, ion

3343

Y.X. Chen, D.Q. Gao, Y.Z. Huang, R.K. Wang, H.B. Yan
IMP, Lanzhou, People's Republic of China

By applying multi-lever inverter technique to ion accelerator power supply, it can provide steady current in wide range, increase the power supply’s equivalent output frequency, then further promote power supply’s response capability and reduce the output ripple current. This article firstly by giving a detailed introduction of composite and basic working process of dipole power supply which also applied the technique mentioned above, interpret the working principle of multi-lever inverter, and illustrate its advantages. However, applying this technique will make controller more complicated, which need to be overcome by digital regulator technique. And meanwhile digital regulator technique can improve the power supply's performance. The second part of this article briefly introduces the overall scheme of digital regulator. And at last, this article illustrate the dipole power supply meet to design target and make some improvement by using the practical results to prove that applying multi-level inverter technique into accelerator power supply is practicable and beneficial.

THPO020

TPS Digital Corrector Magnet Power Converter based on FPGA

feedback, controls, booster, quadrupole

3382

Y.D. Li, Y.-C. Chien, K.-B. Liu
NSRRC, Hsinchu, Taiwan

This thesis presents the design and implementation of a FPGA-based fully digital-controlled programmable power supply.

THPO022

Risk Assessment of the Chopper Dipole Kicker Magnets for the MedAustron Facility

controls, power-supply, kicker, radiation

3388

T. Kramer, T. Stadlbauer
EBG MedAustron, Wr. Neustadt, Austria
M.J. Barnes, M. Benedikt, T. Fowler
CERN, Geneva, Switzerland

The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and ions for both cancer therapy and research. Different types of kicker magnets will be used in the facility, including fast beam chopper dipoles: these allow the beam to be switched on and off for routine operational reasons or in case of emergency. One of the main requirements for the beam chopper system is reliability. A criticality analysis, to chart the probability of failure modes against the severity of their consequences of the fault, has been carried out for the chopper dipole system. This “Failure Mode, Effects, and Criticality Analysis” (FMECA), has been used to highlight failure modes with relatively high probability and severity of consequences: conservative ratings of critical components and appropriate redundancy, together with measurements and interlocks, have been used to reduce the probability and criticality of faults. This paper presents the results of the FMECA.

THPS002

Progress of the 2 MeV Electron Cooler Development for COSY-Jülich/HESR

electron, solenoid, high-voltage, proton

3427

J. Dietrich, V. Kamerdzhiev
FZJ, Jülich, Germany
M.I. Bryzgunov, A.D. Goncharov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva, D.N. Skorobogatov
BINP SB RAS, Novosibirsk, Russia

The 2 MeV electron cooling system for COSY-Jülich was proposed to further boost the luminosity even in presence of strong heating effects of high-density internal targets. The project is funded since mid 2009. The design and construction of the cooler is accomplished in cooperation with the Budker Institute of Nuclear Physics in Novosibirsk, Russia. The 2 MeV cooler is also well suited in the start up phase of the High Energy Storage Ring (HESR) at FAIR in Darmstadt. It can be used for beam cooling at injection energy and is intended to test new features of the high energy electron cooler for HESR. The infrastructure necessary for the operation of the cooler in the COSY ring (radiation shielding, cabling, water cooling etc.) is established. The electron beam commissioning at BINP Novosibirsk is scheduled to start at May of 2011. First results are reported. Final commissioning at COSY-Jülich is planned for the end of 2011.

THPS044

Study of Charge Exchange Injection in HITFiL

injection, ion, synchrotron, emittance

3520

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

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

THPS058

Third Integer Resonance Slow Extraction Using RFKO at High Space Charge.

extraction, resonance, betatron, space-charge

3559

V.P. Nagaslaev, J.F. Amundson, J.A. Johnstone, C.S. Park, S.J. Werkema
Fermilab, Batavia, USA

A proposal to search for direct mu->e conversion at Fermilab requires slow, resonant extraction of an intense proton beam. Large space charge forces will present challenges, partly due to the substantial betatron tune spread. The main challenges will be maintaining a uniform spill shape and moderate losses at the septum. We propose to use "radio frequency knockout" (RFKO) for fine tuning the extraction. Strategies for the RFKO method will be discussed here in the context of the mu->e experiment. Feasibility of this method has been demonstrated using simulations.

THPS074

Design of Superconducting Rotating-gantry for Heavy-ion Therapy

quadrupole, superconducting-magnet, ion, heavy-ion

3601

Y. Iwata, T. Furukawa, A. I. Itano, K. Mizushima, K. Noda, T. Shirai
NIRS, Chiba-shi, Japan
N. Amemiya
KUEE, Kyoto, Japan
T. Obana
NIFS, Gifu, Japan
T. Ogitsu
KEK, Ibaraki, Japan
T. Tosaka, I. Watanabe
Toshiba, Tokyo, Japan
M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Tumor therapy using energetic carbon ions, as provided by the HIMAC, has been performed since June 1994, and more than 5000 patients were treated until now. With the successful clinical results, we constructed a new treatment facility. The new facility has three treatment rooms; two of them have both horizontal and vertical fixed-irradiation-ports, and the other has a rotating-gantry-port. For all the ports, a scanning-irradiation method is applied. The fixed-irradiation-ports were constructed and commissioned, and we are now designing the rotating gantry. This isocentric rotating-gantry can transport heavy ions having 430 MeV/u to the isocenter with irradiation angles of 0-360 degrees. For the magnets, combined-function superconducting-magnets will be employed. The use of the superconducting magnets allowed us to design the compact gantry; the length and radius of the gantry would be approximately 12m and 5m, which are comparable to those of the existing proton gantries. A part of the superconducting magnets will be constructed within this fiscal year. The design of the rotating gantry, including the beam optics as well as details of the superconducting magnets, will be presented.

THPS081

Design Choices of the MedAustron Nozzles and Proton Gantry based on Modeling of Particle Scattering

scattering, proton, vacuum, optics

3621

M. Palm
CERN, Geneva, Switzerland
M. Benedikt, A. Fabich
EBG MedAustron, Wr. Neustadt, Austria
M. Palm
ATI, Wien, Austria

MedAustron, the Austrian hadron therapy center is currently under construction. Irradiations will be performed using active scanning with a proton or carbon ion pencil beam which is subject to scattering in vacuum windows, beam monitors and air gap. For applications where sharp lateral beam penumbras are required in order to spare critical organs from unwanted dose, scattering should be minimal. A semi-empirical scattering model has been established to evaluate beam size growth at the patient due to upstream scattering. Major design choices for proton gantry and nozzle based on the scattering calculations are presented.

THPZ007

Lattice Design of Low Emittance and Low Beta Function at Collision Point for SuperKEKB

emittance, dynamic-aperture, luminosity, lattice

3693

Y. Ohnishi, H. Koiso, A. Morita, K. Oide, H. Sugimoto
KEK, Ibaraki, Japan

Extremely low beta function at the interaction point(IP) and low emittance are necessary to achieve the design luminosity of 8x10³5 cm^-2 s^-1 for a SuperKEKB project. The low emittance with a large Piwinski angle makes this possible with longer bunch longitudinally compared with the vertical beta function at IP. We call this Nano-beam scheme. In this scheme, a beam-beam parameter is realized to be less than 0.09 for the design luminosity. The lattice features, chromaticity corrections, and dynamic aperture are discussed in this article.

THPZ014

LHeC Lattice Design

optics, lattice, insertion, electron

3714

M. Fitterer, O.S. Brüning, H. Burkhardt, B.J. Holzer, J.M. Jowett, K.H. Meß, T. Risselada
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom
A.-S. Müller
KIT, Karlsruhe, Germany

The Large Hadron Electron Collider (LHeC) aims at lepton-proton and lepton-nucleus collisions with centre of mass energies of 1-2 TeV at ep luminosities in excess of 10³3 cm^-2 s^-1. We present here a lattice design for the electron ring option, which meets the design parameters and also the constraints imposed by the integration of the new electron ring in the LHC tunnel.