LINAC2012 - List of Keywords (dipole)

Paper	Title	Other Keywords	Page
SUPB038	Multipole Field Effects for the Superconducting Parallel-Bar Deflecting/Crabbing Cavities	multipole, cavity, superconductivity, luminosity	92
	S.U. De Silva, J.R. Delayen ODU, Norfolk, Virginia, USA S.U. De Silva JLAB, Newport News, Virginia, USA
	The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

SUPB039	Compact Superconducting Crabbing and Deflecting Cavities	cavity, HOM, damping, collider	95
	S.U. De Silva ODU, Norfolk, Virginia, USA S.U. De Silva JLAB, Newport News, Virginia, USA
	Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM110 cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.

MO3A04	Accelerator/Decelerator of Slow Neutrons	neutron, focusing, simulation, controls	133
	M. Kitaguchi Kyoto University, Research Reactor Institute, Osaka, Japan Y. Arimoto, H.M. Shimizu KEK, Ibaraki, Japan P.W. Geltenbort ILL, Grenoble, France S. Imajo Kyoto University, Kyoto, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan Y. Seki RIKEN Nishina Center, Wako, Japan T. Yoshioka Kyushu University, Fukuoka, Japan
	Funding: Supported by the Quantum Beam Fundamentals Development Program MEXT, a Grant-in-Aid for Creative Scientific Research of MEXT Program No.19GS0210 and No.23244047, Yamada Science Foundation, and KEK. An accelerator/decelerator for slow neutron beams has been demonstrated. The energy of a neutron can be increased or decreased by flipping the neutron spin (directly coupled to magnetic dipole moment) in magnetic field. This device is a combination of a gradient magnetic field and an RF magnetic field. Because the RF frequency for the spin flip is a function of the external magnetic field, only neutrons that are located in a specific magnetic field level will be spin-flipped at a given RF frequency. By changing the RF frequency, the energy change can be selected in the gradient magnetic field. The maximum field of the gradient magnet is 1 T, which corresponds to the energy change of 120 neV. The magnetic field linearly decreases to 0.2T within 25 cm. By putting this device on a beamline from a pulsed neutron source, neutron rebuncher is realized. The dense slow neutrons are important to suppress the systematic errors for the measurement of neutron electric dipole moment (nEDM). The combination of spallation neutron source and this neutron rebuncher is suitable to the measurement of nEDM. A review of current status of our plan for nEDM experiment at J-PARC will be also presented.
	Slides MO3A04 [3.750 MB]

MOPB003	Recent Improvements to the Control of the CTF3 High-Current Drive Beam	lattice, controls, linac, optics	180
	B. Constance, R. Corsini, D. Gamba, P.K. Skowroński CERN, Geneva, Switzerland
	In order to demonstrate the feasibility of the CLIC multi-TeV linear collider option, the drive beam complex at the CLIC Test Facility (CTF3) at CERN is providing high-current electron pulses for a number of related experiments. By means of a system of electron pulse compression and bunch frequency multiplication, a fully loaded, 120 MeV linac is used to generate 140 ns electron pulses of around 30 Amperes. Subsequent deceleration of this high-current drive beam demonstrates principles behind the CLIC acceleration scheme, and produces 12 GHz RF power for experimental purposes. As the facility has progressed toward routine operation, a number of studies aimed at improving the drive beam performance have been carried out. Additional feedbacks, automated steering programs, and improved control of optics and dispersion have contributed to a more stable, reproducible drive beam with consequent benefits for the experiments.

MOPB014	Electron Model of a Dogbone RLA with Multi-Pass Arcs	linac, electron, quadrupole, optics	201
	S.A. Bogacz, G.A. Krafft, V.S. Morozov, Y. Roblin JLAB, Newport News, Virginia, USA K.B. Beard Muons. Inc., USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by USDOE STTR Grant DE-FG02-08ER86351 The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.35 MeV/c electron beam is injected in the middle of a 2.9 MeV/pass linac with two double-pass return arcs and is accelerated to 17.4 MeV/c in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The footprint of a complete RLA fits in a 25x7 m area. The scheme utilizes only fixed field magnets for both injection and extraction. The hardware requirements are not very demanding making it straightforward to implement the scaled design using available equipment.

MOPB016	In-situ Measurement of Beam-induced Fields in the S-band Accelerating Structures of the Diamond Light Source linac	linac, multipole, higher-order-mode, wakefield	204
	C. Christou Diamond, Oxfordshire, United Kingdom
	The Diamond pre-injector linac uses two 5.2 m DESY linac II-type accelerating structures to generate a 100 MeV electron beam suitable for injection into the booster synchrotron. The structures are powered independently by two high-power S-band klystrons and are designed to operate at 3 GHz. Higher order modes up to 14 GHz induced by beam in unpowered accelerating and bunching structures have been directly measured using directional couplers in the high-power waveguide network. These modes are compared with an electromagnetic simulation of the structures. The negative impact of higher-order wakes on the bunch trains used at Diamond is considered, and the use of the multipole field measurement for alignment of the beam to the structure is investigated.

MOPB038	Single Shot Bunch-by-Bunch Beam Emittance Measurement of the SPring-8 Linac	linac, injection, emittance, electron	261
	Y. Shoji, K. Takeda LASTI, Hyogo, Japan
	Bunch by bunch emittance of a single shot beam from the SPring-8 electron linac was measured. The linac is operated as an injector to the electron storage ring, NewSUBARU. A high beam stability is required for the stable top-up injection into the ring with a small acceptance. We used the electron ring as a part of the measurement system. The electron beam from the linac was injected into the ring and circulated for many turns. The beam profiles were recorded by a dual-sweep streak camera using the visible light in the ring. The fast sweep separated the bunches in 1 ns macro pulse and the slow sweep separated the profiles at different revolutions. It enabled a multi-record of beam profiles in one camera frame. Betatron oscillation in the ring produced the phase space rotation for the reconstruction of the beam emittance. The ring parameters were optimized for the measurement because the beam storage was not necessary. A stability of the linac beam was evaluated from the shot by shot fluctuation of the emittance and the bunch structure. We also compared the emittances of a front bunch and a rear bunch in the same pulse.

MOPB067	Results and Performance Simulations of the Main Linac Design for BERLinPro	cavity, HOM, linac, quadrupole	333
	A. Neumann, W. Anders, J. Knobloch HZB, Berlin, Germany K. Brackebusch, T. Flisgen, T. Galek, K. Papke, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany B. Riemann, T. Weis DELTA, Dortmund, Germany
	Funding: this work is partly funded by BMBF contract no. 05K10PEA and 05K10HRC The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW LINAC technology for 100-mA-class ERLs. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. We have studied elliptical 7-cell cavities damped by on the whole five waveguides at both ends. Eigenmode computations for geometrical figures of merit show that the present design should allow successful CW linac operation at the maximum beam current of 100 mA/77 pC bunch charge. To verify the results, the external Q factors are compared to the results of S-Parameter simulations that are postprocessed by a pole-fitting technique. First results of scattering parameter measurement on a room-temperature aluminium model are discussed. An outlook presenting the possibilities of combined multi-cavity simulations is included.

TUPB058	An Analytical Cavity Model for Fast Linac-Beam Tuning	multipole, quadrupole, cavity, simulation	609
	Z.Q. He, Z. Zheng TUB, Beijing, People's Republic of China Z.Q. He, Z. Liu, J. Wei, Y. Zhang FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Non-axisymmetric RF cavities can produce axially asymmetric acceleration fields. Conventional method using numerical 3-D field tracking to address this feature is time-consuming and thus not appropriate for on-line beam tuning applications. In this paper, we develop analytical treatment of non-axisymmetric RF cavities. Multipole models of cavities are derived using realistic 3-D field in both longitudinal and transverse dimensions. Then, beam dynamics formulism is established. Finally, special case of FRIB quarter-wave resonators are calculated by the model and benchmarked against 3-D field tracking to ensure the efficiency and accuracy of the model.

TH1A02	Compact Superconducting Crabbing and Deflecting Cavities	cavity, HOM, damping, collider	753
	S.U. De Silva ODU, Norfolk, Virginia, USA S.U. De Silva JLAB, Newport News, Virginia, USA
	Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM110 cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.
	Slides TH1A02 [3.811 MB]

THPB031	Status Report on the French High-intensity Proton Injector Project at SACLAY (IPHI)	rfq, coupling, quadrupole, diagnostics	921
	B. Pottin, M. Desmons, A. France, R. Gobin, O. Piquet CEA/DSM/IRFU, France
	The construction of IPHI (High Power Proton Accelerator) is in its final step of installation. The high intensity light ion source (SILHI) has been built first to produce regularly CW high intensity (over 100 mA) proton beams. The low energy front end of IPHI is based on a 352 MHz, 6 m long Radiofrequency Quadrupole (RFQ) cavity. The RFQ will accelerate beam up to 100 mA with energy up to 3 MeV. A diagnostics line has been designed to measure all the main characteristics of the beam at the RFQ output. In this paper we will present the status for the main components of the injector, in particularly the RFQ fabrication and the RF power facilities.

THPB038	Assembly and RF Tuning of the Linac4 RFQ at CERN	rfq, quadrupole, linac, cavity	939
	C. Rossi, A. Dallocchio, J. Hansen, J.-B. Lallement, A.M. Lombardi, S.J. Mathot, D. Pugnat, M.A. Timmins, G. Vandoni, M. Vretenar CERN, Geneva, Switzerland M. Desmons, A. France, Y. Le Noa, J. Novo, O. Piquet CEA/DSM/IRFU, France
	The fabrication of Linac4 is progressing at CERN with the goal of making a 160 MeV H⁻ beam available to the LHC injection chain as from 2015. In the Linac4 the first stage of beam acceleration, after its extraction from the ion source, is provided by a Radiofrequency Quadrupole accelerator (RFQ), operating at the RF frequency of 352.2 MHz and which accelerates the ion beam to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane kind, has been designed in the frame of a collaboration between CERN and CEA and has been completely machined and assembled at CERN. The paper describes the assembly of the RFQ structure and reports the results of RF low power measurements, in order to achieve the required accelerating field flatness within 1% of the nominal field profile.

THPB062	Multipole Field Effects for the Superconducting Parallel-Bar/RF-Dipole Deflecting/Crabbing Cavities	multipole, cavity, superconductivity, luminosity	981
	S.U. De Silva, J.R. Delayen ODU, Norfolk, Virginia, USA S.U. De Silva JLAB, Newport News, Virginia, USA
	The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

THPB065	Status of the Beam Dynamics Code DYNAC	rfq, emittance, quadrupole, simulation	990
	E. Tanke, J.A. Rodriguez, W. Wittmer, X. Wu FRIB, East Lansing, Michigan, USA S. Valero CEA, Gif-sur-Yvette, France D. Wang NSCL, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The beam dynamics code DYNAC* was originally developed at CERN. For accelerating elements a set of very accurate quasi-Liouvillian beam dynamics equations was introduced, applicable to protons, heavy ions and non-relativistic electrons. Furthermore, DYNAC contains three space charge routines, including a 3D version*. More recently, a numerical method has been added, capable of simulating a multi charge state ion beam in accelerating elements (i.e. cavities). Beam line devices such as sextupoles and quadrupole-sextupole magnets as well as electrostatic devices are now also included. Capability of second order calculations of such elements for a multi charge state beam has been implemented. Benchmarking of the code, in particular for a multi-charge state beam is discussed. Comparison of beam simulations results with beam measurements on the MSU ReAccelerator (ReA) are reported. The possibility of using DYNAC as an online tool for ReA and FRIB is discussed. DYNAC: A Multi-Particle Beam Dynamics Code for Leptons and Hadrons, E.Tanke et al,LINAC2002 **HERSC: A New 3 Dimensional Space Charge Routine for High Intensity Bunched Beams, E.Tanke et al,LINAC2002

THPB079	Development of a Superconducting Focusing Solenoid for CADS	solenoid, focusing, cavity, linac	1011
	W. Wu, S.F. Han, Y. He, L.Z. Ma, D.S. Ni, Z.J. Wang, B.M. Wu, W.J. Yang, X.L. Yang, S.J. Zheng, L. Zhu IMP, Lanzhou, People's Republic of China
	A superconducting focusing solenoid has been designed and developed for the China Accelerator Driven System (CADS). In order to meet the requirement of focusing strength and fringe field while minimizing physical size of the solenoid, the novel optimizing design method based on linear programming method was employed. In this report, we will introduce the design of the solenoid including magnetic field optimization, mechanical design and quench protection. The fabrication and the test results of the solenoid will also be introduced in this report.

Paper

Title

Other Keywords

Page

SUPB038

Multipole Field Effects for the Superconducting Parallel-Bar Deflecting/Crabbing Cavities

multipole, cavity, superconductivity, luminosity

92

S.U. De Silva, J.R. Delayen
ODU, Norfolk, Virginia, USA
S.U. De Silva
JLAB, Newport News, Virginia, USA

The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

SUPB039

Compact Superconducting Crabbing and Deflecting Cavities

cavity, HOM, damping, collider

95

S.U. De Silva
ODU, Norfolk, Virginia, USA
S.U. De Silva
JLAB, Newport News, Virginia, USA

Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM110 cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.

MO3A04

Accelerator/Decelerator of Slow Neutrons

neutron, focusing, simulation, controls

133

M. Kitaguchi
Kyoto University, Research Reactor Institute, Osaka, Japan
Y. Arimoto, H.M. Shimizu
KEK, Ibaraki, Japan
P.W. Geltenbort
ILL, Grenoble, France
S. Imajo
Kyoto University, Kyoto, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
Y. Seki
RIKEN Nishina Center, Wako, Japan
T. Yoshioka
Kyushu University, Fukuoka, Japan

Funding: Supported by the Quantum Beam Fundamentals Development Program MEXT, a Grant-in-Aid for Creative Scientific Research of MEXT Program No.19GS0210 and No.23244047, Yamada Science Foundation, and KEK.
An accelerator/decelerator for slow neutron beams has been demonstrated. The energy of a neutron can be increased or decreased by flipping the neutron spin (directly coupled to magnetic dipole moment) in magnetic field. This device is a combination of a gradient magnetic field and an RF magnetic field. Because the RF frequency for the spin flip is a function of the external magnetic field, only neutrons that are located in a specific magnetic field level will be spin-flipped at a given RF frequency. By changing the RF frequency, the energy change can be selected in the gradient magnetic field. The maximum field of the gradient magnet is 1 T, which corresponds to the energy change of 120 neV. The magnetic field linearly decreases to 0.2T within 25 cm. By putting this device on a beamline from a pulsed neutron source, neutron rebuncher is realized. The dense slow neutrons are important to suppress the systematic errors for the measurement of neutron electric dipole moment (nEDM). The combination of spallation neutron source and this neutron rebuncher is suitable to the measurement of nEDM. A review of current status of our plan for nEDM experiment at J-PARC will be also presented.

Slides MO3A04 [3.750 MB]

MOPB003

Recent Improvements to the Control of the CTF3 High-Current Drive Beam

lattice, controls, linac, optics

180

B. Constance, R. Corsini, D. Gamba, P.K. Skowroński
CERN, Geneva, Switzerland

In order to demonstrate the feasibility of the CLIC multi-TeV linear collider option, the drive beam complex at the CLIC Test Facility (CTF3) at CERN is providing high-current electron pulses for a number of related experiments. By means of a system of electron pulse compression and bunch frequency multiplication, a fully loaded, 120 MeV linac is used to generate 140 ns electron pulses of around 30 Amperes. Subsequent deceleration of this high-current drive beam demonstrates principles behind the CLIC acceleration scheme, and produces 12 GHz RF power for experimental purposes. As the facility has progressed toward routine operation, a number of studies aimed at improving the drive beam performance have been carried out. Additional feedbacks, automated steering programs, and improved control of optics and dispersion have contributed to a more stable, reproducible drive beam with consequent benefits for the experiments.

MOPB014

Electron Model of a Dogbone RLA with Multi-Pass Arcs

linac, electron, quadrupole, optics

201

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

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by USDOE STTR Grant DE-FG02-08ER86351
The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.35 MeV/c electron beam is injected in the middle of a 2.9 MeV/pass linac with two double-pass return arcs and is accelerated to 17.4 MeV/c in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The footprint of a complete RLA fits in a 25x7 m area. The scheme utilizes only fixed field magnets for both injection and extraction. The hardware requirements are not very demanding making it straightforward to implement the scaled design using available equipment.

MOPB016

In-situ Measurement of Beam-induced Fields in the S-band Accelerating Structures of the Diamond Light Source linac

linac, multipole, higher-order-mode, wakefield

204

C. Christou
Diamond, Oxfordshire, United Kingdom

The Diamond pre-injector linac uses two 5.2 m DESY linac II-type accelerating structures to generate a 100 MeV electron beam suitable for injection into the booster synchrotron. The structures are powered independently by two high-power S-band klystrons and are designed to operate at 3 GHz. Higher order modes up to 14 GHz induced by beam in unpowered accelerating and bunching structures have been directly measured using directional couplers in the high-power waveguide network. These modes are compared with an electromagnetic simulation of the structures. The negative impact of higher-order wakes on the bunch trains used at Diamond is considered, and the use of the multipole field measurement for alignment of the beam to the structure is investigated.

MOPB038

Single Shot Bunch-by-Bunch Beam Emittance Measurement of the SPring-8 Linac

linac, injection, emittance, electron

261

Y. Shoji, K. Takeda
LASTI, Hyogo, Japan

Bunch by bunch emittance of a single shot beam from the SPring-8 electron linac was measured. The linac is operated as an injector to the electron storage ring, NewSUBARU. A high beam stability is required for the stable top-up injection into the ring with a small acceptance. We used the electron ring as a part of the measurement system. The electron beam from the linac was injected into the ring and circulated for many turns. The beam profiles were recorded by a dual-sweep streak camera using the visible light in the ring. The fast sweep separated the bunches in 1 ns macro pulse and the slow sweep separated the profiles at different revolutions. It enabled a multi-record of beam profiles in one camera frame. Betatron oscillation in the ring produced the phase space rotation for the reconstruction of the beam emittance. The ring parameters were optimized for the measurement because the beam storage was not necessary. A stability of the linac beam was evaluated from the shot by shot fluctuation of the emittance and the bunch structure. We also compared the emittances of a front bunch and a rear bunch in the same pulse.

MOPB067

Results and Performance Simulations of the Main Linac Design for BERLinPro

cavity, HOM, linac, quadrupole

333

A. Neumann, W. Anders, J. Knobloch
HZB, Berlin, Germany
K. Brackebusch, T. Flisgen, T. Galek, K. Papke, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
B. Riemann, T. Weis
DELTA, Dortmund, Germany

Funding: this work is partly funded by BMBF contract no. 05K10PEA and 05K10HRC
The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW LINAC technology for 100-mA-class ERLs. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. We have studied elliptical 7-cell cavities damped by on the whole five waveguides at both ends. Eigenmode computations for geometrical figures of merit show that the present design should allow successful CW linac operation at the maximum beam current of 100 mA/77 pC bunch charge. To verify the results, the external Q factors are compared to the results of S-Parameter simulations that are postprocessed by a pole-fitting technique. First results of scattering parameter measurement on a room-temperature aluminium model are discussed. An outlook presenting the possibilities of combined multi-cavity simulations is included.

TUPB058

An Analytical Cavity Model for Fast Linac-Beam Tuning

multipole, quadrupole, cavity, simulation

609

Z.Q. He, Z. Zheng
TUB, Beijing, People's Republic of China
Z.Q. He, Z. Liu, J. Wei, Y. Zhang
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Non-axisymmetric RF cavities can produce axially asymmetric acceleration fields. Conventional method using numerical 3-D field tracking to address this feature is time-consuming and thus not appropriate for on-line beam tuning applications. In this paper, we develop analytical treatment of non-axisymmetric RF cavities. Multipole models of cavities are derived using realistic 3-D field in both longitudinal and transverse dimensions. Then, beam dynamics formulism is established. Finally, special case of FRIB quarter-wave resonators are calculated by the model and benchmarked against 3-D field tracking to ensure the efficiency and accuracy of the model.

TH1A02

Compact Superconducting Crabbing and Deflecting Cavities

cavity, HOM, damping, collider

753

S.U. De Silva
ODU, Norfolk, Virginia, USA
S.U. De Silva
JLAB, Newport News, Virginia, USA

Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM110 cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.

Slides TH1A02 [3.811 MB]

THPB031

Status Report on the French High-intensity Proton Injector Project at SACLAY (IPHI)

rfq, coupling, quadrupole, diagnostics

921

B. Pottin, M. Desmons, A. France, R. Gobin, O. Piquet
CEA/DSM/IRFU, France

The construction of IPHI (High Power Proton Accelerator) is in its final step of installation. The high intensity light ion source (SILHI) has been built first to produce regularly CW high intensity (over 100 mA) proton beams. The low energy front end of IPHI is based on a 352 MHz, 6 m long Radiofrequency Quadrupole (RFQ) cavity. The RFQ will accelerate beam up to 100 mA with energy up to 3 MeV. A diagnostics line has been designed to measure all the main characteristics of the beam at the RFQ output. In this paper we will present the status for the main components of the injector, in particularly the RFQ fabrication and the RF power facilities.

THPB038

Assembly and RF Tuning of the Linac4 RFQ at CERN

rfq, quadrupole, linac, cavity

939

C. Rossi, A. Dallocchio, J. Hansen, J.-B. Lallement, A.M. Lombardi, S.J. Mathot, D. Pugnat, M.A. Timmins, G. Vandoni, M. Vretenar
CERN, Geneva, Switzerland
M. Desmons, A. France, Y. Le Noa, J. Novo, O. Piquet
CEA/DSM/IRFU, France

The fabrication of Linac4 is progressing at CERN with the goal of making a 160 MeV H⁻ beam available to the LHC injection chain as from 2015. In the Linac4 the first stage of beam acceleration, after its extraction from the ion source, is provided by a Radiofrequency Quadrupole accelerator (RFQ), operating at the RF frequency of 352.2 MHz and which accelerates the ion beam to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane kind, has been designed in the frame of a collaboration between CERN and CEA and has been completely machined and assembled at CERN. The paper describes the assembly of the RFQ structure and reports the results of RF low power measurements, in order to achieve the required accelerating field flatness within 1% of the nominal field profile.

THPB062

Multipole Field Effects for the Superconducting Parallel-Bar/RF-Dipole Deflecting/Crabbing Cavities

multipole, cavity, superconductivity, luminosity

981

S.U. De Silva, J.R. Delayen
ODU, Norfolk, Virginia, USA
S.U. De Silva
JLAB, Newport News, Virginia, USA

The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

THPB065

Status of the Beam Dynamics Code DYNAC

rfq, emittance, quadrupole, simulation

990

E. Tanke, J.A. Rodriguez, W. Wittmer, X. Wu
FRIB, East Lansing, Michigan, USA
S. Valero
CEA, Gif-sur-Yvette, France
D. Wang
NSCL, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The beam dynamics code DYNAC* was originally developed at CERN. For accelerating elements a set of very accurate quasi-Liouvillian beam dynamics equations was introduced, applicable to protons, heavy ions and non-relativistic electrons. Furthermore, DYNAC contains three space charge routines, including a 3D version**. More recently, a numerical method has been added, capable of simulating a multi charge state ion beam in accelerating elements (i.e. cavities). Beam line devices such as sextupoles and quadrupole-sextupole magnets as well as electrostatic devices are now also included. Capability of second order calculations of such elements for a multi charge state beam has been implemented. Benchmarking of the code, in particular for a multi-charge state beam is discussed. Comparison of beam simulations results with beam measurements on the MSU ReAccelerator (ReA) are reported. The possibility of using DYNAC as an online tool for ReA and FRIB is discussed.
*DYNAC: A Multi-Particle Beam Dynamics Code for Leptons and Hadrons, E.Tanke et al,LINAC2002
**HERSC: A New 3 Dimensional Space Charge Routine for High Intensity Bunched Beams, E.Tanke et al,LINAC2002

THPB079

Development of a Superconducting Focusing Solenoid for CADS

solenoid, focusing, cavity, linac

1011

W. Wu, S.F. Han, Y. He, L.Z. Ma, D.S. Ni, Z.J. Wang, B.M. Wu, W.J. Yang, X.L. Yang, S.J. Zheng, L. Zhu
IMP, Lanzhou, People's Republic of China

A superconducting focusing solenoid has been designed and developed for the China Accelerator Driven System (CADS). In order to meet the requirement of focusing strength and fringe field while minimizing physical size of the solenoid, the novel optimizing design method based on linear programming method was employed. In this report, we will introduce the design of the solenoid including magnetic field optimization, mechanical design and quench protection. The fabrication and the test results of the solenoid will also be introduced in this report.