LINAC2012 - List of Keywords (lattice)

Paper	Title	Other Keywords	Page
SUPB018	Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices	linac, cavity, simulation, proton	47
	R. Ainsworth Royal Holloway, University of London, Surrey, United Kingdom S. Molloy ESS, Lund, Sweden
	The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.

MOPB003	Recent Improvements to the Control of the CTF3 High-Current Drive Beam	controls, linac, dipole, 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.

MOPB034	Novel Technique of Suppressing TBBU in High-energy ERLs	linac, HOM, SRF, electron	249
	V. Litvinenko BNL, Upton, Long Island, New York, USA
	Energy recovery linacs (ERLs) is emerging generation of accelerators promising revolutionize the fields of high-energy physics and photon sciences. One potential weakness of these devices is transverse beam-breakup instability, which may severely limit available beam current. In this paper I am presenting new idea [1] developed for high-energy ERL which could be used for eRHIC, LHeC and, potentially, ILC: a concept of using main ERL linacs and natural chromaticity to suppressing TBBU instabilities by simplifying an ERL lattice. As demonstration of this method, I present tow specific example of eRHIC and LHeC ERLs. [1] V.N. Litvinenko, Chromaticity of the lattice and beam stability in energy recovery linacs, submitted to PR ST-AB

TUPB048	Discussion of the Optimisation of a Linac Lattice to Minimise Disruption by a Class of Parasitic Modes	cavity, coupling, linac, simulation	585
	S. Molloy ESS, Lund, Sweden R. Ainsworth Royal Holloway, University of London, Surrey, United Kingdom
	It is well known that each resonant mode in the RF spectrum of multi-cell accelerating cavities will split into a passband containing a number of modes, and that the coupling of these modes to the beam is dependent on the velocity of the accelerated particles. If these modes are found to degrade the quality of the beam, it is possible to take various measures to damp them, and thus keep their effect below some critical threshold. In the case of the parasitic modes within the same passband as the fundamental accelerating mode, their frequency is typically too close to that of the fundamental to allow their power to be safely extracted, and so cavity designers must rely on the natural damping of the cavity itself. This note contains a theoretical discussion of the coupling of the beam to these passband modes for a large class of accelerating cavities, and provides a mathematical model for use during the design and optimisation of linacs.

TUPB052	Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices	linac, cavity, simulation, proton	591
	R. Ainsworth Royal Holloway, University of London, Surrey, United Kingdom S. Molloy ESS, Lund, Sweden
	The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.

TUPB104	Study of the Beam Dynamics in the RISP Driver Linac	linac, solenoid, quadrupole, cryomodule	705
	H.J. Kim, J.G. Hwang, D. Jeon IBS, Daejeon, Republic of Korea
	Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.3 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the requirements of dynamic errors and correction schemes to minimize the beam centroid oscillation and preserve beam losses under control.

THPB014	Lattice Design and Beam Dynamics Studies for Project X	linac, cryomodule, rfq, emittance	876
	N. Solyak, J.-P. Carneiro, V.A. Lebedev, J.-F. Ostiguy, A. Saini Fermilab, Batavia, USA
	Fermilab is developing Project-X, a high intensity superconducting H⁻ machine for high energy physics experiments. The first stage is 1 mA average, 3 GeV linac operating in CW mode. Its front-end comprises a LEBT section with magnetic focusing and pre-chopping, a 162.5 MHz RFQ and ~10 m long MEBT section which includes a high bandwidth, bunch-by-bunch capable chopper. The latter extracts, out of a nominal 5 mA peak 162.5 MHz train, and arbitrary bunch structure able to meet the requirements of different experiments. Acceleration from 2.1 MeV to 3 GeV is accomplished through five families of SRF cavities operating at three frequencies: Half-wave resonators (162.5 MHz), spoke cavities (two families at 325 MHz) and elliptical cavities (two families at 650 MHz). In this contribution, we present the status of the CW linac lattice design and results from recent beam physics studies.

THPB024	Main Linac Physics Design Study of the C-ADS Project	linac, emittance, cavity, solenoid	900
	F. Yan, Z. Li, C. Meng, J.Y. Tang IHEP, Beijing, People's Republic of China
	Funding: The pilot special funds of Chinese Academy of Science The Chinese ADS project is proposed to build a 1000MW Accelerator Driven sub-critical System before 2032. The accelerator will be operating on CW mode with 10mA average current and the final energy is 1.5GeV. The whole linac are composed of two major sections: the Injector section and the main linac section. There are two different schemes for the Injector section. InjectorI is basing on 325MHz RFQ and superconducting spoke cavities and Injector II is basing on 162.5MHz RFQ and superconducting HWR cavities. The main linac design will be different for different Injector choice. If Injector II scheme is adopted, the main linac bunch current will be doubled. In this paper we studied the main linac design basing on InjectorII scheme. The design principles and the priliminary design results is presented.

Paper

Title

Other Keywords

Page

SUPB018

Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices

linac, cavity, simulation, proton

47

R. Ainsworth
Royal Holloway, University of London, Surrey, United Kingdom
S. Molloy
ESS, Lund, Sweden

The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.

MOPB003

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

controls, linac, dipole, 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.

MOPB034

Novel Technique of Suppressing TBBU in High-energy ERLs

linac, HOM, SRF, electron

249

V. Litvinenko
BNL, Upton, Long Island, New York, USA

Energy recovery linacs (ERLs) is emerging generation of accelerators promising revolutionize the fields of high-energy physics and photon sciences. One potential weakness of these devices is transverse beam-breakup instability, which may severely limit available beam current. In this paper I am presenting new idea [1] developed for high-energy ERL which could be used for eRHIC, LHeC and, potentially, ILC: a concept of using main ERL linacs and natural chromaticity to suppressing TBBU instabilities by simplifying an ERL lattice. As demonstration of this method, I present tow specific example of eRHIC and LHeC ERLs.
[1] V.N. Litvinenko, Chromaticity of the lattice and beam stability in energy recovery linacs, submitted to PR ST-AB

TUPB048

Discussion of the Optimisation of a Linac Lattice to Minimise Disruption by a Class of Parasitic Modes

cavity, coupling, linac, simulation

585

S. Molloy
ESS, Lund, Sweden
R. Ainsworth
Royal Holloway, University of London, Surrey, United Kingdom

It is well known that each resonant mode in the RF spectrum of multi-cell accelerating cavities will split into a passband containing a number of modes, and that the coupling of these modes to the beam is dependent on the velocity of the accelerated particles. If these modes are found to degrade the quality of the beam, it is possible to take various measures to damp them, and thus keep their effect below some critical threshold. In the case of the parasitic modes within the same passband as the fundamental accelerating mode, their frequency is typically too close to that of the fundamental to allow their power to be safely extracted, and so cavity designers must rely on the natural damping of the cavity itself. This note contains a theoretical discussion of the coupling of the beam to these passband modes for a large class of accelerating cavities, and provides a mathematical model for use during the design and optimisation of linacs.

TUPB052

Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices

linac, cavity, simulation, proton

591

R. Ainsworth
Royal Holloway, University of London, Surrey, United Kingdom
S. Molloy
ESS, Lund, Sweden

The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.

TUPB104

Study of the Beam Dynamics in the RISP Driver Linac

linac, solenoid, quadrupole, cryomodule

705

H.J. Kim, J.G. Hwang, D. Jeon
IBS, Daejeon, Republic of Korea

Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.3 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the requirements of dynamic errors and correction schemes to minimize the beam centroid oscillation and preserve beam losses under control.

THPB014

Lattice Design and Beam Dynamics Studies for Project X

linac, cryomodule, rfq, emittance

876

N. Solyak, J.-P. Carneiro, V.A. Lebedev, J.-F. Ostiguy, A. Saini
Fermilab, Batavia, USA

Fermilab is developing Project-X, a high intensity superconducting H⁻ machine for high energy physics experiments. The first stage is 1 mA average, 3 GeV linac operating in CW mode. Its front-end comprises a LEBT section with magnetic focusing and pre-chopping, a 162.5 MHz RFQ and ~10 m long MEBT section which includes a high bandwidth, bunch-by-bunch capable chopper. The latter extracts, out of a nominal 5 mA peak 162.5 MHz train, and arbitrary bunch structure able to meet the requirements of different experiments. Acceleration from 2.1 MeV to 3 GeV is accomplished through five families of SRF cavities operating at three frequencies: Half-wave resonators (162.5 MHz), spoke cavities (two families at 325 MHz) and elliptical cavities (two families at 650 MHz). In this contribution, we present the status of the CW linac lattice design and results from recent beam physics studies.

THPB024

Main Linac Physics Design Study of the C-ADS Project

linac, emittance, cavity, solenoid

900

F. Yan, Z. Li, C. Meng, J.Y. Tang
IHEP, Beijing, People's Republic of China

Funding: The pilot special funds of Chinese Academy of Science
The Chinese ADS project is proposed to build a 1000MW Accelerator Driven sub-critical System before 2032. The accelerator will be operating on CW mode with 10mA average current and the final energy is 1.5GeV. The whole linac are composed of two major sections: the Injector section and the main linac section. There are two different schemes for the Injector section. InjectorI is basing on 325MHz RFQ and superconducting spoke cavities and Injector II is basing on 162.5MHz RFQ and superconducting HWR cavities. The main linac design will be different for different Injector choice. If Injector II scheme is adopted, the main linac bunch current will be doubled. In this paper we studied the main linac design basing on InjectorII scheme. The design principles and the priliminary design results is presented.