HB2006 - List of Keywords (quadrupole)

A B C D E F H I K L O P Q R S T V

quadrupole

Paper	Title	Other Keywords	Page
MOCP04	LHC Upgrade Options and CARE-HHH Activities	luminosity, electron, simulation, dipole	49
	F. Zimmermann CERN, Geneva
	The European Accelerator Network on High Energy High Intensity Hadron Beams (CARE HHH) is developing scenarios for luminosity and energy upgrades of the Large Hadron Collider (LHC). The LHC upgrade options under consideration differ in terms of beam parameters, electron-cloud effects, beam-beam compensation, use of crab cavities, and interaction-region layout. Complementary investigations concern injector upgrades, novel magnet technologies, advanced collimation schemes, and ultimate intensity limitations. Flanking these upgrade studies, an accelerator-physics code web repository has been set up, and an extensive simulation-code benchmarking campaign is being prepared.

TUAY02	End-to-end beam dynamics for CERN Linac4	linac, emittance, rfq, booster	79
	A. M. Lombardi, G. Bellodi, J.-B. Lallement, S. Lanzone, E. Zh. Sargsyan CERN, Geneva M. A. Baylac LPSC, Grenoble R. Duperrier, D. Uriot CEA, Gif-sur-Yvette
	LINAC 4 is a normal conducting H^- linac which aims to intensify the proton flux available for the CERN accelerator complex. This injector is designed to accelerate a 65 mA beam of H^- ions up to 160 MeV for injection into the CERN Proton Synchrotron Booster. The acceleration is done in three stages : up to 3 MeV with a Radio Frequency Quadrupole (the IPHI RFQ) operating at at 352 MHz, then continued to 90 MeV with drift-tube structures at 352 MHz (conventional Alvarez and Cell Coupled Drift Tube Linac) and, finally, with a Side Coupled Linac at 700MHz. The accelerator is completed by a chopper line at 3 MeV and a transport and matching line to the PS booster. After the overall layout was determined based on general consideration of beam dynamics and RF, a global optimisation based on end-to-end simulation has refined some design choices. The results and lessons learned from the end-to-end simulations are reported in this paper.

TUAY04	Beam Dynamics Design of the PEFP 100 MeV Linac	linac, proton, emittance, rfq	99
	J.-H. Jang, Y.-S. Cho, K. Y. Kim, Y.-H. Kim, H.-J. Kwon KAERI, Daejon
	The Proton Engineering Frontier Project (PEFP) is constructing a 100 MeV proton linac in order to provide 20 MeV and 100 MeV proton beams. The linac consists of a 50 keV proton injector including an ion source and a low energy beam transport (LEBT), a 3 MeV radio-frequency quadrupole (RFQ), a 20 MeV drift tube linac (DTL), a medium energy beam transport (MEBT), and the higher energy part (20 MeV ~ 100 MeV) of the 100 MeV DTL. The MEBT is located after the 20 MeV DTL to extract 20 MeV proton beams. The 20 MeV part of the linac was completed and is now under beam test. The higher energy part of the PEFP linac was designed to operate with 8% beam duty. This brief report discusses the design of the PEFP 100MeV linac as well as the MEBT.

TUAY05	Application of the extreme value theory to estimate beam loss in an ion linac, using large scale Monte Carlo simulations	linac, beam-losses, simulation, beam-transport	107
	R. Duperrier, D. Uriot CEA, Gif-sur-Yvette
	The influence of random perturbations of high intensity accelerator elements on the beam losses is considered. This paper presents the error sensitivity study which has been performed for the SPIRAL2 linac in order to define the tolerances for the construction. The proposed driver aims to accelerate a 5 mA deuteron beam up to 20 A. MeV and a 1 mA ion beam for q/A = 1/3 up to 14.5 A. MeV. It consists in an injector (two ECRs sources + LEBTs with the possibility to inject from several sources + Radio Frequency Quadrupole) followed by a superconducting section based on an array of independently phased cavities where the transverse focalization is performed with warm quadrupoles. The correction scheme and the expected losses are described. The Extreme Value Theory is used to estimate the expected beam losses. The described method couples large scale computations to obtain probability distribution functions. The bootstrap technique is used to provide confidence intervals associated to the beam loss predictions. With such a method, it is possible to measure the risk to loose a few watts in this high power linac (up to 200 kW).

TUBY03	Error study of LINAC 4	linac, simulation, emittance, proton	137
	M. A. Baylac, J.-M. De Conto, E. Froidefond LPSC, Grenoble E. Zh. Sargsyan CERN, Geneva
	LINAC 4 is a normal conducting H^- linac which aims to intensify the proton flux available for the CERN accelerator complex. This injector is designed to accelerate a 65 mA beam up to 180 MeV. The linac consists of 4 different types of accelerating structures: the 352 MHz IPHI-RFQ, a 352 MHz 3-tank Drift Tube Linac, a 352 MHz Coupled Cavity Drift Tube Linac, and a 704.4 MHz Side Coupled Linac to boost the beam up to the final energy. As LINAC 4 is also designed as a pre-injector for a high power superconducting linac (3.5 GeV, 4 MW) the requirements on acceptable beam emittance growth, halo formation and particle loss are extremely tight. In order to determine the tolerances on the linac components, we examined the sensitivity of the structure to errors on the accelerating field and on the focusing quadrupoles. Simulations were performed between 3 and 180 MeV with the transport code TRACEWIN to evaluate the emittance growth, energy and phase jitter, halo formation of the transported beam and the amount of lost particles. We will present results on individual sensitivities to a single error, as well as the global impact of simultaneous errors on the beam quality. We will mention a f

WEAX05	Space-Charge Beam Physics Research at the University of Maryland Electron Ring (UMER)*	space-charge, dipole, injection, lattice	218
	S. Bernal, B. L. Beaudoin, D. W. Feldman, R. Feldman, R. B. Fiorito, T. F. Godlove, I. Haber, R. A. Kishek, P. G. O'Shea, C. Papadopoulos, B. Quinn, D. Stratakis, K. Tian, C. Tobin, M. Walter IREAP, College Park, Maryland M. Reiser University Maryland, College Park, Maryland D. F. Sutter HENP, SW Washington
	The University of Maryland electron ring (UMER) is a low-energy, high current recirculator for beam physics research with relevance to any applications that rely on intense beams of high quality. We review the space-charge physics issues, experimental and computational investigations, which are currently being conducted at the UMER facility. The physics issues cover a broad range, but we focus on transverse beam dynamics: halo formation, strongly asymmetric beams, Montague resonances, equipartitioning, etc. Furthermore, we report on recent developments in experiments, simulations, and improved diagnostics for space-charge dominated beams.

WEAZ05	Very Fast Beam Losses at HERA, and what has been done about it	power-supply, beam-losses, luminosity, interaction-region	215
	K. Wittenburg, M. Werner DESY, Hamburg
	During the Luminosity upgrade of HERA in 2000/2001 more than 50 new magnets were installed close to the interaction region to provide a stronger focussing of the two beams. Some of these magnets are located at very large values of the betatron function and therefore act with a large gain on the beam. Sudden changes in the power supply currents had led to very fast beam losses, creating quenches and increased radiation levels. This talk will discuss the improvements made to the HERA machine protection system to make sure that the beam is dumped in time in case of these events.

WEBX04	Measurement strategy for the CERN Linac4 Chopper-line	linac, rfq, simulation, booster	262
	J.-B. Lallement, K. Hanke, H. Hori, A. M. Lombardi, E. Zh. Sargsyan CERN, Geneva
	Linac4 is a new accelerator under study at CERN. It is designed to accelerate H^- ions to 160 MeV of energy, for injection into the existing Proton Synchrotron Booster. The low energy section, comprising an H^- ion source, a 352 MHz Radio Frequency Quadrupole and a 3 MeV chopper line will be assembled at CERN in the next years. Linac 4 is also designed as an injector for the SPL, a high power proton driver delivering 5MW at 3.5 GeV. In this case the beam losses must be limited to 1 W/m and therefore the formation of transverse and longitudinal halo at low energy becomes a critical issue which has to be measured and controlled. The chopper-line is composed of 11 quadrupoles, 3 bunchers and the chopper itself. Its beam dynamics will be characterized with specific detectors and diagnostic lines. In particular the transverse and longitudinal halo will be measured by a Beam Shape and Halo Monitor (BSHM) with a sensitivity of 10.000 particles per bunch and a time resolution of 2ns. In this paper we present the simulation work in preparation for the measurement campaign scheduled in 2008.

WEBX06	Analysis of emittance growth in the Fermilab Booster	emittance, space-charge, injection, resonance	271
	K. Y. Ng Fermilab, Batavia, Illinois X. Huang SLAC, Menlo Park, California S.-Y. Lee IUCF, Bloomington, Indiana
	Multi-particle similations are performed to study emittance growth in the Fermilab Booster. Analysis shows that the sourcce of the vertical emittance growth comes mostly from random errors in skew quadrupoles as well as the transverse space-charge force. Random errors in the dipole fields and the Montague resonance do contribute but to a much lesser extent. The effect of random errors in the quadrupoles is small because the betatron envelope tunes are resonably far away from the half-integer stopband.

WEBZ02	BEAM TRACKING FOR J-PARC 3 GEV RCS INJECTION	injection, septum, electron, emittance	253
	M. J. Shirakata, H. Fujimori KEK, Ibaraki Y. Irie, T. Takayanagi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	In the J-PARC 3 GeV RCS injection system, the orbit-bump magnets of large-bore are located close with each other, and the incoming beam passes through the non-linear field region of the ring quadrupole magnet. Beam behavior under these conditions is analysed by means of the Runge-Kutta method in the three dimensional magnetic field distribution. The charge exchange foil is inserted between the bump magnets. Orbit of the stripped electrons from the foil is also investigated.

THAW01	New simulation capabilities of electron clouds in ion beams with large tune depression	electron, simulation, ion, bunching	279
	J.-L. Vay, M. A. Furman, P. A. Seidl LBNL, Berkeley, California R. H. Cohen, A. Friedman, D. P. Grote, M. Kireeff Covo, A. W. Molvik LLNL, Livermore, California P. Stoltz, S. A. Veitzer Tech-X, Boulder, Colorado J. Verboncoeur UCB, Berkeley, California
	We have developed a new, comprehensive set of simulation tools aimed at modeling the interaction of intense ion beams and electron clouds (e-clouds). The set contains the 3-D accelerator PIC code WARP and the 2-D “slice” e-cloud code POSINST [M. Furman, this workshop], as well as a merger of the two, augmented by new modules for impact ionization and neutral gas generation. The new capability runs on workstations or parallel supercomputers and contains advanced features such as mesh refinement, disparate adaptive time stepping, and a new “drift-Lorentz” particle mover for tracking charged particles in magnetic fields using large time steps. It is being applied to the modeling of ion beams (1 MeV, 180 mA, K+) for heavy ion inertial fusion and warm dense matter studies, as they interact with electron clouds in the High-Current Experiment (HCX) [experimental results discussed by A. Molvik, this workshop]. We will describe the capabilities and simulation results with detailed comparisons against the HCX experiment, as well as their application (in a different regime) to the modeling of e-clouds in the Large Hadron Collider (LHC).

THAW02	New experimental measurements of electron clouds in ion beams with large tune depression*	electron, ion, diagnostics, simulation	288
	A. W. Molvik, R. H. Cohen, A. Friedman, M. Kireeff Covo LLNL, Livermore, California F. M. Bieniosek, P. A. Seidl, J.-L. Vay LBNL, Berkeley, California
	We study electron clouds in high perveance beams (K = 8E-4) with a large tune depression of 0.2 (defined as the ratio of a single particle oscillation response to the applied focusing fields, with and without space charge). These 1 MeV, 180 mA, K+ beams have a beam potential of +2 kV when electron clouds are minimized. Simulation results are discussed in a companion paper [J-L. Vay, this Conference]. We have developed the first diagnostics that quantitatively measure the accumulation of electrons in a beam [M. Kireeff Covo, et al., to be submitted to Phys. Rev. Lett.]. This, together with measurements of electron sources, will enable the electron particle balance to be measured, and electron-trapping efficiencies determined. We measure and simulate ~10 MHz electron oscillations in the last quadrupole magnet when we flood the beam with electrons from an end wall. Experiments where the heavy-ion beam is transported with solenoid magnetic fields, rather than with quadrupole magnetic or electrostatic fields, are being initiated. We will discuss the initial results using electrode sets (in the middle and at the ends of magnets) to either expel or to trap electrons within the magnets.

THAY06	Fast-Pulsed Superconducting Magnets	dipole, ion, synchrotron, antiproton	324
	C. Muehle GSI, Darmstadt
	Up to now only one synchrotron (Nuclotron at JINR, Dubna) has been equipped with fast-pulsed superconducting magnets. The demand for high beam intensities leads to the requirement of fast-pulsed, periodically cycling magnets for synchrotrons and fast-pulsed magnets for storage rings. An example is FAIR (Facility for Antiproton and Ion Research) at GSI, which will consist of two synchrotrons in one tunnel and several storage rings. The fast field ramp rate and repetition frequency introduce many magnet design problems and constraints in the operation of the accelerator. Persistent currents in the superconductor and eddy currents in wire, cable, iron and vacuum chamber reduce the field quality and generate cryogenic losses. A magnet lifetime of 20 years is anticipated, resulting in up to 10⁸ magnet cycles. Therefore special attention has to be paid to magnet material fatigue problems. R&D work is being done in collaboration with many institutions, to reach the requirements mentioned above. Model dipoles were built and tested. The results of the R&D are reported. The advantages of the use of low field, fast pulsed superconducting, compared to resistive, magnets will be discussed.

THAZ02	SNS Commissioning Strategies and Tuneup Algorithms	linac, target, controls, injection	283
	J. Galambos ORNL, Oak Ridge, Tennessee
	The Spallation Neutron Source (SNS) has been recently commissioned. The strategies for the initial beam commissioning of the superconducting linac (SCL) and storage ring will be discussed. The SCL commissioning had to accommodate an unanticipated wide range of cavity performance, compared to design expectations. Methods for setting cavity phases and determination of amplitudes will be discussed. The ring commissioning involved the usual establishment of a circulating beam, and then measurement and correction the tune and beta functions, all with a low intensity beam. Then the gradual increase of beam intensity and commissioning of RF and phase space painting were investigated. The methods to accomplish these tasks will be discussed. In general, the first order beam behavior is well understood. Key factors in the successful commissioning are: flexibility in accommodating beam conditions that are different from the design, good communication between the different groups, and attention to detail. Examples for these factors will be emphasized.

THBZ02	Commissioning strategies for J-PARC linac and L3BT	linac, injection, beam-transport, controls	347
	M. Ikegami, S. Lee KEK, Ibaraki Y. Kondo, T. Ohkawa JAEA, Ibaraki-ken A. Ueno JAEA/LINAC, Ibaraki-ken
	We plan to start the beam commissioning of J-PARC linac with reduced energy of 181 MeV in the end of this year. Detailed commissioning strategies for the linac and the succeeding beam transport line, to which we refer as L3BT or Linac-to-3-GeV-synchrotron Beam Transport, will be presented in this talk. The emphasis will be put on the commissioning procedures for two debuncher cavities and a transverse collimator system located in L3BT, because they are key elements in determining the final beam quality at the injection point to the succeeding 3-GeV synchrotron. The unique design and features of the collimator system are also presented.