| Paper |
Title |
Page |
| WEXFI01 |
Instabilities and Space Charge Effects in High Intensity Ring Accelerators
|
1882 |
| |
- O. Boine-Frankenheim, I. Hofmann, V. Kornilov
GSI, Darmstadt
|
|
| |
This presentation will review beam dynamics in circular accelerators with high beam intensity and space charge effects. The main focus will be on recent theoretical and experimental results related to collective instabilities and resonance crossing with space charge. In the first part of the presentation, the effect of space charge on collective instability thresholds and impedance budgets will be discussed. In this context the effect of space charge induced mode coupling on the longitudinal microwave instability will be illustrated. The stability of longitudinal bunched beam modes and of transverse dipole modes in the presence of space charge will be discussed. Recent work related to the transverse mode coupling instability (TMCI) with space charge will be reviewed. In the second part of the presentation, "incoherent" space charge effects on transverse nonlinear dynamics issues, like nonlinear resonance crossing, will be reviewed.
|
|
|
Transparencies
|
| WEPCH119 |
Beam Performance with Internal Targets in the High-energy Storage Ring (HESR)
|
2197 |
| |
- A. Lehrach, R. Maier, D. Prasuhn
FZJ, Jülich
- O. Boine-Frankenheim, R.W. Hasse
GSI, Darmstadt
- F. Hinterberger
Universität Bonn, Helmholtz-Institut für Strahlen- und Kernphysik, Bonn
|
|
| |
The High-energy Storage Ring of the future International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an antiproton synchrotron storage ring in the momentum range of 1.5 to 15 GeV/c. An important feature of HESR is the combination of phase space cooled beams and dense internal targets (e.g., pellet targets), which results in demanding beam parameter requirements for two operation modes: high luminosity mode with peak luminosities of up to 2·1032 cm-2 s-1, and high resolution mode with a momentum spread down to 10-5, respectively. The beam cooling equilibrium and beam loss with internal target interaction is analyzed. Rate equations are used to predict the rms equilibrium beam parameters. The cooling and intra-beam scattering rate coefficients are obtained from simplified models. Energy loss straggling in the target and the associated beam loss are analyzed analytically assuming a thin target. A longitudinal kinetic simulation code is used to study the evolution of the momentum distribution in coasting and bunched beam. The analytic expressions for the target induced momentum tail are found in good agreement with the simulation results.
*A. Lehrach et al. Beam Performance and Luminosity Limitations in the High-Energy Storage Ring (HESR), Nuclear Inst. and Methods in Physics Research, A44704 (2006).
|
|
| WEPCH141 |
Accelerator Physics Code Web Repository
|
2254 |
| |
- F. Zimmermann, R. Basset, E. Benedetto, U. Dorda, M. Giovannozzi, Y. Papaphilippou, T. Pieloni, F. Ruggiero, G. Rumolo, F. Schmidt, E. Todesco
CERN, Geneva
- D.T. Abell
Tech-X, Boulder, Colorado
- R. Bartolini
Diamond, Oxfordshire
- O. Boine-Frankenheim, G. Franchetti, I. Hofmann
GSI, Darmstadt
- Y. Cai, M.T.F. Pivi
SLAC, Menlo Park, California
- Y.H. Chin, K. Ohmi, K. Oide
KEK, Ibaraki
- S.M. Cousineau, V.V. Danilov, J.A. Holmes, A.P. Shishlo
ORNL, Oak Ridge, Tennessee
- L. Farvacque
ESRF, Grenoble
- A. Friedman
LLNL, Livermore, California
- M.A. Furman, D.P. Grote, J. Qiang, G.L. Sabbi, P.A. Seidl, J.-L. Vay
LBNL, Berkeley, California
- D. Kaltchev
TRIUMF, Vancouver
- T.C. Katsouleas
USC, Los Angeles, California
- E.-S. Kim
PAL, Pohang, Kyungbuk
- S. Machida
CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
- J. Payet
CEA, Gif-sur-Yvette
- T. Sen
Fermilab, Batavia, Illinois
- J. Wei
BNL, Upton, Long Island, New York
- B. Zotter
Honorary CERN Staff Member, Grand-Saconnex
|
|
| |
In the framework of the CARE HHH European Network, we have developed a web-based dynamic accelerator-physics code repository. We describe the design, structure and contents of this web repository, illustrate its usage, and discuss our future plans.
|
|
| THPCH005 |
Considerations for the High-intensity Working Point of the SIS100
|
2793 |
| |
- G. Franchetti, O. Boine-Frankenheim, I. Hofmann, V. Kornilov, P.J. Spiller, J. Stadlmann
GSI, Darmstadt
|
|
| |
In the FAIR project the SIS100 synchrotron is foreseen to provide high-intensity beams of U 28+, including slow extraction to the radioactive beam experimental area, as well as high-intensity p beams for the production of antiprotons. In this paper we discuss the proposal of three different working points, which should serve the different needs: (1) a high intensity working point for U28+; (2) a slow extraction working point (also U28+); (3) a proton operation working point to avoid transition crossing. The challenging beam loss control for all three applications requires a careful account of the effects of space charge, lattice nonlinearities and chromaticity, which will be discussed in detail in this paper. Since tunes are not split by an integer and the injected emittances are different, the Montague stop-band needs to be avoided. Moreover, final bunch compression for the U beam requires a sufficiently small momentum spread, and the risk of transverse resisitive wall instabilities poses further limitations on our choice of working points.
|
|
| THPCH026 |
Parallel 3-D Space Charge Calculations in the Unified Accelerator Library
|
2835 |
| |
- N.L. D'Imperio, A.U. Luccio, N. Malitsky
BNL, Upton, Long Island, New York
- O. Boine-Frankenheim
GSI, Darmstadt
|
|
| |
The paper presents the integration of the SIMBAD space charge module in the UAL framework. SIMBAD is a Particle-in-Cell (PIC) code. Its 3-D parallel approach features an optimized load balancing scheme based on a genetic algorithm. The UAL framework enhances the SIMBAD standalone version with the interactive ROOT-based analysis environment and an open catalog of accelerator algorithms. The composite package addresses complex high intensity beam dynamics studies and has been developed as a part of the FAIR SIS 100 project.
|
|
| THPCH034 |
Transverse Coupling Impedances From Field Matching in a Smooth Resistive Cylindrical Pipe for Arbitrary Beam Energies
|
2853 |
| |
- A.M. Al-Khateeb, A.M. Al-Khateeb, W.M. Daqa
Yarmouk, Irbid
- O. Boine-Frankenheim, R.W. Hasse, I. Hofmann
GSI, Darmstadt
|
|
| |
The transverse coupling impedance is investigated analytically. For an off-axis motion of the beam, the perturbed charge distribution of the beam becomes a function of the azimuthal angle, resulting to first order in the beam displacement in a dipole term which is the source of the transverse impedance. All six components of the electromagnetic field are different from zero and, therefore, both TM and TE modes will be excited in the beam-pipe and coupled to the beam at the inner surface of the resistive wall. Using the dipole source term, a linear combination of TM and TE modes is used to get closed form expressions for the transverse electromagnetic field components excited in the beam-pipe, and a generalized analytic expression for the corresponding transverse coupling impedance. It has been found that the contributions of the TM and the TE modes to the real part of the transverse resistive-wall impedance have similar dependence on the relativistic parameter but with opposite signs, the sum of both always being positive. Some approximate simple formulas for three important regions corresponding to small, intermediate and large frequencies in the ultrarelativistic limit were also obtained analytically.
|
|