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Scaling laws for crossing nonlinear space charge resonances
2007 IEEE Particle Accelerator Conference (PAC)
Year: 2007 | Conference Paper |
Intrinsic fourth order space charge resonances may occur in linear as well as in circular accelerators. The fourth order difference resonance ("emittance exchange" or "Montague" coupling-resonance) and the fourth order structure resonance lead to emittance degradation depending on the strength of space charge, the crossing rate through the resonance and the lattice. Based on fully self-consistent ...Show More
Transverse self-consistent modeling of a 3D bunch in SIS100 with micromap
C. Benedetti;S. Rambaldi;G. Turchetti;G. Franchetti;I. Hofmann
2007 IEEE Particle Accelerator Conference (PAC)
Year: 2007 | Conference Paper |
We present the upgrade of the MICROMAP beam dynamics simulation library to include a 2 1/2 D space charge modeling of a 3D bunch using local slices in z. We discuss the parallelization technique, the performances, several tests and comparison with existing well-established analytical/numerical results in order to validate the code. An application to the SIS 100 synchrotron of the FAIR project at G...Show More
Improving the SIS18 performance by use of the Orbit Response Method
2007 IEEE Particle Accelerator Conference (PAC)
Year: 2007 | Conference Paper |
The GSI heavy ion synchrotron SIS18 will be used as a booster for the new FAIR facility SIS100. A well-controlled linear optics of the SIS18 is necessary for further optimization studies of nonlinear dynamics, resonance induced beam loss, dynamic aperture and nonlinear error measurements. The analysis of the orbit response matrix (ORM) [1] is a powerful tool to calibrate the linear lattice models....Show More
Stability thresholds for transverse dipole modes with nonlinear space charge, chromaticity and octupoles
2007 IEEE Particle Accelerator Conference (PAC)
Year: 2007 | Conference Paper |
Transverse stability due to combinations of chromaticity effect, nonlinear space charge and octupoles of different polarities plays an important role in the determination of the impedance budget for the FAIR synchrotrons. Different analytic approaches have been suggested, for which no direct comparison has been made so far. In order to clarify this issue we perform numerical investigations employi...Show More
High intensity heavy ion beam emittance measurements at the GSI UNILAC
W. Bayer;W. Barth;L. Dahl;P. Forck;P. Gerhard;L. Groening;I. Hofmann;S. Yaramyshev;D. Jeon
The GSI UNILAC, a heavy ion linac originally dedicated for low current beam operation, together with the synchrotron SIS 18 will serve as a high current injector for FAIR (international facility for antiproton and ion research). The UNILAC post stripper accelerator consists of five Alvarez tanks with a final energy of 11.4 MeV/u. In order to meet the requirements of FAIR 15 emA 238U28+, transverse...Show More
Intensity and Bunch-Shape Dependent Beam Loss Simulation for the SIS100
Proceedings of the 2005 Particle Accelerator Conference
Year: 2005 | Conference Paper |
We have studied the combined influence of magnet nonlinearities, space charge and bunch shapes consistent with different RF scenarios on the long-term loss in the planned SIS100 synchrotron of the FAIR project. The simulation is a 3D tracking with” frozen-in” space charge calculation employing the MICROMAP code. Comparing a one-harmonic RF scenario with an alternative double-harmonic scenario we f...Show More
Measurement of the Energy Deposition Profile for238U Ions with Energy 500 and 950 MeV/U in Stainless Steel and Copper Targets
A. Golubev;A. Kantsyrev;V. Luckjashin;A. Fertman;A. Kunin;V. Vatulin;A. Gnutov;Yu. Panova;E. Mustafin;I. Hofmann;D. Schardt;K. Weyrich;N. Sobolevskiy;L. Latysheva
Proceedings of the 2005 Particle Accelerator Conference
Year: 2005 | Conference Paper |
Sub-millimetre wall thickness is foreseen for the vacuum tubes in the magnets of the superconducting dipoles of the SIS100 and SIS300 of the FAIR Project. The Bragg peak of the energy deposition by the U ions in these walls may lie dangerously close to the superconducting cables. Thus the precise knowledge of the dE/dx profile is essential for estimating the heat load by the lost ions in the vicin...Show More
Measurement of the Energy Deposition Profile for238U Ions with Energy 500 and 950 MeV/U in Stainless Steel and Copper Targets
A. Golubev;A. Kantsyrev;V. Luckjashin;A. Fertman;A. Kunin;V. Vatulin;A. Gnutov;Yu. Panova;E. Mustafin;I. Hofmann;D. Schardt;K. Weyrich;N. Sobolevskiy;L. Latysheva
Year: 2005 | Conference Paper |
Benchmarking of Simulation Codes Based on the Montague Resonance in the CERN Proton Synchrotron
I. Hofmann;G. Franchetti;M. Giovannozzi;E. Metral;J. Qiang;R. Ryne;S. Cousineau;J. Holmes;A. Luccio;J. Amundson;P. Spentzouris;F.W. Jones;S. Machida
Proceedings of the 2005 Particle Accelerator Conference
Year: 2005 | Conference Paper |
Experimental data on emittance exchange by the space charge driven “Montague resonance” have been obtained at the CERN Proton Synchrotron in 2002-04 as a function of the working point. These data are used to advance the benchmarking of major simulation codes (ACCSIM, IMPACT, MICROMAP, ORBIT, SIMBAD, SIMPSONS, SYNERGIA) currently employed world-wide in the design or performance improvement of high ...Show More
The GSI synchrotron facility proposal for acceleration of high intensity ion and proton beams
P. Spiller;K. Blasche;O. Boine-Frankenheim;G. Franchetti;B. Franczak;I. Hofmann;P. Hulsmann;K. Kaspar;A. Kramer;G. Moritz;E. Mustafin;H. Reich-Sprenger;P. Schutt
Proceedings of the 2003 Particle Accelerator Conference
Year: 2003 | Conference Paper |
The two-stage synchrotron complex SIS 100/SIS300 is the central part of the proposed "International Accelerator Facility for Ions and Antiprotons" at GSI. The design concept of the synchrotrons will be described with emphasis on the status of R&D work, especially on the novel rapid cycling super-conducting magnets and on the required powerful, low-frequency RF-systems. Furthermore studies are disc...Show More
Nonlinear resonance bench-marking experiment at the CERN proton synchrotron
I. Hofmann;G. Franchetti;M. Giovannozzi;M. Martini;E. Metral
Proceedings of the 2003 Particle Accelerator Conference
Year: 2003 | Conference Paper |
Cited by: Papers (1)
As a first step of a space charge-nonlinear resonance benchmarking experiment over a large number of turns, beam loss and emittance evolution were measured over 1 s on a 1.4 GeV kinetic energy flat-bottom in the presence of a single octupole. By lowering the working point towards the resonance a gradual transition from a loss-free core emittance blow-up to a regime dominated by continuous loss was...Show More
Space-charge driven emittance growth in a 3D mismatched anisotropic beam
Proceedings of the 2003 Particle Accelerator Conference
Year: 2003 | Conference Paper |
In this paper we present a 3D simulation study of the emittance growth in a mismatched anisotropic beam. The equipartitioning driven by a 4th order space-charge resonance can be significantly modified by the presence of mismatch oscillation and halo formation. This causes emittance growth in both the longitudinal and transverse directions which could drive the beam even further away from equiparti...Show More
Application of envelope instability to high-intensity rings
Proceedings of the 2003 Particle Accelerator Conference
Year: 2003 | Conference Paper |
The space-charge limit is imposed by beam response to low-order machine resonances. Here, the coherent response of the beam to such resonances is discussed, including the parametric resonance of collective beam modes with the periodic lattice, also known as the "envelope instability", when the second-order beam modes are considered. The relation of this parametric resonance to the coherent resonan...Show More
Effects of space charge on decoherence in ion beams
O. Boine-Frankenheim;I. Hofmann;Y. Liu;G. Rumolo;A. Al-Khateeb
Proceedings of the 2003 Particle Accelerator Conference
Year: 2003 | Conference Paper |
Cited by: Papers (1)
This paper studies dipolar and quadrupolar decoherence of a bunch in presence of space charge. The centroid of a bunch displaced transversely or longitudinally decoheres due to nonlinearities that cause phase space filamentation and mixing. Here we show that space charge can inhibit decoherence and keep the beam centroid oscillations undamped over long times. This feature complicates the detection...Show More
Emittance coupling in high intensity beams applied to the SNS linac
I. Hofmann;G. Franchetti;O. Boine-Frankenheim;J. Qiang;R. Ryne;D. Jeon;J. Wei
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)
Year: 2001 | Conference Paper |
Cited by: Papers (2)
Space charge can lead to emittance and/or energy exchange in nonequipartitioned high intensity linacs, which is interpreted here in terms of "coherent resonance". In this paper we first compare 2D and 3D simulations in constant focusing, and relate them to self-consistent resonant charts based on analytical theory. We then use these charts to interpret PARMILA simulation results for the SNS linac ...Show More
A study of fast bunch rotation in the negative mass region
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)
Year: 2001 | Conference Paper |
Fast bunch rotation of high-intensity proton or ion bunches above transition is-in principle-supported by the self-bunching effect of the attractive space charge force ("negative mass instability"). Due to the broad-band nature of the space charge impedance, the highest harmonics of this negative mass mode grow fast and inhibit compression, unless the bunch rotation is accelerated by a sufficientl...Show More
Beam dynamics of nonequipartitioned beams in the case of the SPL project at CERN
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)
Year: 2001 | Conference Paper |
The SPL working group at CERN is studying a 2.2 GeV H/sup -/ linac, which recuperates a large amount of RF hardware from the now decommissioned LEP at CERN. During the ongoing design effort for an optimized layout, it was found that in some cases non-equipartitioned beams tend to exchange energy between the longitudinal and the transverse planes. Strict energy equipartition, however, imposes tight...Show More
Cross-plane resonance: a mechanism for very large amplitude halo formation
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)
Year: 2001 | Conference Paper |
In this paper we report on the possibility of very large amplitude halo formation due to a cross-plane resonance, based on a core/test-particle model. Previous analyses of halo formation in mismatched beams (which did not involve a coupling of the phase planes) have found that particles may be driven to amplitudes which are limited to typically three times the edge radius by a 2:1 parametric reson...Show More
Space charge effect on emittance exchange by skew quadrupoles
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)
Year: 1999 | Conference Paper |
Cited by: Papers (1)
For the high current synchrotron SIS it is crucial to improve the multiturn injection efficiency. We study active emittance exchange due to a second order (skew quadrupole) difference resonance which is modified by the presence of space charge. We start from an analytical expression for the coherent tune shift of this resonance and compare it with a computer simulation for the SIS synchrotron latt...Show More
Generation of high power heavy ion beams at GSI
P. Spiller;K. Blasche;O. Boine-Frankenheim;M. Emmerling;B. Franczak;I. Hofmann;S. Lund;U. Ratzinger
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)
Year: 1999 | Conference Paper |
Besides laser- and light ion beams, short pulse duration bunches of intense heavy ion beams are attractive to deposit high specific power in experimental targets. Such volume heated matter is transformed into a plasma state that is characterized by its high density. The GSI accelerator facility offers a unique possibility for the generation of such a solid state density plasma. After the installat...Show More
Coherent coupling criterion for three-dimensional halo formation
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)
Year: 1999 | Conference Paper |
Cited by: Papers (1)
In this paper we study coupling between the transverse and longitudinal degrees-of-freedom in intense, rms mismatched charged particle beams. We find that a coherent (2:1, i.e. parametric) resonance between the transverse and longitudinal mismatch eigenmodes has the effect that a transverse "breathing mode" mismatch can excited longitudinal mismatch and halo. If the resonance condition is not sati...Show More
Simulations of axial bunch compression in heavy ion rings for plasma physics applications at GSI
S.M. Lund;O. Boine-Frankenheim;G. Franchetti;I. Hofmann;P. Spiller
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)
Year: 1999 | Conference Paper |
Cited by: Papers (1)
Simulations of axial bunch compression in heavy-ion rings have been carried out as part of a feasibility study for generating intense beams in a facility at GSI. The compression is implemented by a fast rotation of the longitudinal (/spl par/) phase space and results in greatly increased transverse (/spl perp/) space-charge strength while the bunch is compressed in a dispersive ring from an initia...Show More
Equipartitioning and halo due to anisotropy
Proceedings of the 1997 Particle Accelerator Conference (Cat. No.97CH36167)
Year: 1997 | Conference Paper |
Equipartitioning and certain aspects of halo formation in high-current linac beams are explained in terms of collective multipole oscillations in x-y geometry. For strong space charge tune depression and anisotropy (emittance and/or focusing strength) some eigenmodes can-in principle-become unstable leading to emittance exchange. It is shown that for parameters of practical interest in linac desig...Show More
Generation of extreme states in condensed matter by high power ion beams
V. E. Fortov;V. A. Skvortsov;V. V. Kostin;O. Yu. Vorobjev;I. V. Lomonosov;A. L. Ni;I. Hofmann;B. P. Goel
1992 9th International Conference on High-Power Particle Beams
Year: 1992 | Conference Paper |
Cited by: Papers (1)
The results of 2-D computer simulation of high-power light and heavy ion beams targets interaction are presented. The extreme states and dynamics of shock-waves and high velocity jet formation are described.Show More
Beam dynamics of cooled heavy ion beams
Conference Record of the 1991 IEEE Particle Accelerator Conference
Year: 1991 | Conference Paper |
Cited by: Papers (2)
Evaluation of the collectively modified Schottky spectra as well as beam transfer functions for Ar/sup 18+/ and Kr/sup 36+/ at 250 and 150 MeV/u, respectively, is in agreement with theoretical predictions. Maximum observed phase space densities are compared with thresholds of the microwave instability and with intrabeam scattering. The conventional Keil-Schnell threshold is exceeded in experiment ...Show More
Electron cooling of high-Z ion beams parallel to a guide magnetic field
The cooling of high-Z ion beams through collisions with electrons whose temperature parallel to a guide magnetic field is considerably lower than their perpendicular temperature is considered. For initial electron temperatures, magnetic fields, and charged-particle densities, electrons tend to be trapped in the vicinity of their nearest ion neighbor. This results in an energy exchange with the ion...
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