IPAC2014 - List of Authors (Boine-Frankenheim, O.)

Paper	Title	Page
MOPRI106	Simulation Study of Beam Halo Collimation in the Heavy-ion Synchrotron SIS 100	870
SUSPSNE047	use link to see paper's listing under its alternate paper code
	I.A. Prokhorov TEMF, TU Darmstadt, Darmstadt, Germany O. Boine-Frankenheim, I. Strašík GSI, Darmstadt, Germany
	Funding: Work is supported by German Federal Ministry of Education and Research (BMBF) contract no. 05P12RDRBM The FAIR synchrotron SIS-100 will be operated with high-intensity proton and heavy-ion beams. The collimation system should prevent beam loss induced degradation of the vacuum, activation of the accelerator structure and magnet quenches. A conventional two-stage betatron collimation system is considered for the operation with protons and fully-stripped ions. Particle tracking and ion-collimator interaction simulations of the collimation system were performed. The angular and momentum distributions of the scattered halo particles were described using analytical models and numerical tools like ATIMA and FLUKA. MADX was used for the multi-pass tracking simulations. The results obtained for the collimation cleaning efficiency as a function of the ion species and beam energy together with the detailed beam losses distributions along the ring circumference are presented. This work highlights the main aspects of the collimation of fully-stripped ion beams in the intermediate energy range using conventional two-stage systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI106
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TUPME031	Radiation Pressure Acceleration and Transport Methods	1422
	P. Schmidt, O. Boine-Frankenheim TEMF, TU Darmstadt, Darmstadt, Germany O. Boine-Frankenheim, O. Boine-Frankenheim, I. Hofmann GSI, Darmstadt, Germany I. Hofmann HIJ, Jena, Germany I. Hofmann IAP, Frankfurt am Main, Germany
	Funding: HGS-HIRe for FAIR, HIC for FAIR, Technische Universität Darmstadt, FB 18 TEMF Several projects worldwide such as LIGHT at GSI focus on laser ion acceleration. With the development of new laser systems and advances in the target production a new acceleration mechanism has become of interest: The Radiation Pressure Acceleration (RPA). An ultra short high intense laser pulse hits a very thin foil target and the emerging plasma is ideally accelerated as one piece (light sail regime). The ions reach kinetic energies up to GeV and nearly solid body densities. In this work, the distribution and transport of a RPA plasma is studied. 1D and 2D PIC simulations (software: VSim) are carried out to obtain the phase space distribution of the plasma. The results are compared to fluid models (software: FiPy and USim). A reference model an RPA plasma is obtained which is then used for advanced transport studies. Transport mechanisms (active and passive) are studied, such asμlenses and foil stacks.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME031
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TUPRI017	Artificial Collisions, Entropy and Emittance Growth in Computer Simulations of Intense Beams	1588
	O. Boine-Frankenheim, I. Hofmann, J. Struckmeier GSI, Darmstadt, Germany
	During particle tracking with self-consistent space charge artificial collision between the macro-particles lead to diffusion-like, numerical effects. The artificial collisions generate a stochastic noise spectrum. As a consequence the entropy and the emittance of the particle beam can growth along periodic focusing structures. The growth rates depend on the number of simulation macro-particles and on the space charge tune shifts. For long-term tracking studies the numerical diffusion can lead to incorrect beam loss predictions. In our study we present analytical prediction for the numerical friction and diffusion in 2D and 3D simulations. For simple focusing structures with derive a relation between the friction coefficient and the entropy growth. The scaling of the friction coefficient with the macro-particle number and the space charge tune shift is obtained from 2D and 3D simulations and compared to the analytic predictions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI017
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TUPRI045	Beam Coupling Impedance Simulation in the Frequency Domain for the SIS100 Synchrotron	1665
	U. Niedermayer, O. Boine-Frankenheim TEMF, TU Darmstadt, Darmstadt, Germany O. Boine-Frankenheim GSI, Darmstadt, Germany
	For the quantification of intensity thresholds due to coherent instabilities and beam induced heating in the FAIR synchrotron SIS100 a detailed knowledge of transverse and longitudinal beam coupling impedance is required. Due to the rather long proton and heavy-ion bunches, the relevant spectrum is below 100MHz. For the computation of beam coupling impedances in the low frequency regime, frequency domain methods are more advantageous than (explicit) time domain methods. We show the setup of a 2D finite element code that allows to compute the impedance for arbitrary longituninally homogeneous beam and structure shapes. Perfectly conducting pipes, a dispersive ferrite tube, and thin resistive beam pipe serve as test cases. The influence of the beam velocity on the coupling impedance is studied.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI045
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THPRO092	Stochastic Noise Effects in High Current PIC Simulation	3101
	I. Hofmann, O. Boine-Frankenheim TEMF, TU Darmstadt, Darmstadt, Germany O. Boine-Frankenheim, I. Hofmann GSI, Darmstadt, Germany
	The numerical noise inherent to particle-in-cell simulation of 3D high intensity bunched beams is studied with the TRACEWIN code and compared with the analytical model by Struckmeier (1994). The latter assumes the six-dimensional rms emittance or rms entropy growth can be related to Markov type stochastic processes due to temperature anisotropy and the artificial "collisions" caused by using macro-particles and calculating the space charge effect. Our entropy growth confirms the dependency on bunch temperature anisotropy as predicted by Struckmeier. However, we also find noise generation by the non-Liouvillean effect of the Poisson solver grid, which exists in periodic focusing systems even when local temperature anisotropy is absent - contrary to predictions by Struckmeier's model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO092
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TUPRI019	Incoherent and Coherent Effects of Space Charge Limited Electron Clouds	1594
	F.B. Petrov, O. Boine-Frankenheim, O.S. Haas TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: Work is supported by the BMBF under contract 05H12RD7. Recent studies show that the space charge limited (saturated) electron cloud generated by relativistic bunches has strongly inhomogeneous distribution. In particular, a dense electron sheath is formed near the pipe wall. This feature modifies the stopping powers and the microwave transmission compared with the uniform cloud case. In this paper we investigate further the influence of the space charge limited electron cloud on relativistic bunches. In particular, we focus on the incoherent tune spread and compare the results with the homogeneous cloud case. We derive analytical expressions governing the pinch dynamics of the saturated cloud in round geometry. The contribution of the electron cloud sheath to the wake fields is investigated as well. Findings of the analytical theory are then successfully compared with numerical particle-in-cell simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI019
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THPRO060	Beam-beam Effect on the BTF in Bunched Beams	3011
SUSPSNE053	use link to see paper's listing under its alternate paper code
	P.A. Görgen, O. Boine-Frankenheim TEMF, TU Darmstadt, Darmstadt, Germany W. Fischer BNL, Upton, Long Island, New York, USA
	We present studies on the transverse baseband Beam Transfer Functions (BTFs) in bunched beams at high energies. The goal of the work is to evaluate whether transverse BTFs can be used to diagnose the tune spread arising from transverse nonlinearities such as the beam-beam effect and space charge. We employ an analytic expression to the BTFs of beams under a transverse nonlinear lens arising from a bi-Gaussian charge distribution. We obtain agreement between a simulation model of an electron-lens like configuration and the analytic results. The tune spread for this scenario can be recovered by means of a fit against the analytic expectation. The results are compared with measurements where the beam-beam effect acts as a substitute for the electron lens. A similar behaviour of the BTF is observed. This allows the conclusion that the transverse BTF can be used to diagnose tune spread from an electron-lens. Finally we discuss the problems that arise when trying to recover the tune spread from BTFs of arbitrary non-Gaussian beams and in the presence of coherent beam-beam modes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO060
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Paper

Title

Page

MOPRI106

Simulation Study of Beam Halo Collimation in the Heavy-ion Synchrotron SIS 100

870

SUSPSNE047

use link to see paper's listing under its alternate paper code

I.A. Prokhorov
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim, I. Strašík
GSI, Darmstadt, Germany

Funding: Work is supported by German Federal Ministry of Education and Research (BMBF) contract no. 05P12RDRBM
The FAIR synchrotron SIS-100 will be operated with high-intensity proton and heavy-ion beams. The collimation system should prevent beam loss induced degradation of the vacuum, activation of the accelerator structure and magnet quenches. A conventional two-stage betatron collimation system is considered for the operation with protons and fully-stripped ions. Particle tracking and ion-collimator interaction simulations of the collimation system were performed. The angular and momentum distributions of the scattered halo particles were described using analytical models and numerical tools like ATIMA and FLUKA. MADX was used for the multi-pass tracking simulations. The results obtained for the collimation cleaning efficiency as a function of the ion species and beam energy together with the detailed beam losses distributions along the ring circumference are presented. This work highlights the main aspects of the collimation of fully-stripped ion beams in the intermediate energy range using conventional two-stage systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI106

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPME031

Radiation Pressure Acceleration and Transport Methods

1422

P. Schmidt, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim, O. Boine-Frankenheim, I. Hofmann
GSI, Darmstadt, Germany
I. Hofmann
HIJ, Jena, Germany
I. Hofmann
IAP, Frankfurt am Main, Germany

Funding: HGS-HIRe for FAIR, HIC for FAIR, Technische Universität Darmstadt, FB 18 TEMF
Several projects worldwide such as LIGHT at GSI focus on laser ion acceleration. With the development of new laser systems and advances in the target production a new acceleration mechanism has become of interest: The Radiation Pressure Acceleration (RPA). An ultra short high intense laser pulse hits a very thin foil target and the emerging plasma is ideally accelerated as one piece (light sail regime). The ions reach kinetic energies up to GeV and nearly solid body densities. In this work, the distribution and transport of a RPA plasma is studied. 1D and 2D PIC simulations (software: VSim) are carried out to obtain the phase space distribution of the plasma. The results are compared to fluid models (software: FiPy and USim). A reference model an RPA plasma is obtained which is then used for advanced transport studies. Transport mechanisms (active and passive) are studied, such asμlenses and foil stacks.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME031

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRI017

Artificial Collisions, Entropy and Emittance Growth in Computer Simulations of Intense Beams

1588

O. Boine-Frankenheim, I. Hofmann, J. Struckmeier
GSI, Darmstadt, Germany

During particle tracking with self-consistent space charge artificial collision between the macro-particles lead to diffusion-like, numerical effects. The artificial collisions generate a stochastic noise spectrum. As a consequence the entropy and the emittance of the particle beam can growth along periodic focusing structures. The growth rates depend on the number of simulation macro-particles and on the space charge tune shifts. For long-term tracking studies the numerical diffusion can lead to incorrect beam loss predictions. In our study we present analytical prediction for the numerical friction and diffusion in 2D and 3D simulations. For simple focusing structures with derive a relation between the friction coefficient and the entropy growth. The scaling of the friction coefficient with the macro-particle number and the space charge tune shift is obtained from 2D and 3D simulations and compared to the analytic predictions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRI045

Beam Coupling Impedance Simulation in the Frequency Domain for the SIS100 Synchrotron

1665

U. Niedermayer, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim
GSI, Darmstadt, Germany

For the quantification of intensity thresholds due to coherent instabilities and beam induced heating in the FAIR synchrotron SIS100 a detailed knowledge of transverse and longitudinal beam coupling impedance is required. Due to the rather long proton and heavy-ion bunches, the relevant spectrum is below 100MHz. For the computation of beam coupling impedances in the low frequency regime, frequency domain methods are more advantageous than (explicit) time domain methods. We show the setup of a 2D finite element code that allows to compute the impedance for arbitrary longituninally homogeneous beam and structure shapes. Perfectly conducting pipes, a dispersive ferrite tube, and thin resistive beam pipe serve as test cases. The influence of the beam velocity on the coupling impedance is studied.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI045

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRO092

Stochastic Noise Effects in High Current PIC Simulation

3101

I. Hofmann, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim, I. Hofmann
GSI, Darmstadt, Germany

The numerical noise inherent to particle-in-cell simulation of 3D high intensity bunched beams is studied with the TRACEWIN code and compared with the analytical model by Struckmeier (1994). The latter assumes the six-dimensional rms emittance or rms entropy growth can be related to Markov type stochastic processes due to temperature anisotropy and the artificial "collisions" caused by using macro-particles and calculating the space charge effect. Our entropy growth confirms the dependency on bunch temperature anisotropy as predicted by Struckmeier. However, we also find noise generation by the non-Liouvillean effect of the Poisson solver grid, which exists in periodic focusing systems even when local temperature anisotropy is absent - contrary to predictions by Struckmeier's model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO092

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPRI019

Incoherent and Coherent Effects of Space Charge Limited Electron Clouds

1594

F.B. Petrov, O. Boine-Frankenheim, O.S. Haas
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: Work is supported by the BMBF under contract 05H12RD7.
Recent studies show that the space charge limited (saturated) electron cloud generated by relativistic bunches has strongly inhomogeneous distribution. In particular, a dense electron sheath is formed near the pipe wall. This feature modifies the stopping powers and the microwave transmission compared with the uniform cloud case. In this paper we investigate further the influence of the space charge limited electron cloud on relativistic bunches. In particular, we focus on the incoherent tune spread and compare the results with the homogeneous cloud case. We derive analytical expressions governing the pinch dynamics of the saturated cloud in round geometry. The contribution of the electron cloud sheath to the wake fields is investigated as well. Findings of the analytical theory are then successfully compared with numerical particle-in-cell simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRO060

Beam-beam Effect on the BTF in Bunched Beams

3011

SUSPSNE053

use link to see paper's listing under its alternate paper code

P.A. Görgen, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
W. Fischer
BNL, Upton, Long Island, New York, USA

We present studies on the transverse baseband Beam Transfer Functions (BTFs) in bunched beams at high energies. The goal of the work is to evaluate whether transverse BTFs can be used to diagnose the tune spread arising from transverse nonlinearities such as the beam-beam effect and space charge. We employ an analytic expression to the BTFs of beams under a transverse nonlinear lens arising from a bi-Gaussian charge distribution. We obtain agreement between a simulation model of an electron-lens like configuration and the analytic results. The tune spread for this scenario can be recovered by means of a fit against the analytic expectation. The results are compared with measurements where the beam-beam effect acts as a substitute for the electron lens. A similar behaviour of the BTF is observed. This allows the conclusion that the transverse BTF can be used to diagnose tune spread from an electron-lens. Finally we discuss the problems that arise when trying to recover the tune spread from BTFs of arbitrary non-Gaussian beams and in the presence of coherent beam-beam modes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO060

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)