Author: Hofmann, I.
Paper Title Page
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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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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