Author: Boine-Frankenheim, O.
Paper Title Page
WEAAC2 Simulation of Baseband BTFs Using a Particle-in-cell Code 121
  • P.A. Görgen
    TEMF, TU Darmstadt, Darmstadt, Germany
  • O. Boine-Frankenheim
    GSI, Darmstadt, Germany
  • W. Fischer, S.M. White
    BNL, Upton, Long Island, New York, USA
  A simulation model for transverse bunched beam transfer functions (BTFs) at the base harmonic is presented. It is based on a code including different machine effects, most notably transverse space charge using a two-dimensional (2D) Poisson solver. A simplified model for the simulation of the strong-strong beam-beam effect was implemented using either 2D field data or analytic expressions under the assumption of Gaussian beams for the beam-beam interaction. The validity of the BTF model is verified based on the comparison of BTF and Schottky spectra features with analytic expectations from literature. The simulation model is then applied to the RHIC proton lattice. A linear transfer map is used between interaction points. BTFs including the beam-beam effect are simulated. Measurements are compared to simulation results at machine conditions.  
slides icon Slides WEAAC2 [2.829 MB]  
WEACC2 Space Charge Effects and Focusing Methods for Laser Accelerated Ion Beams 184
  • P. Schmidt, O. Boine-Frankenheim, V. Kornilov, P. Spädtke
    GSI, Darmstadt, Germany
  Funding: GSI Helmholtzzentrum für Schwerionenforschung Planckstr. 1 D-64291 Darmstadt
We employ the 3D PIC simulation code VORPAL to study the transport of laser accelerated proton beams in the framework of the LIGHT project at GSI. Initially the beam is assumed to be neutralized by co-moving electrons. For different initial beam distribution models we study the effect of space charge after the electrons have been removed. The results of the simulations are compared to an envelope model. We derive conditions in terms of the beam parameters and the distance from the production target for a safe removal of the electrons. As an option for the controlled de-neutralization of the beam a thin metallic foil is studied. Besides space charge, we also account for the effect of secondary electrons generated from the foil.
slides icon Slides WEACC2 [0.993 MB]  
THP02 Beam Dynamics Simulations Using GPUs 227
  • J. Fitzek, S. Appel, O. Boine-Frankenheim
    GSI, Darmstadt, Germany
  PATRIC is a particle tracking code used at GSI to study collective effects in the FAIR synchrotrons. Due to the need for calculation-intense simulations, parallel programming methods are being explored to optimize calculation performance. Presently the tracking part of the code is parallelized using MPI, where each node represents one slice of the particles that travel through the accelerator. In this contribution different strategies will be presented to additionally employ GPUs in PATRIC and exploit their support for data parallelism without major code modifications to the original tracking code. Some consequences of using only single-precision in beam dynamics simulations will be discussed.  
FRSAI3 PIC Simulations of Laser Ion Acceleration via TNSA 290
  • L. Lecz
    TEMF, TU Darmstadt, Darmstadt, Germany
  • O. Boine-Frankenheim, V. Kornilov
    GSI, Darmstadt, Germany
  The laser acceleration of protons via the TNSA (Target Normal Sheath Acceleration) mechanism from a thin metal foil (few micrometer) interacting with intense and short (several 100 fs) laser pulse is investigated by using 1D and 2D particle-in-cell electro-magnetic VORPAL [1] simulations. The protons originate from the very thin hydrogen-rich contamination layer on the target rear surface. In the 1D view we have found that two models well describe the longitudinal acceleration in the two extreme cases: quasi-static acceleration [2] for mono-layers and isothermal plasma expansion [3] for thick layers. The grid heating, which is the most important issue in 2D simulations, and its effect on the proton acceleration is discussed. The required numerical parameters and boundary conditions for stable and reliable 2D simulations are also presented.
[2] M. Passoni et al., Phys Rev E 69, 026411 (2004)
[3] P. Mora, Phys. Rev. Lett., 90, 185002 (2003)
slides icon Slides FRSAI3 [4.325 MB]  
MOSCC2 Simulation of Space Effects During Multiturn Injection into the GSI SIS18 Synchrotron 37
  • S. Appel
    GSI, Darmstadt, Germany
  • O. Boine-Frankenheim
    TEMF, TU Darmstadt, Darmstadt, Germany
  The optimization of the Multiturn Injection (MTI) from the UNILAC into the SIS18 is crucial in order to reach the FAIR beam intensities required for heavy ions. In order to achieve the design intensities, the efficiency of the multiturn injection from the UNILAC has to be optimized for high beam currents. We developed a simulation model for the MTI including the closed orbit bump, lattice errors, the parameters of the injected UNILAC beam, the position of the septum and other aperture limiting components, and finally the space charge force and other high-intensity effects. The model is also used to estimate the required proton and heavy-ion beam emittances from the UNILAC and from the projected p-linac. For the accurate prediction of the MTI efficiency a careful validation of the simulation model is necessary. We will present first results of the comparison between experiments and simulation for low and high uranium beam currents.  
slides icon Slides MOSCC2 [2.511 MB]  
Simulation of Transverse Coherent Effects in Intense Ion Bunches  
  • O. Boine-Frankenheim
    TEMF, TU Darmstadt, Darmstadt, Germany
  • V. Kornilov
    GSI, Darmstadt, Germany
  The transverse stability thresholds for intense ion bunches in the FAIR synchrotrons as well as in other injector rings are determined by the interplay of space charge and transverse impedances. Also below the stability threshold space charge causes a strong modification of the head-tail modes, with implications for the interpretation of beam signals from Schottky probes and BTF measurements. In order to predict stability thresholds and signals from stable bunches the simulations should be able to account for the 3D self-consistent space charge field. Furthermore the accurate matching of the longitudinal particle distribution to different rf bucket forms is important in order to correctly resolve the head-tail mode spectrum. Results obtained with the code PATRIC for the FAIR synchrotron will be presented. Some analytic solutions available for code validation are pointed out.  
WESCI2 Numerical Calculation of Beam Coupling Impedances in the Frequency Domain using FIT 193
  • U. Niedermayer, O. Boine-Frankenheim
    TEMF, TU Darmstadt, Darmstadt, Germany
  The transverse impedance of kicker magnets is considered to be one of the main beam instability sources in the projected SIS-100 at FAIR and also in the SPS at CERN. The longitudinal impedance can contribute to the heat load, which is especially a concern in the cold sections of SIS-100 and LHC. In the high frequency range, commercially available time domain codes like CST Particle Studio® serve to calculate the impedance but they become inapplicable at medium and low frequencies which become more important for larger size synchrotrons. We present the ongoing work of developing a Finite Integration (FIT) solver in frequency domain which is based on the Parallel and Extensible Toolkit for Scientific computing (PETSc) framework in C++. Pre- and post-processing are done in MATLAB®. Infinite beam pipe boundary conditions are used. The code is applied to an inductive insert used to compensate the longitudinal space charge impedance in low energy machines. Another application focuses on the impedance contribution of a ferrite kicker with inductively coupled pulse forming network (PFN) and frequency dependent complex material permeability.  
slides icon Slides WESCI2 [3.468 MB]