Author: Kornilov, V.
Paper Title Page
TUAAI3
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.  
 
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]  
 
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.
[1] http://www.txcorp.com/products/VORPAL/
[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]