Author: Pöplau, G.
Paper Title Page
WEPC100 Simulation of the Single Bunch Instability due to the Electron Cloud Effect by Tracking with a Pre-computed 2D Wake Matrix* 2247
 
  • A. Markoviḱ, G. Pöplau, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
 
  Funding: Supported by DFG Contract Nr. RI 814/20-1.
The passage of a positron bunch through an initially homogeneous electron cloud (e-cloud) changes the distribution of the e-cloud in a way that the concentration of electrons in the proximity of the beam axis grows rapidly. The electrons are primarily moving in the transverse plane and are very sensitive on the beam centroid position in that plane. Thus the transverse kick of the e-cloud on the tail particles depends on the centroid position of the head particles of the same bunch. A PIC simulation of the interaction of a positron beam with an e-cloud yields the wake kick from the electrons on the tail particles for a certain offset in the transverse centroid position of the head parts of the bunch. With such a pre-computed 2D wake matrix, for a certain e-cloud density, we investigate the stability of a single bunch by tracking it through the linear optics of the storage ring while at each turn applying the kick from the e-cloud. We examine the positron bunch stability of KEKB-LER and PETRAIII for a certain electron cloud density.
 
 
WEPC101 Simulation of the Interaction of an Electron Beam with Ionized Residual Gas 2250
 
  • G. Pöplau, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
  • A. Meseck
    HZB, Berlin, Germany
 
  Funding: Supported by BMBF under contract number 05K10HRC
Light sources of the next generation such as ERLs require minimal beam losses as well as a stable beam position and emittance over the time. Instabilities caused by ion accumulation have to be avoided. In Rostock the tracking code MOEVE PIC Tracking has been developed for the simulation of space charge influenced beam dynamics, which is recently applied for simulations of the interaction beam - e-cloud. In this paper we apply MOEVE PIC Tracking for simulation of the interaction of the ionized residual gas with an electron bunch. We demonstrate numerical results with parameters planed for the ERL BERLinPro.
 
 
WEPC102 Recent Developments for Efficient 3D Space Charge Computations Based on Adaptive Multigrid Discretizations 2253
 
  • G. Pöplau, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
  • M.J. de Loos
    TUE, Eindhoven, The Netherlands
  • S.B. van der Geer
    Pulsar Physics, Eindhoven, The Netherlands
 
  Funding: Partly supported by BMBF under contract number 05K10HRC
Efficient and accurate space-charge computations are essential for the design of high-brightness charged particle sources. Recently a new adaptive meshing strategy based on multigrid was implemented in GPT and the capabilities were demonstrated. This new meshing scheme uses the solution of an intermediate step in the multigrid algorithm itself to define optimal mesh line positions. In this paper we discuss further developments of this adaptive meshing strategy. We compare the new algorithm with the current meshing scheme of GPT, where the mesh line positions are based upon the projected charge density.