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ASTRA

Paper Title Other Keywords Page
WEPCH114 On the Development of a Self-consistent Particle-in-cell (PIC) Code Using a Time-adaptive Mesh Technique simulation, gun, PITZ, DESY 2182
 
  • S. Schnepp, E. Gjonaj, T. Weiland
    TEMF, Darmstadt
  For a large class of problems the self-consistent simulation of charged particle beams in linear accelerators is necessary. Especially, in all low-energetic sections such as injectors the self-consistent interaction of particles and fields has to be taken into account. Well-known programs like the MAFIA TS Modules typically use the Particle-in-cell (PIC) method for beam dynamics simulations. Since they use a fixed computational grid which has to resolve the bunch adequately, they suffer from enormous memory consumption. Therefore and especially in the 3D case, only rather short sections can be simulated. A remedy to this limitation is the usage of a grid which refines itself in the vicinity of particles. For this purpose, a new code called SMOVE based on a time-adaptive grid is being developed. First promising results will be presented at the conference.  
 
WEPCH120 Simulation of 3D Space-charge Fields of Bunches in a Beam Pipe of Elliptical Shape space-charge, simulation, DESY, damping 2200
 
  • A. Markovik, G. Pöplau, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock
  • K. Floettmann
    DESY, Hamburg
  Recent applications in accelerator design require precise 3D calculations of space-charge fields of bunches of charged particles additionally taking into account the shape of the beam pipe. An actual problem of this kind is the simulation of e-clouds in damping rings. In this paper a simulation tool for 3D space-charge fields is presented where a beam pipe with an arbitrary elliptical shape is assumed. The discretization of the Poisson equation by the method of finite differences on a Cartesian grid is performed having the space charge field solved only in the points inside the elliptical cross-section of the beam pipe taking care of the conducting boundaries of the pipe. The new routine will be implemented in the tracking code ASTRA. Numerical examples demonstrate the performance of the solution strategy underling the new routine. Further tracking results with the new method are compared to established space-charge algorithms such as the FFT-approach.  
 
WEPCH121 3D Space-charge Calculations for Bunches in the Tracking Code ASTRA space-charge, DESY, electron, simulation 2203
 
  • G. Pöplau, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock
  • K. Floettmann
    DESY, Hamburg
  Precise and fast 3D space-charge calculations for bunches of charged particles are of growing importance in recent accelerator designs. One of the possible approaches is the particle-mesh method computing the potential of the bunch in the rest frame by means of Poisson's equation. In that, the charge of the particles are distributed on a mesh. Fast methods for solving Poisson's equation are the direct solution applying Fast Fourier Methods (FFT) and a finite difference discretization combined with a multigrid method for solving the resulting linear system of equations. Both approaches have been implemented in the tracking code ASTRA. In this paper the properties of these two algorithms are discussed. Numerical examples will demonstrate the advantages and disadvantages of each method, respectively.  
 
THPLS115 Simulation and Optimisation of a 100 mA DC Photo-Injector electron, emittance, gun, cathode 3550
 
  • F.E. Hannon, C. Hernandez-Garcia
    Jefferson Lab, Newport News, Virginia
  A prototype 100mA injector is presently being designed and manufactured jointly between Thomas Jefferson National Accelerator Facility (J-Lab) and Advanced Energy Systems (AES). This paper discusses the physics optimisation and performance of the injector, which has been studied using the space-charge tracking code ASTRA. The objective is to operate the 7MeV injector with 135pC electron bunches at 748.5MHz repetition rate. We show that the longitudinal and transverse electron bunch properties can be realised within the constraints of the design.