| Paper |
Title |
Page |
| WEPLT061 |
Influence of Beam Tube Obstacles on the Emittance of the PITZ Photoinjector
|
1981 |
| |
- S. Setzer, W. Ackermann, S. Schnepp, T. Weiland
TEMF, Darmstadt
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For detailed analysis of space charge dominated beams inside an RF Photoinjector PIC-Codes like MAFIA TS2/3 can be used. While the interaction of particles with the sourrounding geometries are taken into account, the applicability of such codes is restricted due to simulation time and memory consumption as well as by numercial noise. Therefore only smaller sections of the whole injector can be calculated. On the other hand codes like ASTRA can be used to simulate the whole injector but no interaction between bunch and geometry is included. To make use of the individual advantages of each code discribed above an interface for bidirectional bunch exchange between the two programs has been implemented. This approach allows for applying the right simulation method depending on the physical effects under investigation. To demonstrate the importance of such an approach the results of detailed numerical studies of the impact of beam tube obstacles like the laser mirror on the achievable emittance of the PITZ RF Photoinjector further downstream will be presented.
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| THPLT037 |
Investigation of Numerical Noise in PIC-Codes
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2559 |
| |
- S. Schnepp, S. Setzer, T. Weiland
TEMF, Darmstadt
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For a detailed analysis of the dynamics of space charge dominated beams a combination of Particle-in-Cell methods with efficient FDTD schemes is widely used. Besides the calculation of the forces acting on the particles the interaction of the beam itself with the surrounding geometries is taken into account. A drawback of this method is its sensitivity to numerical noise in the spectral range nearby the grid cutoff frequency. In this paper we will present results of detailed studies of the impact of the bunch shape on the level of the numerical noise. Furthermore an a priori scheme for efficient noise suppression is derived which does not affect the FDTD update algorithm.
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