Paper |
Title |
Page |
MOPLS136 |
Ion Effects in the Damping Rings of ILC and CLIC
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876 |
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- F. Zimmermann, W. Bruns, D. Schulte
CERN, Geneva
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We discuss ion trapping, rise time of the fast beam-ion instability, and ion-induced incoherent tune shift for various incarnations of the ILC damping rings and for CLIC, taking into account the different regions of each ring. Analytical calculations for ion trapping are compared with results from a new simulation code.
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WEPCH110 |
Calculation of Wake Potentials in General 3D Structures
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2170 |
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- H. Henke
TET, Berlin
- W. Bruns
CERN, Geneva
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The wake potential is defined as an integration along an axis of a structure. It includes the infinitely long beam pipe regions and in case of numerical evaluation leads to pipe wake artefacts. If the structure is cavity like one can position the integration path on the pipe wall and only the integration over the cavity gap remains. In case of axis-symmetric protruding structures it was proposed by O. Napoly et al. to deform the path such that the integration in the pipe regions is again on the wall. The present paper generalizes this method of path deformation to 3D structures with incoming and outgoing beam pipes. Its usefulness is verified with the code GdfidL and no artifacts were observed.
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WEPCH137 |
FAKTOR2: A Code to Simulate the Collective Effects of Electrons and Ions
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2242 |
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- W. Bruns, D. Schulte, F. Zimmermann
CERN, Geneva
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A new code for computing the multiple effects of slowly moving charges is being developed. The basic method is electrostatic particle in cell. The underlying grid is rectangular and locally homogeneous. At regions of interest, e.g., where the beam is, or near material boundaries, the mesh is refined recursively. The motion of the macroparticles is integrated with an adapted timestep. Fast particles are treated with a smaller timestep, and particles in regions of fine grids are also treated with a fine timestep. The position of collision of particles with material boundaries is accurately resolved. Secondary particles are then created according to user-specified yield functions.
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