| Title |
Computation of Beam Coupling Impedance in the Frequency Domain by Means of FIT and FEM |
| Authors |
- U. Niedermayer, O. Boine-Frankenheim, H. De Gersem
TEMF, TU Darmstadt, Darmstadt, Germany
|
| Abstract |
A detailed knowledge of transverse and longitudinal beam coupling impedance is required to quantify intensity thresholds due to coherent instabilities and beam induced heating in ion synchrotrons. Particularly at low frequencies, where the beam pipe dominates the impedance spectrum, analytical calculations are widely used since contemporary time domain methods are inapplicable. We present two different ways to compute the beam coupling impedance in the frequency domain. One is based on FIT and it is implemented in 2D and 3D. The staircase FIT approximates curved structures only poorly, therefore another solver is implemented in 2D based on FEM. The unstructured triangular FEM mesh allows to approximate curved structures better. Furthermore, it allows to compute the space charge impedance, since the shape of the beam and the beam's dipole moment can be represented properly, such that the direct space charge force can be subtracted and only the coherent force remains. Space charge and resistive wall impedance results for GSI and the upcoming FAIR project and the impedance of the beam pipe for the Future Circular Collider (FCC-hh) design study are presented as applications.
|
| Funding |
Supported by GSI, Planckstraße 1, 64291 Darmstadt, Germany |
| Paper |
download TUCWC3.PDF [0.879 MB / 3 pages] |
| Conference |
ICAP2015, Shanghai, China |
| Series |
International Computational Accelerator Physics Conference (12th) |
| Proceedings |
Link to full ICAP2015 Proccedings |
| Session |
PIC, Poisson and Coupling Impedance Solvers |
| Date |
13-Oct-15 14:00–15:30 |
| Main Classification |
F-2 Code Development, Status and Comparison with Measurements |
| Keywords |
impedance, space-charge, dipole, synchrotron, kicker |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Kwok C. Ko (SLAC, Menlo Park, CA, USA); Volker R.W. Schaa (GSI, Darmstadt, Germany); Chuanxiang Tang (Tsinghua University, Beijing, China); Heping Yan (SINAP, Shanghai, China) |
| ISBN |
978-3-95450-136-6 |
| Published |
February 2016 |
| Copyright |
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