| Title |
Longitudinal Wakefield Study for SLAC Rotatable Collimator Design for the LHC Phase II Upgrade |
Submitted |
02-DEC-09 18:09 (UTC) |
| Classification |
05 Beam Dynamics and Electromagnetic Fields |
Modified |
27-MAY-10 01:32 (UTC) |
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Presentation |
Poster |
| Presenter |
Liling Xiao |
Paper ID |
TUPEC079 |
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Paper PDF |
Download |
| Author(s) |
Liling Xiao, Steven Lundgren, Thomas Walter Markiewicz, Cho-Kuen Ng, Jeffrey Claiborne Smith (SLAC, Menlo Park, California) |
| Abstract |
SLAC is proposing a rotatable collimator design for the LHC phase II collimation upgrade. This design has 20 facet faces on each cylindrical jaw surface and the two jaws, which will move in and out during operation, are rotatable in order to introduce a clean surface in case of a beam hitting a jaw in operation. When the beam crosses the collimator, it will excite broadband and narrowband modes that can contribute to the beam energy loss and power dissipation on the vacuum chamber wall and jaw surface. In this paper, the parallel eigensolver code Omega3P is used to search for all the trapped modes in the SLAC collimator design. The power dissipation generated by the beam in different vacuum chamber designs with different jaw end geometries is simulated. It is found that the longitudinal trapped modes in the circular vacuum chamber design with larger separation of the two jaws may cause excessive heating. Adding ferrite tiles on the vacuum chamber wall can strongly damp these trapped modes. The short-range wakefields will also be calculated to determine the broadband beam heating and transverse kick on the beam. We will present and discuss the simulation results. |
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Word Count: 195 Character Count: 1167 |
| Footnote |
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| Funding Agency |
This work was supported by DOE Contract No. DE-AC02-76SF00515 and partially supported by the DOE through the US LHC Accelerator Research Program (LARP). |
