Simulation of HOM Leakage in the PEP-II Bellows

Conference · Tue Jun 07 04:00:00 EDT 2005

OSTI ID:890452

Ng, C -K; Folwell, N; Ge, L; Langton, J; Lee, L -Q; Novokhatski, A

An important factor that limits the PEP-II from operating at high currents is higher-order-mode (HOM) heating of the bellows. One source of HOM heating is the formation of trapped modes at the bellows as a result of geometry variation in the vacuum chamber, for example, the masking near the central vertex chamber. Another source comes from HOMs generated upstream that leak through the gaps between the bellows fingers. Modeling the fine details of the bellows and the surrounding geometry requires the resolution and accuracy only possible with a large number of mesh points on an unstructured grid. We use the parallel finite element eigensolver Omega3P for trapped mode calculations and the S-matrix solver S3P for transmission analysis. The damping of the HOMs by the use of absorbers inside the bellows will be investigated.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 890452
• Report Number(s): SLAC-PUB-11259
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
ACCURACY
Accelerators
ACCPHY
DAMPING
FINGERS
GEOMETRY
HEATING
RESOLUTION
S MATRIX
SIMULATION