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Title: Calculation of the coupling impedances of holes and slots on the liner using MAFIA and scaling

Technical Report ·
DOI:https://doi.org/10.2172/67476· OSTI ID:67476

The location of a liner inside the beam tube is one of the options considered for the Super Colliders. The liner could serve as a synchrotron radiation intercept and also help enhance the vacuum. A definite distribution of holes or slots is required to be located on the liner for pumping out the desorbing gases. There will be wake fields propagating within the liner due to diffraction at discontinuities following the incident beam fields. The effect of these wake fields can be minimized by adopting the least number of pumping holes/slots required and through an optimal choice of hole/slot shape and size. The effect of the wake fields on the beam may be expressed through coupling impedances defined proportional to the corresponding forces integrated through distance per unit charge. It is necessary to compute the impedance of holes and slots and determine the scaling of the impedance with the dimensions of the hole/slot and the liner, in order to optimize the choice of pumping holes/slots. The coupling impedances of slots and holes have been calculated here using the code MAFIA and the scaling assessed. The results compare favorably with existing analytical results.

Research Organization:
Superconducting Super Collider Lab., Dallas, TX (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC35-89ER40486
OSTI ID:
67476
Report Number(s):
SSCL-650; ON: DE95011252
Resource Relation:
Other Information: PBD: Nov 1993
Country of Publication:
United States
Language:
English