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

Technical Report · Mon Nov 01 04:00:00 EST 1993

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

Thiagarajan, V; Barts, T; Kurennoy, S; Chou, W

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
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM TRANSPORT
FREQUENCY DEPENDENCE
IMPEDANCE
LINERS
M CODES
OPENINGS
SUPERCONDUCTING SUPER COLLIDER
TUBES