Resonant impedance of bellows above cutoff
The perturbation method of Chatard-Moulin and Papiernik is used to calculate the longitudinal and transverse impedances, Z(..omega..) and Z/sub perpendicular/(..omega..), of a bellows. The bellows shape is defined by its radius a(z) = a (1 + epsilons(z)), where a is the mean radius, epsilon a small parameter, and s(z) describes the convolution of the bellows. A finite wall conductivity is considered and the resonant contribution to the impedance above the cutoff frequency of the unperturbed chamber is determined, obtaining analytic approximations to the resonant frequencies, quality factors, and shunt impedances. The relation Z/sub perpendicular/(..omega..) = (2c/a/sup 2/)Z(..omega..)/..omega.., of course, does not hold as an identity, but it is found to be a useful relation for the shunt impedances, holding exactly for one family of transverse modes and providing an upper bound on the shunt impedances of the second set of transverse modes.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 5255820
- Report Number(s):
- BNL-28004; CONF-800740-5; TRN: 80-014770
- Resource Relation:
- Conference: 11. international conference on high energy accelerators, Geneva, Switzerland, 7 Jul 1980; Other Information: Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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