ISABELLE cavity gap assemblies
In a storage ring, where beam lifetime is measured in hours, it is necessary to keep the longitudinal impedance, as seen by the beam, very low, even into the gigahertz region. This is necessary to prevent the excitation of longitudinal instabilities. These impedances are due to the resistive wall effect and any deviation from a smooth vacuum chamber such as at pick-up electrodes, vacuum pump stations, rf cavities, etc. At low frequencies, up to 10 to 20 MHz, the low impedance requirement for the cavities can be satisfied by designing the driving power amplifiers with a very low output impedance. For ISABELLE a method has been designed for building a network into the cavity accelerating gaps which will satisfy the impedance criteria to at least 1300 MHz. The maximum allowable impedance at any frequency, f, is given in the form Z/n where n = f/f/sub rotation/. For the ISABELLE accelerating cavity, operating at 235.5 KHz, Z/n must be less than 10 ohms. For the stacking cavity, operating at 4.45 MHz, Z/n < 1 ohm.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6466570
- Report Number(s):
- BNL-29091; CONF-810314-95; TRN: 81-007518
- Resource Relation:
- Conference: Particle accelerator conference, Washington, DC, USA, 11 Mar 1981
- Country of Publication:
- United States
- Language:
- English
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