Localization of RF Breakdowns in a Standing Wave Cavity

Journal Article · Mon Aug 03 04:00:00 EDT 2009 · Phys.Rev.ST Accel.Beams 12:042001,2009

DOI:https://doi.org/10.1103/PhysRevSTAB.12.042001· OSTI ID:962088

Wang, Faya; Adolphsen, Chris

At SLAC, a 5-cell, normal-conducting, L-band (1.3 GHz), standing-wave (SW) cavity was built as a prototype positron capture accelerator for the ILC. The structure met the ILC gradient goal but required extensive rf processing. When rf breakdowns occurred, a large variation was observed in the decay rate of the stored energy in the cavity after the input power was shut off. It appeared that the breakdowns were isolating sections of the cavity, and that the trapped energy in those sections was then partitioned among its natural modes, producing a distinct beating pattern during the decay. To explore this phenomenon further, an equivalent circuit model of cavity was created that reproduces well its normal operating characteristics. The model was then used to compute the spectra of trapped energy for different numbers of isolated cells. The resulting modal patterns agree well with those of the breakdown data, and thus such a comparison appears to provide a means of identifying the irises on which the breakdowns occurred.

• Research Organization: SLAC National Accelerator Laboratory (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 962088
• Report Number(s): SLAC-PUB-13740
• Journal Information: Phys.Rev.ST Accel.Beams 12:042001,2009, Journal Name: Phys.Rev.ST Accel.Beams 12:042001,2009 Journal Issue: 4 Vol. 12; ISSN 1098-4402
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
Accelerators
ACCPHY
BREAKDOWN
DECAY
EQUIVALENT CIRCUITS
POSITRONS
PROCESSING
SPECTRA
STANDING WAVES
STANFORD LINEAR ACCELERATOR CENTER
STORED ENERGY