skip to main content

SciTech ConnectSciTech Connect

Title: RF breakdown of 805 MHz cavities in strong magnetic fields

Ionization cooling of intense muon beams requires the operation of high-gradient, normal-conducting RF structures in the presence of strong magnetic fields. We have measured the breakdown rate in several RF cavities operating at several frequencies. Cavities operating within solenoidal magnetic fields B > 0.25 T show an increased RF breakdown rate at lower gradients compared with similar operation when B = 0 T. Ultimately, this breakdown behavior limits the maximum safe operating gradient of the cavity. Beyond ionization cooling, this issue affects the design of photoinjectors and klystrons, among other applications. We have built an 805 MHz pillbox-type RF cavity to serve as an experimental testbed for this phenomenon. This cavity is designed to study the problem of RF breakdown in strong magnetic fields using various cavity materials and surface treatments, and with precise control over sources of systematic error. We present results from tests in which the cavity was run with all copper surfaces in a variety of magnetic fields.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [3] ;  [3] ;  [3] ;  [4]
  1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. Illinois Inst. of Technology, Chicago, IL (United States)
  4. SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
OSTI Identifier:
1188260
Report Number(s):
BNL--108095-2015-CP
R&D Project: KBCH139; KB0202011; TRN: US1500256
DOE Contract Number:
SC00112704
Resource Type:
Conference
Resource Relation:
Conference: 6th International Particle Accelerator Conference (IPAC’15), Richmond, VA (United States), 3-8 May 2015
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; CAVITY RESONATORS; MHZ RANGE 100-1000; MAGNETIC FIELDS; RF SYSTEMS; BREAKDOWN; KLYSTRONS; MUON BEAMS; COPPER; COMPARATIVE EVALUATIONS; IONIZATION; BEAM COOLING; DESIGN; OPERATION; SURFACE TREATMENTS; CONTROL; ERRORS; MATERIALS