Title: Experimental studies of a high-gradient X-band welded hard-copper split accelerating structure

Journal Article · · Journal of Physics. D, Applied Physics
 [1];  [2];  [2];  [3];  [4]; ORCiD logo [2];  [2]
  1. RadiaBeam Technologies LLC, Santa Monica, CA (United States); SLAC
  2. RadiaBeam Technologies LLC, Santa Monica, CA (United States)
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  4. National Research Nuclear Univ., Moscow (Russia)
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We report on recent research on high-gradient radio frequency (RF) accelerating structures indicates that the use of hard copper alloys provides improvement in high gradient performance over annealed copper. Such structures are made by bonding individually manufactured parts. However, there are no well-established bonding techniques that preserve the hardness, surface finish and cleanliness required for high gradient operation. To preserve the copper hardness, RadiaBeam has developed a novel high-gradient split accelerating structure, based on electron beam welding joining technique. This technique provides efficient bonding with strong, clean welds and minimal thermal loading, while maintaining a clean inner RF environment. Our RF design and fabrication methodology limits the small heat affected zone to the outer cavity envelop, with virtually no distortions or thermal loading of critical RF surfaces. It also incorporates provisions to precisely control the gap despite conventional issues with weld joint shrinkage. To date we have manufactured and validated an RF accelerating structure joined by electron-beam welding that incorporates a novel open split design to significantly reduce the assembly complexity and cost. In this paper, we will present the electromagnetic design of this structure, discuss bonding, and present the results of high-power tests, where the accelerating gradients of 140 MV m-1 with surface peak fields of 400 MV m-1 were achieved for flat-top pulse length of 600 ns with an RF breakdown rate of 10-4 1/(pulsecm).

Research Organization:
RadiaBeam Technologies LLC, Santa Monica, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), High Energy Physics (HEP)
Grant/Contract Number:
AC02-76SF00515; SC0015716
OSTI ID:
1851846
Journal Information:
Journal of Physics. D, Applied Physics, Journal Name: Journal of Physics. D, Applied Physics Journal Issue: 14 Vol. 55; ISSN 0022-3727
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United States
Language:
English

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Related Subjects

43 PARTICLE ACCELERATORS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
electron beam welding
hard copper
high gradients
split accelerating