rf breakdown tests of mm-wave metallic accelerating structures
In this study, we explore the physics and frequency-scaling of vacuum rf breakdowns at sub-THz frequencies. We present the experimental results of rf tests performed in metallic mm-wave accelerating structures. These experiments were carried out at the facility for advanced accelerator experimental tests (FACET) at the SLAC National Accelerator Laboratory. The rf fields were excited by the FACET ultrarelativistic electron beam. We compared the performances of metal structures made with copper and stainless steel. The rf frequency of the fundamental accelerating mode, propagating in the structures at the speed of light, varies from 115 to 140 GHz. The traveling wave structures are 0.1 m long and composed of 125 coupled cavities each. We determined the peak electric field and pulse length where the structures were not damaged by rf breakdowns. We calculated the electric and magnetic field correlated with the rf breakdowns using the FACET bunch parameters. The wakefields were calculated by a frequency domain method using periodic eigensolutions. Such a method takes into account wall losses and is applicable to a large variety of geometries. The maximum achieved accelerating gradient is 0.3 GV/m with a peak surface electric field of 1.5 GV/m and a pulse length of about 2.4 ns.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- AC02-76SF00515
- OSTI ID:
- 1235793
- Alternate ID(s):
- OSTI ID: 1242260; OSTI ID: 1242464; OSTI ID: 1443583
- Report Number(s):
- SLAC-PUB-16494; PRABFM; 011301
- Journal Information:
- Physical Review Accelerators and Beams, Journal Name: Physical Review Accelerators and Beams Vol. 19 Journal Issue: 1; ISSN 2469-9888
- Publisher:
- American Physical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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