U.S. Department of EnergyOffice of Scientific and Technical Information
Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure
Abstract
We report the design, fabrication and high gradient testing of a 17.1 GHz Photonic Band Gap accelerator structure. Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox) input and output cells, with input power of up to 4 MW from a klystron supplied via a TM01 mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87 MV/m at a breakdown probability of 1.19 × 10^-1 per pulse per meter. The PBG structure was tested with 100 ns pulses at power levels of less than 90 MV/m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89 MV/m at a breakdownmore »
- Authors:
-
- OSTI
- Publication Date:
- DOE Contract Number:
- SC0010075
- Research Org.:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
- Sponsoring Org.:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- Subject:
- 43 PARTICLE ACCELERATORS
- OSTI Identifier:
- 1880520
- DOI:
- https://doi.org/10.7910/DVN/SATGTO
Citation Formats
Munroe, Brian J., Zhang, JieXi, Xu, Haoran, Shapiro, Michael A., and Temkin, Richard J. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure. United States: N. p., 2018.
Web. doi:10.7910/DVN/SATGTO.
Munroe, Brian J., Zhang, JieXi, Xu, Haoran, Shapiro, Michael A., & Temkin, Richard J. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure. United States. doi:https://doi.org/10.7910/DVN/SATGTO
Munroe, Brian J., Zhang, JieXi, Xu, Haoran, Shapiro, Michael A., and Temkin, Richard J. 2018.
"Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure". United States. doi:https://doi.org/10.7910/DVN/SATGTO. https://www.osti.gov/servlets/purl/1880520. Pub date:Thu Dec 06 23:00:00 EST 2018
@article{osti_1880520,
title = {Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure},
author = {Munroe, Brian J. and Zhang, JieXi and Xu, Haoran and Shapiro, Michael A. and Temkin, Richard J.},
abstractNote = {We report the design, fabrication and high gradient testing of a 17.1 GHz Photonic Band Gap accelerator structure. Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox) input and output cells, with input power of up to 4 MW from a klystron supplied via a TM01 mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87 MV/m at a breakdown probability of 1.19 × 10^-1 per pulse per meter. The PBG structure was tested with 100 ns pulses at power levels of less than 90 MV/m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89 MV/m at a breakdown probability of 1.09×10^-1 per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.},
doi = {10.7910/DVN/SATGTO},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Dec 06 23:00:00 EST 2018},
month = {Thu Dec 06 23:00:00 EST 2018}
}