High power experimental studies of hybrid photonic band gap accelerator structures
Name
PhysRevAccelBeams.19.081304.pdf
Size
3.79 MB
Format
Adobe PDF
Checksum (MD5)
9718bb388e7e14568abbefe4b76f791b
Author(s)
Zhang, Jiexi
Munroe, Brian James
Xu, Haoran
Shapiro, Michael
Temkin, Richard J
Date Issued
August 2016
Journal
Physical Review Accelerators and Beams
Publisher
American Physical Society (APS)
Citation
Zhang, JieXi et al. “High Power Experimental Studies of Hybrid Photonic Band Gap Accelerator Structures.” Physical Review Accelerators and Beams 19, 8 (August 2016): 081304 © 2016 American Physical Society
Version
Final published version
Abstract
This paper reports the first high power tests of hybrid photonic band gap (PBG) accelerator structures. Three hybrid PBG (HPBG) structures were designed, built and tested at 17.14 GHz. Each structure had a triangular lattice array with 60 inner sapphire rods and 24 outer copper rods sandwiched between copper disks. The dielectric PBG band gap map allows the unique feature of overmoded operation in a TM₀₂ mode, with suppression of both lower order modes, such as the TM₁₁ mode, as well as higher order modes. The use of sapphire rods, which have negligible dielectric loss, required inclusion of the dielectric birefringence in the design. The three structures were designed to sequentially reduce the peak surface electric field. Simulations showed relatively high surface fields at the triple point as well as in any gaps between components in the clamped assembly. The third structure used sapphire rods with small pin extensions at each end and obtained the highest gradient of 19 MV/m, corresponding to a surface electric field of 78 MV/m, with a breakdown probability of 5 × 10⁻¹ per pulse per meter for a 100-ns input power pulse. Operation at a gradient above 20 MV/m led to runaway breakdowns with extensive light emission and eventual damage. For all three structures, multipactor light emission was observed at gradients well below the breakdown threshold. This research indicated that multipactor triggered at the triple point limited the operational gradient of the hybrid structure.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Terms of Use
Creative Commons Attribution 3.0 Unported license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PHYSREVACCELBEAMS.19.081304
