Author: Munroe, B.J.
Paper Title Page
MOP041 17 GHz Overmoded Dielectric Photonic Bandgap Accelerator Cavity 175
 
  • A.M. Cook, B.J. Munroe, M.A. Shapiro, R.J. Temkin
    MIT/PSFC, Cambridge, Massachusetts, USA
 
  Funding: This research is supported by the U.S. Department of Energy, Office of High Energy Physics.
We present the design of an overmoded photonic band gap (PBG) accelerator cavity, made from a 2D lattice of sapphire rods supported between copper plates, that operates in a TM02-like mode at 17 GHz. The cavity does not support the lower-frequency TM01-like mode. Higher-order modes are damped effectively by removing rods from the lattice so that only the operating mode is supported with a high quality factor. The TM02 cavity mitigates the high pulsed heating of the copper surface seen in some metal-rod TM01 PBG cavities, which may be an advantage for high-gradient operation. We discuss plans for testing a 17 GHz TM02 standing-wave cavity at gradients above 100 MV/m.
 
 
THOBN5 Design and Testing of Advanced Photonic Bandgap (PBG) Accelerator Structures 2071
 
  • B.J. Munroe, M.A. Shapiro, R.J. Temkin
    MIT/PSFC, Cambridge, Massachusetts, USA
  • V.A. Dolgashev, S.G. Tantawi, A.D. Yeremian
    SLAC, Menlo Park, California, USA
  • R.A. Marsh
    LLNL, Livermore, California, USA
 
  Photonic Band-gap (PBG) structures continue to be an area of promising research for high gradient accelerators with wakefield suppression. Experimental results on an 11.4 GHz PBG structure tested at high power and high repetition rate at SLAC have shown that high gradients can be achieved in these structures. For PBG structures with thin rods, however, pulsed heating of the inner row of rods is a problem. Following these preliminary results, two new PBG structures have been designed. One structure, designated 1C-SW-A5.65-T4.6-Cu-PBG2-SLAC1, utilizes elliptical inner rods to reduce pulsed heating to an acceptable level; it will be tested at SLAC. A second PBG structure with round rods will be tested at 17.1 GHz at MIT. The MIT research will use the improved diagnostic access of the PBG structure to obtain a better understanding of the breakdown process. We will present preliminary results for the design and testing of these PBG structures.  
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