RF breakdown studies in X-Band klystron cavities

摘要

RF breakdown studies are presently being carried out at SLAC with klystron cavities in a traveling wave resonator (TWR). Different kinds of fabrication methods and several kinds of semiconducting and insulating coatings have been applied to X-Band TM(sub 010) cavities. RF breakdown thresholds up to 250 MV/m have been obtained. Dark current levels were found to be depressed on TiN-coated and single-point diamond turned cavities. A new TM(sub 020) cavity with demountable electrodes has been designed and will be used to test a variety of materials, coatings, and processes. Recent tests of klystron output windows at 119 MW are also presented in this paper.