Development of C-band 50 MW pulse klystron for e/sup +/e/sup -/ linear collider

Hardware R&D for the C-band (5712 MHz) RF system was started as a KEK research program for the e/sup +/e/sup -/ linear collider project in 1996. In order to achieve 500 GeV C.M. energy at the e/sup +/e/sup -/ collision within 25 km site length, the C-band system requests 4080 tubes of 50 MW pulse klystron, which drives the accelerating gradient 32 MV/m at the full beam current. The first 50 MW class klystron at C-band was designed and fabricated (named Toshiba E3746).