High power microwave research at SLAC

Summary form only given. This presentation will report on the efforts at SLAC to produce high power microwave sources for the Next Linear Collider (NLC). The NLC as outlined by SLAC will require 4000 X-band klystrons operating at >50 MW with a 1.2 /spl mu/s pulsewidth. SLAC has recently developed and tested an X-band klystron up to 75 MW. Design and performance data for this tube will be presented. Since the current X-band klystron uses a 25 kW solenoid to focus the electron beam, the power budget for 4000 of these solenoids would be 100 Mw. This was deemed excessive and both superconducting solenoids and PPM focusing were investigated. SLAC has designed and tested a 460 kV, 188 A, PPM focused, beam tester to evaluate PPM focusing for the X-band klystron. Initial results have produced better than 99.9% transmission for the samarium-cobalt, PPM focused device. Both the beam tester results and the design of a PPM focused klystron will be presented.