A type of tube-shaped permanent magnet focusing system of high-power klystron

A useful tube-shaped permanent magnet (TSPM) focusing system of the high-power klystron is presented in this paper. The characteristics of the TSPM focusing system are the adjustable magnetic field curve slope in the cathode transitional area, the low reversal magnetic induction in the klystron collector area and no permanent magnet in the collector area. All above items give the klystron designer an advantageous factor, and it also solves a problem which badges designers who applied the tube-shaped permanent magnet focusing system to the high-power klystron.