The Amplitron as a High Power, Efficient, RF Power Source for Long Pulse, High Resolution Linear Accelerators

An economical systems approach directed toward the generation of long pulse, high average rf power for linear accelerators can be achieved via the use of the Amplitron, an efficient crossed-field amplifier of high phase stability, in conjunction with a newly developed Machlett switch tube. A 3 Gc Amplitron to provide 3 mw peak power (150 kW average power) at 50 /g=m/s pulse lengths is described. A cold secondary emission cathode of platinum is employed which enables a tube life of 10,000 hours to be guaranteed. Operating at a low anode voltage of 54 kV, the Amplitron is compatible with the ML-8549 super power switch tube; a hard tube modulator is thus employed. A single triode will switch a minimum of 10 Amplitrons. Not only is the cost of capital equipment drastically reduced by this unique, highly efficient combination of Amplitron-switch tube, but in addition, with grid control a fine adjustment on output power relative to the monitored beam energy can be made to achieve exceptionally high energy resolution in the beam.