Cathode-Driven, High Gain, Crossed-Field Amplifier

To achieve very high gain in a crossed-field amplifier, the rf drive power is being fed into a cathode slow-wave circuit. The traveling-wave on the cathode will control the space charge and induce current into the anode circuit. The cathode structure used to introduce the rf drive signal will provide a high degree of isolation between the amplified output signal and the rf drive energy. During this report period, the first cathode-driven hot test model was sealed in and performance data were obtained. Initial results show that the space-charge control was obtained with an rf gain of 20 dB. The present power supply is limiting the applied voltage to 39 kV. To obtain the required 50 kV anode voltage, the power supply will be modified. Testing of Model No. 1 will then be continued.