Development program for a 200 kW, CW, 28-GHz gyroklystron. Quarterly report No. 14, July-September 1979

The objective of this program is to develop a microwave oscillator capable of producing 200 kW CW power output at 28 GHz. The use of the gyrotron or cyclotron resonance interaction is being pursued. Testing of miter bend tube S/N 2R9 was continued beyond the work described in Quarterly Report No. 13. It failed at 63 kW CW after several hours of operation, due to a cracked collector ceramic. The succeeding miter bend tube, S/N 7, incorporates several changes intended to reduce the heating of that ceramic. Tube S/N 5, an axisymmetric tube, was pulse tested to 195 kW at 1.2% duty. After consultation with ORNL, tests were interrupted and the test station was assigned to tube No. 7. Most of the assemblies of tube S/N 6, another axisymmetric tube, were completed. However, it was decided to delay completion of the tube to allow incorporation of a revised collector ceramic design.