Investigation and Control of Mechanisms for Pulse Shortening in High Power Microwave Tubes

Period of Performance: 05/04/1998 - 08/04/2000


Phase 2 SBIR

Recipient Firm

Berkeley Research Assoc., Inc.
P.O. Box 241
Berkeley, CA 94701
Principal Investigator

Research Topics


An experimental program is proposed to further investigate the mechanisms for pulse shortening and to develop in situ tube conditioning techniques that will result in multi-microsecond output operation of the Reltron (Titan Corp.) high power microwave tube. The Phase II effort will refine observation of gas evolution and plasma formation that affect the beam-microwave interaction and that are the causes for pulse shortening in the Reltron. Means to reduce the gas loading in critical tube components, especially the grids, cathode, and beam dump will be developed and implemented on a Reltron testbed. The ojective is to demonstrate demountable and interchangeable-cavity Reltron operation with a pulse length of 2 microseconds. The development work will include the selection of construction materials and improved vacuum design for the Reltron that minimize gas evolution during the power pulse. It will also include in situ cleaning and degassing of the cathode and grids by Ohmic, discharge, and radiative heating and by electron beam desorption. Use of the techniques to obtain several microsecond pulse duration in tubes of interest for commercial applications will also be investigated.