DEPRESSED COLLECTORS FOR MEGAWATT GYROTRONS

A PROGRAM IS PROPOSED TO SHOW THE FEASIBILITY OF DEPRESSED COLLECTORS FOR VERY HIGH AVERAGE POWER (APPROX. 1MW) GYROTRON OSCILLATORS FOR FUSION APPLICATIONS. INITIAL CALCULATIONS INDICATE THAT COLLECTION EFFICIENCIES EXCEEDING 75% CAN BE REALIZED. USE OF SUCH A COLECTOR ON A GYROTRON WITH A BASE EFFICIENCY OF 30% WOULD INCREASE THE EFFICIENCY TO OVER 60%. SUCH A DRAMATIC INCREASE IN EFFICIENCY WOULD RESULT IN SUBSTANTIAL SAVINGS IN THE REALIZATION AND OPERATION OF HIGH POWER ELECTRON CYCLOTRON HEATING SYSTEMS IN FUSION DEVICES SUCH AS CIT, ITER, AND OTHERS. IN PHASE I, A STUDY OF THE FEASIBILITY OF THE USE OF COLLECTORS ON MEGAWATT GYROTRONS WITH FREQUENCIES FROM 100 GHZ TO 280 GHZ WOULD BE MADE, AND A DETAILED DESIGN REALIZED FOR A MULTI-STAGE DEPRESSED COLLECTOR FOR A 1 MW, 110 GHZ GYROTRON CURRENTLY BEING DEVELOPED BY DOE. IN PHASE II, THE COLLECTOR WOULD BE FABRICATED AND TESTED.