HIGH-BETA OPERATION OF COMMERCIAL TOKAMAK REACTORS USING HOT ELECTRONS

THIS PROJECT WILL ASSESS THE REQUIREMENTS AND PROVIDE A BASIS FOR DESIGNING AN OPTIMIZED SYSTEM FOR A TOKAMAK REACTOR TO REACH THE HIGH-BETA, "SECOND STABILITY REGIME" FROM STARTUP, USING ELECTRON CYCLO- TRON HEATING (ECH) TECHNIQUES. THE POWER NEEDED TO ACHIEVE A STABLE PLASMA EVOLUTION TO THE "SECOND STAILITY REGIME" USING HOT PARTICLES IS SIGNIFICANTLY REDUCED OVER PREVIOUS ESTIMATES BY THE THREE INGRE- DIENTS OF THE PRESENT APPROACH: (1) THE VOLUME OCCUPIED BY THE HOT ELECTRONS IS REDUCED; (2) MILD PLASMA CROSS-SECTION SHAPING IS USED TO REDUCE THE HOT ELECTRON REQUIREMENTS; AND (3) OPTIMIZED ECH TECHNIQUES DRAMATICALLY REDUCE THE POWER NEEDED TO ACHIEVE A GIVEN HOT ELECTRON ENERGY DENSITY. STABLE, OPTIMIZED SCENARIOS WILL BE DETERMINED FOR THE EVOLUTION OF PRESSURE PROFILES AND PLASMA SHAPE FROM STARTUP TO A STEADY-STATE, HIGH-BETA REGIME. ECH MAY BE USED TO FACILITATE THE FORMATION OF BEAN- SHAPED PLASMAS AS WELL AS TO CREATE THE HOT ELECTRON POPULATION. FR BOTH APPLICATIONS, THE ECH WILL BE REQUIRED ONLY FOR THE TIME NECESARY TO ACHIEVE A STABLE, HIGH-BETA CONFIGURATION.