ENERGY FOR HIGH GRADIENT RF ACCELERATING STRUCTURES.

ENERGY FOR HIGH GRADIENT RF ACCELERATING STRUCTURES. FOR FACILITIES REQUIRING LARGE AMOUNTS OF INSTALLED ENERGY, CAPITAL COST AND EFFICIENCY BECOME CRITICAL. THE OBJECTIVESOF THE PHASE I PROGRAM ARE TO ASSESS THE FEASIBILITY AND ANALYZE THE PERFORMANCE OF AN RF GENERATOR COMPRISING LASER SOURCE, PHOTOCATHODE, AND KLYSTRON CAVITY AND TO DESIGN AN EXPERIMENT TO TEST THE COUPLED SYSTEM. THE DESIGN IS TO BE SUFFICIENTLY COMPLETE TO ASSEMBLE A DEMONSTRATION EXPERIMENTIN PHASE II. USING A PHOTOCATHODE FOR HIGH POWER RF GENERATION IS A WRC CONCEPT THAT ALLOWS A HIGH CURRENT ELECTRON BEAM TO BE BUNCHED AT LOW ENERGY AND AT HIGH FREQUENCY BY IRRADIATING THE PHOTOCATHODE SURFACE WITH A SHORT PULSE, MODE-LOCKED LASER. THE BUNCHED BEAM, AFTER ACCELERATION BY A CONVENTIONAL PULSED POWER DIODE, CAN BE RADIALLY FOCUSED AND DECELERATED IN A KLYSTRON CAVITY TO PRODUCE RF. HIGH POWER RF GENERATION BY PHOTOCATHODES CAN LEAD TO LOW CAPITAL AND OPERATING COST FOR FACILITIES INVOLVING VERY HIGH POWER AND/OR ENERGY LEVELS IN THE RANGE OF 50 MHZ TO ABOUT 3 GHZ.