DESIGN AND DEVELOPMENT OF A TWO-STAGE FEL FOR THE NSWC THOR GENERATOR

THE GOAL OF THE PROPOSED PROGRAM IS TO DEVELOP A HIGH-POWER FREE-ELECTRON LASER (FEL) TO BE DRIVEN BY A NEW ELECTRON ACCELERATOR AT NSWC. THIS ACCELERATOR, CALLED THOR, IS CAPABLE OF OPERATION AT 3 MV AND 1 KA FOR A DURATION OF 1 MICROSEC. AN EFFICIENT (FEL) FOR THIS ACCELERATOR WOULD CONSEQUENTLY BE CAPABLE OF AN EXTREMELY HIGH PEAK POWER (?1 GW) AND ENERGY PER PULSE (?1 KJ). DURING PHASE I OF THE PROGRAM, WE PROPOSE TO DESIGN A TWO-STAGE FEL THAT IS OPTIMIZED FOR OPERATION ON THOR. A TWO-STAGE DEVICE UTILIZES THE HIGH-POWER OUTPUT OF THE FIRST STAGE, WHICH IS A CONVENTIONAL FEL, TO DRIVE A HIGHER FREQUENCY INTERACTION IN THE SECOND STAGE. FOR MAXIMUM FLEXIBILITY, WE PROPOSE TO DESIGN A SYSTEM THAT CAN COUPLE OUT EITHER THE FIRST STAGE OUTPUT (F?-300 GHZ) OR THE SECOND STAGE OUTPUT (F?1-30 THZ). THE PROGRAM WILL ADDRESS SEVERAL KEY ISSUES, INCLUDING THE QUALITY OF THE THOR ELECTRON BEAM AND THE LIMITATIONS IT IMPOSES ON FEL OPERATION, EFFICIENCY ENHANCEMENT OF BOTH THE FIRST AND SECOND STAGES, AND THE DESIGN OF A WIGGLER AND RESONATOR FOR THE FEL. THE FABRICATION AND TESTING OF THESE COMPONENTS AND THEIR INSTALLATION AT NSWC WILL BE PERFORMED DURING PHASE II.