A NOVEL GIGAWATT PULSED POWER MODULATOR FOR RADIO FREQUENCY SOURCES FOR ADVANCED ACCELERATORS

KEY ELEMENTS FOR THE DEVELOPMENT OF FUTURE COLLIDERS ARE THE AVAILABILITY AND COST OF THE RADIO FREQUENCY (RF) POWER REQUIRED. INTENSIVE EFFORTS ARE UNDERWAY TO DESIGN, BUILD, AND TEST MICROWAVE SOURCES THAT CAN BE APPLIED IN THE NEXT GENERATION OF ELECTRON LINEAR COLLIDERS. RF POWER IS REQUIRED AT FREQUENCIES ON THE ORDER OF 10 GHZ AND POWER LEVELS ON THE ORDER OF GW IN 100 NS PULSES. TWO MAIN APPROACHES TO ACQUIRING THESE LEVELS OF POWER ARE (1) PRODUCTION OF RF PULSES OF 1 MUSEC PULSE LENGTH AT A FEW 100 MW, FOLLOWED BY PULSE COMPRESSION, TO OBTAIN THE DESIRED OUTPUT PULSE AND (2) DIRECT GENERATION OF 100 NS, GW PULSES OF RF. THE FIRST APPROACH RELIES ON WELL-DEVELOPED PULSED POWER TECHNOLOGY, BUT THE PULSE COMPRESSION IS INEFFICIENT AND NOT DEMONSTRATED AT THESE POWER LEVELS. THE SECOND APPROACH HAS REQUIRED PULSED POWER SYSTEMS THAT ARE COMPLEX AND REQUIRE FURTHER DEVELOPMENT. IN PHASE I, THIS PROJECT DEVELOPS A NOVEL PULSE POWER MODULATOR CAPABLE OF EFFICIENTLY DRIVING 100 NS PULSED RF SOURCES AT THE GW POWER LEVEL AND HIGHER. THE MODULATOR RELIES ON TWO ADVANCES IN PULSED POWER TECHNOLOGY: THE BACK LIGHTED THYRATRON (BLT) SWITCH WITH DEMONSTRATED PERFORMANCE AT 2.5 GW PEAK POWER AND NOVEL, COMPACT, HIGH EFFICIENCY TRANSMISSION LINE TRANSFORMER TECHNIQUES DEVELOPED AT THE KURCHATOV INSTITUTE OF ATOMIC SCIENCE, MOSCOW. THE DEVELOPED MODULATOR WILL BE CAPABLE OF 100 NS, MEGAVOLT, AND KILOAMP PULSES AT HIGH REPETITION RATES. THE MODULATOR USES A TRANSMISSION LINE TRANSFORMER TECHNIQUE CAPABLE OF >90% EFFICIENCY WITH FAST RISE AND FALL TIMES AND A GOOD FLAT TOP (DV/V <1%). THE INPUT TO THE MODULATOR WILL BE A NETWORK OF BLT SWITCHES OPERATING IN A SERIES AND PARALLEL ARRANGEMENT. A KEY RESULT OF THIS WORK WILL BE TO IMPLEMENT THE BLT SWITCH INTO A HIGH POWER MODULATOR SYSTEM. IF THIS RESEARCH IS SUCCESSFUL, IT WOULD DIRECTLY ADVANCE THE STATE OF THE ART IN SHORT PULSE (100 NS), GIGAWATT POWER LEVEL SOURCES AT 11.4 GHZ FOR FUTURE COLLIDERS.