A novel injection-locked amplitude-modulated magnetron at 1497 MHz

Thomas Jefferson National Accelerator Facility (JLab) uses low efficiency klystrons in the CEBAF machine. In the older portion they operate at 30% efficiency with a tube mean time between failure (MTBF) of five to six years. A highly efficient replacement source (>55-60%) must provide a high degree of backwards compatibility, both in size and voltage requirements, to allow its use as a replacement for the klystron (model VKL7811) presently used at Thomas Jefferson Laboratory, while providing significant energy savings. GENERAL STATEMENT OF HOW THIS PROBLEM OR SITUATION IS BEING ADDRESSED. We will develop a highly reliable, highly efficient RF source based upon a novel injection- locked amplitude-modulated (AM) magnetron with a lower total cost of ownership, operating above 80% efficiency with an MTBF of six to seven years. The design of the RF source will be based upon a single injection-locked magnetron system at 8 kW capable of operating up to 13 kW, using the magnetrons magnetic field to achieve the AM which is required for backwards compatibility to compensate for microphonics and beam loads. WHAT WILL BE DONE IN PHASE I. The novel injection-locked 1497 MHz 8 kW AM magnetron will be designed during Phase I. The low-level RF system, required to maintain injection locking during the AM of the magnetron with the magnetic field controlled, will also be designed. A prototype magnetic assembly for the varying magnetic field will be built and tested to assure operation at the modulation frequencies of the microphonics. COMMERCIAL APPLICATIONS AND OTHER BENEFITS Future applications of the novel injection-locked AM magnetron include, commercial magnetron heating applications for more precise material processing in the chemical industry such as microwave driven particle synthesis. Phased array radar systems will also benefit from the injection locked AM magnetron, whether in ground penetrating radar or microwave power transmission. And, of course, it has accelerator applications worldwide. KEY WORDS: magnetron, injection-locking, amplitude-modulation SUMMARY FOR MEMBERS OF CONGRESS: A backward compatible highly efficient microwave source will be developed to replace the low efficiency, costly klystrons currently used at JLAB. The novel injection-locked AM magnetron has commercial applications in accelerator applications, microwave heating in the chemical industry and applications in phased array radar systems.