Quasi-Optical 3-dB Hybrid for Future High-Energy Accelerators

76232-Future electron accelerators must be driven by intense microwave flows transmitted through oversized waveguides or mirror lines. Such transmission systems will need phase-controlled wave combiners-commutators, and isolators for protecting radio frequency (rf) sources against reflection from the accelerating structure. To meet these requirements, this project will develop quasi-optical concepts ¿ in particular, a 3-dB hybrid built around a metallic grating used in a ¿magic-Y¿ configuration ¿ for the transmission and control of the 100s of MW power levels anticipated. During Phase I, all elements of the magic-Y will be optimized analytically and numerically. A non-vacuum 34.272 GHz model of the magic Y will be built and tested experimentally at low power. An engineering design for the high power (vacuum) compressor will be developed. Similar steps will be taken for an 11.424 GHz version. In Phase II, tests will be conducted at 34.272 GHz using the Ka-band magnicon, and at 11.424 GHz using an X-band magnicon. Commercial Applications and Other Benefits as described by the awardee: The magic-Y should be a promising candidate in future electron accelerators of the next generation, for which need for hundreds of units can be anticipated. Uses in thermonuclear reactors and radar also are anticipated.