High-power microwave production by gyroharmonic conversion and co-generation
- Omega-P, Inc., 202008 Yale Station, New Haven, Connecticut 06520 (United States)
- Physics Department, Yale University, New Haven, Connecticut 06511 (United States)
- Omega-P, Inc., 202008 Yale Station, New Haven, Connecticut 06520 (United States); Physics Department, Yale University, New Haven, Connecticut 06511 (United States)
An rf accelerator that adds significant gyration energy to a relativistic electron beam, and mechanisms for extracting coherent radiation from the beam, are described. The accelerator is a cyclotron autoresonance accelerator (CARA), underlying theory and experimental tests of which are reviewed. The measurements illustrate the utility of CARA in preparing beams for high harmonic gyro interactions. Examples of preparation of gyrating axis-encircling beams of {approximately}400kV, 25 A with 1{lt}a{lt}2 using a 2.856 GHz CARA are discussed. Generation of MW-level harmonic power emanating from a beam prepared in CARA into an output cavity structure is predicted by theory. First measurements of intense superradiant 2nd through 6th harmonic emission from a CARA beam are described. Gyroharmonic conversion (GHC) at MW power levels into an appropriate resonator can be anticipated, in view of the results described here. Another radiation mechanism, closely related to GHC, is also described. This mechanism, dubbed {open_quotes}co-generation,{close_quotes} is based on the fact that the lowest TE{sub sm} mode in a cylindrical waveguide at frequency sw with group velocity nearly identical to group velocity for the TE{sub 11} mode at frequency w is that with s=7, m=2. This allows coherent radiation to be generated at the 7th harmonic co-existent with CARA and in the self-same rf structure. Conditions are found where co-generation of 7th harmonic power at 20 GHz is possible with overall efficiency greater than 80{percent}. It is shown that operation of a cw co-generator can take place without need of a power supply for the gun. Efficiency for a multi-MW 20 GHz co-generator is predicted to be high enough to compete with other sources, even after taking into account the finite efficiency of the rf driver required for CARA. {copyright} {ital 1997 American Institute of Physics.}
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 587027
- Report Number(s):
- CONF-9610281--
- Journal Information:
- AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 398; ISSN 0094-243X; ISSN APCPCS
- Country of Publication:
- United States
- Language:
- English
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