High-gain optical Cherenkov oscillator driven by low-voltage electron beam
- P.N. Lebedev Physics Institute, Moscow (Russian Federation)
A novel scheme of high-gain optical (from IR up to UV) Cherenkov-type oscillator driven by low-voltage high-current electron beam is proposed in the present report. In the scheme discussed the magnetized electron beam propagates above the surface of absorbing medium of complex dielectric susceptibility {epsilon}{omega} = {epsilon}{sub 1}({omega}) + i{epsilon}{sub 2}({omega}), {epsilon}{sub 2}>0. We have found that at frequencies {omega} that {beta}{sup 2}> 2{epsilon}{sub 1}/{vert_bar}{epsilon}{vert_bar}{sup 2} ({beta} = v/c, v is the electron velocity), an amplification of co-propagating slow surface electromagnetic wave is possible. In contrast to the conventional Cherenkov oscillators, the absorption condition {epsilon}2>0 is crucial for the gain, which is absent for transparent medium. The physics of this amplification effect is analogous to that of electron beam dissipative instability. The wavelength generated is determined here by dielectric properties of the surface, and does not depend strongly on electron energy. Thus it is possible to use rather compact low voltage ({le} 1MeV) high-current accelerators as drivers. Optimum oscillation conditions are found to be at frequencies near the resonance absorption lines of surface material (i.e. from IR up to UV). The gain up to {approximately}0.5cm{sup -1} in the near IR ({approximately}10THz, SrF{sub 2} absorption line) is possible for 250keV high current (density {approximately}10{sup 12}cm{sup -3}) electron beam.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- OSTI ID:
- 238703
- Report Number(s):
- BNL-61982-Absts.; CONF-9508156-Absts.; ON: DE96002729; CNN: Grant 93-02-14271; Grant 94-02-06072-a; Grant N9T000; TRN: 96:013192
- Resource Relation:
- Conference: 17. international free electron laser conference, New York, NY (United States), 21-25 Aug 1995; Other Information: PBD: [1995]; Related Information: Is Part Of 17th international free electron laser conference and 2nd international FEL users` workshop. Program and abstracts; PB: 300 p.
- Country of Publication:
- United States
- Language:
- English
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