Accession Number:

ADA265217

Title:

Slow Wave Cyclotron Autoresonance Masers

Descriptive Note:

Final rept. Oct 87-May 91,

Corporate Author:

CALIFORNIA UNIV LOS ANGELES DEPT OF ELECTRICAL ENGINEERING

Report Date:

1991-07-09

Pagination or Media Count:

30.0

Abstract:

Electromagnetic coupling of a gyrating electron beam with an electromagnetic wave having a phase velocity near the speed of light was theoretically and experimentally investigated. For this value of phase velocity, the electrons remain a synchronism even as they lose energy, yielding high efficiency operation. Also, the frequency is upshifted by a factor of 1-beta parallelsup-1 over the gyrotron. Two approaches were pursued. In our conventional fast wave CARM, high beam voltage together with a moderately high perveance combine to produce extremely high power. In our dielectric loaded CARM, the waves are retarded such that a low energy electron beam can access the efficient autoresonant region. We also investigated using dielectric loading to dramatically widen the bandwidth of gyro-TWTs. In the negative energy CRM, a negative energy cyclotron wave with resonance, omega-omega kparallel vparallel, couples to a positive energy, slow waveguide mode. Since the beam mode is a negative energy wave, an initial transverse velocity is not required for wave growth. We have investigated employing dielectric loaded waveguides as the slow wave structure. To provide frequency selective feedback for these microwave generation schemes, Bragg reflectors were developed. A Bragg reflector, which consists of corrugated waveguide, will reflect a wave whose axial wavelength is twice the corrugation period.

Subject Categories:

  • Lasers and Masers
  • Electromagnetic Pulses

Distribution Statement:

APPROVED FOR PUBLIC RELEASE