Microwave radiation from a tunable circular free-electron laser

Journal Article · Thu Oct 01 04:00:00 EDT 1987 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.866453· OSTI ID:5971876

Hartemann, F; Bekefi, G

Measurements of coherent microwave emission from a rotating relativistic electron ring (200 kV, 100 A, 200 nsec) interacting with an azimuthally periodic wiggler magnetic field are reported. Tunable radiation is observed between 12.5 and 18 GHz at power levels of --5 kW. The predicted interactions occur near the crossing points of the TM/sub l//sub m/ electromagnetic waveguide modes, ..omega../sup 2/ = k/sup 2//sub parallel/c/sup 2/+..omega../sup 2//sub c/(l,m), and the beam modes, ..omega.. = (l+N)..cap omega../sub parallel/+k/sub parallel/v/sub parallel/, where ..omega../sub c/ is the waveguide cutoff frequency, ..cap omega../sub parallel/ is the electron cyclotron frequency, k/sub parallel/ is the axial wavenumber, v/sub parallel/ is the axial drift velocity, and N is the number of wiggler periods. These observations are consistent with single-mode operation in the TM/sub 01/ coaxial mode.

• Research Organization: Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 5971876
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 30:10; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
ELECTROMAGNETIC RADIATION
ELECTRON RINGS
FREE ELECTRON LASERS
LASERS
MICROWAVE RADIATION
MOTION
OPERATION
RADIATIONS
ROTATION
TUNING