DocumentCode :
1096419
Title :
A free electron laser oscillator based on a cyclotron-undulator interaction
Author :
Grossman, Arthur A. ; Marshall, T.C.
Author_Institution :
Columbia University, New York, NY, USA
Volume :
19
Issue :
3
fYear :
1983
fDate :
3/1/1983 12:00:00 AM
Firstpage :
334
Lastpage :
339
Abstract :
A free electron laser (FEL) oscillator experiment is described, in which an intense electron beam (750 kV, 20 kA) is prepared in a region of increasing guide magnetic field before injection into an undulator (60 periods, l_{o} = 1.25 cm). The electron motion accordingly has a substantial transverse component ( \\beta _{\\perp } \\approx 0.4 ), and motion at the cyclotron ( \\omega _{c} = eB_{o}/\\gamma mc ) and undulator ( k_{o} V_{z} ) frequencies occurs. Theory predicts, in appropriate geometry, a convectively unstable electromagnetic wave having frequency \\omega _{s} \\approx 2\\gamma _{z}^{2} (\\omega _{c} + k_{o}V_{z}) , where \\gamma _{z} = (1 - \\beta _{z}^{2})^{-1/2} , of the FEL type, where k_{o} = 2\\pi/l_{o} . Megawatt level radiation at 1.7 mm, together with millimeter-harmonics and other microwave emission, is observed in a simple Fabry-Perot resonator system driven above oscillation threshold by a sufficiently large undulator field amplitude. Comparison of spectroscopic data with features of the theory permits identification of the cyclotron-undulator interaction.
Keywords :
Cyclotron radiation; Free electron lasers; Relativistic effects; Cyclotrons; Electromagnetic scattering; Electron beams; Fabry-Perot; Free electron lasers; Frequency; Geometry; Magnetic fields; Oscillators; Undulators;
fLanguage :
English
Journal_Title :
Quantum Electronics, IEEE Journal of
Publisher :
ieee
ISSN :
0018-9197
Type :
jour
DOI :
10.1109/JQE.1983.1071869
Filename :
1071869
Link To Document :
بازگشت