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Title: Microwave emission from relativistic electron beams. Final report, 1 November 1983-31 October 1988

Technical Report ·
OSTI ID:5522495

Profile modification by optical guiding in a Raman free-electron laser operating at microwave frequencies was studied experimentally. A cyclotron autoresonance maser (CARM) amplifier was designed, built, and tested. This CARM operates at 35 GHz with a power output of 10 MW and an efficiency of 3%. Observations of Field Profile Modifications in a Raman Free-Electron Laser Amplifier: The author reports measurements of the spatial distribution of the RF electric-field intensities and phases induced in a free-electron laser amplifier operating in the collective (Raman) regime. The studies are carried out at a microwave frequency of about 10 GHz in a FEL using a mildly relativistic electron beam of about 200 keV energy and 1 - 4A current. The probing of the ponderomotive (space charge) and the electromagnetic waves is accomplished by means of small movable electric dipole antennas inserted into the interaction region. A 35-GHz Cyclotron Autoresonance Maser Amplifier: studies of a cyclotron autoresonance maser are presented. The measurements are carried out at a frequency of 35 GHz using a mildly relativistic electron beam (1.5 MeV, 260 A) generated by a field-emission electron gun followed by an emittance selector that removes the outer, hot electrons. Perpendicular energy is imparted to the electrons by means of a bifilar helical wiggler. Measurements give a small signal gain of 90 dB/m and a saturated power output of 10 MW. The corresponding electronic efficiency is 3%. Computer simulations are also presented.

Research Organization:
Massachusetts Inst. of Tech., Cambridge, MA (USA). Research Lab. of Electronics
OSTI ID:
5522495
Report Number(s):
AD-A-209653/5/XAB
Country of Publication:
United States
Language:
English