Microwave emission from relativistic electron beams
Abstract
Profile modification by optical guiding in a Raman Free Electron Laser (FEL) 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 three percent. We report 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 - 4 A 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 is discussed. 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.
- Publication:
-
Massachusetts Inst. of Tech. Report
- Pub Date:
- March 1989
- Bibcode:
- 1989mit..reptR....B
- Keywords:
-
- Cyclotron Resonance;
- Electric Fields;
- Electromagnetic Interactions;
- Electron Guns;
- Free Electron Lasers;
- Laser Outputs;
- Light Amplifiers;
- Microwave Amplifiers;
- Microwave Emission;
- Relativistic Electron Beams;
- Space Charge;
- Amplification;
- Computerized Simulation;
- Electron Spin;
- Microwave Frequencies;
- Power Efficiency;
- Raman Spectroscopy;
- Signal Measurement;
- Spatial Distribution;
- Nuclear and High-Energy Physics