Particle-in-cell simulations of the lasertron
Abstract
The lasertron is a device for producing intense, very short, pulsed ectron beams. The current is not space-charge limited and follows the laser intensity. The electron pulse is then accelerated out of the device by a constant voltage. In the RF lasertron, the diode becomes an RF cavity. This improves the breakdown characteristics of the device, allowing higher voltages to be applied and hence higher currents to be obtained. The calculations are aimed at producing a 10 nC electron beam with an emittance of less than 40 mm-mrad or use in free-electron laser experiments. A class of electrode shapes was obtained which in the absence of space charge produces no emittance growth. These shapes were studied with the particle-in-cell simulation model ISIS, and the electrodes which produce minimum emittance including the effect of space charge were determined. Unique emittance problems associated with the time dependence of the beam pulse are studied and conditions for reducing these effects are discussed.
- Publication:
-
Presented at the Particle Accelerator Conference
- Pub Date:
- May 1985
- Bibcode:
- 1985paac.conf...13J
- Keywords:
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- Emittance;
- Mathematical Models;
- Particle In Cell Technique;
- Pulsed Lasers;
- Simulation;
- Space Charge;
- Electron Beams;
- Photocathodes;
- Photodiodes;
- Time Dependence;
- Lasers and Masers