Kinetics of slow electrons in excimer laser with electron-beam pumping
Abstract
Gas mixtures with Ar as principal component used as active media of excimer lasers are considered, of concern being the kinetics of slow electrons in such lasers with electron-beam pumping. The corresponding Boltzmann equation and equations of ion-molecular kinetics are solved simultaneously for the low-energy part of the electron energy-distribution function. The kinetic model of such an excimer laser is constructed on this basis, first for the simplest case of pure Ar and then for Ar with an active gas such that dissociative attachment of electrons to its molecules can serve as measure of the electron concentration. Experiments were performed with an Ar:CCl4 and Ar-Xe-HCl mixtures. A kinetic model is presented, on the basis of which is calculated the electron-beam current density as a function of time for a pumped Ar:Xe:HCl mixture. Lowering of the attachment frequency is found to increase the low-energy fraction of beam electrons and thus to decrease the mean beam energy. Complete elimination of attachment, by removal of HCl, is found to lower the mean beam energy still further. So can photoionization and photodetachment. The form of the energy distribution function for plasma electrons was found not to change appreciably with change of the energy spectrum of the low-energy electron source from a Gaussian to a rectangular or triangular one.
- Publication:
-
JPRS Report Science Technology USSR Space
- Pub Date:
- February 1988
- Bibcode:
- 1988RpScT........6A
- Keywords:
-
- Argon;
- Electron Beams;
- Electrons;
- Energy Distribution;
- Excimer Lasers;
- Kinetics;
- Laser Plasmas;
- Laser Pumping;
- Electron Attachment;
- Energy Spectra;
- Hydrochloric Acid;
- Xenon;
- Lasers and Masers