Large Volume Plasma Production by 2.45GHz Microwaves.
Abstract
The ionization and excitation of gases by three different geometries of microwave applicators are investigated. Current-voltage characteristics of a plasma with super-imposed ionization by a 2.45 GHz applicator with transport from a dc field are measured. Electron densities in helium and argon test gases were found to be greater than 10 to the 12th power/cc or thirty times higher than normal plasma cut-off densities. This applicator is also used to determine the percentage of O2a 1 del(g) produced in a pure oxygen microwave discharge. A production of up to 25% at low pressures is measured. A design which specially couples two applicators was implemented resulting in twice the power density and better uniformity. Measurement of the percentage of atomic oxygen produced in an oxygen discharge, determined by NO2 titration, indicates the efficiency of atom production for this system is as high as 43 eV/atom. Microwave power is superimposed on a dc discharge in a quartz tube He-Ne laser in this system. A twin antenna irradiator is used to apply 2.45 GHz pulsed and cw microwave power to a quartz discharge tube containing condensed mercury. The time resolved spectra of pulsed operation shows that the relative intensity of the pulsed ultraviolet output decreases as the microwave sustainer power and thus the pressure is increased. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1977
- Accession Number
- ADA062659
Entities
People
- Rodney Darrah
Organizations
- Universal Energy Systems