title: A catalytic sensor for measurement of radical density in CO2 plasmas.
abstract: A catalytic sensor for the measurement of radical density in weakly ionized CO(2) plasmas, created in a low-pressure electrodeless discharge, is presented. The CO(2) plasma was created in a 4 cm wide borosilicate glass tube inside a copper coil connected to a radio frequency generator operating at 27.12 MHz with a nominal power of 250 W. The dissociation fraction of the CO(2) molecules was measured in the early afterglow at pressures ranging from 10 Pa to 100 Pa, and at distances of up to 35 cm along the gas stream from the glowing plasma. The radical density peaked (2 × 10(20) m-3) at 80 Pa. The density quickly decreased with increasing distance from the glowing plasma despite a rather large drift velocity. The dissociation fraction showed similar behavior, except that the maximum was obtained at somewhat lower pressure. The results were explained by rather intense surface recombination of radicals.
authors: Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia. alenka.vesel@ijs.si
authors: Alenka
authors: A
authors: Vesel
authors: Rok
authors: R
authors: Zaplotnik
authors: Jonathan
authors: J
authors: Iacono
authors: Marianne
authors: M
authors: Balat-Pichelin
authors: Miran
authors: M
authors: Mozetic
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D005740:Gases / Q000737:chemistry / Q000145:classification*; D011312:Pressure; D013499:Surface Properties
chemical_list: D005740:Gases; D002245:Carbon Dioxide