Cathaphoretic confinement of Zn evaporated into helium and neon discharges

Abstract

Cathaphoresis of Zn evaporated into the positive column of helium and neon discharges was investigated both experimentally and theoretically. The side-light intensity of the Zn-I 518.2 nm transition was recorded along a 4.5 cm long positive column discharge with an inner diameter of 3 mm. The buffer gas pressure was varied between 10 and 25 mbar while discharge currents of 20-60 mA were applied to the tube. Reasonably good agreement was found between the experimental data and the theoretically predicted axial distribution of zinc concentration in the tube. The results can be useful in the design of the cathaphoretic confinement section of the different He-Zn laser tubes and a prospective Ne-Zn laser system, which would operate in the deep ultraviolet region (210 nm).