Temporal evolution of plasma from a highly ionized helium capillary discharge
Date
1990
Authors
Villagran, Mayo, author
Rocca, Jorge J., author
IEEE, publisher
Journal Title
Journal ISSN
Volume Title
Abstract
Emission spectroscopy was used to study the temporal evolution of a highly ionized helium plasma generated in a 1-mm-diameter capillary by a fast (90-ns full width at half-maximum (FWHM)) discharge pulse. The time dependence of the plasma density was measured from the Stark broadened line profile of the HeII 468.5-nm transition. A 1.2-kA discharge current pulse was observed to create a plasma density of 8 × 1016 cm-3 in 1 torr of helium. The maximum intensity of HeII transitions occurs in the afterglow of the discharge pulse, following the collisional recombination of totally stripped ions with plasma electrons when the plasma cools. The study is of interest in relation to the possibility of obtaining amplification in the 164.0-nm line of HeII in a capillary discharge.