Abstract

Time functions of the radiance (ITT FW-114, spectral response S–4) were observed, as well as the radiant intensity of high pressure spark channels in argon and helium with pressures between 1 atm and 40 atm, and a constant gap of 0.65 mm. The radiance, as well as radiant intensity, first increases exponentially with pressure and breakdown voltage; later, the radiance curves bend into a saturation plateau in both gases. On the other hand, the radiant intensity does not reach saturation, but shifts its maximum up to 50 nsec after the 8-nsec current maximum. The shift of the radiant intensity and saturation are related and result from the increasing opacity of the channel. The observed 1.65 ratio of the saturation radiances of helium and argon agrees with values reported in microsecond spark channels which have a diameter approximately six times wider.

© 1969 Optical Society of America

Vacuum Ultraviolet Emission from High Density Spark Discharges in Argon and Helium

Lothar Michel and Heinz Fischer
Appl. Opt. 11(4) 899-906 (1972)

Nanosecond High Radiance Standard Source

H. Krompholz and Heinz Fischer
Appl. Opt. 13(1) 203-205 (1974)

On the Saturation Luminance of High Density Microsecond Arc Channels

Heinz Fischer and Lothar Michel
Appl. Opt. 6(5) 935-937 (1967)

Turbulent Eddies in High Density Spark Channels in Helium

Heinz Fischer and Karlheinz Schönbach
Appl. Opt. 7(2) 311-314 (1968)

Expansion of Initial High-Current Spark Channels

Heinz Fischer and C. C. Gallagher
Appl. Opt. 4(9) 1151-1154 (1965)