Abstract:
Positive gain measurements are reported on the flanks of the 3350 Å continuum band in mercury vapour at 3.72 atm. pressure, pumped by a 600 J, 1.5 MeV, 20 nsec. pulsed electron beam. The stimulated emission cross section at three probe wavelengths is approximately 10-18 cm2, exceeding photoabsorption by any process in Hg/Hg2. The laser gain signals are reported to be further enhanced in vapours heated above the saturation temperature, indicating that the upper level is populated by a temperature dependent internal energy reservoir