Search for Light Amplification in a Mixture of Mercury Vapour and Hydrogen

Abstract

F. A. Butayeva and V. A. Fabrikant have recently reported the discovery of a negative temperature in an excited gaseous mixture of mercury vapour and hydrogen between the levels 7³S₁ and 6³P_0,1,2 of mercury¹. They maintain that the populations of the 6³P levels were reduced below that of the 7³S₁ level by the well-known quenching action of hydrogen. The populations were investigated by measuring the transmission coefficient of the gas mixture at the wave-lengths 5461 Å., 4358 Å. and 4047 Å., corresponding to the transitions 7³S₁ – 6³P₂, 7³S₁ – 6³P₁ and 7³S₁ – 6³P₀, the mixture being excited by a d.c. discharge. With a discharge tube of length 36 cm. amplification of about 10 per cent was reported in the λ 5461 Å. and λ 4358 Å. lines for a discharge current of 70 m.amp. with 0.3 mm. mercury hydrogen pressure and saturated mercury vapour at room temperature.