POPULATION-INVERSION IN MIXING HYDROGEN GAS WITH A HIGH-TEMPERATURE PLASMA

Inverted population distributions in the hydrogen atom which appear in the contact phenomenon of hydrogen gas with high-temperature helium plasma are analyzed by a collisional-radiative model associated with energy balance equations. By including the ion temperature effect in the energy balance equations, the collisional-radiative model indicates an inverted population of the hydrogen in the same-order range as the experimentally observed ones. The possibility of lasing at the 656 nm line of hydrogen is discussed in connection with initial conditions of helium plasma and injected hydrogen gas.