At present, direct nuclear pumping is implemented for gas laser media in which the populating of lasing levels occurs as a result of processes occurring in a high — pressure low-temperature plasma formed by ionizing radiation. Sometimes this plasma is called nuclear-excited plasma.

A plasma formed during the stopping of high-energy charged particles in a gas at atmospheric pressure is a thermodynamically non-equilibrium plasma. A plasma of this type, in which the concentration of electrons substantially exceeds its equilib­rium value, is called a supercooled or recombination plasma [1, 2]. In a nuclear — excited plasma (in contrast to a gas-discharge plasma with an ionization type of non-equilibrium), the majority of electrons have energies close to thermal, and recombination processes play a key role in the kinetics of the charged particles.