Mechanisms of population inversion based on the difference between transport cross sections of particles in different quantum states

An analysis is made of possible mechanisms of a partial or total velocity population inversion based on the difference between the transport cross sections of particles in different quantum states m and n. A partial velocity population inversion is due to a difference between the rates of change of the temperature of the active particles in states m and n as a result of collisions with buffer particles having a temperature different from that of the active particles. Total population inversion is due to the different attenuation of the intensities of directional beams of active particles in states m and n as these propagate through the buffer gas.