Light-induced pressure anisotropy and temperature change in atomic gases

Pressure anisotropy and radiative temperature change are investigated in a one-component atomic gas in the field of resonant laser radiation. This is a continuation of the work in Chermyaninov and Chernyak ["Light-induced phenomena in one-component gas: Pressure anisotropy and change of gas temperature," Phys. Fluids 32, 017105 (2020)]. An atomic gas located between infinite parallel plates is considered. A traveling electromagnetic wave propagates along the plates, whose frequency is close to that of electron transitions in gas atoms from a ground state to an excited one. Resonant optical radiation stimulates gas pressure anisotropy and a change in its temperature. General expressions are obtained for the longitudinal and transverse changes in gas pressure, as well as for the optical change in its temperature. The kinetic coefficients that determine the magnitude of these phenomena are calculated for large Knudsen numbers (Kn). The results for atomic and molecular gases are compared. Published under an exclusive license by AIP Publishing.