Two-dimensional equation of gas in cuvettes of nuclear-pumped lasers at not large energy contributions into gas

The analytical calculation of the gas two-dimensional motion in the cuvette of the nuclear-pumped lasers, irradiated by the fission fragments at small energy contributions into gas, is carried out through the method of the variables separation. The distribution of the two-dimensional velocity for the deeply-subsonic flows in the laser cuvettes (hermetic and pumpable ones) is determined. It is shown that the gas two-dimensional motion for the smoothly-heterogeneous energy contribution is divided into two quasi-one-dimensional ones due to the different scale of the longitudinal and transverse coordinates. The gas longitudinal velocity is practically homogeneous across the cuvette and it is determined through the transversely-averaged energy contribution. The transverse velocity is determined by the difference between the local and transversely-averaged contributions