At the VNIIEF, a concept was proposed for a system with transverse gas flowing (relative to the optical axis) [22—24]. This system consists of a set of laser channels with a rectangular cross-section that have planar uranium layers with a width of ~10 cm that are deposited to the inner surface of the channel side walls parallel to the gas flow direction. In order to cool the mixture heated in a channel, a radiator is placed at its outlet. The most convenient and simplest type of radiator consists of a set of thin plates that are positioned parallel to the gas flow and perpendicular to the uranium layers. An identical radiator is placed at the channel inlet which, by virtue of gas heat exchange with the plates, makes it possible to receive the requisite inlet temperature of the working mixture along the entire length of the laser and to equalize its velocity. The laser channel cross-section is shown in Fig. 9.1. The next laser channel can be installed behind the outlet radiator, for which this radiator will also be the inlet radiator, etc. Thus, a chain of laser channels can be built that are merged into a common gas circuit.