A.M.Zabelin, V.O.Alexsandrov, A.N.Safonov.

Problems of the invention are: increase of construction compactness and improvement of operation quality. The offered head includes a cylindrical housing with hermetic end covers, diametric ventilator, gas-discharge cabinet, heat exchanger, optical resonator, which mirrors are anchored on two parallel slabs, tightened with three rods. The rods in cross section are located in vertexes of an equilateral triangle, the lateral surfaces of heat exchanger are perpendicular to the upper part of triangle and cross a vertical diametric plane of housing under a corner 30⁰. The rods on perimeter of triangle are closed by a sheet from a heat-conducting material, between a diametric ventilator and rods there is a baffle for gas stream direction, and inside the housing there is a spatial truss with lateral flanges for units of the head.