Arc heater for thermal driven HF/DF chemical laser

ABSTRACT A new concept of plasma heater has been developed using water vapor as plasma gas (1). It also operates with sulfur-hexafluoride diluted with nitrogen and oxygen; it makes it possible to use it asan F-atoms generator for an arc heated supersonic diffusion lIF/DF laser. The fluorine atoms arccreated by dissociation of SF6 injected directly into thc arc heater with argon, nitrogen and oygcnas diluents. As compared with the well known arc heater (2) in which the fluorinated gas is mixed in an arc heated helium flow, a higher dissociation rate of this gas is obtained. The arc heater ispowered by a rectifier of 500 V and 250 A. For an electrical input power of 80 kW, we obtain athermal efficiency of above 80 % and a specific enthalpy, at the output of the arc heater, of 8.3 MJ/kg. The described F-atoms generator will be equipped in the near future with an axisymmetricnozzle array, in order to complete the entire IIF/DF laser device.1. CHEMICAL LASERS The industrial use of lasers is conditioned by different factors: the power must be high (kW or more), the