초록 ▼

A method and apparatus for tailoring the concentration profiles of reactant and diluent species in the gas stream of a pulsed chemical laser provide a substantially uniform initial chemical reaction rate and index of refraction across the laser cavity. In the preferred embodiment, a gas stream is co

A method and apparatus for tailoring the concentration profiles of reactant and diluent species in the gas stream of a pulsed chemical laser provide a substantially uniform initial chemical reaction rate and index of refraction across the laser cavity. In the preferred embodiment, a gas stream is composed of the two reactant species, molecular hydrogen (or deuterium) and molecular fluorine, diluent species argon and helium, and a trace of oxygen as a preinitiation inhibitor. A substantially uniform initial chemical reaction rate within the laser cavity is obtained by tailoring the concentration profile of the fluorine across the cavity to compensate for the variation in absorption of UV initiation radiation across the cavity along the axis of initiation. The index of refraction of the gas mixture is kept constant within the cavity by varying the concentration of diluent gases to compensate for the variation in the index of refraction that would otherwise result from the tailoring of the fluorine concentration profile. A mathematical model of UV radiation absorption in the laser cavity is developed on the basis of the specific geometry of the laser cavity and its associated source of UV initiation radiation. A radiation absorption analysis is then performed to define the fluorine concentration profile that provides the desired degree of uniformity of the initial chemical reaction rate. An injector/mixer manifold provides a gas stream having the desired reactant gas concentration profile, as well as a diluent gas concentration profile which provides a uniform index of refraction across the reagent stream.

대표청구항 ▼

A method of providing a uniform initial chemical reaction rate in a chemical gas laser wherein a chemical reaction between gaseous reactant species produces excited reaction product species, said laser including a resonant laser cavity and an external source of radiation for initiating said reaction

A method of providing a uniform initial chemical reaction rate in a chemical gas laser wherein a chemical reaction between gaseous reactant species produces excited reaction product species, said laser including a resonant laser cavity and an external source of radiation for initiating said reaction in said cavity by irradiating said gaseous reactant species in a direction of irradiation transverse to the axis of laser emission of said laser, comprising: forming a stream of said gaseous reactant species flowing through said cavity in a direction substantially transverse to said axis of laser emission; varying the concentration of at least one of said gaseous reactant species across said cavity in a direction transverse to the direction of flow of said stream and parallel to the direction of irradiation of said external source of radiation, thereby compensating for attenuation of said radiation within said stream to provide a substantially uniform initial chemical reaction rate within said stream.