Reagent tailoring for a chemical gas laser to obtain uniform initial chemical reaction rate

In a chemical gas laser wherein a stream of reactant gas is caused to flow through a resonant laser cavity in a direction transverse to the optical axis of the laser, and wherein a chemical reaction within said stream of reactant gas is initiated by irradiation of said stream of gas in a direction transverse to the optical axis by an external source of radiation as said gas passes through said cavity, the method of producing a uniform initial chemical reaction rate within said stream of gas passing through said cavity comprising:

• providing an array of gas nozzles in a configuration whereby gas projected from said nozzles flows through said laser cavity in a direction transverse to the optical axis of the laser, the direction of gas flow further being substantially transverse to the direction of irradiation from said external source of radiation;
• forming a stream of reactant gas through said cavity by means of said nozzles;
• and,
• varying the rates of discharge of said reactant gas from said nozzles along a direction of variation substantially parallel to the direction of irradiation from said external source of radiation, to thereby produce within a reaction zone in said cavity a uniform initial chemical reaction rate within said stream of gas.

A method of producing a uniform initial chemical reaction rate in a chemical gas laser wherein a chemical chain reaction between molecular hydrogen and molecular fluorine in a resonant laser cavity forms a population inversion of excited gaseous hydrogen fluoride molecules, and wherein said chemical reaction is initiated by dissociation of fluorine molecules to free fluorine atoms by irradiation along a direction of irradiation from an external source of ultraviolet radiation, comprising:

• providing an array of gas nozzles in a configuration whereby gas projected from said nozzles flows through said resonant laser cavity in a direction transverse to the axis of laser light emission, said direction of gas flow further being substantially transverse to said direction of irradiation from said external source of ultraviolet light;
• forming a stream of gas through said cavity from said nozzles;
• said gas comprising a mixture of said molecular hydrogen and molecular fluorine species and gaseous diluent species;
• and,
• varying the concentration of molecular fluorine projected from said nozzles to thereby produce a uniform rate of initiation of said chemical reaction across said cavity.

A chemical gas laser comprising:

• means forming a laser cavity having a 100% feedback mirror at one end thereof and a partial feedback mirror at the opposite end thereof, said mirrors defining an optical axis of said laser perpendicular to said mirrors;
• means for causing a stream of a reactant gas to flow through said cavity in a direction transverse to said optical axis of said laser;
• a source of radiation for initiating a chemical reaction in said stream of reactant gas as said stream flows through a reaction zone in said cavity between said mirrors, said source of radiation operating to irradiate said reactant gas in said reaction zone in a direction transverse to the direction of flow of said stream of reactant gas;
• and
• means for varying the concentration of said reactant gas in said stream of reactant gas in a direction substantially parallel to the direction of irradiation from said source of radiation to thereby cause a substantially uniform initial chemical reaction rate to occur in said reaction zone of said cavity upon irradiation of said reactant gas by said source of radiation.