Measuring Fluorine Atom Flow Rate For Discharge Driving CW HF/DF Chemical Laser

Discharge driving chemical laser was an important region of chemical laser, the yield and productivity of fluorine atoms are the primary factors influence the power and the efficiency of this kind of laser device. This paper compared the merits and demerits of four kind of fluorine atom flow rate measuring methods , then combined the equipments that we have in our lab, developed a novel one which named titration-HF absorption method.Titration-HF absorption method used the (1-0) vibration rotation transition of discharge driving single-line HF laser as probe light source to monitor the absorption of titration product-ground state HF molecule, then got the relationship between F atom flow rate and titration gas (hydrogen gas) flow rate, the advantages of this method was recommended, the absorption of ground state HF molecule was modeled, which was influenced by gas component, temperature and spectral line.On the principle of titration-HF absorption method, this paper designed the infrared window and the light path, prepared the single-line HF laser and the flow rate control and measure system. by this method, in the condition of different NF3 flow rate and different spectra line, the fluorine atom flow rate of a discharge driving HF/DF chemical laser was measured respectively, we inferred that excessive titration gas injection result in the reduction of temperature and absorptance in the absorption region, and the gas temperature in the range of transmittance reduced with temperature increment. Titration curves showed that the absorption of J=6 rotational state line was stronger, and about 1.0～1.1 fluorine atom dissociated from one NF3 molecule, the method of on-line fluorine atom flow rate measurement was advised. Lastly the reason why need excess hydrogen gas when the laser normal working was analyzed and experimentally verified.Titration-HF absorption method was an useful method of measuring fluorine atom flow rate of discharge driving HF/DF chemical laser, this article pointed out the future works to make the measurement simpler and more useful.