Determination of the absolute concentration of fluorine atoms from the absorption of ultraviolet radiation by FO2 radicals

It is demonstrated experimentally that the early stages of photoinitiation in fluorine-hydrogen lasers may be studied using the absorption of ultraviolet radiation by FO₂ radicals formed as a result of the F+O₂+M→FO₂+M reaction. The absorption cross section of the FO₂ radical in the gas phase was determined at room temperature at the 220 nm wavelength.