Absorption of Deuterium Fluoride Laser Radiation by the Atmosphere

: Absorption of deuterium fluoride (DF) laser radiation by atmospheric gases was measured for five absorbers and 8 laser lines using a single frequency, pulsed DF laser and a large multipass absorption cell. N2O, CH4, C2O, HDO and H2O absorption was investigated for the 2-1 P(6), P(7), P(8), P(10) , and P(11) lines and the 3-2 P(6), P(7), and P(8) lines of the DF laser. For the mid-latitude summer sea level atmospheric model (14.3 torr H20, 1.6 ppm CH4, 0.28 ppm N2O, temperature 296K, total pressure 760 torr) the total molecular absorption coefficients are between 0.318 per km and 0.116 per km corresponding to a transmittance over a 10 km path of from 31 to 73 percent. Assuming the mid- latitude summer model atmosphere, the water vapor continuum absorption coefficient for the eight lines is approximately 0.02 per km. The measured HDO absorption coefficients vary from 0.006 per km to 0.095 per km for the lines studied and the N2O absorption coefficients vary from .002 per km to 0.45 per km. The CH4 absorption coefficients were found to be on the order of 0.0001 or 0.0001 per km. The accuracy of the measured absorption coefficients is + or - 5%. Measurements of H2O absorption at 24 C with 14.3 torr H2O and 760 torr total pressure confirm the water continuum absorption coefficients obtained by extrapolating the high temperature measurements.