Transmission of Doppler Broadened Resonance Radiation through Absorbing Media with Combined Doppler and Pressure Broadening (Nitric Oxide gamma-Bands as an Example)
Final rept. 1 Jul 1974-30 4 Jun 1975
ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN
Pagination or Media Count:
The combined Doppler and pressure broadening parameter has been determined for the 0,0 gamma-band of nitric oxide NO by comparing measured spectral transmission data with the computer transmission using a radiative transfer model. The parameter a, the ratio of collisional plus natural half- width to the Doppler half-width was found to obey the relationship a CpT, where p is the pressure in atmospheres, T is the temperature in K, and C is a constant. The value of C was found to be 1270 or - 200 Katm. This value of C leads to a value for the optical diameter of NO for broadening of 3,5 or - 0.3 A. The determination of the broadening parameter oermits the accurate calculation of the transmission of NO gamma-band radiation through the high temperature, ambient pressure media corresponding to jet engine exhausts, in turn making possible the relating of transmission measurements to the concentration of NO. The application of the measurement and calculating procedure to the measurement problem is discussed.
- Atomic and Molecular Physics and Spectroscopy