Pressure Dependence of the Water Vapor Continuum Absorption in the 3.5 to 4.0 Micrometer Region.
ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND WSMR NM ATMOSPHERIC SCIENCES LAB
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Measurements of water vapor continuum absorption in the 3.5- to 4.0-micrometer region are presented. A deuterium fluoride grating tunable laser was used in conjunction with a 21-m long-path absorption cell. Measurements were performed at 25 C with 14.3 torr of deuterium depleted water vapor one-fiftieth the normal concentration of HDO buffered by pressures of 0, 250, 500, 750, 1000, and 1250 torr of an 8020 mixture of N2O2. From the measurements of the water vapor continuum absorption at 26 laser lines for the six foreign broadening pressures, a foreign-to-self-broadening coefficient of 0.011 with a factor of 2 uncertainty was obtained. This coefficient is an order of magnitude smaller than the value of 0.12 measured under higher temperature and pressure conditions by other workers.
- Atmospheric Physics
- Atomic and Molecular Physics and Spectroscopy