Infrared Optical Properties of Solid Mixtures of Molecular Species at 20 K
Abstract
Infrared transmittance spectra were measured by a Fourier transform spectrometer for 20 K cryofilms of homogeneous mixtures of N2, Ar, NH3, CO, CO2, and H2O molecules. Such cryofilms may contaminate cryogenic optical surfaces of spacecraft or aircraft. The films, cryopumped onto a 20 K germanium substrate, varied from 0.24 to 13 micrometers thick. The spectral domain ranged from 500 to 3700/cm. For all films, the complex refractive index (n = n + iK) was determined at each wavenumber by fitting the experimental behavior of the transmittance with film thickness to a lamellate model of the film and substrate. The model accounts for beam reflection losses as well as attenuation caused by passing the beam through the film and substrate materials. A Kramers-Kronig (KK) technique for obtaining the n values is compared with the thin-film determination of n.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1981
- Accession Number
- ADA094214
Entities
People
- Bobby E. Wood
- J. A. Roux
- K. F. Palmer
Organizations
- Arnold Engineering Development Complex