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Infrared spectra, index of refraction, and optical constants of nitrile ices relevant to titan's atmosphere
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hudson, Reggie Moore, Marla Moore, William Ferrante, Robert |
| Copyright Year | 2010 |
| Description | Spectra and optical constants of nitrite ices known or suspected to be in Titan's atmosphere are presented from 2.5 to 200 microns (4000 to 50 per cm ). These results are relevant to the ongoing modeling of Cassini CIRS observations of Titan's winter pole. Ices studied include: HCN, hydrogen cyanide; C2N2, cyanogen; CH3CN, acetonitrile; C 2H5CN, propionitrile; and HC3N, cyanoacetylene. For each of these molecules we report new measurements of the index of refraction, n, determined in both the amorphous- and crystallinephase at 670 nm. Spectra were measured and optical constants were calculated for each nitrite at a variety of temperatures including 20, 35, 50, 75, 95, and 110 K, in the amorphous- and crystalline-phase. This laboratory effort uses a dedicated FTIR spectrometer to record transmission spectra of thin-film ice samples. Laser interference is used to measure film thickness during condensation onto a transparent cold window attached to the tail section of a closed-cycle helium cryostat. Optical constants, real (n) and imaginary (k) refractive indices, are determined using Kramers-Kronig (K-K) analysis. Our calculation reproduces the complete spectrum, including all interference effects. Index of refraction measurements are made in a separate dedicated FTIR spectrometer where interference deposit fringes are measured using two 670 nm lasers at different angles to the ice substrate. A survey of these new measurements will be presented along with a discussion of their validation, errors, and application to Titan data. |
| File Size | 81069 |
| Page Count | 1 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20100031223 |
| Archival Resource Key | ark:/13960/t2799546s |
| Language | English |
| Publisher Date | 2010-07-17 |
| Access Restriction | Open |
| Subject Keyword | Atmospheric Composition Spectrometers Refractivity Nitriles Ice Infrared Spectra Titan Atmosphere Kramers-kronig Formula Titan Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
