High Resolution Spectra of Methane and its Isotopes
EMSL Project ID
1946
Abstract
The purpose of this proposal is to incorporate the very high-resolution (better than 0.0025 cm-1) spectra of methane obtainable with the Bruker 120HR FTS in our multispectrum least squares analysis technique. The spectral coverage required will extend from roughly 900 cm-1 to about 3500 cm-1. CH3D spectra will be recorded near the lower wavenumber region (900 to 2000 cm-1) and the spectra of 12CH4 and 13CH4 will be recorded from approximately 2500 to 3500 cm-1. In addition to room temperature, some of the 12CH4 spectra will be recorded at both low as well as high temperatures using the temperature controlled cell available at the PNNL. These spectra should help us determine accurately the relaxation matrix coefficients related to the air-broadening and self-broadening coefficients in methane as well as in CH3D. Below is the list of spectra that is proposed to be recorded: 1. 12CH4 spectra at 0.0015 to 0.002 cm-1 resolution at room temperature, -80C and 750C in the spectral region between 2500 and 3500 cm-1. 2. Sample pressures in the above spectra may vary between 0.5 and 10 torr. Path length is 20cm. 3. Low pressure samples of 12CH4 (~ 1torr) broadened with dry Nitrogen with a total pressure of about one atmosphere. This spectrum should be recorded at room temperature. 4. 0.0015 to 0.002 cm-1 spectra of 13CH4 with pressures varying between 0.5 and 10 torr (e.g., 0.5, 1, 3 and 10torr). These spectra are to be recorded at room temperature with a path length of about 20 cm. 5. 12CH3D and if possible 13CH3D spectra will be recorded in the triad region (900 to 2000 cm-1). Spectra using samples of isotopically enriched CH3D at 0.0015 to 0.002 cm-1 resolution are to be obtained at various low pressures ( 1 to 10 torr) using the 20 cm sample cell.
Project Details
Project type
Exploratory Research
Start Date
2000-03-23
End Date
2000-03-31
Status
Closed
Released Data Link
Team
Principal Investigator