Vis-NIR absorption coefficient spectrum of CH4 phase-II at 20 K
- Title
- Vis-NIR absorption coefficient spectrum of CH4 phase-II at 20 K
- DOI
- 10.26302/SSHADE/EXPERIMENT_BS_20130114_001
- Data reference
- Grundy, Will; Schmitt, Bernard (2001): Vis/Near-IR absorption coefficients spectra of liquid CH4, solid CH4-II and CH4-I from 93 to 20 K. SSHADE/GhoSST (OSUG Data Center). Dataset/Spectral Data. https://doi.org/10.26302/SSHADE/EXPERIMENT_BS_20130114_001
- Publications
- Database
- Experimentalists
- Experiment type
- laboratory measurement
- Type
- absorption coefficient
- Intensity unit
- $cm^{-1}$
- Comments
- Band around 3010 cm-1 saturated
- Instrument
- Nicolet 800 – transmission Near-IR
- Sample holder
- Closed cells of variable thicknesses (0.1, 1, 10 mm) in UHV chamber
- Standard medium
- vacuum
- Observation mode
- spectrum
- Spectral range type(s)
- NIR
- Valid spectral range(s)
-
Min - Max ($cm^{-1}$) Sampling ($cm^{-1}$) Resolution ($cm^{-1}$) Position accuracy ($cm^{-1}$) Absorption edge #1 2000.0 - 3002.0 #2 3016.0 - 7000.0 - Scan number
- 100
Definition: incidence and emergence angles are positive with origin at nadir. Emergence angle in transmission is larger than 90° (=180°-i).
- Observation geometry
- direct
- Observation mode
- fixed angles
Illumination
- Type of polarization
- no
Observation
- Type of polarization
- no
- Comments
- possibly partly polarized beam by beamsplitter
- Observation mode
- single spot
- Image size
- 2.5 x 2.5 $mm$
- Resolutions
- 2.5 ${\pm}$ 0.5 $mm$
- Instrument
- Nicolet 800 – transmission Visible/red
- Sample holder
- Closed cells of variable thickness (0.1, 1, 10 mm) in UHV chamber
- Standard medium
- vacuum
- Observation mode
- spectrum
- Spectral range type(s)
- Vis
- Valid spectral range(s)
-
Min - Max ($cm^{-1}$) Sampling ($cm^{-1}$) Resolution ($cm^{-1}$) Position accuracy ($cm^{-1}$) Absorption edge #1 7000.0 - 11400.0 - Scan number
- 100
Definition: incidence and emergence angles are positive with origin at nadir. Emergence angle in transmission is larger than 90° (=180°-i).
- Observation geometry
- direct
- Observation mode
- fixed angles
Illumination
- Type of polarization
- no
Observation
- Type of polarization
- no
- Comments
- possibly partly polarized beam by beamsplitter
- Observation mode
- single spot
- Image size
- 2.5 x 2.5 $mm$
- Resolutions
- 2.5 ${\pm}$ 0.5 $mm$
- Name
- CH4 crystalline II
- Experiment
- Vis/Near-IR absorption coefficients spectra of liquid CH4, solid CH4-II and CH4-I from 93 to 20 K
- Date begin
- 2001-01-01
- Release date
- 2018-02-27 11:43:15 UTC+0000
- Version (Date)
- #1 (2018-02-27 11:43:15 UTC+0000, Updated: 2019-12-28 16:55:13 UTC+0000)
- History
-
Date Mode Version Status Comments 2017-11-17 17:16:56 UTC+0000 first import #1 valid version 2012-09-24: new CH4 phase-II absorption coefficient spectrum 20K (near-IR)
- Analysis
- Lambert absorption coefficient spectra α(ν) were computed from transmission spectra, using procedures described by Grundy et al. (1993) and Grundy and Schmitt (1998), based on the Beer–Lambert absorption law. Different sample thicknesses (0.1, 1, 10mm) and measurements in Vis and NIR ranges were concatenated over different wavelength portions to derive this absorption coefficient spectrum. Negative noise set to 3e-4 cm-1
- Quality flag
- 3
- Validator(s)