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Results for “line shape”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Apodization Control of Line Shape in Spectrometer

Kaiser-Bessel apodization function reduces unwanted sidebands. Report discusses apodization in Fourier-transform spectrometer (FTS) for Advanced Moisture and Temperature Sounder (AMTS). Purpose of apodization in instrument to control shape of spectrum in wavenumber space to keep radiation at other wavelengths in passband of spectrometer out of AMTS wavenumber channel.

Pires, Antonio↗
NASA NTRS1988

Measurement of electron-attachment line shapes, cross sections, and rate constants in HI and DI at ultralow electron energies

Electron-attachment cross sections are reported in the electron energy range 0-150 MeV, at an energy resolution of 6.5 MeV (full width at half maximum) for the molecules HI and DI. Use is made of the Kr photoionization method to obtain cross sections for HI, and a signal intercomparison technique to obtain cross sections and the thermal-attachment rate constant for DI. Attachment properties of the two molecules are very similar. The ratio of attachment cross sections is discussed in terms of the reduced-mass dependence of the dissociation width and the survival probability, and in terms of spectroscopic thresholds and rotational populations for attachment at 300 K. Approximate potential-energy curves for the lowest states of the neutral molecule and negative ion are given.

Alajajian, S. H.↗
NASA NTRS1980

Effects of velocity averaging on the shapes of absorption lines

The velocity averaging of collision cross sections produces non-Lorentz line shapes, even at densities where Doppler broadening is not apparent. The magnitude of the effects will be described using a model in which the collision broadening depends on a simple velocity power law. The effect of the modified profile on experimental measures of linewidth, shift and amplitude will be examined and an improved approximate line shape will be derived.

Pickett, H. M.↗