NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Optical absorption of carbon and hydrocarbon species from shock heated acetylene and methane in the 135-220 nm wavelength rangeAbsorption spectroscopy of carbon and hydrocarbon species has been performed in a shock tube at an incident shock condition for a wavelength range of 135-220 nm, in order to obtain information needed for calculating radiation blockage ahead of a planetary probe. Instrumentation consisted of high frequency response pressure transducers, thin-film heat transfer gages, or photomultipliers coupled by light pipes. Two test-gas mixtures, one with acetylene and the other with methane, both diluted with argon, were used to provide a reliable variation of C3 and C2H concentration ratio. Comparison of tests results of the two mixtures, in the temperature range of 3750 + or - 100 K, showed the main absorbing species to be C3. The wavelength for maximum absorption agrees well with the theoretical values of 7.68 eV and 8.03 eV for the vertical excitation energy, and a value of 0.90 for the electronic oscillator strength, obtained from the measured absorption band, is also in good agreement with the predicted value of 0.92.
Document ID
19810054763
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Shinn, J. L.
(NASA Langley Research Center Space Systems Div., Hampton, VA, United States)
Date Acquired
August 11, 2013
Publication Date
June 1, 1981
Subject Category
Chemistry And Materials (General)
Report/Patent Number
AIAA PAPER 81-1189
Meeting Information
Meeting: Thermophysics Conference
Location: Palo Alto, CA
Start Date: June 23, 1981
End Date: June 25, 1981
Sponsors: American Institute of Aeronautics and Astronautics
Accession Number
81A39167
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available