NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Shock-tube studies of atomic silicon emission in the spectral range 180 to 300 nmEmission spectroscopy of shock-heated atomic silicon was performed in the spectral range 180 to 300 nm, in an environment simulating the ablation layer expected around a Jovian entry probe with a silica heat shield. From the spectra obtained at temperatures from 6000 to 10,000 K and electron number densities from 1 quadrillion to 100 quadrillion per cu cm, the Lorentzian line-widths were determined. The results showed that silicon lines are broadened significantly by both electrons (Stark broadening) and hydrogen atoms (Van der Waals broadening), and the combined line-widths are much larger than previously assumed. From the data, the Stark and the Van der Waals line-widths were determined for 34 silicon lines. Radiative transport through a typical shock layer was computed using the new line-width data. The computations showed that silicon emission in the hot region is large, but it is mostly absorbed in the colder region adjacent to the wall.
Document ID
19780038693
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Prakash, S. G.
(Stanford University Stanford, Calif., United States)
Park, C.
(NASA Ames Research Center Entry Technology Branch, Moffett Field, Calif., United States)
Date Acquired
August 9, 2013
Publication Date
January 1, 1978
Subject Category
Atomic And Molecular Physics
Report/Patent Number
AIAA PAPER 78-234
Meeting Information
Meeting: Aerospace Sciences Meeting
Location: Huntsville, AL
Start Date: January 16, 1978
End Date: January 18, 1978
Sponsors: American Institute of Aeronautics and Astronautics
Accession Number
78A22602
Funding Number(s)
CONTRACT_GRANT: NSG-2085
Distribution Limits
Public
Copyright
Other

Available Downloads

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