Vacuum ultraviolet absorption in a hydrogen arcjetAtomic absorption spectroscopy was utilized to measure the ground state atomic hydrogen number density in the plasma produced in a low power hydrogen arcjet. A microwave driven hydrogen plasma was used as the source of radiation resonant with the vacuum ultraviolet Lyman alpha transition. The suitability of this radiation source is discussed. The optical depth of this transition prevented measurements at locations where the ground state atomic hydrogen number density was larger than 3 x 10 exp 19/cu m. These results indicate that other single-photon optical diagnostic techniques are equally ineffective in locations of higher hydrogen number density unless the spectral line shape of the atomic hydrogen absorbers is known.
Document ID
19920071431
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Manzella, David H. (NASA Lewis Research Center Cleveland, OH, United States)
Cappelli, Mark A. (Stanford University CA, United States)