Rydberg State Stark Spectroscopy and Applications to Plasma Diagnostics
Final rept. Oct 1985-Sep 1989
WRIGHT RESEARCH AND DEVELOPMENT CENTER WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
Rydberg state Stark spectroscopy of triplet and singlet helium has been applied to measure the electric field profile in DC glow discharges. Stark splittings of triplet helium were used to map the field profile in the cathode sheath of a parallel plate discharge. Simulations of the observed spectra enabled the direct determination of the field gradient, hence the space charge density, in the sheath. The polarization dependence of the Stark effect was exploited to determined the field direction as well as magnitude electronic field vector. Measurements of low electric fields 50 vcm were attempted by observing the linewidth of high Rydberg states n 25 and applying standard line broadening approaches used in plasma diagnostics. However, it is shown that these approaches use approximations which are inappropriate for helium spectra and for the plasma conditions found in the glow discharges investigated in this study. Keywords Plasmasphysics, Atoms, Stark effect, Atomic spectroscopy.
- Atomic and Molecular Physics and Spectroscopy
- Plasma Physics and Magnetohydrodynamics