Rydberg State Stark Spectroscopy and Applications to Plasma Diagnostics
Abstract
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 v/cm) 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: Plasmas(physics), Atoms, Stark effect, Atomic spectroscopy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1990
- Accession Number
- ADA225248
Entities
People
- James R. Shoemaker
Organizations
- Wright Laboratory