Investigation of electric fields in current-carrying plasmas using forbidden-line spectroscopy
Abstract
Knowledge of the evolution of electric fields in plasmas under pulsed currents is of high importance for improving fundamental understanding and for various applications. In this report we describe the investigation of electric fields using laser-spectroscopy in a plasma of n_e=2× 10^14 cm-3 during 200 kA, 80 ns pulse. Resonant laser pumping allows for simultaneous observations of the allowed and the forbidden transitions. In this study, using coaxial configuration, the plasma is doped with a laser-produced lithium beam, followed by pumping of a selected transition of LiI using a tunable laser. The observations, together with novel line-shape calculations recently developed, allow for obtaining the electric fields. We believe that these measurements yield for the first time the evolution of the electric field generated by currents in the plasma with a nanosecond temporal resolution and a sub-millimeter spatial resolution. The relation between the fields observed and the Hall-fields or sheath fields in the plasma will be discussed.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 2004
- Bibcode:
- 2004APS..DPPBO3003T