Direct measurement of solar plasma electric fields has received relatively little attention considering the central importance of such fields in energy release, and in plasma and energetic particle acceleration in the solar atmosphere. This project's aim is to carry out ground-based measurements of such fields to validate the promising "electrograph" technique of electric field remote sensing based on measurement of the transverse Stark effect in solar hydrogen lines. Present work so far has centered on development and operation of a Mk I electrography at the NSO Evans Facility at Sacramento Peak, using the high Balmer and Paschen series lines. We are presently upgrading the SPO instrument to increase its sensitivity to 1 volt cm-1. This project will carry out two specific observational tests of this sensitivity, and to operate it on a daily basis to with flares, eruptive filaments, sunspots and faculae. The project will also requests support to extend this technique farther into the infrared, to include promising hydrogen lines out to beyond 10 . Some of this IR work is getting underway in late 1992, using the newly installed IR grating in the main McMath spectrograph at Kitt Peak, and the new NSO IR array. The results of these investigations will be compared to the discharge and reconnection models of flares, to models of post-flare loops, filament eruptions, and also to recent ideas on solar abundance variations. #
