CAREER: Electric Fields in Space Plasmas--Aurora and Charging

Dartmouth College, Hanover NH

Investigators

Abstract

Electric fields in plasmas are a unifying theme of many aspects of space plasma physics. This project will focus on two particular questions about space plasma behavior. (1) What are the structure and dynamics of electric fields in return-current auroral regions, and how do they interact with the lower ionosphere? (2) What is the structure of electric fields around charged objects in plasmas such as spacecraft and rocket payloads and their instrumentation, and how do these fields color our interpretation of low energy plasma measurements? The study will involve ground-based observations, the sounding-rocket program at Dartmouth, satellite data analysis and laboratory studies. It will also incorporate extensive student projects, both graduate and undergraduate. The study will weave together the studies of our sounding-rocket Dartmouth College group into a unified scientific effort, providing links and correspondences between the different projects. The effects of return current auroral regions on magnetosphere/ionosphere coupling are only beginning to be quantitatively explored, and the Dartmouth sounding-rocket group is well placed between the satellite and ground based communities to draw connections between the various data sets. An important part of quantifying the low-altitude, low-energy beginnings of ionospheric coupling is a careful interpretation of spacecraft charging effects on thermal particle measurements; the structure of sheaths around charged instrumentation is a question that interests both space and laboratory plasma physicists. A Dartmouth laboratory facility will be developed to provide a tool for exploring these effects. The student-driven continued development of the laboratory plasma facility at Dartmouth will provide new infrastructure for students in laboratory and space plasmas, and will build connections between the Dartmouth physics program and other space plasma programs.