This award supports cooperative research in plasma physics between Loren Steinhauer of Spectra Technology, Inc. of Bellevue, Washington and Roberto Clemente of the University of Campinas in Brazil. Measurements have shown edge-layer thicknesses several times larger than expected for simple outflow of plasma. A promising explanation is that an electrostatic potential barrier is spontaneously established near the ends of the FRC (field reversed conviguration) which reduces the outflow rate. This idea has never been modelled theoretically. Since the edge-layer confinement is better than expected, the implications for a thermonuclear plasma may be a significantly reduced size requirement for a reacting FRC. The proposed research is to construct complementary models to explain the observed edge layer properties; a fluid-based model will be developed by Clemente, and a kinetic model by Steinhauer. The FRC concept is a highly promising fusion plasma concept with possible application to terrestrial fusion-electric energy (especially the low- radioactivity D-3He fuel cycle), space-based power systems, and space propulsion. The proposed work would benefit the U.S. FRC program by enlisting a researcher from another country in a project of significant interest to an existing domestic program. The proposed work would also benefit the Brazilian effort on plasma physics by enabling one of its scientists to collaborate with a researcher at a laboratory where major FRC experimental and theoretical work is in progress. In addition, the substantial computation skills at STI, including access to the National Magnetic Fusion Energy Computer Center (Livermore, California) are available in support of the research.