Modeling PFRC SOL with UEDGE

Abstract

The Princeton Field-Reversed Configuration (PFRC) is an experimental mag netic confinement device located at the Princeton Plasma Physics Laboratory. The current PFRC is second in a proposed series of devices culminating in a small D-He3 nuclear fusion device with niche applications in spacecraft propulsion. In this device, the scrape-off layer (SOL) is plasma skin around the fusion core that serves both to transport energy from the core to the ends of the device and to rapidly exhaust fu sion products. SOL particles enter the layer as cold molecules, then ionize and heat as they flow across the SOL to the exhaust end. This thesis considers the behavior of this scrape-off layer through simulations in UEDGE, a well-developed plasma transport code. UEDGE approximates the plasma as a 2D fluid and solves the fluid equations using modified Braginskii equations. We will describe the power and particle transport over a range of input parameter spaces, including fusion power from the core, puffed gas input, and rate of gas pumping at the far end. We will also identify and examine phenomena that develop, such as deep detachment in the gasbox and choked flow in the magnetic nozzles, to understand device operation at a deeper level than previously achieved. With this understanding, I recommend directions for further SOL simulation research and for PFRC design and operation generally.