PPPL-3641 is available in pdf format.

Confinement of Neutral Beam Ions in the National Spherical Torus Experiment

Authors: D.S. Darrow, S.S. Medley, A.L. Roquemore, and A. Rosenberg

Date of PPPL Report: December 2001

Presented at: the IAEA Technical Committee Meeting on Energetic Particles in Magnetic Confinement Systems in Gothenburg, Sweden, October 8-11, 2001.

The loss of neutral-beam ions to the wall has been measured in the National Spherical Torus Experiment (NSTX) by means of thermocouples, an infrared (IR) camera, and a Faraday cup probe. The losses tend to exhibit the expected dependences on plasma current, tangency radius of the injector, and plasma outer gap. However, the thermocouples and the Faraday cups indicate substantially different levels of loss and this difference has yet to be understood.