Solid State Neutral Particle Analyzer Array on NSTX
Authors: K. Shinohara, D.S. Darrow, A.L. Roquemore, S.S. Medley, and F.E. Cecil
Date of PPPL Report: May 2004
Presented at: the 15th APS High Temperature Plasma Diagnostics Conference, 19-22 April, 2004, San Diego, CA. Proceedings to be published in Review of Scientific Instruments.
A Solid State Neutral Particle Analyzer (SSNPA) array has been installed on the National Spherical Torus Experiment (NSTX). The array consists of four chords viewing through a common vacuum flange. The tangency radii of the viewing chords are 60, 90, 100, and 120 cm. They view across the three co-injection neutral beam lines (deuterium, 80 keV (typ.) with tangency radii 48.7, 59.2, and 69.4 cm) on NSTX and detect co-going energetic ions. A silicon photodiode used was calibrated by using a mono-energetic deuteron beam source. Deuterons with energy above 40 keV can be detected with the present setup. The degradation of the performance was also investigated. Lead shots and epoxy are used for neutron shielding to reduce handling any hazardous heavy metal. This method also enables us to make an arbitrary shape to be fit into the complex flight tube.