Application of Natural Diamond Detector to Energetic Neutral Particle Measurements on NSTX
Authors: A.G. Alekseyev, D.S. Darrow, A.L. Roquemore, V.N. Amosov, A.V. Krasilnikov, D.V. Prosvirin, and A.Yu. Tsutskikh
Date of PPPL Report: March 2003
Published in: Review of Scientific Instruments 74 (March 2003) 1905-1908.
Two natural diamond detectors have been installed on the National Spherical Torus Experiment (NSTX) to look at escaping neutrals at or near the neutral-beam-injection energy. Time-resolved measurements have been obtained from these detectors at various tangency radii. The close proximity of the detector to the vessel required the development of a very fast low-noise preamplifier, which has been shown to be superior to similar commercial units. With this amplifier arrangement, electromagnetic pick-up noise was reduced to acceptable levels. However, radiation shielding was required to reduce the background levels from neutron-induced pulses in the detector. Calibration data along with the measured energy resolution is presented in the useful energy range of NSTX. Example data from plasma discharges will also be presented.