High-Spatiotemporal-Resolution Hard-X-Ray Diagnostic System on NanChang Spherical Tokamak

The high-spatiotemporal-resolution hard-X-ray diagnostic on the NanChang Spherical Tokamak (NCST) for fast electron research is presented. The 31 detectors of diagnosis are all composed of a lutetium yttrium oxyorthosilicate crystal coupled silicon photomultiplier, with an energy detection range of 20 to 300 keV. The detectors are symmetrically distributed on the vertical plane of the NCST, of which 9 have a spatial resolution of about 5 mm and the others have a resolution of about 21 mm. A detailed account of the main characteristics and performance of the diagnostic system is reported, as well as preliminary results on electron cyclotron resonance heating (ECRH) experiments, which will help to understand the fast electron dynamics produced by ECRH.