Plasma diagnostics using vacuum ultraviolet radiation and soft X-rays in the GAMMA 10 tandem mirror device

摘要

Plasma diagnostics using vacuum ultra violet (VUV) and X-ray radiation in the world largest tandem-mirror plasma-confinement-device GAMMA 10 are reported. In particular, the detection characteristics of microchannel plates (MCP) with 50 channels (anodes) are investigated using synchrotron radiation ranging from VUV to an X-ray regime (12 eV to 82.5 keV) for the purpose of detector fundamental researches as well as their development studies. These investigations also provide applications of MCP as imaging detectors including applications for spatially and temporally resolved plasma VUV and soft X-ray diagnostics. It is found that the detection efficiency of MCP remains within one order of magnitude through dozens eV to several tens keV along with the physical mechanism interpretations of the MCP energy response, and the response uniformity of each channel for an imaging use is experimentally investigated. Using these detailed and precise MCP calibration data, we apply the MCP not only for a plasma-radiation imaging detector so as to reconstruct spatial profiles of emissivity but for a plasma diagnostic tool to measure plasma-electron velocity distribution functions.