Charge exchange neutral particle analysis with natural diamond detectors on LHD heliotron

Semiconductor detectors based on natural diamonds have been installed on th e Large Helical Device (LHD) heliotron to measure the energy distribution o f charge exchange fast neutral particles from different viewing angles. Adv antages of a natural diamond detector (NDD) are (1) very compact size, (2) relatively easy handling, and (3) high energy resolution. Although NDDs are sensitive to visible light, vacuum ultraviolet, and soft x rays, unfavorab le pulses produced by such radiation were greatly reduced by choosing an ap propriate stainless steel shield in this experiment. In LHD, the time-resol ved energy distribution of counter-going beam ions and ion cyclotron range of frequency-produced energetic ions have been successfully obtained by mea ns of an NDD. The performance of NDDs as a neutral particle analyzer and it s good suitability to LHD plasmas were demonstrated throughout this work. ( C) 2001 American Institute of Physics.