Horizontal, vertical, and radial high-energy particle distribution measurement system in Large Helical Device

A horizontal, vertical, and radial high-energy particle distribution measurement system, which consists of the time-of-flight neutral particle analyzer (TOF-NPA), the silicon detector neutral particle analyzer (SD-NPA), and pellet charge exchange (PCX) analyzers, is successfully installed in the Large Helical Device (LHD). In a horizontal scan, it is interesting to measure the pitch angle distribution and to investigate the loss cone feature obtained by it. The pitch angle distribution from 40° to 100° can be obtained by horizontal scanning of the TOF-NPA during a long discharge of over 100 s sustained by the NBI2 (coinjection) at the magnetic axis of 3.6 m. With a vertical scan, the heating deposition profile of the ion cyclotron resonance heating (ICH) has been discussed. The deposition profile can be obtained by the vertical scan of the SD-NPA. The region where the high-energy particle is generated agrees with the location of the resonance layer of the ICH. Similar results can be obtained by the PCX me...