Recent Progress of Neutron Spectrometer Development for LHD Deuterium Plasmas

Mitsutaka ISOBE, Kunihiro OGAWA, Siriyaporn SANGAROON, Guoqiang ZHONG, Tieshuan FAN
2022 Plasma and Fusion Research  
The commissioning of three different types of D-D neutron energy spectrometer has been performed in the Large Helical Device (LHD) to accelerate energetic-ion physics studies in a non-axisymmetric system. Because the LHD is equipped with negative-ion-source-based tangential neutral beam injectors (N-NBs) characterized by high energy up to 180∼190 keV, a significant Doppler shift of D-D neutron energy from 2.45 MeV is expected. Two different compact neutron energy spectrometers, i.e., a
more » ... nal liquid organic scintillator, designated as EJ-301, and a newly developed Cs 2 LiYCl 6 :Ce with 7 Li-enrichment called CLYC7, having tangential sightlines, have shown up-and/or down-shifted D-D neutron energy, as expected according to the direction of N-NB injection. In addition, with the aim of study on a perpendicular energetic ion tail, created by wave heating with ion cyclotron resonance frequency, a neutron energy spectrometer named the Time of Flight Enhanced Diagnostic (TOFED) is being developed. The TOFED is based on a time-of-flight technique and is characterized by highenergy-resolution and a high-counting-rate capability. Commissioning of the TOFED is now ongoing. Recent advances of neutron energy spectrometer development for LHD deuterium plasmas are described.
doi:10.1585/pfr.17.2402008 fatcat:diz7rsog7vds3azzmhowdvwjxu