@article{oai:nifs-repository.repo.nii.ac.jp:00011121, author = {ISOBE, Mitsutaka and OGAWA, Kunihiro and SANGAROON, Siriyaporn and ZHONG, Guoqiang and Fan, Tieshuan}, issue = {Special Issue 1}, journal = {Plasma and Fusion Research}, month = {Mar}, note = {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 conventional liquid organic scintillator, designated as EJ-301, and a newly developed Cs2LiYCl6:Ce with 7Li-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 high-energy-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.}, title = {Recent Progress of Neutron Spectrometer Development for LHD Deuterium Plasmas}, volume = {17}, year = {2022} }