Progress on Integrated Neutron Diagnostics for Deuterium Plasma Experiments and Energetic Particle Confinement Studies in the Large Helical Device During the Campaigns from FY2017 to FY2019

To achieve a steady-state fusion burning plasma, energetic particle confinement studies have been performed in fusion devices. Deuterium plasma experiments in the Large Helical Device starting from March 2017 have expanded the energetic ion confinement study toward a helical-type fusion reactor. To conduct this study, integrated neutron diagnostics, such as a wide dynamic range neutron flux monitor composed of three sets of detectors, a neutron activation system with two irradiation ends, three vertical neutron cameras, four types of scintillating fiber detectors, and a fast time response neutron fluctuation detector, were installed based on the plan and were working stably, as designed. Moreover, an energetic particle confinement study was advanced by utilizing integrated neutron diagnostics. Furthermore, the results of the energetic particle confinement study using neutron diagnostics obtained from FY2017 to FY2019 are reviewed in this paper.