Plasma and Fusion Research

Volume 15, 1202087 (2020)

Rapid Communications

Regression Approach for Acquiring a Quantitative Guidance toward Updating the Deuterium-Deuterium Fusion Neutron Emission Rate in the Large Helical Device
Kunihiro OGAWA1,2), Masayuki YOKOYAMA1,2) and Mitsutaka ISOBE1,2)
National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
The Graduate University for Advanced Studies, SOKENDAI, Toki 509-5292, Japan
(Received 15 October 2020 / Accepted 2 November 2020 / Published 11 December 2020)


A regression approach has been adopted to acquire a quantitative guidance for updating the total neutron emission rate (Sn) in the Large Helical Device (LHD) with employing the externally controllable parameters such as heating power and plasma density. A deduced regression expression is worthwhile to understand for the contribution of an individual parameter during high Sn discharges, and then to be exploited in the experiment planning to update the record Sn value in LHD in the coming campaigns. It was found that Sn in high Sn discharges in LHD is expressed as Sn = 1014.25 × ne_avg0.52 × PN-NB0.69 × PP-NB0.37, where ne_avg, PN-NB, and PP-NB represent the line-averaged electron density [1019 m−3] and the injection power of negative and positive ions based neutral beam injection [MW], respectively. This expression shows that, among three parameters, PN-NB is essential for achieving high Sn in this employed high Sn discharge database.


Large Helical Device (LHD), total neuron emission rate, deuterium fusion reaction, regression approach

DOI: 10.1585/pfr.15.1202087


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