Diagnostic of Fusion Neutrons on EAST Tokamak Using 4H-SiC Detector
Bing Hong, Guoqiang Zhong, Liqun Hu, R.X. Zhang, Ruijie Zhou, Kai Li, L. Huang, Weikun Chen
Abstract
Due to significant radiation hardness, thermal properties, low sensitivity to gamma rays, and fast response, the 4H-SiC detector exhibits promising properties in measuring the neutron production in the high-power fusion devices. To demonstrate the potential value of the 4H-SiC detectors as a neutron flux monitor and a neutron spectrometer on experimentally advanced superconducting tokamak (EAST) during the 2021 EAST deuterium–deuterium plasma experimental campaigns, the 4H-SiC detector covered with a 25- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> -thick <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> LiF film 95% enriched in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> Li and the 4H-SiC detector covered with a 1.5-mm-thick polyethylene layer were installed on a viewport located at the mid-plane of port F outside the EAST vacuum vessel and operated continuously during the whole experimental campaign with the goal to measure both the total and the time-dependent neutron emission from the plasma. The results are compared with those obtained with detectors routinely working at EAST ( <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">235</sup> U Fission Chambers). Despite their small active volumes, the 4H-SiC detectors were able to measure the total and the time-dependent neutron emission with good reliability and stability. The results of this work not only demonstrated the satisfactory performance of the 4H-SiC detector in the harsh environment of a mixed neutron–gamma high-radiation field and strong electromagnetic field, but also its applicability as a neutron spectrometer and a neutron flux monitor for fusion deuterium–plasma experiments.