A Stacked Diamond Detector-Based D–T Neutron Spectrometer for Neutronics Studies in Magnetic Confinement Fusion

The realization of a fusion power plant necessitates robust diagnostic tools, especially for detecting the 14 MeV neutrons produced in D–T fusion reactions, to assess and optimize plasma performance. Fusion neutron detection plays a crucial role in directly evaluating the fusion reaction rate, which is a key indicator for achieving sustained and efficient energy production, an essential goal for future DEMOnstration power plants. Recognizing this critical need, Thailand is actively advancing the development of fusion diagnostics for D–T neutrons through international collaborations with the National Institute for Fusion Science (NIFS), Japan, and the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP), China. This initiative focuses on the development of a compact stacked diamond detector system designed for high-performance fusion neutron measurements. The detector design incorporates three layers of single-crystal chemical vapor deposition (scCVD) diamond, enabling the detection of fusion neutrons within a specific energy range relevant to current and future fusion devices. The developed system is currently undergoing development and is scheduled for testing and calibration at the Advanced Industrial Science and Technology (AIST), Japan. Following successful validation, the compact stacked diamond detector is scheduled for installation and experimental campaigns at the Experimental Advanced Superconducting Tokamak (EAST) at ASIPP, China, in the fourth quarter of 2025. This collaborative effort represents a significant step towards enhancing Thailand's capabilities in fusion technology and contributing to the global pursuit of fusion energy.