Neutron Emission Profile Measurement and Fast Charge Exchange Neutral Particle Flux Measurement for Transport Analysis of Energetic Ions in JT-60U

Abstract

This paper describes diagnostics for transport analysis of energetic ions in JT-60U. Line integrated neutron emission profiles are measured using Stilbene neutron detectors, which are installed as a neutron emission profile monitor. The flux and energy distribution of charge exchange neutral particles are measured using a natural diamond detector (NDD). These measurements in the presence of bursting instabilities in the frequency range of Alfvén Eigenmode induced by negative-ion-based neutral beam injection, which are called Abrupt Large-amplitude Events, indicate that energetic ions are transported from the core region in the plasma due to a resonance interaction between energetic ions and the instabilities. Development of a digital signal processing (DSP) system for a neutron detector and a NDD enabling a sampling rate in the MHz class is proceeding. The DSP system for the neutron detector successfully discriminates between neutrons and gamma-rays in tests using neutron/gamma-ray sources.

Fusion product diagnostics based on commercially available chemical vapor deposition diamond detector in large helical device

“…This is feasible due to its relatively wide band gap of 5.5 eV, which is wider than that of silicon 1.14 eV. Fusion plasma diagnostics based on a diamond detector, such as a neutral particle analyzer [15][16][17][18][19][20], a recoiled proton detector [21,22], and a deuterium-tritium (D-T) neutron detector [23] based on 12 C(n,𝛼) 9 Be reactions [24] have been developed. To measure the ion temperature of 9 keV through D-T neutron energy spectrum broadening [25], the energy resolution of the detector to the D-T neutron should be less than 4% [26].…”

Development of a High Sampling Rate Data Acquisition System Working in a High Pulse Count Rate Region for Radiation Diagnostics in Nuclear Fusion Plasma Research

“…Therefore, a high pulse count rate capability is desired for high time-resolved measurements. A scintillation detector with pulse shape discrimination ability has been commonly utilized in fusion research, especially as the neutron energy spectrum measurement [23][24][25][26][27] or neutron emission profile measurement [28][29][30][31][32]. To obtain better performance of neutron and gammaray discrimination, data acquisition with a high sampling rate is required [33][34][35].…”

Cycle for a Fusion Neutron Source

“…1. ТИН является ключевой системой гибридного реактора и должен обеспечивать стационарный поток термоядерных нейтронов с мощностью более 10-50 МВт, что близко к достигнутым импульсным зна-чениям существующих установок JET и JT-60U [1,2]. В отличие от чистого термоядерного реактора без делящихся материалов необходимая мощность термоядерной реакции может быть до 100 раз меньше в связи с тем, что основное энерговыделение происходит в бланкете, содержащем делящиеся материалы.…”