7月17日 Gamma-ray diagnostics at ITER with tungsten first wall

　　报告题目：Gamma-ray diagnostics at ITER with tungsten first wall

　　报告时间：7月17日（星期三）下午2:00-3:30

　　报告地点：四号楼 601会议室

　　报告人：Prof. Alexander Shevelev

　　主持人：张洋 研究员

　　报告人简介：

　　Dr Alexander Shevelev is a researcher at the Ioffe Institute of the Russian Academy of Sciences, Saint Petersburg, Russia. He studied Nuclear Physics in the St. Petersburg State Technical University, Russia, where obtained his M. Sc. His Ph.D. degree in Plasma Physics he obtained in the Ioffe Institute specializing in gamma-ray and hard X-ray spectrometry of high temperature plasmas. He studied runaway electrons and fast ions at the GLOBUS-M2, TUMAN-3M, FT-2 (RF), JET (UK), and ASDEX Upgrade (Germany) tokamaks, participated in and supervised the development of diagnostic equipment for plasma facilities based on the use of gamma-ray, HXR, and neutron spectrometry methods, supervised nuclear physics research at the cyclotron of the Ioffe Institute. He is a member of the Russian diagnostic team in the ITER Project and leader of the Gamma-ray Spectrometry group in the Ioffe Institute, member of the Diagnostics and Energetic Particle ITPA expert teams. He published more than 100 publications in peer-reviewed scientific journals, participated in numerous scientific conferences and meetings.

　　报告简介：

　　The change in the material of ITER's first wall has led to adjustments in extracting information about energetic particles using gamma-ray spectrometry methods. However, these adjustments are not fundamental since instead of reactions involving hydrogen and helium isotopes with Be, reactions with B-10 and B-11 isotopes may be analyzed. The essential requirement for applying these techniques is the availability of a spatial distribution of boron impurities in the plasma. The gamma-ray spectrometer in the NPA system can provide crucial information on the distribution of fast particles in hydrogen and deuterium plasma during the SRO (Start of Research Operation) and FPO (Fusion Power Operations) phases. Alpha particle diagnostics is possible by measuring the intensities and line shapes of the 3.09, 3.68 and 3.85 MeV gamma-ray transitions of the 13C nucleus produced in the 10B(α,pγ)13C reaction. In the DT plasma, measurements of these gamma rays are hampered by the high-intensity gamma-ray background from the tokamak chamber wall induced by 14 MeV neutrons. However, the experiments with three-ion ICRF heating may provide an opportunity to study the behaviour of MeV alpha particles even before the fusion operation starts. The capability of obtaining information on the fusion rate in D-T, D-3He and p-T reactions, as well as on the distribution of the runaway electrons by gamma-ray spectrometry measurements, will not be significantly affected by the replacement of the first wall.