5月14日Seminar of DTE2 in JET from Professor Jeronimo GARCIA

　　题目：Seminar of DTE2 in JET from Professor Jeronimo GARCIA

　　时间：2024年5月14日 星期二 下午14:00

　　地点：控制大厅三楼会议室

　　主持人：张斌

　　报告人：GARCIAOLAYA/JERONIMO

　　报告内容：In 2021, deuterium-tritium experiments (DTE2) were performed in JET for the first time since the 1997 D-T campaigns in TFTR and JET (DTE1). This represents the culmination of a plan in support of ITER that started with the conception of the ITER-like wall (ILW: W divertor and Be first wall) in 2006, and included several enhancements, as well as dedicated experimental campaigns to expand the operational space in JET-ILW and prepare the plasmas required to exploit JET’s currently unique tritium handling capabilities.

　　DTE2 delivered fusion energies exceeding the previous record (59MJ compared to 22MJ in DTE1) thus demonstrating the compatibility of sustained high performance D-T plasmas with the ILW. The fusion power in the different operational scenarios performed is consistent with predictions made before DTE2. Experiments designed to address specific physics questions provide a unique set of data, with several notable preliminary results. Compared to their deuterium counterparts, D-T plasmas require lower input power to reach the high confinement mode (H-mode) relied on in ITER and show better energy confinement. A clear impact of the D-T mixture on the plasma edge (H-mode pedestal) pressure and core thermal confinement is observed. As expected from physical sputtering predictions, the total W source is higher and its impact in the plasm core stronger, but the concentration in the plasma remains tolerable, at least in part due to strong core heating and screening. Observations of alpha particles and of alpha-driven instabilities were obtained, providing a unique dataset for testing predictions. D-T plasmas in conditions of destabilized fast ion modes, low rotation and high electron heating show very good confinement in the presence of a new I-mode regime which is easily accessed in D-T. Efficient core heating and impurity control was observed with the Ion Cyclotron Radio Frequency schemes considered for ITER D-T operations: 3He minority heating, and 3-ion scheme D-9Be-T where the Be is that naturally present in the ILW. The influence of the constraints of T operation and neutron rate D-T generation on the operation of JET and how will also be discussed.

　　Implications for future tokamak devices, such as ITER, will be discussed and highlighted.