3月25日 五室第274期研讨会（邀请报告）

报告一:  Status of IFERC (International Fusion Energy Research Center) Project

报告二：Two-stage crash process in resistive drift ballooning mode driven ELM crash

报告人： Prof. M. Yagi1，Dr. Haruki Seto2

（QST Rokkasho Institute for Fusion Energy）

主持人：  夏天阳研究员

时  间：  2025年3月25日（星期二）下午14:00-16:00

地  点：  控制大厅3楼会议室

报告人一摘要： 

The International Fusion Energy Research Centre (IFERC) is one of the three projects executed by the EU and Japan under the Broader Approach Agreement.  The IFERC Project supports the other joint fusion projects (ITER, IFMIF/EVEDA, JT60-SA) and contributes to the development of the next generation of fusion devices after ITER, such as DEMO. IFERC has three lines of activity. The Computational Simulation Centre (CSC) supports the EU and JA fusion communities with super-computer resources in order to design components for present day and future machines, to interpret plasma physics data, and to model and design the future operation of ITER and DEMO. The DEMO Design and DEMO R&D activities aim to share and develop the design of the next generation of fusion devices, and to study and develop materials for these devices, towards a fusion reactor producing electricity. The ITER Remote Experimentation centre (REC) aims to develop remote participation techniques, to give access to ITER scientists to the future ITER operation results, and facilitate world-wide collaboration in the ITER exploitation

In 2020, the review of the IFERC Project Plan to orient the IFERC activities was performed following the priorities given by the Steering Committee (SC) for BA phase II; (1) to provide the support for ITER, IFMIF/EVEDA, and JT-60SA, (2) to consolidate know-how for future fusion reactors through the production of databases, inputs to engineering hand books, and review of lessons learned in the existing fusion projects. In this talk, present status of IFERC project will be overviewed.

报告人二摘要：

We report a two-stage crash process in edge localized mode (ELM) driven by resistive drift-ballooning modes (RDBMs) numerically simulated in a full annular torus domain with a scale-separated four-field reduced MHD (RMHD) model using the BOUT++ framework. In the early nonlinear phase, the small first crash is triggered by linearly unstable RDBMs, and magnetic islands are nonlinearly excited by nonlinear coupling of RDBMs as well as their higher harmonics. Here, m is the poloidal mode number, n is the toroidal mode number, the q=2 rational surface exists near the pressure gradient peak, and q is the safety factor. Simultaneously, middle-n RDBM turbulence develops but is poloidally localized around X-points of the magnetic islands, leading to the small energy loss. The second large crash occurs in the late nonlinear phase. Higher harmonics of magnetic islands well develop around the q=2 surface via nonlinear coupling and make the magnetic field stochastic by magnetic island overlapping. Turbulence heat transport develops at X-points of higher harmonics of magnetic islands, resulting in the turbulence spreading in the poloidal direction. The large second crash is triggered when the turbulence covers the whole poloidal region so that the magnetic island generation and magnetic field stochastization before the large crash can be interpreted as ELM precursors. It is concluded that the ELM trigger is attributed to the turbulent spreading in the poloidal direction in synchronization with the magnetic field stochastization and the crash is driven by ExB  convection rather than the conventional Rechester–Rosenbluth anomalous electron heat transport.

欢迎感兴趣的老师同学参加！