Academic Seminars 2021 No.116 -- D.T. Escande

==== Aix-Marseille Université ====

时间：2021年12月6日 周一 14:00

方式：Zoom会议（会议号859 3707 2148；密码434889）

报告人：D.T. Escande  教授

邀请人：朱平 教授

题目：Increasing the Density Limit in Tokamaks by ECRH Assisted Ohmic Start-up

摘要：As yet, stellarators benefit from higher density limits than tokamaks. This higher limit might not be intrinsic to the stellarator, but only to its mode of breakdown: the massive use of ECR power with high neutral density. Starting from present (fortunately non-acrobatic) ECR assisted ohmic start-up scenarios, it might be possible to reach stellarator-like density limits in tokamaks by increasing progressively and simultaneously the ECR power and the initial neutral density [1]. Recently, it was shown that the density limit results from a radiative limit due to impurities in three magnetic configurations: the L-mode tokamak, the Reversed Field Pinch, and the stellarator [2-4]. Therefore, one may try to push this limit toward higher values by increasing the plasma purity. For tokamaks, a new plasma-wall self-organization theory [1] suggests this increase might result from the above high ECR power and initial neutral density scenario. The basic idea of this theory is the existence of a time delay in the feedback loop relating radiation and impurity production on divertor plates.

[1] D. F. Escande, F. Sattin, and P. Zanca (submitted to Nucl. Fusion) https://hal.archives-ouvertes.fr/hal-03266627

[2] P. Zanca, F. Sattin, D.F. Escande, and JET Contributors, Nucl. Fusion 59, 126011 (2019)

[3] P. Zanca, F. Sattin, D.F. Escande, G. Pucella, and O. Tudisco, Nucl. Fusion 57, 056010 (2017)

[4] P. Zanca P., F. Sattin, D.F. Escande, and JET Contributors (submitted to Plasma Phys. Controlled Fusion)

报告人简介：Dominique Escande 教授是国际著名磁约束等离子体理论物理学家，在RFP等离子体准单螺旋态自组织过程等诸多领域都有原创性贡献，曾担任法国Tore Supra, 意大利 RFX 等装置实验室等主要研究部门主管，主持多次重要国际学术会议，目前任法国马赛大学高等研究员，国家科学研究中心荣誉退休研究主任等。