Experimental, numerical and analytical evaluation of -thrust for fast-liquid-metal-flow divertor systems of nuclear fusion devices

Nuclear Fushion

article

A.E. Fisher¹  J. Al-Salami²  B. Wynne¹  Z. Sun³  T. Tanaka⁴  T. Kunugi⁵  J. Yagi⁶  K. Kusumi⁶  Y. Wu⁶  G. Yamazaki⁷  C. Hu²  K. Hanada²  E. Kolemen¹  F. Saenz¹ 

[1] Princeton University, Princeton;Research Institute for Applied Mechanics, Kyushu University;Princeton Plasma Physics Laboratory, Princeton;National Institute for Fusion Science;Zhejiang University;Kyoto University;The Graduate University for Advanced Studies

关键词: liquid metals;    nuclear fusion;    3D-MHD simulation;    divertor;    magnetohydrodynamics;    FreeMHD;   

DOI  :  10.1088/1741-4326/ace9e9

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

Divertor systems of fusion devices are exposed to intense heat loads from plasmas, which degrade solid plasma-facing components. Fast liquid metal (LM) flow divertors may be more advantageous for this purpose but have risk of piling due to intense magnetohydrodynamic (MHD) drag. However, severe deceleration of the flow could be countered with the injection of currents that are transverse to external magnetic fields, allowing to thrust the flow with mathbf{jimes B}(Lorentz) forces. Given that the injection of currents as an approach to propel LM-divertor flows has remained experimentally understudied, this article focuses on the evaluation of mathbf{jimes B} -thrust and finding its drawbacks. mathbf{j imes B} -thrust was experimentally tested with free-surface-LM flows, a vertical magnetic field and an externally applied current. Experiments were reviewed with a theoretical model, showing agreement in the trends of theory and experiments. Full 3D-MHD-free-surface-flow simulations were also performed with FreeMHD and confirmed the sensitivity to unstable flow behavior in LM systems when applying external currents. Furthermore, excessive power requirements are expected for the implementation of mathbf{jimes B} -thrust at the reactor scale, making these systems inefficient for commercial devices. This paper evidences that the simple operation of a LM-flow divertor with mathbf{j imes B} -thrust, without any of the instabilities caused from reactor plasmas or parasitic currents, already presents intrinsic challenges.

【 授权许可】

Unknown