近日，西班牙塞维利亚大学的J. Dominguez-Palacios&M. Garcia-Munoz及其研究团队取得新进展。他们揭示了高能离子对托卡马克等离子体边缘局域模的影响。相关研究成果已于2025年1月6日在国际知名学术期刊《自然—物理学》上发表。

据悉，国际热核聚变实验堆（托卡马克）最高效、最有前景的运行模式是高约束模式。然而，在这种模式下，等离子体边缘可能会发生周期性弛豫。这些边缘局域模会对聚变装置的完整性构成威胁。

该研究团队利用非线性混合动理学-磁流体力学模拟，揭示了高能离子对托卡马克中边缘局域模时空结构的强烈影响。等离子体边缘的快离子与边缘局域模产生的电磁扰动之间，发生共振相互作用，导致能量和动量交换。例如，高能离子会改变边缘局域模的振幅、频谱和崩溃时机。模拟结果再现了某些观测中，边缘局域模突然且大幅崩溃的特征。

研究结果表明，在国际热核聚变实验堆中，预计聚变产生的α粒子与中性束注入的离子（这是主要的加热源和快粒子源）之间将发生强烈相互作用，并伴随着预测的边缘局域模扰动。这项工作加深了对存在高能粒子时，边缘局域模崩溃背后物理机制的理解，并强调了在高能离子动理学效应的优化，以及开发无边缘局域模的控制技术和运行模式中，考虑这些效应的重要性。

附：英文原文

Title: Effect of energetic ions on edge-localized modes in tokamak plasmas

Author: Dominguez-Palacios, J., Futatani, S., Garcia-Munoz, M., Jansen van Vuuren, A., Viezzer, E., Gonzalez-Martin, J., Toscano-Jimenez, M., Oyola, P., Todo, Y., Suzuki, Y., Sanchis, L., Rueda-Rueda, J., Galdon-Quiroga, J., Hidalgo-Salaverri, J., Chen, H., Rivero-Rodriguez, J. F., Velarde, L.

Issue&Volume: 2025-01-06

Abstract: The most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is the high-confinement mode. In this regime, however, periodic relaxations of the plasma edge can occur. These edge-localized modes pose a threat to the integrity of the fusion device. Here we reveal the strong impact of energetic ions on the spatio-temporal structure of edge-localized modes in tokamaks using nonlinear hybrid kinetic–magnetohydrodynamic simulations. A resonant interaction between the fast ions at the plasma edge and the electromagnetic perturbations from the edge-localized mode leads to an energy and momentum exchange. Energetic ions modify, for example, the amplitude, frequency spectrum and crash timing of edge-localized modes. The simulations reproduce some observations that feature abrupt and large edge-localized mode crashes. The results indicate that, in the International Thermonuclear Experimental Reactor, a strong interaction between the fusion-born alpha particles and ions from neutral beam injection, a main heating and fast particle source, is expected with predicted edge-localized mode perturbations. This work advances the understanding of the physics underlying edge-localized mode crashes in the presence of energetic particles and highlights the importance of including energetic ion kinetic effects in the optimization of edge-localized mode control techniques and regimes that are free of such modes.

DOI: 10.1038/s41567-024-02715-6

Source: https://www.nature.com/articles/s41567-024-02715-6