The Role of Plasma-Molecule Reactions in Influencing detachment.

等离子体分子反应在影响分离中的作用。

• 批准号: 2445307
• 金额: --
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2445307
• 关键词: Role; Plasma; Molecule; Reactions; Influencing

Heat exhaust is a critical issue for future fusion reactors and it will need to be mitigated through divertor plasma detachment, in which the divertor plasma undergoes a reduction in momentum, power and particle flux en-route to the divertor target plates. Long-legged, strongly baffled divertor chambers intensify plasma-neutral interactions (MAST-U, TCV, STEP, SPARC, ARC) and facilitate detachment. In such divertors, plasma-molecular collisions, as well as plasma chemistry, can play an important role.This study presents a new insight into plasma-molecular kinetics through analysis of data from MAST-U and TCV, and comparison of this with simplified models, and simulations. High resolution D2 Fulcher band measurements (via divertor spectroscopy) on these machines allow the rovibrational distribution of the molecules to be obtained, providing information on plasma-molecule energy and momentum transfer and interactions. Detailed temporally and spatially resolved analyses of the rotational temperatures in MAST-U (4000-9000 K) [3] and TCV (2000-5000 K), and the vibrational distributions in both devices (v = 0, 1, 2, 3), show a connection between the rotational and vibrational distribution. Different divertor configurations (Super-X, Elongated and Conventional in MAST-U); baffling (with and without SILO baffles in TCV); and different fuelling locations and heating levels in both devices, have been studied. We find that rotational temperature increases during attached and detached conditions before the overall cooling of the divertor. A simplified model including energy transfer during elastic collisions between ions and molecules; molecule lifetime; and transport time, are consistent with these findings. Exhaust simulations are also consistent. Such elastic collisions in high neutral pressures, combined with these longer molecular lifetimes, lead to significant energy and momentum dissipation - i.e. deepening detachment. An isotopic study has also been carried out on TCV.References:[1] K. Verhaegh et al 2021 Nucl. Fusion 61 106014,[2] K. Verhaegh et al 2023 Nucl. Fusion 63 016014[3] N. Osborne et al 2024 Plasma Phys. Control. Fusion 66 025008

排热是未来聚变反应堆的一个关键问题，需要通过偏滤器等离子体分离来缓解，其中偏滤器等离子体在到达偏滤器靶板的途中经历动量、功率和粒子通量的减少。长腿，强烈挡板偏滤器室加强等离子体中性相互作用（MAST-U，TCV，STEP，ARC），并促进分离。在这样的偏滤器，等离子体分子碰撞，以及等离子体化学，可以发挥重要的作用。这项研究提出了一个新的见解等离子体分子动力学通过分析数据从MAST-U和TCV，并与简化的模型，模拟比较。在这些机器上的高分辨率D2 Fulcher带测量（通过偏滤器光谱学）允许获得分子的振转分布，提供等离子体分子能量和动量转移和相互作用的信息。对MAST-U（4000-9000 K）[3]和TCV（2000-5000 K）中的旋转温度以及两种设备（v = 0，1，2，3）中的振动分布进行了详细的时间和空间分辨分析，显示了旋转和振动分布之间的联系。对不同的偏滤器配置（MAST-U中的Super-X、加长型和常规型）、挡板（TCV中有和没有筒仓挡板）以及两种装置中不同的加料位置和加热水平进行了研究。我们发现，旋转温度增加，在附着和分离的条件下，整体冷却的偏滤器。一个简化的模型，包括离子和分子之间的弹性碰撞过程中的能量转移，分子寿命和运输时间，与这些发现是一致的。排气模拟也是一致的。这种在高中性压力下的弹性碰撞，加上这些较长的分子寿命，导致显着的能量和动量耗散-即加深脱离。对TCV也进行了同位素研究。Verhaegh等人2021 Nucl. Fusion 61 106014，[2] K. Verhaegh等人2023 Nucl. Fusion 63 016014[3] N. Osborne等人2024血浆物理对照。Fusion 66 025008