Development of Synergetic Fueling Control Compatible with Confinement Improvement and Sustainability of High-Temperature Plasma

建立高温等离子体控制方案是未来聚变堆的前提。这项研究注意到了外控加注和等离子体中约束和可持续的内在属性的协同效应。基于积累的物理知识和先进的加油技术，在大型螺旋装置(LHD)上进行了试验研究，以开发一种加油方案。LHD是一个很好的实验平台，因为它只需要外部线圈就可以产生稳定的磁场来限制高温等离子体。外部燃料对内部变量(温度、密度、压力等)的影响归因于粒子源的产生。热输运和颗粒输运是相互联系的，直接电荷交换损失、循环间接电荷交换损失、辐射损失和动量损失是非线性耦合。而注丸充填岩心具有良好的效率和缺点…更均匀地显著减少了回收颗粒，在高密度区的约束和燃料效率的降低以及核心温度的大扰动是令人担忧的。本研究对注丸与注气的协同作业进行了深入的探索，并对两者的协同效应进行了量化。本研究揭示了等离子体边界局部神经压力升高与堆芯约束性能之间的关系。即使在密度梯度极大的情况下，当弹丸注入燃料时，结合在等离子体边界上实现低中性压力的条件，也会抑制粒子扩散。提高泵送能力的壁面调节和避免中性物质堵塞的磁力配置相结合是一个关键因素。在这种操作中，密度分布变得高度峰值，因此中心密度达到每立方米10到21的1.2倍，这比聚变反应堆的常规要求大几倍。这一发现提出了一种创新的方案，即具有超高密度和相对低温的聚变反应堆。应该注意的是，高密度操作缓解了工程需求。对这一新的操作制度的记录已经取得了进展，这表明，通过重复添加颗粒燃料并穿透颗粒扩散势垒，中心密度和温度都可以保持恒定。较少

Establishment of a control scheme of high-temperature plasmas is prerequisite for a future fusion reactor. This research has paid attention to a synergetic effect of external control of refueling and intrinsic property of confinement and sustainability in plasmas. Based on the accumulated knowledge of physics and developed technology on fueling, experimental studies to develop a fueling scheme have been conducted in the Large Helical Device (LHD). LHD is a good experimental platform since it can generate steady-state magnetic field to confine high temperature plasmas only by external coils. Effect of external fueling on internal variables (temperature, density, pressure, etc.) is attributed to generation of particle source. Heat and particle transports are linked with each other, where direct charge exchange loss, indirect charge exchange loss due to recycling, radiation loss and momentum loss are non-linearly coupled. While core fueling by pellet injection has good efficiency and cons … More equently reduces recycling particles significantly, degradation of confinement and fueling efficiency in the high density regime and large perturbation in the core temperature are concerned. In this research, cooperative operation of pellet injection and gas puff has been explored carefully and their synergetic effect has been quantified. This study indicates the relation between local increase of neural pressure in the plasma boundary and performance of core confinement. Particle diffusion is suppressed even with extremely large density gradient when fueling by pellet injection is combined with the condition to enable low neutral pressure at the plasma boundary. Combination of wall conditioning to enhance pumping capability and magnetic configuration to avoid plugging of neutrals is a key element. In this operation, density profile becomes highly peaked and consequently the central density reached 1.2 times 10 to the 21st per cubic meters which is several times larger than a regular requirement for a fusion reactor. This finding suggests an innovative scenario of a fusion reactor with super-high density and relative low temperature. It should be noted that high density operation mitigates, engineering demand. Documentation of this new operational regime has progressed, which suggests that both central density and temperature can be kept constant with repetitive pellet fueling with penetration inside the particle diffusion barrier. Less