arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2103.00325physics.plasm-ph
收藏

聚变级托卡马克中逃逸电子产生的模拟及杂质注入抑制

Simulation of runaway electron generation in fusion grade tokamak and suppression by impurity injection

Ansh Patel, Santosh P. Pandya

摘要:

在像ITER这样的聚变级托卡马克的中断期间,在热淬火(TQ)期间之后会感应出大的电场,这可以产生大量的逃逸电子(RE),其可以在电流淬火阶段(CQ)中携带高达10 MA的电流,能量高达几十MeV [1-3]。这些逃逸电子由于其局部能量沉积而可能对面向等离子体的部件造成显著损坏。为了减轻这些影响,已经提出了高Z原子的杂质注入[1-3]。在本文中,我们使用了一个自洽的0 D托卡马克破裂模型,该模型在PREDICT程序[6]中实现,该程序已被升级以考虑杂质注入对RE动力学的影响,如[4-5]中所建议的。主要的稀土产生机制,如二次雪崩机制以及主要的稀土产生机制,即Dreicer,热尾,氚衰变和康普顿散射(从激活壁发射的γ射线)已被考虑在内。在这些模拟中,考虑到杂质的影响,考虑到稀土与自由和束缚电子的碰撞,以及从完全和部分屏蔽的核电荷的散射。这些修正也在相对论性试验粒子模型中实现,以模拟动量空间中的RE动力学。我们表明,杂质的存在下有一个非均匀的影响失控电子分布函数。我们还表明,与杂质离子碰撞引起的俯仰角散射和同步辐射损失的综合效应导致RE能量分布函数的更快耗散[7]。不同的稀土产生机制的变化,在不同阶段的中断,主要是之前和之后的杂质注入的报告。

英文摘要:

During disruptions in fusion-grade tokamaks like ITER, large electric fields are induced following the thermal quench (TQ) period which can generate a substantial amount of Runaway Electrons (REs) that can carry up to 10 MA current with energies as high as several tens of MeV [1-3] in current quench phase (CQ). These runaway electrons can cause significant damage to the plasma-facing-components due to their localized energy deposition. To mitigate these effects, impurity injections of high-Z atoms have been proposed [1-3]. In this paper, we use a self-consistent 0D tokamak disruption model as implemented in PREDICT code [6] which has been upgraded to take into account the effect of impurity injections on RE dynamics as suggested in [4-5]. Dominant RE generation mechanisms such as the secondary avalanche mechanism as well as primary RE-generation mechanisms namely Dreicer, hot-tail, tritium decay and Compton scattering (from γ-rays emitted from activated walls) have been taken into account. In these simulations, the effect of impurities is taken into account considering collisions of REs with free and bound electrons as well as scattering from full and partially-shielded nuclear charge. These corrections were also implemented in the relativistic test particle model to simulate RE-dynamics in momentum space. We show that the presence of impurities has a non-uniform effect on the Runaway Electron Distribution function. We also show that the combined effect of pitch-angle scattering induced by the collisions with impurity ions and synchrotron emission loss results in the faster dissipation of RE-energy distribution function [7]. The variation of different RE generation mechanisms during different phases of the disruption, mainly before and after impurity injections is reported.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑