Abstract

The results of the development of a two-dimensional MHD code for carrying out computational studies of the dynamics of plasma current sheath in spherical chambers with a plasma focus are presented. Equations of magnetohydrodynamics with allowance for magnetic field diffusion, thermal conductivity and plasma radiation are used in this work. An implicit scheme is used in the calculation of the magnetic field, which makes it possible to describe the motion of plasma in a low-density region behind the plasma sheath. The formulas that take into account the possible appearance of anomalous resistance in the plasma are used to calculate the plasma conductivity. The neutron yield is calculated with allowance for thermonuclear and beam–target neutron generation mechanisms. The effect of the minimum residual gas density behind the plasma sheath on the cumulation of the plasma sheath is studied. The effects of magnetic field diffusion, thermal conductivity and anomalous plasma resistance on the plasma sheath dynamics are considered. The calculations are performed for two spherical plasma-focus chambers operating with currents up to 1 and 2 MA and neutron yields to 10¹² and 1.5 × 10¹³ DT neutrons, respectively. The comparison of the calculated dependences with experimental data on the current, voltage and neutron yield made it possible to refine the parameters used in the calculations and achieve a satisfactory agreement between the simulation and experiment.

中文翻译：

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球形等离子体焦点腔室内物理过程的MHD模拟，考虑中子产生

摘要

提出了二维MHD代码的开发结果，该代码用于对具有等离子体焦点的球形腔室中的等离子体电流鞘的动力学进行计算研究。在这项工作中使用了磁流体动力学方程，其中考虑了磁场扩散，热导率和等离子体辐射。在磁场的计算中使用隐式方案，这使得可以描述等离子体在鞘鞘后面的低密度区域中的运动。考虑到等离子体中异常电阻的可能出现的公式可用于计算等离子体电导率。计算中子产率时要考虑到热核和射束目标中子产生机理。研究了等离子体鞘后面的最小残留气体密度对等离子体鞘累积的影响。考虑了磁场扩散，热导率和异常等离子体电阻对等离子体鞘层动力学的影响。计算是针对两个球形等离子体聚焦腔进行的，这些腔的工作电流分别为1和2 MA，中子产率为10¹²和1.5×10 ¹³ DT中子。将计算出的相关性与电流，电压和中子产率的实验数据进行比较，使得有可能改进计算中使用的参数，并在模拟和实验之间取得令人满意的一致性。