Boyle G J, Thévenet M, Chappell J, Garland J M, Loisch G, Osterhoff J, D'Arcy R
Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany.
University College London, Gower Street, London WC1E 6BT, United Kingdom.
Phys Rev E. 2021 Jul;104(1-2):015211. doi: 10.1103/PhysRevE.104.015211.
A model describing the evolution of the average plasma temperature inside a discharge capillary device including Ohmic heating, heat loss to the capillary wall, and ionization and recombination effects is developed. Key to this approach is an analytic quasistatic description of the radial temperature variation which, under local thermal equilibrium conditions, allows the radial behavior of both the plasma temperature and the electron density to be specified directly from the average temperature evolution. In this way, the standard set of coupled partial differential equations for magnetohydrodynamic (MHD) simulations is replaced by a single ordinary differential equation, with a corresponding gain in simplicity and computational efficiency. The on-axis plasma temperature and electron density calculations are benchmarked against existing one-dimensional MHD simulations for hydrogen plasmas under a range of discharge conditions and initial gas pressures, and good agreement is demonstrated. The success of this simple model indicates that it can serve as a quick and easy tool for evaluating the plasma conditions in discharge capillary devices, particularly for computationally expensive applications such as simulating long-term plasma evolution, performing detailed input parameter scans, or for optimization using machine-learning techniques.
开发了一个描述放电毛细管装置内平均等离子体温度演化的模型，该模型包括欧姆加热、向毛细管壁的热损失以及电离和复合效应。这种方法的关键是对径向温度变化进行解析准静态描述，在局部热平衡条件下，这允许直接从平均温度演化确定等离子体温度和电子密度的径向行为。通过这种方式，磁流体动力学（MHD）模拟的标准耦合偏微分方程组被一个单一的常微分方程所取代，从而在简单性和计算效率方面有相应提高。针对一系列放电条件和初始气体压力下的氢等离子体，将轴上等离子体温度和电子密度计算结果与现有的一维MHD模拟进行了基准测试，并证明了良好的一致性。这个简单模型的成功表明，它可以作为一种快速简便的工具，用于评估放电毛细管装置中的等离子体条件，特别是对于计算成本高昂的应用，如模拟长期等离子体演化、进行详细的输入参数扫描或使用机器学习技术进行优化。
