Investigation of phase transition processes arises from atomic and radiative property of plasmas for EUV and X-ray laser applications

本文研究了激光等离子体和放电等离子体中不均匀结构的形成机制，考虑了等离子体的原子和辐射特性引起的相变过程。我们建立了一个详细的钨原子模型，它对聚变等离子体感兴趣。对模型的尺寸进行了参数化，并通过灵敏度研究和基准计算提高了平均电荷和辐射功率损耗的计算精度。我们还研究了放电等离子体中的渗透跃迁。我们基于SF6的材料特性（如电离和附着系数）来研究其放电的发展，以重现从最初的局部放电到后来的阶梯引线生长导致击穿的实验观察。通过原子模型、辐射转移模型和相变模型的结合，将提高对等离子体结构形成的理解。

We investigate the mechanism of formation of the inhomogeneous structure in laser produced plasmas and discharge plasmas, by taking the phase transition processes into account, which originate from atomic and radiative properties of plasmas. We develop a detailed atomic model of tungsten, which is interested in fusion plasmas. The size of the model is parameterized, and accuracy of the calculation of mean charge and radiative power loss is improved by sensitivity studies and benchmark calculations. We also investigate percolation transition in discharge plasmas. We investigate development of discharge in SF6 based on its material properties such as ionization and attachment coefficient to reproduce experimental observations from initial partial discharge to later growth of the stepped leader to cause breakdown. By combining both atomic model, radiative transfer model and phase transition model understanding of structure formation in the plasmas will be improved.