AI 中文总结
本研究利用OMEGA激光装置的实验获取温稠密铜的K边吸收数据，将其与两类模型对比，发现结合激发态投影缀加波势的密度泛函理论可较好建模K边区域，凸显需改进温稠密等离子体的密度依赖原子建模。
AI 中文摘要
温稠密物质仍是实验表征和预测精度建模的具有挑战性的区域。最近已开发出用于产生、表征和诊断均匀温稠密物质的实验平台，使得能与模型进行详细比较。在此，我们介绍在OMEGA激光装置开展的实验，该实验将埋层靶压缩并加热至温稠密物质条件，其中靶被加热至约20 eV的温度，并被压缩至25 g/cm^3的密度。我们利用X射线吸收光谱探测该温稠密等离子体，使用K边和束缚-束缚吸收特征来约束等离子体的温度和电荷态分布。我们将这些测量结果与两种类型的模型进行比较：具有详细电子结构和特设密度效应的碰撞-辐射模型，以及结合激发态投影缀加波势的密度泛函理论多离子模型。两种方法均未完全复现观测数据。我们表明，K边区域的宽结构和位置可通过结合激发态投影缀加波势的密度泛函理论进行建模。将密度泛函理论结果与包含特设密度效应的碰撞-辐射模型方法进行对比，后者与实验观测结果不完全一致，凸显了温稠密等离子体中对改进的密度依赖原子建模的需求。
英文摘要
Warm dense matter remains a challenging regime to characterize experimentally and to model with predictive accuracy. Recent experimental platforms have been developed to generate, characterize, and diagnose uniform warm dense matter, enabling detailed comparisons with models. Here, we present experiments conducted at the OMEGA laser facility that compress and heat a buried layer target to warm dense matter conditions, where the targets are heated to temperatures of approximately 20 eV and compressed to densities of 25 g/cm^3. We probe the warm dense plasma using x-ray absorption spectroscopy, using the K-edge and bound-bound absorption features to constrain the temperature and charge state distribution of the plasma. We compare these measurements with two types of models: collisional-radiative models with detailed electronic structure and ad-hoc density effects, and a multi-ion model based on density functional theory in combination with excited-state projector augmented-wave potentials. Neither approach fully reproduces the observed data, We show that the broad structure and position of the K-edge region can be modeled using density functional theory in combination with excited-state projector augmented-wave potentials. The density functional theory results are contrasted with a collisional-radiative model approach that incorporates ad-hoc density effects, which show incomplete agreement with the experimental observations, highlighting a need for improved density-dependent atomic modeling in warm dense plasmas.
Comments9 pages, 5 figures
