原子间电子跃迁的耦合对稠密等离子体光吸收的影响

There are couplings between the electronic transition processes of two nearest neighbor atoms in dense matters, such as the Rydberg blockade in cold dense gases and the interatomic Auger and autoionization transitions. There are two kinds of the couplings: one is due to the interactions between the final states of electron transitions occuring in each atom's own and makes the transitions cannot take place independently; the other one is the electronic transitions between different atoms. The matter density in inertial controled fusion and laser impact on solid target produced plasmas can be much higher than the normal solid state metters, and therefore the above mentioned two kinds of channel couplings exist normally in dense plasmas. The couplings between the electron transition channels of different atoms can change the photon absorption cross section distribution and even cause quantum interferences compared with the isolated atoms. Opacity, one of the most important quantities in inertial controled funsion, solar physics, and laser material interaction researches, depends strongly on the details of the photon absorption cross section of the atoms and must be calculated with adequate consideration of the interatomic effect in dense plasmas. In this project, physical models describing the interatomic electron transition channel coupling will be developed resulting formulas of calculating the coupling strength. Numerial calculations for the cross section and opacity with proper statistial relative atomic distributions in the plasmas.

稠密介质中相邻原子的电子跃迁过程会产生相互影响，例如冷稠密原子气中的里德堡态阻塞、固体中原子之间的俄歇跃迁和自电离等。可以看出此类相互作用有两类：一是相邻原子各自内部电子跃迁的末态之间存在相互作用，使得其各自内部的电子跃迁过程不能独立发生，二是相邻原子之间发生的跨原子的电子跃迁过程。在惯性约束聚变和激光辐照固体材料等过程中涉及的稠密等离子密度可以远超过通常的固体密度，所以上述两类相邻原子之间电子跃迁过程的耦合在稠密等离子体中都普遍存在。这种电子跃迁通道之间的耦合可以显著改变原子辐射吸收截面分布并在通道之间产生量子干涉效应，直接影响光辐射在稠密等离子体中的传输特性，而这种传输特性对惯性约束聚变、恒星结构、激光物质相互作用等研究至关重要。本项目将建立原子间电子跃迁通道耦合的物理模型，推导计算耦合强度的矩阵元，编写数值计算模块，结合稠密等离子体中原子相对分布的统计结果，给出等离子体整体辐射吸收。

在惯性约束聚变和激光辐照固体材料等过程中涉及的稠密等离子密度可以远超过通常的固体密度。其中，相邻原子的电子跃迁过程会产生相互影响，例如冷稠密原子气中的里德堡态阻塞、固体中原子之间的俄歇跃迁和自电离等。这种电子跃迁通道之间的耦合可以显著改变原子辐射吸收截面分布并在通道之间产生量子干涉效应，直接影响光辐射在稠密等离子体中的传输特性，而这种传输特性对惯性约束聚变、恒星结构、激光物质相互作用等研究至关重要。在本项目中，我们首先利用量子朗之万方程描述稠密等离子体中原子和环境（电离电子、热辐射光子、离子等）的相互作用，研究了稠密等离子体中电子、离子环境对原子、离子内部电子结构、能级和跃迁的影响；其次，完成了相邻原子间Auger跃迁和辐射跃迁的数值计算程序的编制，讨论了内壳层双Auger跃迁在x-射线激光电离原子内壳层电子后的级联电离和激发过程；最后，发展了大规模量子力学密度矩阵主方程方法，在其中引入相干和非相干相互作用，分别描述原子系统在激光等相干驱动下以及自发辐射和电子碰撞等非相干作用下，原子系统激发、电离、复合等非平衡动力学过程的系统理论。