标题： 双芯孔谱学研究超强X射线脉冲与氖相互作用产生的瞬态等离子体 显示英文标题

标题： Double core-hole spectroscopy of transient plasmas produced in the interaction of ultraintense x-ray pulses with neon

摘要： 双核心空穴（DCH）光谱在与光子能量从937 eV到2000 eV的超强X射线脉冲相互作用的氖原子系统中被系统地研究。 采用在详细能级计数近似中实现的时间依赖速率方程，用于研究高度瞬态等离子体的能级布居和发射特性的动态演化。 对于光子能量在937-1030 eV范围内的X射线脉冲，其中存在氖电荷态单核心空穴（SCH）态的$1s\rightarrow 2p$共振吸收，内壳层共振吸收（IRA）效应在布居和DCH光谱的时间演化中起重要作用。 通过研究光子能量为944 eV的X射线脉冲的相互作用，详细说明了这种IRA物理效应，该能量对应于Ne$^{3+}$的SCH态（$1s2s^22p^4$、$1s2s2p^5$和$1s2p^6$）的$1s\rightarrow 2p$共振吸收。 在对X射线脉冲的空间和时间分布进行平均后，研究了光子能量为937、944、955、968、980和990 eV（分别对应Ne$1s\rightarrow 2p$的共振能量，Ne$^{2+}$-Ne$^{7+}$）的DCH光谱。 讨论了产生DCH态的复杂机制，以937和980 eV处的DCH光谱为例。 对于大于1362 eV的光子能量，在相互作用中没有共振吸收，导致DCH光谱的物理图像相似。 主要的DCH态是由Ne$^{7+}$-Ne$^{9+}$的更高电离阶段引起的，而来自较低电荷态Ne$^{2+}$-Ne$^{6+}$的DCH光谱则要弱得多。 随着X射线光子能量的增加，低电荷态的贡献变得更大。 显示英文摘要

摘要： Double core-hole (DCH) spectroscopy is investigated systematically for neon atomic system in the interaction with ultraintense x-ray pulses with photon energy from 937 eV to 2000 eV. A time-dependent rate equation, implemented in the detailed level accounting approximation, is utilized to study the dynamical evolution of the level population and emission properties of the highly transient plasmas. For x-ray pulses with photon energy in the range of 937-1030 eV, where $1s\rightarrow 2p$ resonance absorption from single core-hole (SCH) states of neon charge states exist, inner-shell resonant absorption (IRA) effects play important roles in the time evolution of population and DCH spectroscopy. Such IRA physical effects are illustrated in detail by investigating the interaction of x-ray pulses at a photon energy of 944 eV, which corresponds to the $1s\rightarrow 2p$ resonant absorption from the SCH states ($1s2s^22p^4$, $1s2s2p^5$ and $1s2p^6$) of Ne$^{3+}$. After averaging over the space and time distribution of the x-ray pulses, DCH spectroscopy at photon energies of 937, 944, 955, 968, 980, and 990 eV (corresponding to the $1s\rightarrow 2p$ resonance energies of Ne$^{2+}$-Ne$^{7+}$, respectively) are studied in detail. The complex mechanisms of producing the DCH states are discussed, taking the DCH spectroscopy at 937 and 980 eV as examples. For photon energy larger than 1362 eV, there are no resonance absorption in the interaction, resulting in a similar physical picture of DCH spectroscopy. The dominant DCH states are due to higher ionization stages of Ne$^{7+}$-Ne$^{9+}$, while the DCH spectroscopy from lower charge states Ne$^{2+}$-Ne$^{6+}$ are much weaker. With the increase of x-ray photon energy, the contributions from the lower charge states become larger.