Study of Spin-forbidden Ionization and Excitation via Inner-shell Excitation

通过将光子能量调谐到作为中间态的内壳层激发，除了软X射线光电子谱和软X射线发射谱中的自旋允许多重态之外，还可以观察到自旋禁戒跃迁。本研究利用光电子共振谱和光子发射谱来揭示自旋禁戒的价态电离态和价态激发态。这种共振光谱的理论和实验方法的开发。在理论研究方面，本文采用从头算R矩阵/多量子亏损理论（MQDT）方法，对开壳层分子中的束缚态和连续态进行了系统的理论分析。将该方法应用于NO和O_2等开壳层分子。我们成功地区分了内壳层激发和单个分子的特性。本工作建立了合理处理芯-价交换相互作用的理论方法，在实验方法上，研制了新型的下一代软X射线发射谱仪。目前的能量分辨率约为4，500。这个分辨率是世界上最好的，比以前的最好分辨率高得多。对CCD探测系统进行了改进，使其能够探测C、N、O等离子体激发的软X射线。透射光栅系统也被设计成用于检测通过C、N和O 1 s激发发射的软X射线。建立了处理自旋禁戒价态激发的实验方法。此外，用新研制的团簇光电子装置揭示了在单分子体系中，团簇形成后可观察到禁带。

The spin-forbidden transitions become observable in addition to spin-allowed multiplets in the soft X-ray photoelectron spectra and soft X-ray emission spectra by tuning the photon energy to the inner-shell excitation as an intermediate state. In this research, resonant spectroscopy of photoelectron and photon emission was applied to reveal spin-forbidden valence ionized states and valence excited states. Theoretical and experimental approaches for such resonant spectroscopy were developed. Spin multiplets are produced due to exchange interaction ; therefore, multiplet interaction in open-shell molecules was especially studied in detail.In the theoretical approaches, an ab initio R-matrix/Multi Quantum Defect Theory (MQDT) method was newly developed to analyze systematically both the bound state below the ionization threshold and the continuum state above the threshold. This R-matrix/MQDT approach was applied to open-shell molecules such as NO and O_2. We successfully distinguished between characteristics of inner-shell excitation and of individual molecule. The theoretical approach to treat core-valence exchange interaction reasonably has been established in this work.In the experimental approaches, a new-type and next-generation soft X-ray emission spectrometer was developed. The present energy resolution was about 4,500. This resolution is the best in the world and is much higher than the previous best resolution. The CCD detection system was improved to detect soft X-rays emitted via C, N and O is excitation. The transmission grating system was also designed to detect soft X-rays emitted via C, N and O 1s excitation. The experimental approach to treat spin-forbidden valence excitation has been established in this work. In addition, it is revealed with a newly-developed cluster photoelectron apparatus that forbidden bands in a single molecular system are observable after molecular cluster formation.