We present a review on the photoionization bands that can be found in the far ultraviolet part of the spectrum using all sapphire cells in absorption experiments with hot alkali vapor. We describe cesium and rubidium dimers which have very pronounced photoionization bands together with bialkali mixtures like KCs and RbCs. We explain the origin of these peculiar bands as special molecular transitions between the ground state of the neutral molecule and exited states of the ionized molecule as a direct ionization process. We also described the diffuse bands as transition from the same ground state molecule to doubly excited molecular state, as an indirect ionization process. Finally, we believe that these two pathways may interfere resulting in a complex structure revealing the observed diffuse bands.

我们使用所有蓝宝石电池在热碱蒸气吸收实验中对可以在光谱的远紫外部分找到的光电离带进行了综述。我们描述了铯和铷二聚体，它们具有非常明显的光电离带以及双碱混合物，如 KCs 和 RbCs。我们将这些特殊带的起源解释为中性分子的基态和电离分子的激发态之间的特殊分子跃迁，作为直接电离过程。我们还将漫带描述为从相同基态分子到双激发分子态的转变，作为间接电离过程。最后，我们认为这两种途径可能会相互干扰，从而导致复杂的结构，从而揭示出观察到的扩散带。