Instrumatational development of laser spectroscopic analyzer for mass-selected RF ion trapped species

1.用俘获离子光解光谱研究了苯酚与NH_3、H_2O、对二氧六环等接受氢分子络合后阳离子的稳定形态。366 ~ 465 nm范围内的电子谱显示，苯酚- nh_3配合物的基态离子由一个苯氧自由基和一个铵离子组成，而其他离子则是苯酚离子与未质子化受体的配合物。讨论了质子在基态转移和离子激发态的离解过程。苯酚与N(CH_3)_3氢键配合阳离子的电子能谱。利用光解光谱结合射流冷却分子络合离子生成的新方法，对NH_3和H_2O进行了研究。该方法包括苯酚的电离，然后是射流膨胀，以有效地形成复合离子以及冷却。在苯酚与N(CH_3)_3和NH_3的络合离子中，得到了分辨良好的振动带，包括分子间拉伸振动带。在此基础上讨论了这些配合物的离子形式和中性形式的区别。提出了一种在空间上限制质量选择离子并以低动能将其提取到固体表面的新技术。该技术结合了射频离子捕获和KrF准分子激光的多光子电离。从SF_6光解离的SF_5^+离子与其他离子分离，并在圆柱形离子阱中储存至少100ms。储存的离子以10eV左右的低动能被提取到表面。这项技术对于研究大量选择、状态指定和极低动能离子的表面反应，以及开发可用于在原子尺度上控制半导体表面结构的蚀刻工艺，应该是有用的。

1.Stable forms of cations of phenol complexed with hydrogen-accepting molecules such as NH_3, H_2O or p-dioxane were investigated with trapped ion photodissociation spectroscopy. Electronic spectra in the range 366-465 nm reveal that the ground-state ion of the phenol-NH_3 complex consists of a phenoxy radical and an ammonium ion, whereas other ions are complexes of phenol ions with unprotonated acceptors. Dissociation processes involving the proton transfer in the ground and the excited states of the ions are discussed.2.Electronic spectra of hydrogen-bonded complex cations of phenol with N(CH_3)_3. NH_3 and H_2O were investigated by photodissociation spectroscopy combined with a new method for the generation of jet-cooled molecular complex ions. The method involves the ionization of phenol followed by a jet expansion for the efficient formation of the complex ions as well as for the cooling. Well-resolved vibronic bands, including the bands due to intermolecular stretching vibrations, were obtained for the complex ions of phenol with N(CH_3)_3 and NH_3. Differences between the ionic and neutral forms of these complexes were discussed on the basis of the results.3.A new technique is proposed for spatially confining mass-selected ions and extracting them to a solid surface at low kinetic energy. This technique combines rf ion trapping with multiphoton ionization by a KrF excimer laser. SF_5^+ ions photodissociated from SF_6 were separated from other ionic species and stored in the cylindrical ion trap cell for at least 100ms. The stored ions were extracted onto the surface with low kinetic energies around 10eV.This technique should be useful for studying surface reactions with mass-selected, state-specified, and very-low-kinetic-energy ions and for developing etching processes that can be used to control the surface structure of semiconductors on an atomic scale.