紫外光诱导光电子发射负离子源的阈值光电子成像仪设计 (cited: 2)

设计了一套紧凑的光电子成像装置，它包括解离式光电子贴附负离子源、垂直安装的高分辨阈值光电子速度成像装置和线性飞行时间质谱仪．紫外光辐射金属表面诱导低能光电子发射，再通过低能电子贴附超声分子束产生高强度和冷的负离子源．结合这种负离子源和飞行时间质谱-光电子成像仪装置，仪器的质量分辨能达到200左右，能量分辨优于3%(即对1 eV动能的电子，分辨达到30 meV)．此外，使用该实验装置获得了CH₃S^-和S₂^-在611.46 nm下的低能阈值光电子成像结果．同时得到了CH₃S和S₂的更精确的电子亲和势分别为1.8626±0.0020和1.6744±0.0035 eV．初步的结果证明了该装置对研究阈值光电子成像精确测量光电子亲和势非常有效

Design Near-threshold Photoelectron Imaging Spectrometer Based on UV Laser Induced Photoelectron Emission Anion Source (cited: 2)

We have developed a compact photoelectron imaging facility, including an anion source with dissociative photoelectron attachment to molecules, a linear time-of-flight mass spec-trometry (TOFMS), and an orthogonal high-resolution threshold photoelectron velocity map imaging spectrometer (VMI). Intense and cold cluster anions were prepared in photoelectron-attachment processes upon pulsed UV laser ablation of metal target. Combining this anion source with TOFMS-VMI, the achieved mass resolution is about 200, and the electron ki- netic energy resolution is better than 3%, i.e., 30 meV for 1 eV electrons. More importantly, low-energy photoelectron imaging spectra for CH₃S^- and S₂^- at 611.46 nm are obtained. In both cases, the refined electron a±nities are determined to be 1.8626±0.0020 eV for CH₃S and 1.6744§±0.0035 eV for S₂, respectively. Preliminary results suggest that the apparatus is a powerful tool for estimating precise electron affinities values from threshold photoelectron imaging spectroscopy