A versatile electron-ion coincidence spectrometer for photoelectron momentum imaging and threshold spectroscopy on mass selected ions using synchrotron radiation
A versatile electron-ion coincidence spectrometer for photoelectron momentum imaging and threshold spectroscopy on mass selected ions using synchrotron radiation
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DOI：
10.1063/1.3079331
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发表时间：
2009-02-01
影响因子：
1.6
通讯作者：
Nahon, Laurent
中科院分区：
文献类型：
--
作者：
Garcia, Gustavo A.;Soldi-Lose, Heloise;Nahon, Laurent
我们提出了一个名为DELICIOUS II的光电子-光离子符合（PEPICO）光谱仪，它结合了速度图成像装置与Wiley-McLaren飞行时间分析仪，用于研究气相样品与同步辐射（SR）的相互作用。这个多功能的系统是能够提供光电子图像的质量选择的化合物与Δ E/E=5%的动能分辨率和17 eV的带宽，以及阈值光电子光谱的测量分辨率为0.8 meV，如所示的氩的3 p（-1）电离。该仪器也用于阈值PEPICO实验，允许选择母离子的内部状态，对于轻质量（< 40 amu）具有亚meV分辨率，对于100 amu的质量具有通常2 meV分辨率，并且具有高于200的质量分辨能力。提取字段的连续操作和电子的飞行时间的独立性很好地适应于SR的准连续多聚束模式。这与电子和离子检测的高透射率一起，允许高的重合计数率，并便于减去假重合。我们说明了光谱仪的符合操作原理的例子，从价光电离的Ar+ CF 4的混合物和。
We present a photoelectron-photoion coincidence (PEPICO) spectrometer named DELICIOUS II which combines a velocity map imaging apparatus with a Wiley-McLaren time of flight analyzer for the study of gas phase samples in interaction with the synchrotron radiation (SR). This versatile system is capable of providing photoelectron images on mass-selected compounds with kinetic energy resolutions of Delta E/E=5% and a 17 eV bandwidth, as well as threshold photoelectron spectra with a measured resolution of 0.8 meV, as demonstrated on the 3p(-1) ionization of argon. This instrument is also employed for threshold PEPICO experiments, allowing the selection of the parent ion's internal state with sub-meV resolution for light masses (< 40 amu) and with typically 2 meV resolution for a mass of 100 amu and with a mass resolving power above 200. The continuous operation of the extraction fields and the independence from the electron's time of flight are well adapted to the quasicontinuous multibunch mode of the SR. This, together with the high transmission of both the electron and ion detection, allows a high coincidence counting rate and facilitates the subtraction of false coincidences. We illustrate the spectrometer's coincidence principle of operation with examples from the valence photoionization of an Ar+Xe mixture and of CF4.