Momentum mapping spectrometer for probing the fragmentation dynamics of molecules induced by keV electrons
Momentum mapping spectrometer for probing the fragmentation dynamics of molecules induced by keV electrons
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DOI：
10.1088/0957-0233/22/5/055901
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发表时间：
2011-05
影响因子：
2.4
通讯作者：
R. Singh;P. Bhatt;N. Yadav;R. Shanker
中科院分区：
文献类型：
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作者：
R. Singh;P. Bhatt;N. Yadav;R. Shanker
我们描述了一种新的实验装置，用于研究由keV电子的影响引起的分子的碎裂动力学，使用众所周知的反冲离子动量谱技术。该装置主要由一个用于离子分析的时间和位置敏感的多击粒子检测器和一个用于检测喷射电子的通道电子倍增器检测器组成。详细描述了设置的不同组件和用于数据采集的相关电子设备及其工作原理。为了验证装置的可靠性能，我们记录了碰撞诱导的离子光谱的CO2分子的keV电子的影响。获得了20和26 keV电子与CO_2分子的稀靶气体离解电离碰撞产生的CO ~+：O ~+、C ~+：O ~+和O ~+：O ~+离子对的信息。在本实验条件下，谱仪对CO ~+和O ~+离子在飞行时间轴方向和垂直于电子束方向的动量分辨分别为10.0 ± 0.2和15.0 ± 0.3 Au。
We describe a new experimental setup for studying the fragmentation dynamics of molecules induced by the impact of keV electrons using the well-known technique of recoil ion momentum spectroscopy. The apparatus consists of mainly a time- and position-sensitive multi-hit particle detector for ion analysis and a channel electron multiplier detector for detecting the ejected electrons. Different components of the setup and the relevant electronics for data acquisition are described in detail with their working principles. In order to verify the reliable performance of the setup, we have recorded the collision-induced ionic spectra of the CO2 molecule by the impact of keV electrons. Information about the ion pairs of CO+:O+, C+:O+ and O+:O+ resulting from dissociative ionizing collisions of 20 and 26 keV electrons with a dilute gaseous target of CO2 molecules has been obtained. Under conditions of the present experiment, the momentum resolutions of the spectrometer for the combined momenta of CO+ and O+ ions in the direction of the time-of-flight axis and perpendicular to the direction of an electron beam are found to be 10.0 ± 0.2 and 15.0 ± 0.3 au, respectively.