发表机构
Leiden University（莱顿大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对低温冰紫外光解产物检测受探测器动态范围限制的问题，提出脉冲离子偏转法，通过精确控制偏转电压抑制丰度物种，将灵敏度提高30倍，成功测量复杂有机分子。
AI 中文摘要
2014年，我们引入了一种新的实验方法，利用激光烧蚀结合电离和飞行时间质谱（ToF-MS）来研究天体物理感兴趣的低温冰的紫外光加工。该装置MATRI$^2$CES（用于研究星际冰的质量分析工具）使我们能够检测低丰度的新形成物种。然而，我们发现随着分子复杂性的增加，较大光产物的检测受到探测器动态范围的阻碍。在这里，我们介绍一种克服此问题的方法，并期望该方法对其他研究领域的类似应用有用。该概念基于一个精确控制的高能脉冲器，它调节ToF-MS偏转板上的电压，以偏转最丰富的物种并阻止它们到达探测器。通过这种方式，探测器灵敏度可以从2500 V的工作电压提高到3000 V。首先使用氩基质说明其适用性，其中$^{40}$Ar$^+$离子被偏转，以将$m/z=20$处$^{40}$Ar$^{2+}$和$m/z=80$处$^{40}$Ar$_2^+$的检测灵敏度提高30倍。同样，我们表明，在紫外辐照的甲醇冰中，可以测量到相当大的复杂有机分子。
英文摘要
In 2014, we introduced a new experimental approach to study the UV photo-processing of cryogenic ices of astrophysical interest using laser ablation in combination with ionization and time-of-flight mass spectrometry (ToF-MS). The setup, MATRI$^2$CES (Mass Analytical Tool to Research Interstellar ICES), allowed us to detect newly formed species at low abundances. However, we found that with increasing molecular complexity, the detection of larger photoproducts was hindered by the dynamic range of the detector. Here, we introduce a method to overcome this issue that we expect to be useful for similar applications in other research fields. The concept is based on a precisely controlled high-energy pulser that regulates the voltage across the deflection plates of the ToF-MS to deflect the most abundant species and prevent them from reaching the detector. In this way, the detector sensitivity can be increased from an operating voltage of 2500~V up to 3000~V. The applicability is first illustrated using an argon matrix, in which $^{40}$Ar$^+$ ions are deflected to increase the detection sensitivity for $^{40}$Ar$^{2+}$ at $m/z=20$ and $^{40}$Ar$_2^+$ at $m/z=80$ by a factor of 30. Similarly, we show that substantially larger complex organic molecules can be measured in UV-irradiated methanol ice.
Comments24 pages, 8 figures
Journal refRev. Sci. Instrum. 95, 023304 (2024)
