Ultrasensitive resonance ionization mass spectrometer for evaluating krypton contamination in xenon dark matter detectors
Ultrasensitive resonance ionization mass spectrometer for evaluating krypton contamination in xenon dark matter detectors
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用于评估氙暗物质探测器中氪污染的超灵敏共振电离质谱仪
DOI：
10.1016/j.nima.2015.06.037
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
C. Ito
中科院分区：
文献类型：
--
作者：
Y. Iwata;H. Sekiya;C. Ito
用超灵敏的共振电离质谱仪测量Xe暗物质探测器中的氪(Kr)污染，可以测量Pppt或Pppt级的Xe。气体样品通过脉冲超音速阀门被引入飞行时间质谱仪，没有任何冷凝。利用波长为212.6 nm的纳秒脉冲激光，样品中的84Kr原子与其他Kr同位素一起被共振电离，然后84Kr离子被质量分离并由质谱仪检测，以测量Kr杂质浓度。在我们目前的设置下，可以检测到纯Ar气体中约0.4ppt的Kr杂质，测量时间为1000ppt S。尽管Xe中的Kr检测灵敏度预计约为Ar的一半，但我们的光谱仪可以将Xe中的Kr污染评估到亚ppt级别。
An ultrasensitive resonance ionization mass spectrometer that can be applied to evaluate krypton (Kr) contamination in xenon (Xe) dark matter detectors has been developed for measuring Kr at the parts-per-trillion (ppt) or sub-ppt level in Xe. The gas sample is introduced without any condensation into a time-of-flight mass spectrometer through a pulsed supersonic valve. Using a nanosecond pulsed laser at 212.6 nm,84Kr atoms in the sample are resonantly ionized along with other Kr isotopes.84Kr ions are then mass separated and detected by the mass spectrometer in order to measure the Kr impurity concentration. With our current setup, approximately 0.4 ppt of Kr impurities contained in pure argon (Ar) gas are detectable with a measurement time of 1000 s. Although Kr detection sensitivity in Xe is expected to be approximately half of that in Ar, our spectrometer can evaluate Kr contamination in Xe to the sub-ppt level.