Krypton-81 Dating in Polar Ice Samples

根据宇宙起源的81Kr（半衰期为21万年）的直接测量，提出了一种新的方法来测定极性冰或其他环境样品的年龄，这些样品的年龄在5万年至100万年之间。该方法包括对从冰中提取的氪进行同位素富集，然后使用基于激光的共振电离光谱技术对81Kr进行超灵敏探测。81Kr技术的可行性将通过测量从南极洲Allan Hills地区收集的两个旧冰样本和两个现代冰样本中的81Kr来证明。该结果将为开发商业81kr测年设备提供基础，该设备除了极地冰测年外，还将在地下水测年、水文学、太阳中微子研究和陨石研究中具有重要应用。

A new method for dating polar ice or other environmental Samples which are 50,000 years to 1,000,000 years old is proposed, based on the direct measurements of cosmogenic 81Kr (half-life = 210,000 yrs.). The method consists of isotopic enrichment of the krypton extracted from the ice followed by ultrasensitive detection of the 81Kr using the laser-based technique of Resonance Ionization Spectroscopy. Feasibility of the 81Kr technique will be demonstrated by measuring 81Kr in two old ice samples and two modern ice samples collected from the Allan Hills area of Antarctica. The results will provide the basis for development of a commercial 81Kr-dating facility which will have important applications, in addition to polar ice dating, in groundwater dating, hydrology, solar neutrino studies, and meteorite studies.