Development Completion of Rare Krypton Isotope Analysis for the Geosciences and First Validation Measurements

0119110本奖项为完成测量两种稀有氪同位素Kr-81和Kr-85丰度所需技术的开发提供部分支持。这些同位素在大气中的浓度是稳定和已知的，可能是各种环境研究的理想示踪剂。KR-81的半衰期为22.9万年，它可以确定古代冰或地下水在20000至100万年的时间范围内从大气中分离了多长时间。同样，Kr-85的半衰期为10.8年，可以确定1到50年的隔离时间。例如，这些类型的测量可以提供对地下水运动的重要洞察，确定污染渗透的途径，并为全面资源管理提供投入。由于在化学上是惰性的，预计氪同位素将通过消除与地下环境相互作用的复杂性，提供比其他化学活性示踪剂更可靠的结果。这笔赠款赞助的工作包括完成对现有仪器的必要改进，以及将该技术应用于几个重要的地下水问题，以突出其实用性。

0119110ThonnardThis award provides partial support to complete development of technology necessary for measuring the abundance of two rare krypton isotopes, Kr-81 and Kr-85. These isotopes, whose concentration in the atmosphere is stable and known, are potentially ideal tracers for a variety of environmental studies. Kr-81, with a 229,000 year half-life, can determine how long ancient ice or ground water has been isolated from the atmosphere in the 20,000 to 1,000,000 year time range. Similarly, Kr-85, with its 10.8 year half-life, can determine isolation times in the 1 to 50 year time range. These type of measurements can, for instance, provide important insight into the movement of groundwater, identify pathways for pollution infiltration, and provide input to overall resource management. Being chemically inert, it is anticipated that the krypton isotopes will provide more reliable results than other, chemically active tracers, by eliminating the complexity of interactions with the underground environment. The work sponsored by this grant includes completion of the necessary improvements to existing instrumentation, and application of the technique to several important groundwater problems to highlight its utility.***