A New UV Laser Oxygen Extraction System for In Situ 18O Measurement

该奖项支持一项可行性研究，以测试一种新的系统，该系统使用脉冲准分子激光发射紫外线（193纳米），从硅酸盐岩石或矿物的厚截面表面定量释放氧气。该系统将被设计成在不显著加热样品的情况下通过破坏键从表面释放分子。释放出来的分子随后与氟气体反应，释放出氧气，氧气以二氧化碳气体的形式被送入质谱仪。该系统有望改进现有的稳定同位素质谱激光源。稳定同位素质谱使用较长波长的激光，在释放含氧分子之前熔化样品，从而导致虚假的同位素分馏和方法的空间分辨率下降。

This award supports a feasibility study to test a new system for the quantitative release of oxygen from the surfaces of thick sections of silicate rocks or minerals by use of a pulsed excimer laser emitting in the ultraviolet (193 nm). The system will be designed to release molecules from the surface by breaking bonds without heating the sample significantly. The released molecules then are reacted with fluorine gas to liberate oxygen which is fed to a mass spectrometer in the form of CO2 gas. The system is expected to improve existing laser sources for stable isotope mass spectrometry which use longer wave length lasers that melt the sample before releasing oxygen-containing molecules, thereby causing spurious isotope fractionation and a degradation of the spatial resolution of the method.