High-Vacuum Extraction of Helium and Other Gases from Milligram Samples of Minerals and Rocks Using a Ytterbium Fiber Optic Laser in Scanning Mode

The main techniques used for gas extraction from solid geological samples for geochronological studies are their thermal destruction either in an isothermal mode, for example in a double vacuum furnace, or under the action of laser radiation. Approaches based on the use of laser technologies are more express and have a low-background. The article describes an original high-vacuum experimental setup based on an ytterbium fiber optic laser for gas extraction from milligram samples of rocks and minerals in a scanning mode. In the proposed configuration, a static vacuum of 10–8 Torr can be achieved in the high vacuum laser cell. Heating of individual mineral grains to a temperature of over 1800°C is ensured. Using the example of the international standard for (U,Th)–He dating—Durango apatite—it is demonstrated that the laser installation ensures complete extraction of radiogenic helium from the mineral and can be used for isotope-geochronological studies.