Mack Kennedy with Mass Spectrometer (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption Berkeley Lab geochemist B. Mack Kennedy used this mass spectrometer (foreground) to determine helium isotope ratios in samples of surface fluids from the northern Basin and Range. Credit Roy Kaltschmidt Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.