This award will provide partial support for engineering development of a secondary ion resonant ionization mass spectrometer system at the Lamont-Doherty Geological Observatory of Columbia University. The system being developed includes a pulsed-laser excited, two-photon, ionization step which should provide a significantly superior source of ions for mass spectrometry of rare elements like osmium. Improved sensitivity in the analysis of osmium isotopes in geological samples would be a significant advance because of the potential of the rhenium-187 to osmium-187 decay system (half-life of 42 billion years) to unravel problems of the chemical evolution of the crust and mantle and for dating cosmochemical events.
