Calibration of an elastic recoil setup for D/H-ratios close to natural abundance

Nominally Anhydrous Minerals (NAM) in the Earth's mantle contain trace amounts of hydrogen, as a result of the NAM's ability to incorporate hydroxyl ions. The isotopic composition of these hydrogen reservoirs is for the Earth's crust, well characterized. The knowledge of the isotopic composition of the Earth's interior on the other hand is limited. It is believed that the hydrogen composition in the interior is isotopically heterogeneous and that there may exist several reservoirs of hydrogen, characterized by different deuterium/hydrogen-ratios. Characterization of these hydrogen reservoirs can provide valuable information about the mass transport of hydrogen during the evolution of the planet. In this work we present a variant of the proton-proton scattering technique with which we are capable of performing simultaneous measurements of deuterium and hydrogen. The method has been tested with a 2.9 MeV deuteron beam on a polyethylene standard, with D/H ratio close to the natural abundance, and on a thin sample of Muscovite with a hydrogen concentration of 4800 wt-ppm. This is followed by a discussion about limitations and capabilities of the technique. (C) 2014 The Authors. Published by Elsevier B.V.