How much Uranium is in the Earth? Predictions for geo-neutrinos at KamLAND

Geo-neutrino detection can determine the amount of long-lived radioactive elements within our planet, thus providing a direct test of the Bulk Silicate Earth (BSE) model and fixing the radiogenic contribution to the terrestrial heat. We present a prediction for the geo-neutrino signal at KamLAND as a function of the Uranium mass in the Earth. The prediction is based on global mass balance, supplemented by a detailed geochemical and geophysical study of the region near the detector. The prediction is weakly dependent on mantle modeling. If BSE is correct, Uranium geo-neutrinos will produce between 25 and 35 events per year and 10^32 protons at Kamioka.