In the last ten years, the use of gamma-ray spectrometry for geological mapping and mineral exploration has shown considerable growth. With this growth, standardized procedures have been developed for the calibration and processing of the airborne measurements so that they will be independent of survey parameters. This paper describes some of the new developments to convert airborne data to gro...

The South Pole-Aitken basin (SP-A) is the largest and oldest basin on the Moon. The basin has usually been interpreted to exhibit a degraded circular structure, but here we demonstrate that the topography, iron and thorium signatures of the basin are well described by ellipses with axes measuring 2400 by 2050 km and centered at 53 , 191 E. Topography, abundances of iron, thorium, and the distri...

Electron antineutrinos accompanying the β-decays of long-lived isotopes of uranium, thorium, and potassium in the earth carry information about the quantity and distribution of these geologically important, heat-producing isotopes. This letter discusses terrestrial antineutrino flux measurements at both a continental and an oceanic site. A combined analysis of both measurements provides informa...

________________________________ _________ _ Introduction and acknowledgments __________________ _ Distribution of uranium and thorium in igneous rocks __ _ ~age 91 91 92 Processing ________________ ___ ___ ___ ______ _________ _ Energetics and ·cost ________________ ----------------Conclusions ______________________ ___ _______ ______ _ Page

the stereochemistry of the actinide elements has recently undergone considerable development and a wide variety of coordination numbers and geometries have been observed. this structural versatility arises from the lack of strong crystal field effects for the 5f-electronic configurations as well as from the large ionic radii of these metal ions, which change markedly with oxidation number, or a...

The impact of coherent light propagation on the excitation and fluorescence of thorium nuclei in a crystal lattice environment is investigated theoretically. We find that in the forward direction, the fluorescence signal exhibits characteristic intensity modulations dominated by a sped-up initial decay signal that is orders of magnitude faster. This feature can be exploited for the optical dete...