Time-Resolved Measurement of Interatomic Coulombic Decay in Ne_2

The lifetime of interatomic Coulombic decay (ICD) [L. S. Cederbaum et al., Phys. Rev. Lett. 79, 4778 (1997)] in Ne_2 is determined via an extreme ultraviolet pump-probe experiment at the Free-Electron Laser in Hamburg. The pump pulse creates a 2s inner-shell vacancy in one of the two Ne atoms, whereupon the ionized dimer undergoes ICD resulting in a repulsive Ne^{+}(2p^{-1}) - Ne^{+}(2p^{-1}) state, which is probed with a second pulse, removing a further electron. The yield of coincident Ne^{+} - Ne^{2+} pairs is recorded as a function of the pump-probe delay, allowing us to deduce the ICD lifetime of the Ne_{2}^{+}(2s^{-1}) state to be (150 +/- 50) fs in agreement with quantum calculations.Comment: 5 pages, 3 figures, accepted by PRL on July 11th, 201

Assessment of the hydrogeology and water quality in a near-shore well field, Sarasota, Florida /

Shipping list no.: 96-0321-P.Includes bibliographical references (p. 49-50).Mode of access: Internet

Multi-stage metamorphic and metasomatic imprints on apatite-monazite-xenotime assemblages in a set of small iron oxide-apatite (IOA) ore bodies, Prins Karls Forland, Svalbard

On Prins Karls Forland, Svalbard Archipelago, a set of small iron oxide-apatite (IOA) ore bodies have been discovered within a crustal shear zone, which deformed the polymetamorphosed Neoproterozoic metasedimentary rocks. The ores have various styles and grades of deformation and distinct mineral assemblages whose compositions record a multi-stage tectonothermal and metasomatic history. These IOA ore bodies can be subdivided into fluorapatite-bearing and predominant low-Th monazite in the upper section of the shear zone and FCl apatite-bearing and predominant high Th-monazite in the structurally lower higher-grade deformed part. The first stage of alteration for these ore bodies resulted in metasomatic alteration of the apatite and liberation of REE and P redeposited as monazite and xenotime. The transport of dissolved REE and P was likely enhanced by deformation. The second stage of alteration had a distinct impact on the individual ore bodies, which resulted in the Th-enrichment of a small subset of the monazite grains in the upper section of the shear zone. In the lower section of the shear zone most of the monazite was replaced by high Th monazite. Here the original fluorapatite is enriched in Cl, Mn, and Sr, most probably due to interaction with CaCl2-rich fluids enriched in Sr and Mn that was scavenged from the hosting metasediments and altered metagabbros. Contrasting textures, mineral assemblages, and the geochemistry of the ores from distinct localities reflect involvement of compositionally different fluids from the gabbroic rocks and surrounding metasedimentary rocks during the protracted tectonothermal evolution of Prins Karls Forland. Therefore, it is concluded that the IOA ore bodies most likely resulted due to the fractionation of Fe, P, Ca, and REE from hypersaline fluids associated with the gabbros. Once deposited, these IOA ore bodies were subsequently altered during at least one and perhaps two later metamorphic events