High-Temperature Superconducting Level Meter for Liquid Argon Detectors

Capacitive devices are customarily used as probes to measure the level of noble liquids in detectors operated for neutrino studies and dark matter searches. In this work we describe the use of a high-temperature superconducting material as an alternative to control the level of a cryogenic noble liquid. Lab measurements indicate that the superconductor shows a linear behaviour, a high degree of stability and offers a very accurate determination of the liquid volume. This device is therefore a competitive instrument and shows several advantages over conventional level meters.Comment: 13 pages, 11 figures. Accepted for publication in JINS

Direct WIMP identification: Physics performance of a segmented noble-liquid target immersed in a Gd-doped water veto

We evaluate background rejection capabilities and physics performance of a detector composed of two diverse elements: a sensitive target (filled with one or two species of liquefied noble gasses) and an active veto (made of Gd-doped ultra-pure water). A GEANT4 simulation shows that for a direct WIMP search, this device can reduce the neutron background to O(1) event per year per tonne of material. Our calculation shows that an exposure of one tonne $\times$ year will suffice to exclude spin-independent WIMP-nucleon cross sections ranging from $10^{-9}$ pb to $10^{-10}$ pb.Comment: 17 pages, 5 figures. Version accepted for publication in JCA

K−K^--Nucleus Scattering at Low and Intermediate Energies

We calculate $K^-$-nucleus elastic differential, reaction and total cross sections for different nuclei ($^{12}$C,$^{40}$Ca and $^{208}$Pb) at several laboratory antikaon momenta, ranging from 127 MeV to 800 MeV. We use different antikaon-nucleus optical potentials, some of them fitted to kaonic atom data, and study the sensitivity of the cross sections to the considered antikaon-nucleus dynamics.Comment: Only 4 pages, Latex, 3 Figures. This version is much shorter than the previous one. Some details and references have been omitte

Performance of a cryogenic system prototype for the XENON1T Detector

We have developed an efficient cryogenic system with heat exchange and associated gas purification system, as a prototype for the XENON1T experiment. The XENON1T detector will use about 3 ton of liquid xenon (LXe) at a temperature of 175K as target and detection medium for a dark matter search. In this paper we report results on the cryogenic system performance focusing on the dynamics of the gas circulation-purification through a heated getter, at flow rates above 50 Standard Liter per Minute (SLPM). A maximum flow of 114 SLPM has been achieved, and using two heat exchangers in parallel, a heat exchange efficiency better than 96% has been measured

The Borborema Pegmatite Province, NE-Brazil revisited

Considering the internal structure, mineralogical distribution and geochemical data on K-feldspar, white micas, Nb-Taoxides, tourmalines, garnet and spinel, it becomes clear that the pegmatites classified as "heterogeneous" (Johnston 1945) include examples of several types and subtypes of LCT family, Rare Element Class pegmatites if the modern pegmatite classification models of Černý & Ercit 2005 are applied: at least examples of the beryl-columbite, beryl-columbite-phosphate and complex-spodumene,complex-lepidolite (±gemmologic elbaite)and albite (± cassiterite) pegmatite types and subtypes were ntatively identified. The impossibility to determine a granitelinked zoned regional distribution of these types may be the result of the fact that there is no single central source pluton but several smaller granitic intrusions in the province and the zoning around them may overlap each other

Estudio y caracterización de algunas 5-E-aldoximino-4-glucosilaminopirimidinas

The reaction between 1,6-dihydro-5-formil-4-β-D-(tetra-O-acetyl)glucopyranosylamino-1-methyl-2-methoxy-6-oxo-pyrimidine and an excess of ClH.H2NOH yields 5-E-aldoximine derivative as the only product. On the basis of its chemical behaviour and espectroscopic data we propose its structure.La reacción de 1,6-dihidro-5-formil-4-β-D-(2 ', 3 ' 4 ', 6 '-tetra-O-acetil)-glucopiranosilamino-1-metil-2-metoxi-6-oxopirimidina con exceso de ClH.H2NOH permite aislar 5-E-aldoximino derivado como único producto. La estructura del mismo ha sido establecida en base a pruebas químicas y espectroscópicas