63 research outputs found
Purification of molybdenum oxide, growth and characterization of medium size zinc molybdate crystals for the LUMINEU program
The LUMINEU program aims at performing a pilot experiment on neutrinoless
double beta decay of 100Mo using radiopure ZnMoO4 crystals operated as
scintillating bolometers. Growth of high quality radiopure crystals is a
complex task, since there are no commercially available molybdenum compounds
with the required levels of purity and radioactive contamination. This paper
discusses approaches to purify molybdenum and synthesize compound for high
quality radiopure ZnMoO4 crystal growth. A combination of a double sublimation
(with addition of zinc molybdate) with subsequent recrystallization in aqueous
solutions (using zinc molybdate as a collector) was used. Zinc molybdate
crystals up to 1.5 kg were grown by the low-thermal-gradient Czochralski
technique, their optical, luminescent, diamagnetic, thermal and bolometric
properties were tested.Comment: Contribution to Proc. of Int. Workshop on Radiopure Scintillators
RPSCINT 2013, 17-20 September 2013, Kyiv, Ukraine; to be published in EPJ Web
of Conferences; expected to be online in January 2014; 6 pages, 6 figures,
and 3 table
Scintillating bolometers based on ZnMoO4 and Zn100MoO4 crystals to search for 0ν2β decay of 100Mo (LUMINEU project): first tests at the Modane Underground Laboratory
The technology of scintillating bolometers based on zinc molybdate (ZnMoO4) crystals is under development within the LUMINEU project to search for decay of 100Mo with the goal to set the basis for large scale experiments capable to explore the inverted hierarchy region of the neutrino mass pattern. Advanced ZnMoO4 crystal scintillators with mass of ∼0.3 kg were developed and Zn100MoO4 crystal from enriched 100Mo was produced for the first time by using the low-thermal-gradient Czochralski technique. One ZnMoO4 scintillator and two samples (59 g and 63 g) cut from the enriched boule were tested aboveground at milli-Kelvin temperature as scintillating bolometers showing a high detection performance. The first results of the low background measurements with three ZnMoO4 and two enriched detectors installed in the EDELWEISS set-up at the Modane Underground Laboratory (France) are presented
Electron Injection to Unoccupied Electronic States in Organic Semiconductor Thin Films Studied by Inverse Photoemission Spectroscopy (INTERFACE SCIENCE-Molecular Aggregates)
Inverse photoemission spectroscopy (IPES) in the vacuum ultraviolet region was applied to directly observe behaviors of electron injection into unoccupied electronic states in perylene-3,4,9,10- tetracarboxylic dianhydride (PTCDA) thin films due to alkali metal. By the analysis of the observed results the amount of injected electrons per PTCDA molecule was evaluated with relation to the dopant concentration. The derived relationship has been explained with the aid of DV-X calculations of energy levels concerned
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