Journals
2015 EN
D. V. Poda · E. Armengaud · Q. Arnaud
+90 more
The technology of scintillating bolometers based on zinc molybdate(ZnMoO$_4$) crystals is under development within the LUMINEU project to searchfor 0$\nu$2$\beta$ decay of $^{100}$Mo with the goal to set the basis for largescale experiments capable to explore the inverted hierarchy region of theneutrino mass pattern. Advanced ZnMoO$_4$ crystal scintillators with mass of$\sim$~0.3 kg were developed and Zn$^{100}$MoO$_4$ crystal from enriched$^{100}$Mo was produced for the first time by using the low-thermal-gradientCzochralski technique. One ZnMoO$_4$ scintillator and two samples (59 g and 63g) cut from the enriched boule were tested aboveground at milli-Kelvintemperature as scintillating bolometers showing a high detection performance.The first results of the low background measurements with three ZnMoO$_4$ andtwo enriched detectors installed in the EDELWEISS set-up at the ModaneUnderground Laboratory (France) are presented.
Journals
2015 EN
Iuliana Vasiliev · GertJan Reichart · Arjen Grothe
+5 more
Since the Miocene the Black Sea proved to be highly sensitive to fluctuations in the hydrological cycle because of its recurrent restricted connections with the open ocean and the location between the dry Mediterranean and more humid higher northern latitudes. Although the Black Sea formed one of the foci of the 1975 Deep Sea Drilling Project Leg 42B, robust tools to reconstruct past changes in its hydrological cycle were lacking at that time. Here we revisit the sedimentary succession (Hole 380A) and determined compound-specific carbon (δ13C) hydrogen isotope ratios (δD) of terrestrial and aquatic biomarkers to investigate changes in the hydrological budget of the Black Sea during the late Miocene. The δ13C and δD isotopic composition of n-alkanes as well as alkenones and palynology indicate large environmental changes in the Black Sea and/or in the sources of the water entering the Black Sea during the late Miocene. The δD of alkenones, showing an enrichment of more than 80‰ at the end of the Miocene, implies a major shift in basin hydrology, possibly resulting in severely increased salinity. These changes in δD composition of the alkenones coincide with both with sharp shifts in reconstructed sea surface temperature and palynological assemblages. Two intervals with negative water budget were identified, most likely caused by enhanced evaporation. The older and longer dry/evaporative phase predates the Maeotian/Pontian boundary (regional stages) at ~ 6.1 Ma. The younger drying phase corresponds to the Messinian Salinity Crisis. This shift to highly evaporative conditions is related to a similar shift previously observed in a Messinian (Pontian) sedimentary succession from the Taman Peninsula (Russia). These recurrent dry phases likely reflect regional climatic shifts over a significantly larger area around the Black Sea area during the upper Miocene.
Journals
2015 EN
Konstantin Oblov · Anastasia Ivanova · Sergey Soloviev
+4 more
In this paper, a method of producing the metallization on the alumina ceramic substrate by micropowders of ruthenium dioxide sintering using laser radiation with 10.6 micrometers length (carbon dioxide laser) is described. During the work parameters of the mask, allowing to reduce the width of the laser spot as well as to get a mildly sloping profile of the radiation intensity, due to which more uniform sintering of the powders and pastes based on them takes place, are calculated
Journals
2015 EN
Konstantin Oblov · Anastasia Ivanova · Sergey Soloviev
+3 more
The target of this work is the demonstration of advanced approaches able to provide rapid prototyping by using laser technology ceramic MEMS platforms for chemical sensor operating under harsh environmental conditions and, on the other hand, to assure microhotplate stable at high temperature, which can be used for the deposition of high working temperature gas sensing materials, for example, oxides of tin, gallium, zirconium and hafnium. As substrate ceramic material in work using alumina oxid
Journals
2015 EN
Konstantin Oblov · Anastasia Ivanova · Sergey Soloviev
+4 more
During the topology creation by the selective laser sintering method experimental samples of microheater based on ruthenium dioxide micro-powder were made. The resulting structures were used as microheaters to measure changes in the thermal conductivity of gases. A power comparison of standard platinum spiral element widely used in catalytic thermal sensors and microheater produced by the new technology showed the advantage of the latter
Journals
2015 EN
V. I. Troyan · P. V. Borisyuk · Yu. Yu. Lebedinskiǐ
+1 more
The technique of thin film forming of NaThxFy compounds on the Si (111) surface by electron-beam evaporation was developed. It is shown that the band gap of pure thorium fluoride is 6.7eV; of sodium fluoride – 9.5eV, while in compounds of thorium-sodium fluoride NaTh1.3F6.2 it takes the value 7.1eV. It was found that prolonged electron beam exposure leads to the recovery of thorium fluoride followed by oxidation of thorium atoms
Journals
2015 EN
V. I. Troyan · P. V. Borisyuk · Yu. Yu. Lebedinskiǐ
+1 more
The paper presents the results of the study of local formation of thorium oxide coatings on SiO2/Si(111) surface by electrochemical deposition. It was found that the electrochemical deposition of thorium atoms from thorium nitrate solution of Th(NO3)4 with the presence of water on silicon surface results in local formation of thorium compounds. The results of surface analysis by local XPS indicate that these compounds represent a thorium-, silicon-, oxygen- and carbon-based compounds. After 6hours annealing at 600°C at atmosphere carbon pulled completely, and the cluster formed film consists of oxygen and thorium only. It was shown that this system can be promising for further research of nuclear low-lying isomeric transition in 229Th isotope when irradiated by an electron beam
Journals
2015 EN
Konstantin Oblov · Anastasia Ivanova · Sergey Soloviev
+4 more
We present a novel approach to the fabrication of MEMS devices, which can be used for gas sensors operating in harsh environment in wireless and autonomous information systems. MEMS platforms based on ZrO2/Y2O3 (YSZ) are applied in these devices. The methods of ceramic MEMS devices fabrication with laser micromachining are considered. It is shown that the application of YSZ membranes permits a decrease in MEMS power consumption at 4500C down to ∼75 mW at continuous heating and down to ∼ 1 mW at pulse heating mode. The application of the platforms is not restricted by gas sensors: they can be used for fast thermometers, bolometric matrices, flowmeteres and other MEMS devices working under harsh environmental conditions
Journals
2015 EN
Konstantin Oblov · Anastasia Ivanova · Sergey Soloviev
+3 more
In this paper, we describe a novel cost-effective and simple technology for the production glass MEMS applied as microhotpalte platform for metal oxide gas sensors. The basis of the technology is magnetron sputtering of platinum heating layer followed by precise laser engraving and cutting used for heater patterning. As a result of the technology, we demonstrate the glass microhotplate cantilever with thickness of 30μm equipped with platinum microheater with dimension of about 500×500μm. The cantilever type MEMS microhotplate demonstrate very high stability at working temperatures up to 600 0C, which gives possibility to use it for the low-scale fabrication microhotplate of metal oxide gas sensors
Journals
2015 EN
STAR Collaboration L. Adamczyk · STAR Collaboration J. K. Adkins · STAR Collaboration G. Agakishiev
+354 more
We report measurements of Upsilon meson production in p+p, d+Au, and Au+Aucollisions using the STAR detector at RHIC. We compare the Upsilon yield to themeasured cross section in p+p collisions in order to quantify any modificationsof the yield in cold nuclear matter using d+Au data and in hot nuclear matterusing Au+Au data separated into three centrality classes. Our p+p measurementis based on three times the statistics of our previous result. We obtain anuclear modification factor for Upsilon(1S+2S+3S) in the rapidity range |y|<1in d+Au collisions of R_dAu = 0.79 +/- 0.24 (stat.) +/- 0.03 (sys.) +/- 0.10(pp sys.). A comparison with models including shadowing and initial stateparton energy loss indicates the presence of additional cold-nuclear mattersuppression. Similarly, in the top 10% most-central Au+Au collisions, wemeasure a nuclear modification factor of R_AA=0.49 +/- 0.1 (stat.) +/- 0.02(sys.) +/- 0.06 (pp sys.), which is a larger suppression factor than that seenin cold nuclear matter. Our results are consistent with complete suppression ofexcited-state Upsilon mesons in Au+Au collisions. The additional suppression inAu+Au is consistent with the level expected in model calculations that includethe presence of a hot, deconfined Quark-Gluon Plasma. However, understandingthe suppression seen in d+Au is still needed before any definitive statementsabout the nature of the suppression in Au+Au can be made.