Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

ϒ production in p–Pb collisions at √sNN=8.16 TeV

ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at √sNN = 5.02 TeV and with theoretical calculations.publishedVersio

Low temperature thermal and plasma enhanced atomic layer deposition of ruthenium using RuO4 and H2/H2-plasma

A thermal (RuO4/H-2-gas) and a plasma enhanced (RuO4/H-2-plasma) atomic layer deposition (ALD) process for deposition of Ru are reported. The ALD characteristics and film properties of both processes are presented. The thermal process is compared to the plasma process in terms of film properties as a function of sample temperature. Finally, a discussion about the probable ALD reaction mechanisms is given

Near room temperature plasma enhanced atomic layer deposition of ruthenium using the RuO4-precursor and H-2-plasma

A plasma enhanced ALD process for Ru using RuO4 and H-2-plasma is reported at sample temperatures ranging from 50 degrees C to 100 degrees C. At 50 degrees C, low impurity content Ru thin films were grown with a saturated growth rate of 0.11 nm per cycle. A study of the influence of various process parameters on the Ru film properties is given

Atomic layer deposition of ruthenium at 100 °C using the RuO4-precursor and H2

In this paper we report a low temperature (100 degrees C) ALD process for Ru using the RuO4-precursor (ToRuS (TM)) and H-2 as the reactant. The thermal decomposition behaviour of the precursor in the range of 50 degrees C-250 degrees C was investigated and it was found that thermal decomposition of RuO4 to RuO2 starts at a sample temperature of 125 degrees C. The RuO4/H-2 process (0.0045 mbar/4 mbar) was attempted at temperatures below this decomposition limit and it was found that ALD growth of pure Ru is possible in a narrow temperature window near 100 degrees C. The growth rate during steady state growth was found to be 0.1 nm per cycle. The Ru film nucleated easily on a wide range of substrates (H-terminated Si, TiN, Pt and Al2O3). Although the films are grown at a low temperature, they are considerably pure and are of good quality as evidenced by a resistivity of 18 mu Omega cm for an 18 nm film and a relative atomic concentration of impurities <5% as determined by XPS. It is hypothesized that the reaction of the RuO4 molecule with the Ru-surface leading to a monolayer of RuO2 is the mechanism that ensures a self-saturated behaviour of the first half reaction, which is a critical requirement to achieve a well-behaved ALD process

Se-Containing inks for the formation of CuInSe2 films without gas-phase selenization

To make thin film photovoltaics (TFPV) more competitive with classic Si-based devices, research is focusing on the production of absorber layers. Printable inks containing nanocrystal (NC) precursors are explored, since a variety of NCs can be synthesized in apolar media. When printing photovoltaic absorber layers of NCs such as CIGS, the formation of a dense thin film is required, which is however hampered by the presence of the organic ligands. Our research focusses on CuInS2 NCs, for which the original steric stabilizers are exchanged for inorganic moieties containing sulfide or selenide species. This leads to an ink stabilized by charge that, apart from the solvent, doesn’t introduce unwanted components in the film. In CIGS processing, crystal growth is typically promoted by a gas-phase selenization step after film deposition. However, this introduces an additional process step that involves working with toxic gasses in a closed atmosphere. We show that introducing Se-containing moieties to stabilize CuInS2 dispersions enables us to enhance NC sintering and transformation, without the need for a selenization step. Two inks were prepared: both containing (N2H5)2Se capped CIS NCs and one of them containing Se NPs as well. Upon thermal annealing under He atmosphere phase transformation from CIS to CISe was observed with in situ XRD, resulting in a close-to pure CISe phase in both cases. Finally, we address the prospects of using this approach to form CIGS absorber layers for TFPV

Plasma enhanced atomic layer deposition of ruthenium below 100°C using RuO4 and H2-plasma

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