Pulse-shape discrimination with PbWO4_4 crystal scintillators

The light output, $\alpha/\beta$ ratio, and pulse shape have been investigated at $-25^\circ$ C with PbWO$_4$ crystal scintillators undoped, and doped by F, Eu, Mo, Gd and S. The fast $0.01-0.06 \mu$s and middle $0.1-0.5 \mu$s components of scintillation decay were observed for all the samples. Slow components of scintillation signal with the decay times $1-3 \mu$s and $13-28 \mu$s with the total intensity up to $\approx50$ have been recognized for several samples doped by Molybdenum. We found some indications of a pulse-shape discrimination between $\alpha$ particles and $\gamma$ quanta with PbWO$_4$ (Mo doped) crystal scintillators.Comment: 12 pages, 5 figures, submitted to NIM

Proton-Antiproton Pair Production in Two-Photon Collisions at LEP

The reaction e^+e^- -> e^+e^- proton antiproton is studied with the L3 detector at LEP. The analysis is based on data collected at e^+e^- center-of-mass energies from 183 GeV to 209 GeV, corresponding to an integrated luminosity of 667 pb^-1. The gamma gamma -> proton antiproton differential cross section is measured in the range of the two-photon center-of-mass energy from 2.1 GeV to 4.5 GeV. The results are compared to the predictions of the three-quark and quark-diquark models

Low temperature afterglow from SrAl 2 O 4 : Eu, Dy, B containing glass

V.V. acknowledges the financial support of ERDF PostDoc project No. 1.1.1.2/VIAA/3/19/440 (University of Latvia Institute of Solid State Physics, Latvia) and LP the Academy of Finland (Flagship Programme, Photonics Research and Innovation PREIN 320165 and Academy Project -326418) for the financial support. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01- 2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART 2 .SrAl2O4: Eu, Dy, B particles were added in a phosphate glass (90NaPO3-10NaF (in mol%)) using the direct doping method. For the first time, the composition of the particles prior to and after embedding them in the glass was analysed using EPMA analysis. Boron was found to be incorporated in already distorted surroundings creating new trapping centers in the particles which are thought to be favourable for the tunnelling process and so for the afterglow at 10K. Despite the partial decomposition of the particles, the glass exhibit afterglow at low temperature confirming to be promising materials for low temperature applications.ERDF 1.1.1.2/VIAA/3/19/440; LP the Academy of Finland 320165 and 326418; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017 TeamingPhase2 under grant agreement No. 739508, project CAMART

Radioluminescence, thermoluminescence and dosimetric properties of ZnO ceramics

Two types of ZnO ceramics were fabricated and characterized by XRD, SEM methods. The radioluminescence spectra were measured within the 300–550 K range. The defect luminescence band peaking at ~2.35 eV is the dominant one in radioluminescence spectra in both of the fabricated ceramics. The thermostimulated luminescence (TSL) glow-curves were measured after X-ray irradiation at 300 K. It was concluded that the complex overlapping peak within the 320–450 K temperature range consists of two components (~360–375 K and 400–420 K). The ratio of component intensities differs in both ceramics. The positions of high temperature TSL components (480–520 K) also differ in both samples; therefore not only sintering conditions but also the properties of the initial powder are very important for characteristics of TSL. A linear dependence of peak intensity on irradiation dose was observed up to ~3 kGy for ceramic 1 and up to 9 kGy for ceramic 2. © 2017 Elsevier Ltd and Techna Group S.r.l

Ocrelizumab versus Interferon Beta-1a in Relapsing Multiple Sclerosis

Supported by F. Hoffmann–La Roche

Luminescence and Transient Absorption of CdWO4\text{}_{4} Crystals

Luminescence and transient absorption of the oxygen-deficient CdWO$\text{}_{4}$ crystal were studied. The electron transitions from the excited state of the luminescence center to some higher energy state are responsible for the transient absorption observed. The scheme of luminescence center levels is proposed from the obtained experimental results