Energy transfer in neutron irradiated Gd2SiO5Gd^2SiO^5-Ce crystals

AbstractOptical absorption and luminescence of synthetic initial and neutron irradiated Gd2SiO5–Ce (0.5 mol.%) crystals was studied. Optical absorption spectra (1–6 eV) were measured using UV-Visible Helios Alpha spectrophotometer at T=300K. Time-resolved luminescence spectra (1.5–6 eV), luminescence excitation spectra (4–20 eV) and decay kinetics were recorded at SUPERLUMI station (DESY, Hamburg). Reactor neutron’s irradiation (fluence of 4⋅1018 cm−2) leads to the effective production of defects. There were not registered any new luminescence bands in the irradiated samples, but radiation defects take significant part in the processes of energy transfer to luminescence centers

Quality assessment of indoor radon measurements. Results of the international radon in-field intercomparison study

The article presents the results of the international radon in-field intercomparison study for passive radon measurement devices. The tests were organized by the environmental agency of the administrative region of Piemonte (Ivrea, Italy). Coverage of participants was 49 laboratories from 15 countries (Italy, Hungary, France, Great Britain, Lithuania, Russia, Sweden, Spain, Bulgaria, Argentina, Australia, Finland, Ireland, Greece and Slovenia). The certified radon passive devices included SSNTDs and electret detectors. SSNTDs are mostly represented by PADC plastic (CR-39) and nitrocellulose film (LR-115-2) detectors. Radon measuring devices were tested in long-term exposure modes at low and high radon levels (tests 1 and 2) and short-term exposure mode at the simultaneous presence of radon and thoron in the atmosphere (test 3). The intercomparison study was carried out in real conditions of operated buildings with different climatic conditions. The main purpose of this study was to evaluate the quality (accuracy and reliability) of the radon measurements under situations similar to the ones in which devices are normally exposed. In comparison with electrets, solid-state track detectors showed to have generally better reproducibility. For the electrets, the most «comfortable» radon measurement conditions were prolonged exposure at high radon levels. There was no significant fading effect of SSNTD at long-term exposure observed. The paper presents the results of the quality assessment of REI-4 passive device based on LR-115-2 widely used for radon monitoring studies in the Russian Federation