Optical anisotropy and electronic structures of CdMoO4 and CdWO4 crystals: Polarized reflection measurements, x-ray photoelectron spectroscopy, and electronic structure calculations

Copyright (c) 2008 American Physical SocietyArticlePHYSICAL REVIEW B. 77(15): 155118 (2008)journal articl

Growth, Mechanical, Thermal and Spectral Properties of Cr3+∶MgMoO4 Crystal

This paper reports the growth, mechanical, thermal and spectral properties of Cr3+∶MgMoO4 crystals. The Cr3+∶MgMoO4 crystals with dimensions up to 30 mm×18 mm×14 mm were obtained by TSSG method. The absorption cross-sections of 4A2→4T1 and 4A2→4T2 transitions are 12.94×10−20 cm2 at 493 nm and 7.89×10−20 cm2 at 705 nm for E//Ng, respectively. The Cr3+∶MgMoO4 crystal shows broad band emission extending from 750 nm to 1300 nm with peak at about 705 nm. The emission cross-section with FWHM of 188 nm is 119.88×10−20 cm2 at 963 nm for E//Ng. The investigated results showed that the Cr3+∶MgMoO4 crystal may be regarded as a potential tunable laser gain medium

Feasibility Study of VUV Sensitization Effect of Tb3+

The possibility to use Tb3+ as luminescence sensitizer for enhancement of the conversion efficiency of vacuum-ultraviolet (VUV) radiation into visible light was examined. We studied the luminescence properties of K3Tb(PO4)2 and Ba3Tb(PO4)3 activated by Eu3+, and of SrAl12O19 co-doped with Mn2+ and Tb3+ at excitation over the 120 to 300nm wave-length range. It is shown that Tb3+ ions, exhibiting a strong absorption band in the VUV, can provide efficient sensitization of Eu3+ and Mn2+ emissions for excitation in this spectral range, giving rise to intense red and green luminescence, respectively. This study provides a proof for the concept of VUV sensitization, which enables the engineering of luminescence materials with improved efficiency for excitation from a noble gas discharge. © Taylor and Francis Group, LLC

Development of techniques for characterisation of scintillation materials for cryogenic application

The multi-photon counting (MPC) technique was designed to record photon emission of scintillators and, as a very powerful method of material characterisation, is enjoying increasing popularity. The technique is especially advantageous for the analysis of slow scintillation processes and the investigation of temperature-dependent scintillator properties. The paper describes the latest development of the technique aiming to improve performance and widen the scope of applications. The results from characterising MgF 2 are presented to illustrate the capabilities of the MPC technique. © 2012 Elsevier Ltd. All rights reserved

VUV sensitisation of Eu3+ emission by Tb3+ in Ba3Tb(PO4)(3)-Eu

The luminescence properties of Ba3Tb0.9Eu0.1(PO4)3 and Ba3Gd0.9Eu0.1(PO4)3 phosphors were studied for excitation over the 120-300 nm wavelength range. It is found that Tb3+, which exhibits a strong vacuum-ultraviolet (VUV) absorption band, provides sensitisation of Eu3+ emission in this host. This effect can be used to develop phosphors with enhanced conversion efficiency of the VUV radiation into visible light. © 2009 Elsevier B.V. All rights reserved

Scintillators for cryogenic applications: State-of-art

The latest results on the low-temperature characterisation of scintillation materials selected for rare event search are reviewed. The temperature dependences of the light output and decay time are analysed on the basis of the current understanding of the underlying physical processes that control the emission of light in solids. It is shown that scintillation properties of the materials under study are adequate for the purpose of cryogenic experiments searching for rare events. From the analysis of the performance characteristics it is concluded that currently ZnWO 4 is the most suitable scintillation target for dark matter search

The use of calcium silicate bricks for retrospective dosimetry

The suitability of calcium silicate bricks (CSBs) for the retrospective measurement of gamma dose using luminescence techniques has been investigated. Bricks of this type are distinguished from fired clay bricks by containing negligible clay and requiring comparatively low temperature treatment during manufacture. They have been used widely in the construction of buildings in the Former Soviet Union since the 1970s but hitherto have not been used for retrospective dosimetry measurements. A procedure based on the use of the 210°C thermoluminescence (TL) peak of quartz was tested with granular quartz extracted from three types of CSB, one of which had been taken from a settlement downwind of Chernobyl. The degree to which the residual geological TL signal within the temperature range of the 210°C TL peak had been reduced during manufacture varied with brick type; the levels of residual TL corresponded, in the samples tested, to absorbed doses in the range (<5 mGy–100 mGy). The TL sensitivity of the quartz was generally sufficient to measure absorbed doses of 20 mGy and above. An estimate of the cumulative fallout dose obtained with the CSB from the contaminated settlement was in good agreement with that obtained in a previous study based on measurements with a fired clay brick from the same building