Search

Four sulfide compounds' attenuation features of gamma-ray (Ag 2 ZnSnS 4 , Ag 2 ZnSnSe 4 , ZnS, and Ag 2 S) were described in this paper by a new software Phy-X/PSD. We calculated radiation attenuation parameters for the selected samples for a broad range of energies (0.015–15 MeV), including linear attenuation, the mean free path, the half-value layer, and total atomic and electronic cross-sections. The effective atomic number and the effective conductivity were also analyzed to investigate the radiation attenuation features. Also, the analyzed samples' buildup factors were studied. The samples' parameters were compared to materials frequently used to shield against radiation, including ferrite, chromite, barite, magnetite, and RS (253 G18, 360, 520) glass. Due to MFP and HVL values, Ag 2 S has better attenuation features than all the other samples utilized in the comparison. Fast neutron removal cross-sections (FNRCS) were also studied, and the best neutron attenuation composite among the samples under study, according to the FNRCS data, is Ag 2 S (0.116 cm−1). [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the photoluminescence and thermoluminescence properties of gamma ray induced rare earth doped yttrium gadolinium mixed oxide phosphor. The europium (Eu3+) was used as rare earth dopant. The phosphor was prepared by chemical co-precipitation method according to the formula (Y2−x−y Gd x ) O3: Euy 3+ (x=0.5; y=0.05). The photoluminescence emission spectrum of the prepared phosphor shows intense peaks in the red region at 615nm for 5D0→7F2 transitions and the photoluminescence excitation spectra show a broad band located around 220–270nm for the emission wavelength fixed at 615nm. The thermoluminescence studies were carried out after irradiating the phosphor by gamma rays in the dose range from 100Gy to 1KGy. In the thermoluminescence glow curves, one single peak was observed at about 300°C of which the intensity increases linearly in the studied dose range of gamma rays. The glow peak was deconvoluted by GlowFit program and the kinetic parameters associated with the deconvoluted peaks were calculated. The kinetic parameters were also calculated by various glow curve shape and heating rate methods. [Copyright &y& Elsevier]

Abstract: This paper reports thermoluminescence(TL), optical absorption and TL emission studies that are made on Ce3+ doped KCl single crystals irradiated at room temperature. The glow curve and optical absorption studies indicate the participation of Ce3+ ions in the TL process. The TL study suggests the presence of low concentration of Ce3+ ions which reduces the TL efficiency with respect to pure KCl samples. On F bleaching γ irradiated crystals Z1 centers are observed. A broader and strongly intense violet blue emission at 290, 370, 423 and 488nm has been observed with 240nm excitation. This emission has been attributed due to the transition from 5d(2D) excited energy level to the 4f1 ground stable energy level (2F5/2 and 3F7/2) of Ce3+ doped KCl crystals. [Copyright &y& Elsevier]

Abstract: In this paper, we present size dependent electron momentum density distribution in ZnS. ZnS nanoparticles of size 3.8nm and 2.4nm are synthesized using the chemical route and characterized by X-ray diffraction (XRD). The Compton profile measurements are performed on both the nano-sized as well as bulk ZnS samples employing 59.54keV gamma-rays from 241Am source. The results reveal that the valence electron density in momentum space becomes narrower with reduction of particle size. To evaluate the charge transfer on compound formation, the ionic model based calculations for a number of configurations of Zn+x S−x (0.0≤x≤2) are also performed utilizing free atom Compton profiles. These results suggest different amounts of charge transfer in these materials varying from 1.2 to 2.0 electron from Zn to S atom. [Copyright &y& Elsevier]