Development of SiO2 based doped with LiF, Cr2O3, CoO4 and B2O3 glasses for gamma and fast neutron shielding

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bünyamin Aygün ◽  
Erdem Şakar ◽  
Abdulhalik Karabulut ◽  
Bünyamin Alım ◽  
Mohammed I. Sayyed ◽  
...  

AbstractIn this study, the fast neutron and gamma-ray absorption capacities of the new glasses have been investigated, which are obtained by doping CoO,CdWO4,Bi2O3, Cr2O3, ZnO, LiF,B2O3 and PbO compounds to SiO2 based glasses. GEANT4 and FLUKA Monte Carlo simulation codes have been used in the planning of the samples. The glasses were produced using a well-known melt-quenching technique. The effective neutron removal cross-sections, mean free paths, half-value layer, and transmission numbers of the fabricated glasses have been calculated through both GEANT4 and FLUKA Monte Carlo simulation codes. Experimental neutron absorbed dose measurements have been carried out. It was found that GS4 glass has the best neutron protection capacity among the produced glasses. In addition to neutron shielding properties, the gamma-ray attenuation capacities, were calculated using newly developed Phy-X/PSD software. The gamma-ray shielding properties of GS1 and GS2 are found to be equivalent to Pb-based glass.

2013 ◽  
Vol 743-744 ◽  
pp. 613-622 ◽  
Author(s):  
Zhe Fu Li ◽  
Xiang Xin Xue ◽  
Pei Ning Duan ◽  
Ang Tian ◽  
Shu Xian Li ◽  
...  

Four novel boron containing ores/epoxy composites were prepared by using nature ludwigite green ore (NLGO), artificial ores including boron containing iron ore concentrate (BCIOC), boron rich slag (BRS) and boron mud (BM) as neutron absorbers, which were obtained by dressing from NLGO, blast furnace separation from BCIOC and borax production, respectively. The microstructure of the composites was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). Shielding properties of the composites against thermal and Cf-252 fast neutron were measured. Factors affecting the shielding properties were investigated. Energy deposition, absorbed dose and half value layers of the composites against neutron penetration were simulated by Monte Carlo method, and a simulated function was obtained. The results showed that the composites were compact and the particles of ores were homogeneous. Ascending boron mole numbers per unit volume (nB) in the composites can obviously enhance the macroscopic absorbing cross section (Σthermal) and improve the shielding properties for thermal neutron. The relationship of Σthermal and nB follows the equation of Σthermal=0.218+450.490nB. And the relationship of average atomic number (Z) of boron containing ores composites and the macroscopic removal cross section for fast neutron follows the equation of Σremoval=0.042exp (-Z/5.70)+0.032. Enhancement of the shielding abilities against Cf-252 fast neutron can be achieved by using the composites with low average atomic number.


2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Segundo Agustín Martínez Ovalle

Monte Carlo calculations were carried out where compounds with positron-emitters radionuclides, like FDG (18F), Acetate (11C), and Ammonium (13N), were incorporated into a soft tissue volume, in the aim to estimate the type of particles produced their energies, their mean free paths, and the absorbed dose at different distances with respect to the center of the volume. The volume was modeled with a radius larger than the maximum range of positrons in order to produce 0.511 keV annihilation gamma-ray photons. With the obtained results the absorbed dose, in various organs and tissues able to metabolize different radiopharmaceutical drugs, can be estimated. The code used was GEANT4.


Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.


2002 ◽  
Vol 57 (4) ◽  
pp. 517-524 ◽  
Author(s):  
Hu-Xia Shi ◽  
Bo-Xian Chen ◽  
Ti-Zhu Li ◽  
Di Yun

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