Glasses were prepared from the compositions of 25Gd_2O_3-10 CaO-10 SiO_2-（55–x）B_2O_3-xDy_2O_3（where x is 0.0 mol.%–1.0 mol.%） by the conventional melt-quenching technique at 1400 oC. The results demonstrated th...Glasses were prepared from the compositions of 25Gd_2O_3-10 CaO-10 SiO_2-（55–x）B_2O_3-xDy_2O_3（where x is 0.0 mol.%–1.0 mol.%） by the conventional melt-quenching technique at 1400 oC. The results demonstrated the increase in the glass density with respect to the increase in the doping concentrations of Dy_2O_3. Nine absorption bands were observed. The emission spectra of the developed glass showed two strong peaks at 577 nm（~4F_（9/2）→~6H_（13/2）） and 482 nm（~4F_（9/2）→~6H_（15/2））. The highest emission intensity was observed from the developed glass prepared at 0.4 mol.% of Dy_2O_3, as the efficient energy transfer took place from Gd^（3＋） to Dy^（3＋）. From the X-ray induced optical luminescence, the emission spectra were identical to those from PL measurements, but with the highest intensity observed from the glass quenched at 0.45 mol.% of Dy_2O_3. Finally, the integral scintillation efficiency of the developed glass was determined at 27% of that of the commercially available BGO crystal.展开更多
The radiation shielding efficiency of material depends upon photon attenuation, exposure buildup factors and neutron removal capacity. A newly developed Pb-free gadolinium-based glasses in compositions(80-x) B_2O_3-10...The radiation shielding efficiency of material depends upon photon attenuation, exposure buildup factors and neutron removal capacity. A newly developed Pb-free gadolinium-based glasses in compositions(80-x) B_2O_3-10 Si O_2-10 Ca O-x Gd_2O_3(where x = 15, 20, 25, 30 and35 mol%) had completely been investigated for their shielding efficiency with Geant4 simulation for mass attenuation coefficients and neutron total macroscopic cross section and by calculating exposure buildup factors.The exposure buildup factors for photon energy from 0.015 to 15 Me V had been calculated up to 40 mean free paths using five factors geometric progression method. The mass attenuation coefficients of the Pb-free glasses were simulated for energies from 223 to 2614 ke V and compared with the possible available experimental results. The neutron shielding efficiency of these glasses was discussed by calculating neutron total macroscopic cross section for energies from 1 e V to 14.1 Me V. Present investigations are found to be very useful for applications in nuclear engineering.展开更多
基金Project supported by National Research Council of Thailand(NRCT)(GB_59_14)
文摘Glasses were prepared from the compositions of 25Gd_2O_3-10 CaO-10 SiO_2-（55–x）B_2O_3-xDy_2O_3（where x is 0.0 mol.%–1.0 mol.%） by the conventional melt-quenching technique at 1400 oC. The results demonstrated the increase in the glass density with respect to the increase in the doping concentrations of Dy_2O_3. Nine absorption bands were observed. The emission spectra of the developed glass showed two strong peaks at 577 nm（~4F_（9/2）→~6H_（13/2）） and 482 nm（~4F_（9/2）→~6H_（15/2））. The highest emission intensity was observed from the developed glass prepared at 0.4 mol.% of Dy_2O_3, as the efficient energy transfer took place from Gd^（3＋） to Dy^（3＋）. From the X-ray induced optical luminescence, the emission spectra were identical to those from PL measurements, but with the highest intensity observed from the glass quenched at 0.45 mol.% of Dy_2O_3. Finally, the integral scintillation efficiency of the developed glass was determined at 27% of that of the commercially available BGO crystal.
基金National Research Council of Thailand(NRCT)for supporting this researchDepartment of Radiologic Technology,Faculty of Associated Medical Sciences,Chiang Mai University for support
文摘The radiation shielding efficiency of material depends upon photon attenuation, exposure buildup factors and neutron removal capacity. A newly developed Pb-free gadolinium-based glasses in compositions(80-x) B_2O_3-10 Si O_2-10 Ca O-x Gd_2O_3(where x = 15, 20, 25, 30 and35 mol%) had completely been investigated for their shielding efficiency with Geant4 simulation for mass attenuation coefficients and neutron total macroscopic cross section and by calculating exposure buildup factors.The exposure buildup factors for photon energy from 0.015 to 15 Me V had been calculated up to 40 mean free paths using five factors geometric progression method. The mass attenuation coefficients of the Pb-free glasses were simulated for energies from 223 to 2614 ke V and compared with the possible available experimental results. The neutron shielding efficiency of these glasses was discussed by calculating neutron total macroscopic cross section for energies from 1 e V to 14.1 Me V. Present investigations are found to be very useful for applications in nuclear engineering.
