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1.
《Ceramics International》2020,46(3):3190-3202
In this study, nuclear shielding qualities of glass-ceramics with chemical composition Na2O3–BaO–PbO–Nb2O5–SiO2–Al2O3 containing different amount of BaO and PbO were investigated. The μρ values were simulated using GEANT4 toolkit at 0.015–20 MeV wide energy range and the obtained results were verified by theoretical WinXCOM results. The variables such as μρ, HVL, MFP, Zeff, Neff, EBF and EABF were computed to determine the gamma-ray shielding performances of studied glass ceramics. The results revealed that increase in PBO and BaO percentages in glass samples has caused to decrease the HVL, MFP, EBF and EABF values and increase μρ, Zeff values. It has been seen that N28 and S24 samples own superior protection ability against gamma radiation. In addition, the shielding capacity of these glass ceramics against charged and uncharged particles were predicted by determination of MSP and PR values for alpha, proton and ΣR values for neutrons. It has been concluded that PbO and BaO addition improve radiation shielding competences of glass ceramics. The data obtained from this study will be beneficial for designing glass ceramics shields for radiation protection enforcements.  相似文献   

2.
《Ceramics International》2019,45(11):14058-14072
Alkali lead vanadate glasses with moderate concentrations of PbO were prepared and analyzed to test their use as promising candidates for radiation shielding. The physical parameters of these glasses are specified and discussed in details. The code MCNPX was utilized to determine the mass attenuation coefficient μm that is used to evaluate the interaction of radiation with shielding materials. The results were then compared with the values collected from the XMuDat program and XCOM. The simulation results overlaps and highly correlated with XMuDat and XCOM. In addition, the results showed that μm, the effective atomic number (Zeff), removal cross-sections, (ΣR) and experimental results of the prepared glasses increase, while the half value layer (HVL), exposure and energy absorption build-up factor (EBF and EABF) values decrease with the increase of lead oxide (PbO) content from 30 to 45 mol%. In order to maximize the benefits from the determination of the radiation factors, the experimentally determined physical parameters and the elastic coefficients of this type of glass were also calculated.  相似文献   

3.
《Ceramics International》2020,46(15):23337-23346
The radiation shielding capacity of 80B2O3–(20-x) Na2O–x CdO (where x = 0, 2, 4, 6, 8, 10, 12 and 14 mol%) cadmium-doped sodium borate glasses was evaluated. The linear attenuation coefficient (LAC) of the studied glasses was simulated using the Monte Carlo simulation code (MCNP-5) for gamma photons with energy between 0.01 and 15 MeV. Other pivotal gamma ray shielding parameters such as mass attenuation coefficient (MAC), half value layer (HVL), effective atomic number (Zeff), and buildup factors (EBF and EABF) for the selected cadmium-doped sodium borate glasses were examined. The achieved data showed that, BNC 8 glass with CdO contents of 14 mol % possesses the highest LAC and varied between 0.0650 and 83.636 cm-1 and also it has thinner HVL than other BNC glasses and varied between 0.008 and 10.686 cm for gamma ray energy between 0.01 and 15 MeV. Moreover, the removal cross sections of fast neutrons (ΣR) were also calculated theoretically for the selected cadmium-doped sodium borate glasses. The obtained data shows that the insertion of CdO appears to enhance gamma ray and neutron shielding capacity. BNC8 with CdO content (14 mol%) was found to possess the best shielding parameters among the studied cadmium-doped sodium borate glasses.  相似文献   

4.
《Ceramics International》2020,46(14):22766-22773
Gamma radiation, neutrons, protons, and alphas particles shielding competences for gallium germanate-tellurite (GeO2.TeO2.Ga2O3) glasses doped with Pr6O11 were tested. The investigated glasses were named as GTGPr1, GTGPr2, GTGPr3, and GTGPr4. Mass attenuation coefficients (MAC) for the proposed glasses were calculated utilizing Phy-X/PSD program and simulated by MCNP5 simulation codes in the photon energy range of 0.015–15 MeV. With the help of MAC values, the linear attenuation coefficient (LAC), half value layer (HVL), mean free path (MFP), and effective atomic number (Zeff) were calculated. Moreover, the absorbed dose received from 137Cs with activity 10 μCi was calculated in presence of the studied glasses. Buildup factors (BUFs) include exposure buildup factor (EBF), and energy absorption buildup factor (EABF) for all investigated glasses were also calculated. Results reflected that the GTGPr4 glass has the highest MAC, LAC values and lowest HVL among other selected germanate glasses. The values of Zeff were around 0.04 MeV varied between 43.07 and 48.19, while at 1.5 MeV were between 18.70 and 21.25. The GTGPr1 possesses the highest values of BUFs around the studied range of energy, while GTGPr4 glasses possesses the lowest values. Moreover, the fast neutron removal cross section was (ΣR = 0.02151 and 0.01942 cm2 g−1) for GTGPr1 and GTGPr4, respectively. The investigated glasses can be useful to construct superior radiation shielding materials to use in nuclear medicine applications.  相似文献   

5.
《Ceramics International》2020,46(5):6046-6051
Gamma and neutron shielding potential of the newly developed xAg2O-(35-x)[0.5V2O5-0.5MoO3]-65TeO2 (x = 0, 5, 10, 15, 20 and 25 mol%) quaternary tellurite glass system were investigated computationally by means of Geant4 Monte Carlo simulations and Phy-X software. Gamma ray shielding capabilities were studied via the mass attenuation coefficient (μm), transmission fractions (T), effective atomic number (Zeff), half value layer (HVL) and mean free path (MFP) parameters and for the photon energies of 0.284, 0.356, 0.511, 0.662, 1.173 and 1.330 MeV. Fast neutron removal cross-section (∑R) parameter of the glasses was calculated to assess the neutron shielding capabilities. The results of this study revealed that tellurite glass containing 25% moles of Ag2O has highest μm and Zeff and lowest T, HVL and MFP values due to the high atomic number of Ag. In this study it was also seen that the ∑R of the investigated glass system increases with the increase of Ag2O fraction and ∑R values of the studied glasses are higher than barite added concrete and close to the ∑R of the PbO added borate glasses.  相似文献   

6.
《Ceramics International》2020,46(15):23357-23368
Impacts of lead and bismuth oxides insertion on a novel glass system of P2O5, B2O3, Li2O, Al2O3 according the formula 25B2O3–25P2O5–10Li2O–5Al2O3–5ZnO-xPbO+ (30-x)Bi2O3, x = 5,10, 15, 20, 25 mol%. The mass attenuation coefficient (μm = μ/ρ) simulated between 0.015 and 15 MeV using MCNP and calculated theoretically using Phy-X/PSD program. Based on the simulated μm, other significant parameters such as linear attenuation coefficient (LAC), half and tenth value layer (HVL, TVL), mean free path (MFP), and effective atomic number (Zeff) were calculated for fabricated glasses. The G-P fitting methods were used to calculate the exposure and energy absorption buildup factors (EBF and EABF) for fabricated glasses. Furthermore, fast neutron removal cross sections (ΣR) were calculated theoretically for fabricated glasses. The prepared glasses were effective shielding material which can reduce fast neutrons as well as gamma rays.  相似文献   

7.
《Ceramics International》2020,46(7):9096-9102
The important gamma and neutron radiation shielding parameters of the Dy3+ doped (65-x)Na2B4O7–15SiO2–20MoO3-xDy2O3 (x = 0, 5, 10, 15, 20 mol%) glass quaternary system were investigated to provide decisive information for their application in radiation environment. Gamma and neutron attenuation properties of the glass systems studied here were evaluated in terms of the mass attenuation coefficient (μm), transmission fraction (TF), half value layer (HVL), mean free path (MFP), effective atomic number (Zeff), exposure buildup factors (EBF) and fast neutron removal cross-section (∑R) parameters. Investigation of the each aforementioned parameter was performed thanks to the utilization of Monte Carlo simulations along with the Phy-X/PSD database. The photon attenuation characteristics were evaluated for gamma ray energies varying between 0.284 and 5.0 MeV. This study indicated that increase of the Dy2O3 content from 0% to 20% mole, enhances the gamma shielding capability due to the increase of the parameters μm and Zeff. In this study it was also observed that ∑R increases from 0.099 to 0.107 cm−1 as the molar fraction of Dy2O3 increases.  相似文献   

8.
《Ceramics International》2020,46(15):23347-23356
This work was carried out to specify the effect of Gd2O3 on the gamma and neutron radiation shielding capacities of tellurite rich glasses with 75TeO2+15ZnO+(10-x)Nb2O5+xGd2O3 (TZNG), where (x = 0, 1, 1.5, 2 and 2.5 mol%) nominal composition. The mass attenuation coefficients (μ/ρ) of the studied glasses were acquired with GEANT4 Monte Carlo codes and the results were found to match the theoretical Phy-X values. Next, the variables of Effective atomic number (Zeff), Half Value Layer (HVL) and Mean Free Path (MFP) were calculated employing μ/ρ values. According to the corollaries, the increment of Gd2O3 insertion to the tellurite based glasses was enhanced the μρ and Zeff values for total photon, electron, proton and alpha interactions whereas it was dropped the HVL and MFP values. It is also observed that the total stopping powers of the glasses for electron interaction were declined. The geometric progression (GP) approximation was employed to determine the exposure buildup factor (EBF) for the proposed glasses. The EBFs showed the lowest values for TZNG-E glass with 2.5% mole Gd2O3 addition. Finally, the fast neutron reduction capacity of the TZNG glasses was surveyed by calculating the effective removal cross-sections (ΣR) of the glasses. It is determined that the ΣR values increased with enhancing Gd2O3 content since the addition of Gd2O3 increased the glass density. Consequently, the TZNG-E glass with the highest Gd2O3 additive is the more skillful nominee for gamma-ray and neutron security applications among the investigated glasses.  相似文献   

9.
This research article aims to study the effect of CdO addition on the radiation shielding characteristics of boro-tellurite glasses in the composition of 50B2O3 - (50-x) TeO2- xCdO, where x = 0, 10, 20, 30, 40 and 50 mol%. These glasses were exposed to gamma radiation and the transmitted gamma photons were evaluated for energies varying from 15 keV to 15 MeV using Geant4 simulation toolkit. The number of transmitted photons was then used to characterize the gamma shielding for the studied glasses in terms of linear/mass attenuation coefficients, MFP, Zeff, and HVL. The simulation outcomes were theoretically confirmed by using Phy-X software. The beta (electron) shielding characterization of the involved glasses was also investigated by determining the projectile range and stopping power using ESTAR software. Additionally, the fast neutron shielding characterization of the glasses was achieved by evaluating removal cross-section (ΣR). The results reveal that the CdO has a small influence on the shielding performance of the boro-tellurite glasses against gamma, beta, and neutron radiations. The shielding performance of the boro-tellurite glasses was compared with that of common shielding materials in terms of MFP. It can be concluded that the boro-tellurite glasses regardless of the concentration of CdO content have promising shielding performance to be used for radiation applications.  相似文献   

10.
《Ceramics International》2020,46(4):4795-4800
The purpose of this work is to investigate the effect of increasing Bi2O3 mol% on the radiation shielding parameters of tellurite glass system with the formula Bi2O3–Na2O– V2O5– TiO2–TeO2 by using Phy-X/PSD computer software between 15 keV and 10 MeV. The results showed that the attenuation factor is very large at 15 keV. The mass attenuation coefficient (μ/ρ) at 15 keV lies within the range of 55.96–67.03 cm2/g for the selected samples. The μ/ρ for the investigated samples at 10 MeV is in the range of 0.0365–0.0392 cm2/g. The results also revealed that the addition of Bi2O3 enhances the effective atomic number (Zeff) and the sample corresponding to the lowest and highest amount of Bi2O3 (coded as TeBTi1 and TeBTi6) has the lowest and highest Zeff. Moreover, Zeff has high values between 15 keV and 0.1 MeV and the maximum Zeff occurs at 0.1 MeV (equal to 61.01, 62.67, 64.10, 65.34, 66.44 and 67.41 for TeBTi1– TeBTi6 samples respectively). The half value layer (HVL) increased when the energy changes from 15 keV to 10 MeV and the lowest HVL occurs at 15 keV for the sample coded as TeBTi6 and equal to 0.0025 cm, while the HVL at this energy for TeBTi1 is 0.0056 cm. Also, we calculated the tenth value layer (TVL) for the present system and we found that TVL reduces with the increment of Bi2O3 content, and the sample corresponding to 22 and 0 mol% of Bi2O3 and TiO2 respectively namely TeBTi6 possesses the lowest value of TVL, thus has the best radiation attenuation performance in comparison to other selected glasses. Also, we evaluated the effective removal cross-sections of fast neutrons (∑R) for the investigated glass system and we found that the ∑R values increase with increase the concentration of Bi2O3.  相似文献   

11.
Six different lithium bismuth boro-tungstate glasses with chemical composition 20Li2O-(20-x)Bi2O3-xWO3-60B2O3 (x = 0, 1, 2, 3, 4 and 5 mol%) were produced by the quenching method. Then, the glasses were investigated by means of their optical, mechanical, chemical durability and gamma ray shielding properties. Measured values of density and ultrasonic velocities were used to determine the elastic properties of the glasses. The optical band gap determined using the absorbance spectrum fitting (ASF) model was found to decrease under Bi2O3/WO3 substitution. The presence of BO3, BO4, BiO6, and WO4 structural groups in the glasses was confirmed by Fourier transform infrared spectroscopy (FTIR). The dissolution rate in the glass 20Li2O–15Bi2O3–5WO3–60B2O3 (LBWB5) was found to be 10 times lower than 20Li2O-20Bi2O3– 60B2O3. Mass attenuation coefficients (MAC) values of the produced glasses were determined using the MCNPX Monte Carlo code and Phy-X/PSD program. The photon attenuation parameters such as half value layer (HVL), mean free path (MFP), effective atomic number (Zeff), exposure buildup factor (EBF) and energy absorption buildup factor (EABF) were also studied. The obtained results showed that Bi2O3/WO3 substitution has a direct impact on the photon attenuation abilities of produced glasses. More specifically, HVL values increased from 0.252 × 10?2 cm for LBWB0 glass to 0.275 × 10?2 cm for LBWB5 glass. However, different trends were observed for the photon buildup factors for the produced glasses. It can be concluded that the produced glasses have promising structural, optical, and photon attenuation properties to be used for gamma shielding applications.  相似文献   

12.
《Ceramics International》2020,46(12):19880-19889
This paper focuses on the evaluation of the radiation attenuation properties of 15CaF2-10CaO-5B2O3-(65-x)P2O5-xNiO-5BaO (where 0 ≤ x ≤ 1.0 mol%) bioactive glasses. The radiation attenuation features of these glasses were investigated by determining different factors including mass attenuation coefficient (μ/ρ), exposure and absorption buildup factors (EBF and EABF), neutron removal cross section (NRCS), and effective atomic number (Zeff) for photon, proton, and carbon ion interactions. Geant4 toolkit and Phy-X program were employed for simulations and calculations procedures. The results revealed that NiO content in the studied bioactive glasses has a significant effect on photon interaction and an insignificant effect on the charged particle interactions. The Zeff values of the studied glasses were observed in the range of 18–20 for photon interaction, 10.7–10.9 for proton interaction, and 10.0–10.7 for carbon ion interaction. The NRCS values were 0.087, 0.088, 0.089, 0.090, and 0.091 cm-1 for x = 0, 0.4, 0.6, 0.8 and 1.0 mol%, respectively. The studied bioactive glasses showed a good ability to attenuate gamma radiation at energies of medical applications.  相似文献   

13.
《Ceramics International》2020,46(12):20251-20263
In this study, five different glasses encoded Pb25, Pb30, Pb35, Pb40 and Pb45 based on xPbO- (50-x) MoO3–50V2O5 (25 ≤ x ≤ 45 mol %) glass system were fabricated. MCNPX code, XCOM and XMuDat have been utilized to compute the mass attenuation coefficient (μm) values of the xPbO-(50-x)MoO3–50V2O5 glass system at 0.015–15 MeV photon energies. X-ray diffraction (XRD), was characterized for fabricated glasses. Moreover, different shielding parameters such as Half Value Layer, Tenth Value Layer, relaxation length, effective atomic numbers and effective electron densities, basic gamma-ray attenuation properties such as Exposure Buildup Factors (EBF) and Energy Absorption Buildup Factors (EABF) at different penetration depths, Effective Removal Cross Section against fast neutrons have been calculated. In addition to nuclear radiation shielding parameters, numerous physical and mechanical parameters were determined. The experimental elastic modulus results were compared using the theoretical models Makishima-Mackenzie and Rocherulle model. The values of these moduli have been compared to their experimental values. The results observed that the composition has the highest value of PbO (45 mol. %) showed excellent nuclear radiation shielding and elastic properties.  相似文献   

14.
《Ceramics International》2020,46(2):1323-1333
This study aimed to provide a large-scale investigation on direct effect of K2O additive nuclear radiation shielding properties of calcium phosphate based bioactive quaternary P2O5–CaO–Na2O–K2O glasses. A gamma ray attenuation setup has been modeled in MCNPX (v-2.6–0) simulation code using Monte Carlo simulation technique. Next, all the bioactive glasses have been defined considering their chemical properties and material densities, respectively. The mass attenuation coefficients (MAC) have been calculated by using MCNPX code and obtained results have been used for determination of another vital gamma-ray shielding parameters. Moreover, a detailed calculation has been done for determination of exposure buildup factor (EBF) and energy absorption buildup factor (EABF) of investigated bioactive glasses which should be considered as important parameters for interaction properties of ionizing radiation with material environment. In addition, effective removal cross sections for fast neutrons have been calculated. To compare our results, obtained HVL values of the present investigation have been compared with copper oxide and cobalt oxide substituted bioactive glasses. Among the investigated bioactive glasses, the maximum MAC values were reported for PCNK60 sample with higher K2O additive. It can be concluded that chemical structure of additive materials in the bioactive glasses is strongly related with the radiation attenuation properties of bioactive glasses.  相似文献   

15.
《Ceramics International》2020,46(13):21000-21007
The influence of BaO on the optical characteristics and nuclear radiation shielding properties for 60B2O3-(40-x)Li2O-xBaO: x = 0, 5, 10, 15, and 20 mol% glasses was investigated. Various optical parameters such as optical transmission and reflection loss (TOptical, RLoss), molar refraction and molar polarizability (RMolar, αMolar), optical and static dielectric coefficients and metallization criterion (εOptical, εStatic, MCriterion), and metallization property according to refractive index and optical energy gap (M(nLinear), M(EOptical)), were determined. The results confirmed that RMolar changes directly with αMolar, while TOptical changes inversely with RLoss. The mass attenuation coefficient (μ/ρ) was investigated using WinXCOM software and the results showed that all the S1–S5 glasses have good attenuation ability at 284 keV due to their high mass attenuation coefficients (μ/ρ). The highest and lowest values of μ/ρ occurred at 284 keV and 1.33 MeV respectively and varied between 0.1055 and 0.1361 cm2/g and 0.0526–0.0534 cm2/g. The linear attenuation coefficient (μ) increased with the gradual addition of BaO from glass S1→S5. The results showed that the effective atomic number (Zeff) for S1 is almost constant, while S5 possessed the highest Zeff values. The half value layer (HVL) was estimated and the effect of BaO on this parameter was analyzed. At 284 keV, the HVL values were 2.8192, 2.3847, 2.1597, 1.9687 and 1.8936 cm for S1–S5 glasses respectively. The S5 sample possessed the least HVL, and accordingly, had better attenuation capabilities than the S1–S4 samples. Therefore, lithium borate glasses with high concentration of BaO can be applied in several optical and medical applications.  相似文献   

16.
《Ceramics International》2020,46(10):16452-16458
This paper focuses on the effect of Bi2O3 content (up to 80 mol%) on mechanical features and radiation shielding characteristics of boro-tellurite glasses within TeO2–B2O3–Bi2O3 system. The basic mechanical parameters such as oxygen molar volume, packing density, hardness, and elastic moduli were studied based on Makishima–Mackenzie's theory. The shielding studies of the TeO2–B2O3–Bi2O3 glasses included gamma, electron and neutron radiations. The newly developed Phy-X/PSD program and Geant4 simulation were used to calculate the shielding parameters such as mass attenuation coefficient (μ/ρ), tenth value layer (TVL), mean free path (MFP), stopping power (ψe)), removal cross section (RCS), CSDA range, effective atomic number (Zeff), and half value layer (HVL). The concentration of Bi2O3 content had a significant effect on the gamma shielding competence of the investigated glasses. Form the results of gamma shielding studies, the highest μ/ρ (99.845 cm2/g) occurred at 0.015 MeV for TBB80 and the lowest μ/ρ (0.039 m2/g) occurred at 4 MeV for TBB40. The maximum values of Zeff for gamma interaction occurred at 0.02 MeV and they were 77.26, 78.81, 79.94, 80.80, and 81.48 for TBB40, TBB50, TBB50, TBB60, TBB70, and TBB80, respectively. The gamma shielding features of the investigated glasses were compared with those of various ordinary concretes, and Pb-free, Pb-based, and commercial glasses. The Bi2O3 content had also a considerable influence on the electron shielding competence of the tested glasses. The maximum values of Zeff for electron interaction occurred at 14 MeV and they were 44.58, 47.72, 50.41, 52.75, and 53.73 for TBB40, TBB50, TBB50, TBB60, TBB70, and TBB80, respectively. The results revealed that the bismuth boro-tellurite glasses could be useful for the shielding against gamma, electron, and neutron radiations, wherein the Bi2O3 content can be balanced according to the type and energy of radiation.  相似文献   

17.
This study aimed to investigate the gamma-ray and neutron attenuation parameters of cobalt oxide and nickel oxide substituted ten bioactive glasses. The mass attenuation coefficient (μ/ρ) for the selected bioactive glasses was calculated using MCNPX code in photon energy range (0.02?MeV - 20?MeV) and the results were compared with the output of WinXcom software. Other vital gamma-ray attenuation parameters such as half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Zeff), and effective electron density (Nel) for the selected bioactive glasses were also calculated for each approach. Gamma-ray and neutron transmission factors as well as neutron effective removal cross-sections of each bioactive glass (ΣR) were also taken into consideration to underline the distinctive parameters. Additionally, exposure buildup factor (EBF) values were found with G-P fitting approach depending on the energy and penetration depths. The results points that, the lowest HVL, TVL and MFP values and the highest neutron effective removal cross-sections (ΣR) values are the characteristics of NiO4C and CoO-4. The results indicate that the density of the material affects the photon and neutron interaction parameters. While NiO4C has the lowest TF values for both gamma and neutron radiation, the highest ΣR values are collected from NiO4C glass material. The gamma and neutron transmission factors (TF) of the studied bioactive glasses support the aforementioned results. The lowest Zeff values were generated for 45S5C and 45S5 ordinary glasses, while CoO-4 and NiO4C doped glasses are having the highest values of Zeff. EBF values of the glasses were also calculated in the energy range 0.015–15?MeV up to 40 mfp. The smallest EBF values were measured for CoO-4 and NiO4C glasses. It can be concluded that NiO4C bioactive glass outperformed compared to other studied samples and is a promising bioactive glass for gamma-ray and neutron attenuation.  相似文献   

18.
《Ceramics International》2020,46(11):19078-19083
This study examines the basic mechanical parameters and radiation shielding properties of (100−x)TeO2+xZnO+4NiO glasses (where x = 9.6, 19.2, 28.8, and 38.4 mol%) glass system. The mechanical study included basic parameters such as hardness, packing density, elastic moduli, and Poisson's ratio. Shielding ability of the glasses was tested against gamma and neutron radiations as well as against charged particles such as electron, proton, and alpha. Geant4 simulations and theoretical calculations by using Phy-X computer program were carried out to estimate mass attenuation coefficient (μ/ρ), neutron removal cross section (RCS), transmission factors namely; half value layer (HVL) and mean free path (MFP), and effective atomic number for total interaction of gamma (Zeff-G), electron (Zeff-E), proton (Zeff-P), and alpha (Zeff-A) radiations. The results showed that ZnO concentration had a significant influence on the mechanical properties and the shielding capability for glasses involved. The values effective atomic number were in the range of 30.2–46.1 for Zeff-G, 21.2–26.5 for Zeff-E, 16.9–19.7 for Zeff-P, and 15.3–18.6 for Zeff-A, respectively. The current glasses can act as superior shielding material as compared with those of Pb-free glasses, commercial glasses, and traditional concrete.  相似文献   

19.
Six compositions of 1 mol % Dy3+-doped multicomponent borate glasses containing single Li2O, Na2O, K2O and mixed Li2O–Na2O, Li2O–K2O, and Na2O–K2O oxides have been synthesized by well-known melt-quenching technique. Following the measured density and refractive index values, various physical parameters were estimated for all the glass samples and differences in them are correlated with structural changes. To explore optical properties like absorption edge (λcut-off), optical band gap energy (Eopt), and Urbach energy (ΔE), optical absorption spectra were recorded for all the glasses. The Eg has been calculated using Davis and Mott theory for direct allowed, and indirect allowed transitions and the results were reported. The Eg values are also estimated using absorption spectrum fitting (ASF) method. The optical parameters variations have also been associated with the structural changes occurring in the glasses with different alkali/mixed alkali oxides content presence. The shielding properties of the prepared glasses were studied in terms of effective atomic numbers (Zeff), mean free path (MFP), half value layer (HVL) and macroscopic effective removal cross-section (ΣR). From these results, it was found that Potassium (K) glass shows superior gamma ray shielding properties due to a higher value of Zeff and lower values of both MFP and HVL. These results indicate that the prepared glasses might be utilized in place of some common shielding materials to shield γ-rays and neutrons.  相似文献   

20.
In this study, a series of Bi2O3 reinforced bariumtelluroborate (TBX) glasses with the nominal composition 20TeO2 + (50-x)B2O3 + 29.5BaO + xBi2O3 + 0.5Er2O3 (where x=0,5,10,15 and 20 in wt%) were manufactured using traditional melt-quenching method. The structural and compositional studies were performed by using XRD and FTIR spectra. In general, the glass matrix consists of the trigonal-planar and tetrahedral units of borates, tellurate and tellurite groups of tellurites, and the non-bridging oxygen (nBO). In addition to that, BiO3 and BiO6 groups are present in top-order glasses. The gamma-ray shielding (γ-RS) ability was evaluated through the vital parameters like the mass-attenuation coefficient (MAC), mean free-path (MFP), half-value layer (HVL), and effective atomic-number (Zeff). TB20 glass is happened to be the best candidate by giving the highest value for MAC and the lowest MFP and HVL, owing to its large density, 6.922 g/cm3. The fast neutron-removal cross-section (∑R) is assessed to investigate the neutron shielding capacity of TBX glasses. The γ-rays shielding properties of TBX glasses were observed better than some ordinary shields such as barite-concrete and commercial shielding glasses developed by SCHOTT Company.  相似文献   

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