Theoretical Mass Attenuation Coefficients Research Articles

Impact of Bulk and Nano Bismuth Oxide on the Attenuation Parameters of Bentonite Barite Composites

Since bentonite can absorb neutrons and gamma rays without sacrificing structural integrity, it is frequently used as the main shielding material in many nuclear installations. Recently, there has been a trend toward enhancing the shielding qualities of bentonite by adding various chemicals. However, the majority of the added materials either require particular handling procedures or pose health risks. The availability of environmentally friendly additives would be wonderful. The addition of barite to bentonite composites greatly raises the density of the specimens. Additionally, the performance of bentonite–barite composites as radiation shielding materials is improved by adding various amounts of bulk and nano Bi2O3 as a filler (6%, 13%, and 20%). Energy dispersive X-ray analysis (EDX) was used to determine the chemical makeup of the produced specimens. The scanning electron microscopy (SEM) pictures showed the samples’ cross-sections’ porosity and homogeneity. 241Am, 133Ba, 137Cs, and 60Co are radioactive sources that emit energies of 59.53, 80.99, 356.01, 661.66, 1173.23, and 1332.5 keV, respectively, and the NaI (Tl) scintillation detector was used in this investigation. The area under the peak of the observed energy spectra was measured using the Genie 2000 program in both the specimen’s absence and presence. The coefficients for linear and mass attenuation were calculated. To determine the theoretical mass attenuation coefficients, the XCOM program was utilized and then compared to the corresponding experimental values. Various radiation shielding parameters dependent on the linear attenuation coefficient were computed for each studied composite. These parameters include the mean free path (MFP), half value layer (HVL), and tenth value layer (TVL). Also, the Zeff and the EABF were determined for each specimen. According to the findings, bismuth oxide was added to bentonite–barite composites to reduce the transmitted flux through the specimens, which increased the LAC of the bentonite–barite composites. Furthermore, adding nanosized bismuth oxide particles increased the sample’s density and improved the material’s shielding properties. At a photon energy of 0.356 keV, the relative deviation (∆%) between the experimental nano- and micro values for Bi2O3 (20 wt%) was 12.1974, confirming that the nanoparticles increase attenuation efficiency.

Assessing the Accuracy of Mass Attenuation Coefficients for Soft X-ray EPMA.

The use of soft X-rays in electron probe microanalysis (EPMA) has gained renewed interest over the past decades due to the advent of new detector technologies. Because X-ray absorption is the dominant correction for soft X-rays, a reliable set of mass attenuation coefficients (MACs) is needed for accurate composition determination. Although several MAC tabulations cover the soft X-ray range, the accuracy of such tabulations below 1 keV is not firmly established. In this study, we assess the accuracy of MAC tabulations in the soft X-ray region by comparing tabulated values for Be, B, C, N, O, and F Kα X-rays with experimental data available in the literature. We find that the 1993 semi-empirical MAC compilation of Henke et al. [(1993). Low-energy X-ray interaction coefficients: Photoabsorption, scattering, transmission and reflection at E=50-30000 eV, Z=1-92. Atom Data Nucl Data Tables54, 181-342] and the more recent theoretical MAC calculations of Sabbatucci and Salvat [(2016). Theory and calculation of the atomic photoeffect. Rad Phys Chem121, 122-140] perform slightly better than the rest of the considered tabulations. The Sabbatucci-Salvat dataset also provides the best agreement with the few existing experimental measurements for Al L2,3M X-rays.

Evaluation of mass attenuation coefficient of concrete sample for different traits

Concrete is widely used in the world and is the main material for civil construction. Due to its properties, it has different uses such as structural, filling and shielding. The aim of this work is to compare experimental and theoretical mass attenuation coefficient for concrete with different traits and determine the one with the best performance. For this, density, X-ray diffraction, mass attenuation coefficient (experimental with a Cs137 source, simulated by MCNP and theoretical determined with XCOM platform) and compressive strength were determined for three different traits of cement mortar (standardized sand, conventional sand and artificial sand). The X-ray diffraction showed more compounds for artificial sand’s samples. Density showed no significant variation. The samples showed a good agreement for experimental, simulated and theoretical mass attenuation coefficient. Standardized sand’s samples had the best performance for mechanical test, with a compressive strength 47.4% higher than artificial sand’s samples and 38.2% higher than conventional sand’s samples. It is possible to conclude that, since mass attenuation coefficient showed no significant difference, standardized sand’s samples is more indicated to be used for shielding than the others.

Radiation shielding parameters and Micro-Raman spectral analysis of some pyroclastic rocks

In this study, the radiation shielding parameters of some pyroclastic rocks (Karabakir, Elazığ) were experimentally measured at 59.54–661.62 keV energy region. In addition, theoretical mass attenuation coefficients were calculated. Fast neutron removal cross section, exposure buildup factor, mass stopping power and projected range values for proton (H1) and alpha (He+2) particles were theoretically determined. The equivalent dose rates due to fast neutrons absorption by rock samples was measured experimentally using a241Am–Be fast neutron source with 10 mCi activity. Also, the elemental analysis of pyroclastic rocks was done by instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Minerals type and rock strength were evaluated by micro-Raman spectroscopy methods. The dose rate at detector is D0 when there is no sample between the neutron source and the detector, the dose rate at detector is Dd when there is a K-8 rock sample. The difference between the dose rates (Ds), was calculated and the equivalent dose rate absorbed by the K-8 rock sample was obtained as 0.2667 μSv⁄h. It is observed that K-8 rocks sample is a promising choice for gamma, neutron, proton and alpha shielding.

Photon interaction of molybdenum (Mo) based cesium tri-molybdate (Cs2Mo3O10) and disodium dimolybdate (Na2Mo2O7) single crystal scintillators

Both single crystals, molybdenum-based cesium tri-molybdate and disodium dimolybdate single crystal scintillators were investigated for gamma-rays interaction. The theoretical mass attenuation coefficients have been calculated by the WinXCom program. The 137Cs source was used in the experiment that was irradiated with eight different photon energies using the Compton scattering technique. The theoretical result shows that the mass attenuation coefficient of both scintillators depends on photon energy and decreases with increasing of photon energy. The molybdenum-based cesium tri-molybdate shows higher values of the mass attenuation coefficient than disodium dimolybdate scintillator all the energy range. The experimental result shows the same trend and are good agreement with theoretical. The values of molybdenum-based cesium tri-molybdate show decreased from 22.15 to 7.7 ( × 10−2 cm2/g) and the disodium dimolybdate scintillator shows decreased from 16.05 to 7.4 ( × 10−2 cm2/g). Moreover, the partial interaction, the effective atomic number, and the effective electron density were also investigated.

Optical, structural, physical, and nuclear shielding properties, and albedo parameters of TeO2–BaO–B2O3–PbO–V2O5 glasses

In this study, glass systems were constructed according to the formula 34TeO2∙xBaO∙35B2O3∙(30-x)PbO∙1V2O5 (x=0, 5, 10, 15, 20, 30 mol%). The gamma, neutron, proton, and alpha shielding characteristics of the glasses were evaluated for nuclear security applications. The mass attenuation coefficient (MAC), half-value layer, mean free path, effective atomic number, and radiation protection efficiency (RPE) were experimentally measured in the energy range of 59.54–661.62 keV. In addition, the theoretical MAC values were determined. The exposure buildup factor, fast neutron removal cross section, mass stopping power, and projected range values for proton (H1) and alpha (He+2) particles were theoretically determined. Albedo parameters were measured for the prepared glasses at photon energy of 59.54 keV. The optical and structural properties were studied using X-ray diffraction, FT-IR Fourier transform infrared, ultraviolet–visible, and electron paramagnetic resonance spectroscopy. The glass samples comprised structural units such as TeO4, TeO3, BO3, and BO4. The spin Hamiltonian parameters, g∥, g⊥, A∥, A⊥, dipolar hyperfine coupling parameter, P, and Fermi contact parameter, κ, were calculated. The molecular orbital parameters, α2, β2, and γ2, were determined by optical absorption spectroscopy. The number of bonds per unit volume in the glasses ranged between 8.763 and 9.212×1028 m−3. The most reflective compound among the glasses investigated was BaO. Good agreement was found between the theoretical and experimental MAC values. TeBaBPbV1 glass was identified as a potential candidate for use in neutron, gamma, proton, and alpha shielding.

Enhancement of Bentonite Materials with Cement for Gamma-Ray Shielding Capability.

The gamma-ray shielding ability of various Bentonite–Cement mixed materials from northeast Egypt have been examined by determining their theoretical and experimental mass attenuation coefficients, μm (cm2g−1), at photon energies of 59.6, 121.78, 344.28, 661.66, 964.13, 1173.23, 1332.5 and 1408.01 keV emitted from 241Am, 137Cs, 152Eu and 60Co point sources. The μm was theoretically calculated using the chemical compositions obtained by Energy Dispersive X-ray Analysis (EDX), while a NaI (Tl) scintillation detector was used to experimentally determine the μm (cm2g−1) of the mixed samples. The theoretical values are in acceptable agreement with the experimental calculations of the XCom software. The linear attenuation coefficient (μ), mean free path (MFP), half-value layer (HVL) and the exposure buildup factor (EBF) were also calculated by knowing the μm values of the examined samples. The gamma-radiation shielding ability of the selected Bentonite–Cement mixed samples have been studied against other puplished shielding materials. Knowledge of various factors such as thermo-chemical stability, availability and water holding capacity of the bentonite–cement mixed samples can be analyzed to determine the effectiveness of the materials to shield gamma rays.

Investigation of Gamma-ray Shielding Features of Several Clay Materials Using the EPICS2017 Library

In this study, the investigation of the Electron-Photon Interaction Cross Sections 2017 (EPICS2017) library on the radiation shielding properties of several clay materials is presented. The EPICS2017 library was interpolated in the recommended interpolation law through the EpiXS program. Calculations were made for the mass attenuation coefficients (MACs), mean free paths (MFPs), half-value layers (HVLs), tenth-value layers (TVLs), and effective atomic numbers (Zeff) of the materials, in photon energies ranging between 1 keV and 100 GeV. The results from EPICS2017 were compared with values from experimental and theoretical methods used in characterizing the photon shielding properties. Experimental MACs agreed well with the EPICS2017 evaluations with percent deviations ranging from 0.1–5.3%. The theoretical MAC values derived using EPDL97 and XCOM-NIST strongly agreed with EPICS2017, with percent deviations ranging from 0.0–0.7% for the discrete gamma-ray energies between 609–1764 keV. Overall, ball clay and kaolin clay demonstrated the most desirable radiation shielding characteristics. From these findings, the EPICS2017 library was demonstrated as an important alternative in future photon shielding research of general construction and building materials. The EpiXS is a versatile tool to compute the radiation shielding parameters mentioned, specifically in using EPICS2017 as a photoatomic library.

Measurement of Total Electronic Cross-Section, Total Atomic Cross-Section, Effective Atomic Numbers, Effective Electron Densities and Kerma for Some Br Compounds

The aim of this study is to calculate the experimental and theoretical the mass attenuation coefficient some Br compounds by using transmission method. Also using these values were determined the total electronic section, total atomic section, effective atomic number, effective electron density and Kerma. We performed the calculations of these values in attenuation by using direct excitation experimental geometry. The total attenuation cross sections of some halogene Br compounds were measured in a narrow beam good geometry using a high resolution Si(Li) detector in the energy with γ photons at 59.543 keV from Am-241 annular source. Theoretical mass attenuation coefficient values were computed from the XCOM data programme, based on mixture rule method. This study provide new insight into the literature since the values of effective atomic number, electron density and Kerma for some Br compounds have not been determined before. According to the results shown in mass attenuation coefficient, Zeff and Neff of Br compounds are closely associated with chemical structure. This research were undertaken to explore how Bromine compounds is gamma ray shielding material.

Synergistic effect of nano‐bentonite and nanocadmium oxide doping concentrations on assembly, characterization, and enhanced gamma‐rays shielding properties of polypropylene ternary nanocomposites

It has been confirmed from an experimental, as well as a theoretical, standpoint that metal oxide polymer nanocomposites (MPNCs) represent a new category of advanced materials effective in radiation shielding. In this study, novel (PP/CdO-NPs-NBent) ternary nanocomposites were designed, based on doping polypropylene (PP) with two different nanofillers, namely cadmium oxide nanoparticles (CdO-NPs) and nano-bentonite (NBent), to function as promising alternatives for γ-ray shielding. The PP/(x)CdO(40-x)NBent nanocomposites samples for x = 0.0, 10.0, 20.0, 30.0, and 40.0 wt% filling concentration were fabricated using the compression molding technique. The surface morphology of the nanoparticles, as well as the corresponding nanocomposites, along with their structural and thermal characteristics was studied using TGA, XRD, SEM, and FT-IR. A NaI detector was used along with different γ-ray photon energies (356.01, 661.66, 1173.23, and 1332.50 keV) to measure the mass attenuation coefficient of the nanocomposites being studied, as a function of the percentage of both CdO-NPs and NBent NPs. In order to verify the applicability of classic “mixture role” on mass attenuation coefficient of anisotropic composites, theoretical mass attenuation coefficient at different photon energies was calculated using XCOM software based on the weight fraction and mass attenuation coefficient of each constituent element among PP/CdO-NPs-NBent nanocomposites. The results indicated that the mass attenuation values of the studied nanocomposites are in the same line with results of XCOM simulation code at all the selected range of γ-ray photon energies. The mean free path, the half value layer, the effective electron density, and the effective atomic number were also calculated to find out the radiation shielding characteristics of the new nanocomposites. Based on the results obtained, it was proven that the addition of CdO-NPs to the nanocomposites elevated their mass attenuation coefficient, effective atomic number, and effective electron density more than the addition of NBent. The achieved results revealed that the NC2 nanocomposite sample with 40.0 wt% CdO-NPs had the highest values for mass attenuation coefficient (0.1283 ± 0.96 at 356.01 keV), effective electron density (3.941 ± 0.15 at 356.01 keV), and effective atomic number (41.84 ± 0.34 at 356.01 keV) and the smallest values for half value layer (2.3941 at 356.01 keV) and mean free path (3.3096 at 356.01 keV). As such, it is this nanocomposite that is best at attenuating γ-rays of all the nanocomposites tested. Highlights Polypropylene was doped with nanoparticles of CdO and bentonite as nanofillers. The developed nanocomposites (PP/CdO-NPs-NBent) were characterized. The bulk densities increased from 1.641 ± 0.72 to 4.034 ± 0.45 g/cm3. μm, Zeff, Nel, HVL, and MFP were measured vs (wt%) of CdO-NPs and NBent. The assembled (PP/CdO-NPs-NBent) was found highly protective against γ-rays.

Measurement of Photon Matter Interaction Parameters for some Iodine Compounds

In this study, total atomic cross-section (σta), total moleculer cross-section (σtm) total electronic cross-section (σte), effective atomic number (Zeff), effective electron density (Neff) and Kerma (K) were determined both experimentally and theoretically values for some iodine compounds. Experimental mass attenuation coefficient (µ/ρ) values for some iodine compounds were calculated with the data obtained from the test results. The theoretical mass attenuation coefficient values of these compounds were calculated with the WinXCOM data program. Also, we have performed the measurements for the calculations of experimental values mass attenuation coefficient using direct transmission experimental geometry. The transmission photon intensity of halogene iodine compounds were measured in a narrow beam experiment geometry was used 59.543 keV γ-ray from an 241Am radioactive source. The tranmissions spectra from iodine compounds were recorded with a Si (Li) detector having a resolution of 155 eV FWHM at 5.9 keV (55Fe) and coupled to a 1024 channel analyzer through a spectroscopic amplifier. This study was provided that new insights into the literature since mass attenuation coefficient experimental values of some I compounds have not been determined previously. More research should be done to observe the changes in the chemical structure of iodine compounds with gamma-ray interaction. This study will shed light on further research.

Tungsten-based material as promising new lead-free gamma radiation shielding material in nuclear medicine.

The main objective of this study was to evaluate the efficacy of tungsten carbide as new lead-free radiation shielding material in nuclear medicine by evaluating the attenuation properties. The elemental composition of tungsten carbide was analysed using Field-Emission Scanning Electron Microscopy (FESEM) with energy dispersive X-ray (EDX). The purity of tungsten carbide was 99.9%, APS: 40-50µm. Three discs of tungsten carbide was fabricated with thickness of 0.1cm, 0.5cm and 1.0cm. Three lead discs with similar thickness were used to compare the attenuation properties with tungsten carbide discs. Energy calibration of gamma spectroscopy was performed by using 123I, 133Ba, 152Eu, and 137Cs. Gamma radiation from these sources were irradiated on both materials at energies ranging from 0.160MeV to 0.779MeV. The experimental attenuation coefficients of lead and tungsten carbide were compared with theoretical attenuation coefficients of both materials from NIST database. The half value layer and mean free path of both materials were also evaluated in this study. This study found that the peaks obtained from gamma spectroscopy have linear relationship with all energies used in this study. The relative differences between the measured and theoretical mass attenuation coefficients are within 0.19-5.11% for both materials. Tungsten carbide has low half value layer and mean free path compared to lead for all thickness at different energies. This study shows that tungsten carbide has high potential to replace lead as new lead-free radiation shielding material in nuclear medicine.

Evaluation of gamma rays shielding competence for bentonite clay /PVA polymer matrix using MCNPX code

Radiation shielding capability in terms of mass and linear attenuation coefficients, half value layer, tenth value layer, and mean free path haven been evaluated for natural bentonite coated by polyvinyl alcohol polymer (PVA) using Monte Carlo simulation (MCNPX) and XCOM program. All data were determined at gamma photons energies 662, 1173 and 1332 keV emitted from point sources of 137Cs and 60Co, respectively, and compared with calculated experimental data. XCOM results of mass attenuation coefficients showed better agreement with experimental data in comparison with MCNPX code. The relative deviations between experimental and theoretical mass attenuation coefficients are 4.3, 2.5 and 1.25 % at 662, 1173 and 1332 (keV) while deviation between simulated and experimental mass attenuation coefficients are -3.1, -10.96 and -10.35 % at the same energies, respectively. The relative deviation between simulated shielding factors HVL, TVL and MFPwith experimental data exhibit the same behavior as mass attenuation coefficient and having average relative deviations percentage equal to 2.5, 13.4 and 13.8 % at the studied energies, respectively.

Physical, optical and gamma-ray shielding properties of BaO- La2O3-B2O3 and BaO-Na2O-B2O3 glass systems at 662 keV

In this work, glasses with composition xBaO : 20La2O3: (80-x)B2O3 and xBaO : 20Na2O3: (80-x)B2O3 (where x= 15, 20,25 and 30 mol%) were prepared using melt-quenching method. Physical, optical and gamma-ray shielding properties were investigated and compared with theoretical calculations. 137Cs was used as γ-source for investigating experimental mass attenuation coefficient at 662 keV energy. The theoretical mass attenuation coefficient was calculated using WinXcom program. The density and the molar volume show increasing trend with increase in BaO concentration. Transmission spectra shows dissimilarity in their transmittance for BaO-Na2O-B2O3 and BaO-La2O3-B2O3 glasses. BaO-Na2O-B2O3 glasses show higher transmittance in the visible region than compared to BaO-La2O3-B2O3 glasses. Mass attenuation coefficients, Zeff show increasing trend whereas HVL at 662 keV show decreasing trend with increase in BaO concentration for these both these glasses. Theoretical and experimental mass attenuation results are in good agreement with each other. The synthesized glasses show potential use for radiation shielding material applications.

Photon Interaction Parameters Investigations for Some ZnO–Al2O3–Fe2O3–P2O5 Glasses at 59.4 keV Incident Photon Energy

Total mass attenuation coefficient (μm), total photon interaction cross-section, effective atomic numbers (Zeff) and electron densities (Ne) of 15ZnO(17.5 – x)Al2O3 · xFe2O3 · 67.5P2O5 glass system (x = 0, 7.5, 12.5, 17.5) and 15ZnO(25 – x)Al2O3 · xFe2O3 · 60P2O5 glass system (x = 0, 25) have been investigated at 59.54 keV energy photon emitted by 100 mCi 241Am point source employing narrow beam transmission geometry. Experimental results have been compared with theoretically calculated values using WinXCOM (2001). Mixture rule is employed to calculated theoretical mass attenuation coefficient values for each sample. Good agreement has been observed between experimental and theoretical values within experimental uncertainties. The selected glass sample with maximum contribution of Fe2O3 with ZnO has maximum value of mass attenuation coefficient and effective atomic number. It is found that measured values are in agreement within 2% of theoretical results. The measurement of mm, Zeff, interaction cross-section and Ne enhances the understanding of glass sample characteristics. The prepared glass samples are found to have potential applications in radiation shielding, as well as numerous applications in the fields of medicine and industry.

Evaluation of radiation absorption capacity of some soil samples

Abstract The aim of the present work is to investigate the radiation absorption capacity of different soil samples in Turkey. For this purpose, we used a γ ray transmission geometry to measure the mass attenuation coefficients of eight soil samples collected between Bingöl city and Solhan district, Turkey at different γ-ray energies in the range of 13.94–88.04 keV. The radioactive sources utilized in the experiment were 241Am, 109Cd and 133Ba. FFAST and WinXCOM programs were used to evaluate the theoretical mass attenuation coefficients values of the selected soil samples. There is a good agreement between experimental and theoretical results. Additionally, the mass attenuation coefficients values used to evaluate different radiation shielding parameters such as effective atomic number, half value layer and mean free path. The variation of shielding parameters was examined for soil composition and photon energy. The obtained results revealed that S6 soil sample is the best soil in terms of shielding effectiveness among all the collected soils due to lower values for half value layer and mean free path. The effective removal cross-section (Σ R ) of fast neutrons for the collected soils was also computed to examine neutrons shielding properties of the soil samples. It is found that the Σ R values for the soil samples are almost constant and lie within the range (0.04286–0.04949 cm−1).

Gamma-ray attenuation coefficients and transmission thickness of high consistency heavyweight concrete containing mineral admixture

In the study, high consistency heavyweight concrete mixtures containing barite aggregate were produced by using some common mineral admixtures (viscosity modifier, silica fume and fly ash) at various water/binder ratios and binder contents. Gamma-ray linear attenuation coefficients of the concrete mixtures were determined by using gamma sources of 137Cs and 60Co in NaI(Tl) gamma spectrometry system. The relationship between specimen thickness and transmission of the rays was constituted by emphasizing their mean free path, half-value layer, and tenth-value layer. Moreover, experimental mass attenuation coefficients of the concrete specimens were determined and compared with theoretical mass attenuation coefficients calculated by XCOM software depending on elemental fractions of these concrete in equivalent energies (662 keV, 1173 keV and 1332 keV). As a result, the replacement of the aforementioned admixtures with ordinary cement negatively affected the linear attenuation coefficients of the heavyweight concrete. A relative change of up to 25% was observed between the least and the highest attenuation thickness values at a certain gamma-ray transmission. A good regression relationship has been established between density and linear attenuation coefficients, density and mean free path, and density and half- or tenth-value layers of the heavyweight concrete. Theoretical (XCOM) mass attenuation coefficients were found similar to the experimental mass attenuation coefficients of the heavyweight concretes. Although there is a good linear regression relation between the theoretical and experimental mass attenuation coefficients at 662 keV energy of gamma rays, the relations were disappeared at 1173 and 1332 keV energies of gamma rays.

Radiation shielding property of structural polymer composite: Continuous basalt fiber reinforced epoxy matrix composite containing erbium oxide

For protecting human body and equipment against radiation in nuclear power industry, radiation medicine and aerospace exploration, advanced materials possessing good shielding capability, low density and high mechanical strength and modulus are in urgent demand. In this study, radiation protective basalt fiber (BF) reinforced epoxy matrix composite containing erbium oxide (Er2O3) particles was fabricated by prepreg-autoclave process, in order to make a novel mechanical/radiation shielding composite. For prepared unidirectional and quasi-isotropic BF/Er2O3 composite laminates, basalt fibers and Er2O3 particles distributed uniformly, and no obvious agglomeration of particles and defects were found. NaI(Tl) detector was used to test mass attenuation coefficient for evaluating X and gamma rays shielding performance at different photon energies ranging from 31 keV to 662 keV. The experimental results indicate that BF/Er2O3 composite shows good X and gamma rays shielding performance, and mass attenuation coefficient of BF/Er2O3 composite is much larger than that of aluminum in relatively low energy from 31 keV to 80 keV. The effect of prepreg stacking consequence on shielding performance was also discussed. In addition, to verify the applicability of classic “mixture role” on mass attenuation coefficient of anisotropic composites, theoretical mass attenuation coefficient at different photon energies was calculated using XCOM software based on the weight fraction and mass attenuation coefficient of each constituent element among BF/Er2O3 composite. It is found that there is maximum deviation of 10.3% between experimental and theoretical results. Thus, it is believed that the method is suitable for predicting shielding performance of continuous fiber reinforced composite materials. Considering the advantages in light weight and high mechanical property, the studied three-phase composite is promising for using in radiation shielding structure application.

Determination of mass attenuation coefficients and effective atomic numbers for compounds of the 3d transition elements

Abstract In this study, we aimed to determine mass attenuation coefficient ( μ m ) and effective atomic number ( Z e f f ) for some compounds of the 3d transition elements such as CoO, CoF2, CoF3, Cr2O3, CrF2, CrF3, FeO, Fe2O3, MnO2, TiO2, V2O3, VF3, V2O5, VF4 and ZnO at 19.63 and 22.10 keV photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. The experimental results of μ m are compared with the theoretical results. Also, effective atomic numbers of compounds of the 3d transition elements have been determined by using experimental and theoretical mass attenuation coefficients. The agreement of measured values of effective atomic numbers with theoretical calculations is quite satisfactory.

Investigation on the Behaviours of TiB2 Reinforced B4C-SiC Composites Against Co-60 Gamma Radioisotope Source

In the present study, the gamma attenuation behaviours of the Titanium diboride (TiB2) reinforced boron carbide (B4C)-silicon carbide (SiC) composite materials were investigated against Co-60 gamma radioisotope source. In the experiments TiB2 unreinforced and 2% and 4% TiB2 (by volume) reinforced B4C-SiC composite materials were used. In the composite materials B4C/SiC ratio has been realized as 6/4 by volume. The linear and mass attenuation coefficients of the samples were carried out for Co60 gamma radioisotope source which has two energy peaks (1.17 and 1.33 MeV). Then mass attenuation coefficients and half-value thicknesses (HVT) of the materials were calculated. Experimental mass attenuation coefficients were compared with the theoretical values which were calculated from XCOM computer code. Furthermore HVTs of the samples were evaluated and compared each other. It has been seen that the experimental and theoretical mass attenuation coefficients are closed to each other and differences are under 10 percent. In addition, TiB2 reinforced B4C-SiC composites have smaller HVTs than unreinforced one. Moreover 4% TiB2 reinforced B4C-SiC composite has smaller HVT than the 2% reinforced sample. Reinforcing TiB2 and increasing TiB2 ratio increase the gamma attenuation property of the B4C-SiC composites against Co-60 gamma radioisotope source.