Gamma-ray Mass Attenuation Coefficients Research Articles

Fabrication and characterisation of TeO2-based composite doped with Yb3+ and Bi3+ for enhanced radiation shielding safety

Heavy metal and rare earth ions are known for altering the optical and radiation transmission data of glasses. This study presents the influence of Yb3+ and Bi3+ on the optical and radiation safety application potentials of the TNBY glass system. Optical parameters were estimated for the glasses using standard expressions. The gamma ray mass attenuation coefficient was estimated through XCOM computation and FLUKA simulations for 15 keV – 15 MeV photons. The optical parameters of the glasses were altered depending on the concentration of Yb and Bi ions. The RMol and αm x10-24 assumes the value of 6.190 cm3/mol and 2.456 cm3 for TNBY-02, 6.197 cm3/mol and 2.459 cm3 for TNBY-05, 6.197 cm3/mol and 2.459 cm3 for TNBY-10, 6.102 cm3/mol and 2.422 cm3 for TNBY-15, and 6.235 cm3/mol and 2.474 cm3 for TNBY-Bi10. The μρ obtained through the FLUKA simulation and XCOM agreed well within 1%. The μρ of the TNBY glasses varies with energy within the limits of 0.0335 – 44.676 cm2/g, 0.0339 – 46.783 cm2/g, 0.0340 – 50.031 cm2/g, 0.0342 – 53.185 cm2/g, and 0.0350 – 55.795 cm2/g for TNBY-02, TNBY-05, TNBY-10, TNBY-15, and TNBY-Bi10 accordingly. Also, the least (maximum) value of the half value thickness appears at 15 keV (6000 keV) with values of 0.0029 (3.82) cm, 0.0027 (3.75) cm, 0.0025 (3.63) cm, 0.0023 (3.40) cm, and 0.0021 (3.37) cm for TNBY-02 – TNBY-Bi10 correspondingly. Generally, the photon shielding ability and dosimetry potential of the glass system improved with Yb3+ and Bi3+ weight content of the glasses. TNBY-Bi10 showed potentials to outperform some traditional and contemporary gamma absorbers such as concrete, commercial glass shields, and recently investigated glass materials. The TNBY-glasses recommended for gamma radiation inhibition functions such as nuclear waste container, structural and source shields.

Study of the structural and shielding properties of unsaturated polyester/lead oxide nanocomposites against gamma-rays

In this study, lead oxide nanorods were synthesized without surfactants in an aqueous medium at room temperature. Different percentages of lead oxide nanorods were added to an unsaturated polyester polymer matrix to have various wt% nanocomposites. The gamma-ray mass attenuation coefficients were measured as a function of the weight percentages of lead oxide at different thicknesses. This was done with radioactive source Ra-226. The unsaturated polyester/lead oxide nanorods composite was treated with 1, 2.5, 5, 10, 15, 20, 40, and 60 wt% lead oxide nanorods, as different proportions of the filler. According to the results, the best radiation attenuation was for 60 wt% nanocomposite. In such a nanocomposite, the optimal half value layer, tenth value layer, and mean free path were about 2.4, 7.6, and 3.35 cm, respectively.

Fabrication, structural, optical, physical and radiation shielding characterization of indium (III) oxide reinforced 85TeO2-(15–x)ZnO-xIn2O3 glass system

This work aimed to evaluate the structural, optical, and physical features of several types of glasses based on 85TeO2-(15–x)ZnO-xIn2O3 (x = 2, 4, 6, and 8 mol%) system. As a result, five different samples were synthesized utilizing the melting-annealing technique. The Archimedes method was used to calculate the densities of the synthesized glasses. The structural, optical, physical, and radiation interaction characteristics of the sample were determined using XRD investigations, Raman spectra, and advanced modelling methods, producing optical band gap, refractive index, and Urbach energy values. The glass densities increased from 5.6091 g cm−3 to 5.6754 g cm−3 by increasing In2O3 reinforcement from 2 to 8 mol %. Urbach energies increased consistently from 0.1399 to 0.1439 eV as In2O3 concentration increased, apart from a drop to 0.1345 eV at x = 8. The optical transmittance and absorption characteristics altered nearly monotonically with increasing In2O3 ratios, showing that these characteristics may be estimated and controlled using In2O3 additive. By substituting ZnO with In2O3 within the structure, the optical band gap was dramatically enlarged. Additionally, at simulated energies greater than 0.02 MeV, the gamma-ray mass attenuation coefficient grows monotonically with In2O3 reinforcement. As a result, it can be stated that the high concentration In2O3 to TeO2–ZnO glass combination is a good synergetic tool for integrating structural, optical, and radiation properties.

Neutron and gamma radiation shielding Ni based new type super alloys development and production by Monte Carlo Simulation technique

In the present study, five different type of new super alloys have been developed and produced which have high temperature resistance for both gamma and fast neutron radiation shielding. These super alloys have been produced with powder methodology by using the materials such as iron (Fe), rhenium (Re), boron carbide (B4C), nickel (Ni), chromium (Cr), boron (B), copper (Cu), tungsten (W), tantalum (Ta). Gamma-ray Mass attenuation coefficients, half value layer effective atom number, mean free path and fast neutron total macroscopic cross section, transmission number values have been theoretically calculated by using Geant 4 code, WinXCom and Phy-X / PSD software. In addition, experimentally equivalent dose measurements have been carried out by using 241Am-Be fast neutron source. Sulfuric acid abrasion, compressive strength, temperature resistance and weldability tests have been made. The results are compared with 316LN nuclear stainless steel because of its common use in nuclear shielding applications and all new type super alloy samples have shown better radiation absorption ability for both gamma and fast neutron. It has been determined that these new type super alloys can be used in nuclear applications for better shielding.

Fabrication, characterization, simulation and experimental studies of the ordinary concrete reinforced with micro and nano lead oxide particles against gamma radiation

The concrete is considered as an important radiation shielding material employed widely in nuclear reactors, particle accelerators, laboratory hot cells and other different radiation sources. The present research is dedicated to the shielding properties study of the ordinary concrete reinforced with different weight fractions of lead oxide micro/nano particles. Lead oxide particles were fabricated by chemical synthesis method and their properties including the average size, morphological structure, functional groups and thermal properties were characterized by XRD, FESEM-EDS, FTIR and TGA analysis. The gamma ray mass attenuation coefficient of concrete composites has been calculated and measured by means of the Monte Carlo simulation and experimental methods. The simulation process was based on the use of MCNP Monte Carlo code where the mass attenuation coefficient (μ/ρ) has been calculated as a function of different particle sizes and filler weight fractions. The simulation results showed that the employment of the lead oxide filler particles enhances the mass attenuation coefficient of the ordinary concrete, drastically. On the other hand, there are approximately no differences between micro and nano sized particles. The mass attenuation coefficient was increased by increasing the weight fraction of nanoparticles. However, a semi-saturation effect was observed at concentrations more than 10 wt%. The experimental process was based on the fabrication of concrete slabs filled by different weight fractions of nano lead oxide particles. The mass attenuation coefficients of these slabs were determined at different gamma ray energies using 22Na, 137Cs and 60Co sources and NaI (Tl) scintillation detector. The experimental results showed that the HVL parameter of the ordinary concrete reinforced with 5 wt% of nano PbO particles was reduced by 64% at 511 keV and 48% at 1332 keV. Reasonable agreement was obtained between simulation and experimental results and showed that the employment of nano PbO particles is more efficient at low gamma energies up to 1Mev. The proposed concrete is less toxic and could be prepared in block form instead of toxic lead blocks.

An investigation of gamma ray mass attenuation from 80.1 to 834.86 keV for fabric coating pastes used in textile sector

In the present study, we investigate several textile coating pastes used in the market based on their radiation protection capability for gamma rays. The gamma ray mass absorption coefficients of some coating pastes doped with antimony, boron and silver elements have been investigated. It has been determined that the gamma ray mass attenuation coefficient decreases rapidly as the energy of the gamma rays increases. It was determined that the doping of the main printing paste with silver and antimony considerably increased the gamma ray absorption capability of main paste. However, the doping of the paste with boron reduces the mass absorption of gamma rays. In particular, the gamma ray mass absorption power of the main paste doped with silver and antimony was determined to be useful in the gamma energy range from 80 to 140 keV. This indicates that the newly doped textile material may be considered for radiation protection in the case of low-energy gamma rays .

Evaluation of optical and gamma ray shielding features for tungsten-based bismuth borate glasses

A series of six tungsten-based bismuth borate glasses with a xWO3- 20 Bi2O3- 20 Na2O2- (60-x) B2O3), 0≤ x ≤ 5 wt% chemical composition were synthesized by using the solid-state conventional method. The structures of the fabricated samples were studied with X-ray diffraction analysis. Optical features such as the energy gap (Eg), Urbach energy (Eu), steepness parameter (S), refractive index (n) and Fermi level energy (EF) were measured for the fabricated glasses with a UV–Vis–NIR spectrophotometer. Furthermore, a Monte Carlo simulation code (MCNP-5) was applied to estimate the gamma ray mass attenuation coefficient (MAC) for the fabricated glasses. The simulated data showed that the insertion of WO3 increases the MACs of the fabricated samples: the highest and lowest MACs were obtained for the W6 and W1 glasses, respectively. Then, the simulated MAC was used to calculate the mean free path (MFP) for all the fabricated glasses. The thinnest MFP was achieved by W6 (increasing from 0.007 to 70,560 between 0.015 and 15 MeV, respectively), while the thickest MFP was achieved by W1 (increasing from 0.0100 to 8.975 between 0.015 and 15 MeV, respectively). Moreover, new Phy-x/PD software was used to calculate MAC, MFP, equivalent atomic number (Zeq) and the exposure and energy absorption buildup factors (EBF and EABF). The simulated and calculated results showed that adding WO3 enhances the shielding properties of the synthesized glass.

The degradation of gamma-ray mass attenuation of UOX and MOX fuel with nuclear burnup

Nondestructive gamma-ray spectrometry of nuclear fuel is routinely performed in axial gamma scanning devices and more recently with gamma emission tomography. Following the irradiation of a fresh nuclear fuel with high intensity neutron flux in a nuclear reactor core, a great number of gamma-emitting radionuclides are created. These can be utilized for gamma spectrometric techniques. However, due to the high density and atomic number of the nuclear fuel, self-attenuation of gamma-rays is a challenge, which requires attenuation correction in order to perform accurate analysis of the source activity in the fuel.In this study, the degradation of the gamma-ray mass attenuation with burnup was investigated and, in addition, a predictive model was created by investigating the attenuation change at various gamma energies caused by the burnup of the nuclear fuel. This model is intended for use by spectrometry practitioners inspecting nuclear fuel. To this aim, the energy-dependent gamma-ray mass-attenuation coefficients were investigated as a function of burnup for UOX, and three MOX fuels having different initial Pu contents. The Serpent 2 reactor physics code was used to simulate the burnup history of the fuel pins. The nuclide inventory of the Serpent 2 output is combined with the NIST XCOM database to calculate the mass attenuation coefficients.The mass attenuation coefficient of the fuel was found to decrease with the fuel burnup, in the range of a few percent, depending on the burnup and gamma energy. Also, a theoretical burnup dependent swelling model was imposed on fuel density to see how linear attenuation coefficient of fuel material is changed. Furthermore, greater effect may be expected on the transmitted intensity, where a simulation study of a PWR assembly revealed that the contribution from the inner rods in a scanned fuel assembly increased by tens of percent compared to the one with non-irradiated fresh fuels, when shielded by the outer rods of the assembly. A sensitivity analysis was performed in order to test the effect of a number of geometrical and operational reactor parameters that were considered to potentially effect the mass attenuation coefficient. Finally, a simple-to-use predictive model was constructed providing the mass-attenuation coefficient [cm2/g] of fuel as a function of burnup [MWd/kgHM] and initial Pu content [wt%]. The resulting predictive model was optimized by using the nonlinear regression method.

Gamma ray shielding characteristics of Sn-20Bi and Sn-20Bi-0.4Cu lead-free alloys

As a result of the expansion in the different uses of gamma ray sources and as a result of the harmful effects of radiation exposure, scientific research remains in need of finding and developing materials used as radiation shields. In the present study, shielding parameters of Sn-20Bi (SB) and Sn-20Bi-0.4Cu (SBC) lead-free alloys solidified with and without the effect of a rotating magnetic field (RMF) have been studied. Gamma ray mass attenuation coefficient (μt/ρ) was measured experimentally for the studied alloys at photon energy of 356, 511, 662, 1173, 1274, and 1332 KeV. The experimental μt/ρ values were compared with the calculated values by using the WinXCom and MCNP5 programs for alloys solidified without RMF. Besides, WinXCom and MCNP5 were used to calculate μt/ρ for gamma ray photons of energy range of 10−3-102 MeV. The atomic and electronic cross sections (σa and σe) and hence the effective atomic number (Zeff) and effective electron density (Neff) were calculated. The mean free path (MFP) of photons was calculated and introduced to MCNP5 input file to calculate the gamma ray energy buildup factor (EBF). The results of μt/ρ are shown to be highly compatible between the theoretical WinXCom and simulated MCNP5 programs and with the experimental values. The results of the shielding parameters confirm that the alloys under study are good shielding materials against gamma rays.

Gamma Radiation Studies on Organic Nonlinear Optical Materials in the Energy Range 122–1330 keV

Gamma ray mass attenuation of some nonlinear optical (NLO) materials has been studied experimentally using transmission experiment in the energy range 122–1330 keV. The selected NLO materials were radiated by radioactive point sources (57Co, 133Ba, 22Na, 137Cs and 60Co) of strength 5 mCi. Theoretical values were calculated on the basis of mixture rule using WinXCOM program. Good agreement between theoretical and experimental values was observed. Gamma ray mass attenuation coefficient (μm) values were used to determine other radiological parameters such as σt,a, σt,el, Zeff and Neff. The behavior of μm with the incident photon energy (E) has been discussed. From the obtained results, it is observed that the radiological parameters are affected severely by increasing the intensity of photon energy.

Computation of the mass attenuation coefficient of polymeric materials at specific gamma photon energies

The gamma ray mass attenuation coefficients of ten synthetic polymeric materials, namely, polyethylene (PE), polystyrene (PS), polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), Polyethylene terephthalate (PET), Polyvinyl pyrrolidone (PVP), Polytetrafluoroethylene (PTFE), Polypropylene (PP) and Polymethyl methacrylate (PMMA) have been calculated using second order polynomial equation and logarithmic interpolation formula at selected gamma photon energies, in the energy range starting from 14.4keV up to 1332keV. It is important to note that second order polynomial equation fits very well with NIST data for all the polymeric materials considered here, for gamma photon energies ranging from 300keV up to 2000keV. Third order polynomial fitting is best suited for lower gamma photon energies (from 10keV up to 200keV).

Structural and Physical Properties Study of Some Phosphate Glasses Used for Radiation Shielding

Mossbauer Effect (ME) and Infrared (IR) spectroscopes are used to study the structure of some iron-sodium phosphate glasses containing strontium, with composition [(70-x) mol% P2O5. x mol% SrO, 15 mol% Fe2O3.15 mol% Na2O, where x= 3, 6,9,12 and 15]. These glasses can have many interesting applications especially as gamma ray attenuators.The amorphous nature and the glassy state character of these glasses can be confirmed from comparing the experimental and empirical values of both their density and molar volume. It was found that, as SrO was gradually increased the density increased while the molar volume decreased which may be due to the gradual decrease of the number of oxygen ion density in the glass networks.The micro-hardness and magnetic susceptibility are also increased, which can be attributed to the gradual migration of iron from glass network modifier (GNM) to glass network former (GNF) positions, as confirmed by IR and ME results. IR and ME analysis indicated that both ferric and ferrous have tetrahedral and octahedral symmetry respectively and acting as GNF and GNM at different SrO contents. The gradual replacement of P2O5 by SrO force the iron to transfer from GNM to GNF.The gamma-ray mass attenuation coefficient increased with the gradual increase of Sr2+ as heavy metal, while the HVL decreased. On the other hand the attenuation coefficient decreased with the increase of gamma-ray photon energy. So, these glasses can be used as transparent shielding materials for low gamma-ray energies and to capsulate the radio-active wastes, while the sample containing 15 mol% SrO, exhibits the highest attenuation coefficient. Â

Gamma-ray mass attenuation coefficient and half value layer factor of some oxide glass shielding materials

The variation in dosimetric parameters such as mass attenuation coefficient, half value layer factor, exposure buildup factor, and the photon mean free path for different oxide glasses for the incident gamma energy range 0.015–15MeV has been studied using MicroShield code. It has been inferred that the addition of PbO and Bi2O3 improves the gamma ray shielding properties. Thus, the effect of chemical composition on these parameters is investigated in the form of six different glass compositions, which are compared with specialty concrete for nuclear radiation shielding. The composition termed ‘Glass 6’ in this paper has the highest mass attenuation and the smallest half value layer and may have potential applications in radiation shielding. An example dry storage cask utilizing an additional layer of Glass 6 as an intermediate shielding layer, simulated in MicroShield, is capable of reducing the exposure rate at the cask surface by over 20 orders of magnitude compared to the case without a glass layer. Based on this study, Glass 6 shows promise as a gamma-ray shielding material, particularly for dry cask storage.

A comprehensive study for mass attenuation coefficients of different parts of the human body through Monte Carlo methods

The gamma-ray mass attenuation coefficients of blood, bone, lung, eye lens, adipose, tissue, muscle, brain and skin were calculated at different energies (60, 80, 150, 400, 500, 600, 1000, 1250, 1500, and 2000 keV) by various theoretical methods such as FLUKA, GEANT4 Monte Carlo (MC) methods and XCOM program in this work. Calculated coefficients were also compared with the National Institute of Standards and Technology (NIST) values. Obtained results were highly in accordance with each other and NIST values. Our results showed that FLUKA was quite convenient in comparison to GEANT4 in the calculation of the mass attenuation coefficients of the used human body samples for low-energy photons (60, 80, and 150 keV) when compared with the NIST values.

A theoretical way to determine gamma-ray mass attenuation coefficients of materials

The gamma-ray mass attenuation coefficients of various absorber materials such as Ag, Al, Au, Bakelite, Cu, Fe, Pb, Plexiglas, Si, Sn, water, and Zn were determined theoretically at different gamma-ray energies and different absorber thicknesses in order to investigate how the number of gamma photons and their energies affect the calculation of mass attenuation coefficients of the absorbers since no study such a comprehensive work here was encountered. For this purpose, the FLUKA Monte Carlo (MC) and XCOM programs were used. Calculated coefficients were compared to the literature values and found to agree well with them. The FLUKA MC program was successful in the calculation of gamma-ray mass attenuation coefficients of materials as was XCOM. The coefficient results were affected by the number of incident gamma photons in the calculation, and a high incident photon number was suggested.

Mass attenuation coefficient calculations of different detector crystals by means of FLUKA Monte Carlo method

Calculations of gamma-ray mass attenuation coefficients of various detector materials (crystals) were carried out by means of FLUKA Monte Carlo (MC) method at different gamma-ray energies. NaI, PVT, GSO, GaAs and CdWO4 detector materials were chosen in the calculations. Calculated coefficients were also compared with the National Institute of Standards and Technology (NIST) values. Obtained results through this method were highly in accordance with those of the NIST values. It was concluded from the study that FLUKA MC method can be an alternative way to calculate the gamma-ray mass attenuation coefficients of the detector materials.

Calculation of gamma-ray mass attenuation coefficients of some Egyptian soil samples using Monte Carlo methods

Monte Carlo simulations, FLUKA and Geant4, were performed to study mass attenuation for various types of soil at 59.5, 356.5, 661.6, 1173.2 and 1332.5 keV photon energies. Appreciable variations are noted for all parameters by changing the photon energy and the chemical composition of the sample. The simulations parameters were compared with experimental data and the XCOM program. The simulations show that the calculated mass attenuation coefficient values were closer to experimental values better than those obtained theoretically using the XCOM database for the same soil samples. The results indicate that Geant4 and FLUKA can be applied to estimate mass attenuation for various biological materials at different energies. The Monte Carlo method may be employed to make additional calculations on the photon attenuation characteristics of different soil samples collected from other places.

Monte Carlo calculations for gamma-ray mass attenuation coefficients of some soil samples

We developed a simple Monte Carlo code to determine the mass attenuation coefficients of some soil samples at nine different gamma-ray energies (59.5, 80.9, 122.1, 159.0, 356.5, 511.0, 661.6, 1173.2 and 1332.5keV). Results of the Monte Carlo calculations have been compared with tabulations based upon the results of photon cross section database (XCOM) and with experimental results by other researchers for the same samples. The calculated mass attenuation coefficients were found to be very close to the theoretical values and the experimental results.

Lead- and Bismuth-Borate Fly-Ash Glasses as Gamma-Ray-Shielding Materials

Values of the gamma-ray mass attenuation coefficient for fly-ash glasses in the system: xBi2O3-0.2B2O3-yFly Ash and xPbO-0.2B2O3-yFly Ash (x = 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40 and y = 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40) have been determined experimentally at 81-, 356-, 511-, 662-, 1173-, and 1332-keV photon energies using a narrow-beam transmission method. These coefficients of glasses are then used to determine their interaction cross sections, the photon mean free path, effective atomic numbers, and the electron densities. Results have indicated that these fly-ash glasses have potential applications in low-energy gamma-ray shielding.

Comparative study of lead borate and bismuth lead borate glass systems as gamma-radiation shielding materials

Gamma-ray mass attenuation coefficients have been measured experimentally and calculated theoretically for PbO–B 2O 3 and Bi 2O 3–PbO–B 2O 3 glass systems using narrow beam transmission method. These values have been used to calculate half value layer (HVL) parameter. These parameters have also been calculated theoretically for some standard radiation shielding concretes at same energies. Effect of replacing lead by bismuth has been analyzed in terms of density, molar volume and mass attenuation coefficient.