Atomic Number Density Research Articles

Novel multi-energy X-ray imaging methods: Experimental results of new image processing techniques to improve material separation in computed tomography and direct radiography.

We present novel multi-energy X-ray imaging methods for direct radiography and computed tomography. The goal is to determine the contribution of thickness, mass density and atomic composition to the measured X-ray absorption in the sample. Algorithms have been developed by our own to calculate new X-ray images using data from an unlimited amount of scans/images of different tube voltages by pixelwise fitting of the detected gray levels. The resulting images then show a contrast that is influenced either by the atomic number of the elements in the sample (photoelectric interactions) or by the mass density (Compton scattering). For better visualization, those images can be combined to a color image where different materials can easily be distinguished. In the case of computed tomography no established true multi-energy methodology that does not require an energy sensitive detector is known to the authors. The existing dual-energy methods often yield noisy results that need spatial averaging for clear interpretation. The goal of the method presented here is to qualitatively calculate atomic number and mass density images without loosing resolution while reducing the noise by the use of more than two X-ray energies. The resulting images are generated without the need of calibration stan-dards in an automatic and fast data processing routine. They provide additional information that might be of special interest in cases like archaeology where the destruction of a sample to determine its composition is no option, but a increase in measurement time is of little concern.

An Investigation on Gamma-Ray Shielding Properties of Zr-Based Bulk Metallic Glasses

Studies on bulk metallic glasses (BMGs) have grown considerably, especially in recent years, due to their noticeable properties such as high glass forming ability, corrosion resistance, large elastic limit, chemical, mechanical and magnetic properties. Among the known and studied samples of BMGs, Zr-based ones have been appointed as possible examples in biomaterial and structural material studies due to their good mechanical and corrosive properties and good biocompatibility. In this study, considering the importance of Zr-based BMGs, an investigation on their gamma-ray shielding properties have been done where five different samples have been utilized which are Zr51Al14.2Ni15.9Cu18.9, Zr52Al12.9Ni13.8Cu21.3, Zr53Al11.6Ni11.7Cu23.7, Zr54Al10.2Ni9.4Cu26.4 and Zr55Al8.9Ni7.3Cu28.8. Mass attenuation coefficients of the samples have been obtained by using Geant4 and XCOM between 0.1-15 MeV incident photon energy. Also, mean free path (MFP), half-value layer (HVL), tenth-value layer (TVL), effective atomic number (Zeff) and electron density (Neff) values of the samples in the given energy range have been obtained. Obtained results have been graphed for better visual comparison and interpretation.

Investigation of Photon Attenuation Properties of CR-39 Lens

The purpose of this study is to investigate photon attenuation parameters of Colombia Resin-39 (CR-39) lens, which are linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Zeff) and effective electron density (Neff). MACs were determined theoretically and with simulation in the energy range from 0.01 to 105 MeV. Also, obtained MACs of CR-39 lens were compared with MACs of pure aluminum and lead. Theoretically obtained Zeff values were compared with Zeff results obtained by the computer software.The results of this study are; a) the theoretically obtained MACs values are in agreement with MACs obtained results from simulation software, b) the theoretically obtained Zeff values are in agreement with Zeff obtained by the computer software c) the MACs of CR-39 lens are much lower than MACs of pure lead whereas there is not too much differences between MACs of CR-39 and pure aluminium d) the HVLs, TVLs and MFPs rise with increasing photon energy while the LACs and MACs reduce with increasing photon energy.

The use of rocks in lieu of bricks and concrete as radiation shielding barriers at low gamma and nuclear medicine energies

Occupational and public radiation exposure could be minimized with the use of rocks. Rocks are relatively high-density materials, which could be used as a protective shielding barrier at facilities where ionizing radiation is used. These can include medical diagnostic radiology (Dental, Mammography, General and CT) and nuclear medicine (NM) centers. There is need to know potential shielding capabilities of rocks at low gamma and nuclear medicine energies; and compare with brick and concrete. In the present study, mass attenuation coefficients (MACs), effective atomic number (EAN) and effective electron density (EED) of the different rock samples were determined using WinXCom computer program and other relevant equations at 20, 30, 40, 60, 140 (Tc-99 m) and 364 keV (I-131). The results were compared with that of concrete and brick at the energies of interest. The result of this work shows that rocks are better used instead of concrete and brick at 20, 30, 40 and 60 keV. At 140 and 364 keV, all the considered materials performed nearly same which implies all could be used while the optimum considering all other necessary factors should be preferred.

Metal-Organic Framework Glasses Possess Higher Thermal Conductivity than Their Crystalline Counterparts.

The thermal conductivity (κ) of glasses is known to always be lower than that of their corresponding crystals due to the stronger phonon-phonon scattering in the former. However, it is unknown whether this relation holds for metal-organic frameworks. Here, we report our discovery of an inverse relation in κ between glass and crystal for two zeolitic imidazolate frameworks (ZIFs), ZIF-4 and ZIF-62, that is, melt-quenched ZIF-4 and ZIF-62 glasses possess higher thermal conductivities than their crystalline counterparts. We find that the ZIF crystal pellets exhibit ultralow κ (∼0.1 W m-1 K-1) and that the higher κ of the ZIF glasses is due to the collapse of internal cavities and higher atomic number density in the latter. For other systems like oxides, vitrification causes higher free volume, but the opposite is found for the ZIFs, that is, lower free volume owing to the partial collapse of the crystalline framework upon melting.

Effective atomic number and electron density of some biologically important lipids for electron, proton, alpha particle and photon interactions

X-ray, γ-ray and charged particle interaction parameters of biomolecules are useful in medical diagnosis and radiation therapy as exposure to radiations can cause energy of photons and charged particles to be deposited in body through various interaction processes. With this in view, the effective atomic number (Zeff) and electron density (Neff) of some biologically important lipids for X-ray, γ-ray and charged particle interactions were studied in the energy range 10 keV–500 MeV using logarithmic interpolation method. A non-monotonic variation in Zeff values was observed for protons and alpha particles in low and intermediate energy regions respectively whereas a sudden increase in Zeff was observed for electron interaction in higher energy region. Zeff values were maximum in higher energy region for total electron interactions whereas maximum values of Zeff for total alpha particle interactions were at relatively lower energies. Highest Zeff values were found at lower energy region of photoelectric absorption dominance for photon interactions. Variation in Neff seems to be similar to variation in Zeff as they are inter-related.

Interfacial properties of aqueous solutions of butanol isomers and cyclohexane

Phase behavior at water-oil and water-air interfaces has received much attention in the past sixty years. The study of detergents as surfactants and their applications to industry is widely known and under constant study. Other molecules, such as alcohols, can also act like surfactants between water and nonpolar molecules. Hydrotropes are amphiphilic molecules, with both a hydrophobic and a hydrophilic section, that also reduce the interfacial tension between two liquids or a vapor and a liquid. Tert-butyl alcohol (TBA) is a well-studied hydrotrope, but its behavior is not completely understood at low molar compositions in aqueous solution. In addition, few studies have examined the influence of different butanol isomers on the interfacial dynamics of mixtures. We used molecular dynamics to study the behavior of all four butanol isomers at the interface of water and cyclohexane. We observed a rapid decrease in surface tension at very low hydrotrope concentrations, < 1 mol% in water, in agreement with previous experimental and simulation studies. The effect of different butanol isomers on the interfacial properties between an aqueous and an organic phase was examined looking at its dependence on hydrotrope concentration and chemical structure. We characterized the position of the hydrotrope molecules at the interface using atom number density profiles, radial distribution functions, and hydroxyl tilt angles with respect to the z-axis (perpendicular to the water-cyclohexane interface). There is statistical difference on the effect of some isomers on the disruption of the interface at low hydrotrope concentrations. Our studies show the chemical structure of these molecules affects the water-oil interface in different ways, which could potentially affect the use of one isomer over the other in different applications.

Materials parameters and ion-induced track formation

ABSTRACTThe role of various materials parameters in track formation is discussed. Experimental information is utilized showing a direct quantitative relationship in different solids between the melting points Tm and the ion-induced track radii Re without involving other materials parameters. It is shown for Θ = Tm − Tir (Tir – irradiation temperature) that Θ∼exp{−Re2/w2} for Se/N = constant, where Se and N are the electronic stopping power and the number density of atoms and w = 4.5 nm. The validity of this universal-type relation is demonstrated for 14 different insulators including LiNbO3 and BaFe12O19. It is shown that the thermal diffusivity D, the heat of fusion L the band gap energy Eg and the absorption radius αe of the electron distribution must not affect the track sizes as this would not be coherent with this identical behavior. Original reports on LiNbO3 and BaFe12O19 with opposite conclusions are critically analyzed. It is shown that an arbitrary value of the ion energy was used in the analysis that modified substantially the results leading to an undue justification of the contribution of L and Eg in apparent agreement with the experimental data.

Dynamics of a hollow cathode discharge in the frequency range of 1–500 kHz

We present results from 2D axisymmetric fluid simulations of the partially-ionized Xe gas in a 25-A cathode discharge, for a range of flow rates (5–20 sccm) in which transition between the so-called spot and plume modes has been observed in laboratory experiments. The simulations for the first time capture very well the characteristic rise of the peak-to-peak amplitude in the keeper voltage oscillations with decreasing flow rate—the so-called ‘plume margin’—thereby allowing for a closer interrogation of the processes that drive them. The oscillations are found to be due to plasma dynamics in the near-plume region that increase in amplitude as the flow rate is reduced. The cathode interior remains largely quiescent and changes in the emitter peak temperature do not exceed 2% across the entire range of flow rates examined. Along the cathode centerline the amplitude of the electron density oscillations peak at a location where the number density of the Xe atoms has diminished to its minimum value and the degree of ionization is close to one. The computed spectra reveal that most of the oscillation power resides in the frequency range of 100–300 kHz. These frequencies are much greater than the local ionization collision frequency ( < 10 kHz), and are associated with wavelengths of several centimeters. Such wavelengths are many orders of magnitude greater than λD. The waves are largely longitudinal with wave vector in the axial direction, and phase velocity ω/k > 10 km s−1, which is more than 6× greater than the ion acoustic speed. Though the computed and measured plume margins are in good agreement the measured spectra show that most of the power resides between ∼60 and 90 kHz, lower than the computed range (100–300 kHz), and exhibits a sharper distribution. It is argued this is due to the presence of a rotational mode in the experiment that is coupled with the longitudinal mode, yielding a complex 3D plasma motion that cannot be captured by the simulations due to the assumption of azimuthal axisymmetry, but that it is indeed the longitudinal plasma motion that drives the transition from spot to plume modes. An anomalous resistivity has been invoked in the simulations that is based on the formulations of Sagdeev and Galeev for the saturation of IAT which is long known to exist in these discharges. Though the simulations do not account for possible anomalous heating of the ions, the idealized model for the electrons is found to be sufficient in capturing the abovementioned dynamics, yielding a multiplication coefficient α of the anomalous collision frequency να = αωpe(Te/Ti)(ue/uTe) that is within a factor of two of the estimated theoretical value.

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.

Influence of sputtered species ionisation on the hysteresis behaviour of reactive HiPIMS with oxygen admixture

In this paper, the hysteresis behaviour of a reactive magnetron sputtering process with oxygen admixture is studied by both experiment and model. The ground state number densities of titanium atoms and ions, and the deposition rates in high power impulse magnetron sputtering discharge were determined for a constant average applied power and pulse duration, while the repetition frequency and reactive gas supply were varied. The hysteresis curve reduced in width and shifted towards the lower oxygen supply with a decrease in the repetition frequency. These experimentally observed trends were well reproduced by a modified Berg model. The presented model utilised measured ionisation fraction of sputtered species and considered the back-attraction of the ionised sputtered species to the target. Significance of the back-attraction process was observed as large fraction of ionised sputtered particles was found to be lost back to the target. This drastically decreased the number of particles deposited onto the substrate, which reduced not only the deposition rate, but also the gettering of the reactive gas. Consequently, the simulated hysteresis curve was shifted and reduced in width as it was observed experimentally.

Effect of surface treatment and crystal orientation on hot corrosion of a Ni-based single-crystal superalloy

The effect of surface preparation and crystal orientation was investigated for a TMS-138 single crystal superalloy under Type I and Type II hot corrosion conditions. The superalloy was cut along the {100} and {110} planes on which grit blasting, mechanical polishing and electro-polishing surface finishes were conducted. At 900 °C grit blasting or electropolishing distorted the surface and altered the γ-γ’ structure of the alloy provoking higher corrosion rates than on mechanically polished surfaces. The electropolished surface revealed that crystal planes with higher atomic number density have an increased corrosion resistance. The anisotropy effects were not observed with Type II exposures.

Problem-dependent compression method for burnup library

The process of burnup library compression method that based on the Generalized Perturbation Theory (GPT) is optimized. An iteration process is added to the selection of candidate nuclides to ensure the atom number density of target nuclides be accurately simulated. In addition, a concept of problem-dependent compressed burnup library is proposed. The problem-dependent compressed burnup libraries for 6.5%UO2, 1.8%UO2, MOX, Gd2O3-UO2 fuels and a general compressed burnup library for these four fuels are generated. There exists great difference in nuclides among different compressed burnup libraries. The numerical results of PWR pin cell cases and a 4 × 4 Gd-bearing multi-cell system show that the problem-dependent compressed burnup library can significantly reduce the memory usage and time consumption of burnup calculation while keeping sufficient accuracy in kinf prediction. Finally, a fast reactor pin cell case shows that the compression theory is also applicable to the burnup problem of fast spectrum.

Dependence of Detonation Velocity of Explosives on Effective Atomic Number and Effective Electron Density of the Explosives

Detonation velocity is one of the most important characteristics of explosives. For solid hydro carbon-based explosives it is generally greater than 4000 m/s. Detonation velocity depends to some extent upon the particle size of the explosives, increased charge diameter and increased confinement of the explosive. There is no report indicating the dependence of detonation velocity on the effective atomic number and effective electron density of the explosive. In the present work, we have arbitrarily chosen eight explosives. Four of these have detonation velocity between 9400 and 10100 m/s, and the other four has detonation velocity between 4500 and 5300 m/s. Direct method was used to calculate effective atomic number and effective electron densities various explosives. On calculating effective atomic number and effective electron density, it was found that detonation velocity of explosives does depend upon these two parameters. For explosives with high detonation velocity, effective atomic number is high and effective electron density is low while for low detonation velocity explosives it is reverse. It was also found that the variation of effective atomic number and effective electron density as a function of gamma ray energy can be explained on the basis of three different gamma ray inter action mechanism of gamma rays with matter.

Mô phỏng hệ đo Rayleigh-Compton bằng phương pháp Monte Carlo

In this study, the Monte Carlo method is applied for simulating the Rayleigh-Compton measurement system using the Si(Li) detector on MCNP6 software. In which, incident photon’s energy is 59.54 keV of 241Am source and the scattering angle is determined at 124o. The targets are elements in the range of atomic numbers from 13 to 82. Besides the simulation, the theoretical values of Rayleigh-Compton ratio were calculated basing on NRFF, RFF, MFF models on MATLAB software. The results of the Rayleigh-Compton ratio from the simulation and the theoretical calculation have an average discrepancy of 4%. In conclusion, by utilizing the Rayleigh-Compton measurement system model, the effective atomic number and electron density of compounds can be determined more accurately, conveniently, and quickly.

Lidar Technology Based on Fiber System and its Application

The sodium atom existed in the metal layer of the earth’s atmosphere has a high atomic number density and a large scattering cross section. Sodium layer can act as a good tracer for atmospheric detection in the middle and lower-thermosphere (MLT) region. The sodium fluorescence lidar uses ultrashort pulsed laser to excite sodium atoms, which enabling simultaneous detection of wind and temperature in the middle and upper atmosphere. This paper reports on the development of sodium fluorescence laser radar in recent years, especially the integration of fiber-coupled optical switches and fiber-coupled acousto-optic frequency modulation technologies, which greatly improved the stability and reliability of lidar system and reduced the maintenance of lidar operation, laying a good foundation for the application of lidar observations under harsh environments. This technology has been applied to the sodium wind/temperature lidar in Yangbajing, Tibet and has been running stably for a long time.

Experimental investigation of spin noise spectroscopy of rubidium atomic ensemble

Spin noise spectroscopy is a very sensitive undisturbed spectroscopic technique for measuring atomic spin fluctuations by using a far-detuned probe laser beam. In this paper, we describe an experimental setup for measuring the spin noise spectroscopy. The spin noise spectra of Rubidium atomic vapor cell filled with 10 Torr of Neon gas and 20 Torr of Helium gas as buffer gas are investigated in a magnetically shielded environment. The dependence of the spin noise power spectral density, separately, on the probe beam’s intensity (&lt;i&gt;I &lt;/i&gt;), the probe beam’s frequency detuning (&lt;i&gt;Δ&lt;/i&gt;) and Rubidium atomic number density (&lt;i&gt;n&lt;/i&gt;) are measured. The integrated power of Rubidium atomic spin noise spectra is scaled as&lt;inline-formula&gt;&lt;tex-math id="M1"&gt;\begin{document}$ {I^2}$\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M1.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M1.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;. Owing to homogeneous broadening, the full width at half maximum of transmission spectrum of the same cell is broadened to &lt;inline-formula&gt;&lt;tex-math id="M2"&gt;\begin{document}$\Delta {\nu _t} = {\rm{6}}.{\rm{9}}\;{\rm{GH}}{\rm{z}}$\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M2.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M2.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;. Center frequency of transmission spectrum is set to be &lt;inline-formula&gt;&lt;tex-math id="M3"&gt;\begin{document}$\varDelta = {\rm{0}}$\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M3.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M3.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;. The probe beam’s frequency detuning is larger than the half width at half maximum of the transmission spectrum &lt;inline-formula&gt;&lt;tex-math id="M4"&gt;\begin{document}$\left| \varDelta \right| &gt; {{\Delta {\nu _t}}}/{{\rm{2}}}$\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M4.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M4.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;, so the integrated power of Rubidium atomic spin noise spectra is scaled as &lt;inline-formula&gt;&lt;tex-math id="M5"&gt;\begin{document}$\varDelta^{-1}$\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M5.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M5.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;. And there is a dip for &lt;inline-formula&gt;&lt;tex-math id="M6"&gt;\begin{document}$|\varDelta| &lt; {{\Delta {\nu _t}}}/{{\rm{2}}}$\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M6.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M6.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt; as a result of collisions between the buffer gas and Rubidium atoms. The integrated power of Rubidium atomic spin noise spectra is scaled as &lt;inline-formula&gt;&lt;tex-math id="M7"&gt;\begin{document}$ \sqrt n $\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M7.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="23-20201103_M7.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;. The Rubidium atomic spin's transverse relaxation time becomes shorter while the temperature increases. Only at the condition of non-perturbative probe, including far-off-resonant laser, weak laser intensity and uniform transverse magnetic field, the measured full width at half maximum will be close to the intrinsic linewidth of spin noise spectrum. In this way, we can obtain the Rubidium atomic spin's transverse relaxation time. This work can be applied to the field of physical constants precision measurement, like Lande &lt;i&gt;g&lt;/i&gt; factor and isotopic abundance ratio. In addition, it provides an important reference for developing the high signal-to-noise ratio and compact spin noise spectrometer.

Investigating photon interaction characteristics of FexNi1-x alloys

In this research article, radiation absorption qualifications of the Fe–Ni alloys were explored. The mass attenuation coefficients (μρ) of FexNi1-x (x = 0.20, 0.52, 0.55, 0.61 and 0.64) alloys in different concentrations have been determined experimentally for 59.54 keV photon energy and the results were matched with μρ values of the alloys found by using WinXCOM program. The results for μρ values were consistent with each other. Half value layer (HVL), effective atomic number (Zeff) and electron density (Nel) were calculated by utilizing the μ of the alloy under study. Also, equivalent atomic numbers have been calculated for each alloys and compared with Zeff. Some differences were observed in the selected absorption parameters according to the change of the concentrations of alloys.

Synthesis and characterization of lead borate glasses comprising cement kiln dust and Bi2O3 for radiation shielding protection

The low cost and high efficient radiation shielding materials are necessary to protect the human being from the exceedingly used harmful nuclear radiations. The cement kiln dust (CKD) is the largest waste stream from cement plants that harm the environment. In this study, new glasses containing moderate contents of CKD for radiation shielding had been synthesized by the melt quenching technique. The synthesized glasses had the chemical formula (25−x)PbO–32CKD–40B2O3–3BaO– xBi2O3 (0 ≤ x ≤ 25 mol%). NaI (Tl) scintillation detector and pulse-echo techniques were used to investigate the radiation shielding and the mechanical features of the investigated samples. The mass attenuation coefficient (μm), half-value layer (HVL), tenth value layer (TVL), mean free path (mfp), radiation protection efficiency (RPE), effective atomic number (Zeff) and effective electron density (Nel) parameters for glass samples have been determined experimentally. The G-P fitting method was used to calculate the exposure (EBF) and energy absorption buildup factor (EABF) for the prepared glass samples in the photon energy range of 0.015–15 MeV up to 40 mfp. The specific absorbed fraction of the energy (SAFE), the relative dose distribution (RDD) and the neutron shielding parameters have been computed. Moreover, the elastic moduli of the investigated glasses were determined by considering the measured values of the ultrasonic velocities at 5 MHz and the density. The investigated glasses are considered as a promising candidate for radiation application.

Radiation shielding and physical properties of lead borate glass-doped ZrO2 nanoparticles

Zirconium oxide (ZrO2) nanoparticles have been prepared and examined by XRD. The transparent lead alkali borate glass systems of formula xZrO2–20PbO2–(80 − x)·Na2B4O7 (0 ≤ x ≤ 24 mol%) are prepared by melting quench method and doped by zirconia nanoparticles. Deconvolution of its FTIR reveals to increase the N4 fraction boron atoms. This result reveals the Zr4+ which forms BO4 network units. The density and refractive index of chosen glass are increased due to add of ZrO2 nanoparticles. Both ultrasonic velocities (longitudinal vL and shear vT) increase with the ZrO2 content increase. The packing density, bulk modulus and Young’s modulus increase with increasing of ZrO2 nanoparticle content. The attenuation coefficients of the studied glasses have been measured at different energies (356, 662, 1173 and 1332 keV) using narrow beam transmission geometry. The obtained results indicated that, the values of the mass attenuation coefficient (µm), the effective atomic number (Zeff) and effective electron density (Nel) of the glass samples decreased with the increase in the ZrO2 concentration at the energies (662,1173and 1332 keV), while these parameters (µm, Zeff and Nel) increased with the increase in the ZrO2 concentration at 356 keV. The samples are irradiated 30 min by argon glow discharge plasma (GDP). The values of optical band gap decreased slowly with ZrO2 nanoparticles increased and after plasma irradiation.