Atomic Cross Sections Research Articles

A comprehensive study of radiation shielding parameters of chalcogens-rich quaternary alloys for nuclear waste management

The current study examines the impact of metal additives on the shielding characteristics of Se76Te20Sn2M2 (where M = Ge, In, Sb, and Pb). These glasses are useful as shielding materials against high-energy radiation, such as X-rays and ϒ-rays, because these glasses have better values of shielding parameters compared to other potential candidates in the race for nuclear safety applications. To this end, we have calculated various radiation-related protection parameters using an online application called Phy-X/PSD. Using this program, we have estimated a complete list of radiation shielding parameters. The impact of the fourth element M (M = Ge, In, Sb, and Pb) on these parameters is also discussed.The maximum mass attenuation coefficient (MAC) was recorded at a photon energy of 15 keV for the incorporation of lead. Half-value layer (HVL) values peaked at 6 MeV and it attained its maximum value for germanium. The highest and lowest values of the linear attenuation coefficients (LAC) were obtained for Se76Te20Sn2Pb2 and Se76Te20Sn2Ge2 alloys respectively. Notably, the Se76Te20Sn2Pb2 alloy exhibited the highest values of effective atomic number (Zeff), electron density (Neff), atomic cross-section (ACS), and electronic cross-section (ECS), indicating superior shielding performance. Conversely, energy absorption buildup factors (EABF) and exposure buildup factors (EBF) were highest for Se76Te20Sn2Ge2 alloy. Neutron attenuation was most effective in the Se76Te20Sn2In2 and Se76Te20Sn2Pb2 compositions. Overall, the incorporation of lead in the parent glass demonstrated superior shielding capability compared to the other compositions studied.

Radiation Shielding Properties of Nickel, Copper and Iron Based Alloys

This study explores the radiation shielding properties of Iron-based and Nickel-based alloys with Cobalt composition to evaluate their performance in photon attenuation and shielding applications. The objectives of this work are to determine linear and mass attenuation coefficients (LAC, MAC), half and tenth value layers (HVL, TVL), mean free path (MFP), effective atomic number and electron density (Zeff, Neff), effective conductivity (Ceff), atomic cross section (ACS) and electronic cross section (ECS) of nickel and iron base alloy with Cobalt using Phy-X/PSD within 0.001 MeV to 10 MeV. The result shows Iron and Nickel-based alloys have electron densities around 10²³ electrons per gram, with increased Iron concentration improving low-energy photon attenuation. Nickel-based alloys have a higher MAC and LAC compared to Iron-based oxides, indicating better photon absorption per unit mass and thickness, respectively. Nickel-based alloys exhibit a lower HVL and TVL, indicating greater attenuation and absorption efficiency for photons, especially at lower energies. Conversely, Iron-based alloys, while showing higher HVL and TVL. Nickel-based alloys exhibited higher electron densities the Iron-based alloys and Zeff values for Nickel based alloys, ranging from 27.1 to 27.8 while Iron-based alloys with Zeff between 26.2 and 26.8. Ceff in Iron-based alloys was stable at (1.50 to 1.74) x 10⁹ S/m, while Nickel-based alloys showed significant fluctuations below 0.01 MeV. Nickel-based alloys also had higher ACS and ECS, indicating superior photon interaction, especially at lower energies. These results highlight Nickel based alloys' greater efficacy in low-energy photon attenuation and the stable performance of Iron based alloys at higher energies.

DeepCSNet: a deep learning method for predicting electron-impact doubly differential ionization cross sections

Abstract Electron-impact ionization cross sections of atoms and molecules are essential for plasma modelling. However, experimentally determining the absolute cross sections is not easy, and ab initio calculations become computationally prohibitive as molecular complexity increases. Existing AI-based prediction methods suffer from limited data availability and poor generalization. To address these issues, we propose DeepCSNet, a deep learning approach designed to predict electron-impact ionization cross sections using limited training data. We present two configurations of DeepCSNet: one tailored for specific molecules and another for various molecules. Both configurations can typically achieve a relative L2 error less than 5%. The present numerical results, focusing on electron-impact doubly differential ionization cross sections, demonstrate DeepCSNet's generalization ability, predicting cross sections across a wide range of energies and incident angles. Additionally, DeepCSNet shows promising results in predicting cross sections for molecules not included in the training set, even large molecules with more than 10 constituent atoms, highlighting its potential for practical applications.

Enhanced radiation shielding efficiency of polystyrene nanocomposites with tailored lead oxide nanoparticles

In this study, we investigated a novel polymer nano-composite, PS-PbO, containing two distinct nano-sizes of lead oxide nanoparticles (PbO-A and PbO-B), in addition to the bulk size (PbO-K). These nanoparticles were embedded separately in a polystyrene (PS) matrix at different weight percentages (10%, 15%, 25%, and 35%) using roll mill mixing and compressing molding. Our evaluation focused on the radiation attenuation ability of PS-PbO and the effect of particle size, considering gamma-ray energies ranging from 0.06 to 1.3 MeV (from sources like 241Am, 133Ba, 137Cs, and 60Co). The linear attenuation coefficient (LAC) was determined by analyzing samples of the synthesized composite with different thicknesses. Then, various shielding parameters were calculated, including total molecular, atomic, and electronic cross-sections (σmol, σatm, σel), as well as the effective atomic number and the electron density (Zeff and Neff). Surprisingly, modifying PbO particle sizes had a significant impact on shielding efficiency. For instance, the composite with 25 wt% of the smallest PbO-B particles showed a 26.7% increase in LAC at 0.059 keV compared to the composite with 25 wt% of PbO-K (larger particles). Notably, the LAC peaked at low energy (0.059 keV), close to the K-edge of Pb, where interaction is directly proportional to Z4. With increasing PbO concentrations, the LAC of PS-PbO composites increased steadily. Additionally, as PbO concentration increased, the composite’s effective atomic number Zeff and the electron density Neff increased, leading to a greater total Gamma-ray interaction cross-section. Furthermore, when comparing the Half-Value Layers of the novel nanocomposite to traditional lead shielding, a 70% reduction in mass was observed. Notably, the composite containing the smallest nano-size of PbO exhibited the highest radiation-shielding efficiency among all combinations and could therefore be used to create inexpensive and lightweight shields.

Investigation of the potential of zinc oxide-copper oxide nanocomposites as shielding against gamma ray, physical, and structural properties

The mass attenuation coefficient (μ/ρ) is examined in the experimental and theoretical way for five concentrations of ZnO–CuO nanocomposites. These samples have been synthesized by the Co-precipitation method. XRD investigation demonstrated an improvement in crystallite size by examining structure factors in a range (11.5–26) nm. The mass attenuation coefficient (μ/ρ) was measured experimentally at gamma-ray energies of radioisotopes 133Ba (356) keV, 22Na (511 and 1275) keV, 137Cs (662) keV, and 60Co (1173 and 1333) keV using narrow beam geometry NaI(Tl) detector. The samples were subjected to theoretical study using the Phy-X/PSD program for comparison with the experimental results. Total atomic cross sections (σt,a), electronic cross sections (σt,e), and effective atomic number (Zeff) were calculated using the obtained μ/ρ values. The findings demonstrate that there is generally good agreement between theoretical and experimental calculations, which supports the suitability of ZnO–CuO nanocomposites for gamma radiation shielding.

Quantifying the resonant photoemission of radiation damaged Pu

The resonant photoelectron spectroscopy (ResPes) of new and aged δ-Pu(Ga) is reassessed by using the small oxygen contaminant peaks as an independent and quantitative check upon conventional cross-photon-energy normalization. Good agreement is found between the measured oxygen intensities and the atomic cross section calculations. Consistent with earlier analyses, the radiation induced damage in the aged samples is found to compress and sharpen the 5f peaks. This is associated with increased localization of the 5f bands, corresponding to the 5f density of states calculations that show a narrowing of 5f bandwidth with cluster size diminishment.

BaO-doped Na2O–CaO–P2O5 bioactive glasses: A closer look at radiation attenuation properties for medical applications

This study investigates the nuclear radiation attenuation characteristics of bioactive glasses with the system (26-x)Na2O-xBaO-29CaO–45P2O5, where x represents the molar percentage of BaO (0, 5, 10, 15). For this purpose, several parameters of shielding gamma radiation, such as the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), effective atomic number (Zeff), effective electron density (Neff), atomic cross-section (ACS), electronic cross-section (ECS), equivalent atomic number (Zeq), and transmission factor (TF) were calculated. The calculations were performed across different photon energy ranges (0.015–15 MeV) using Phy-X/PSD software and validated using the WinXCOM program. The results obtained from both the software platforms exhibited a high degree of agreement. Among the investigated glasses, the BNCP-15 glass, which had the highest BaO concentration, demonstrated the highest values for MAC, LAC, Zeff, Neff, ACS, ECS, and Zeq, while displaying the minimum values for HVL, TVL, MFP, and TF. For example, the LAC values at 15 MeV were found to be 0.056, 0.063, 0.070, and 0.077/cm for BNCP-0, BNCP-5, BNCP-10, and BNCP-15, respectively. Consequently, the BNCP-15 glass exhibited superior radiation attenuation performance in comparison to the other BNCP glasses examined in this study.

L- and M-subshell ionization cross-sections of heavy atoms by electron and proton impact

Inner-shell ionization has many applications related to material analysis. However, full theoretical calculations in heavy multielectronic atoms are scarce. In this contribution, we assess proton and electron impact Li and Mi-subshell ionization cross-sections of heavy targets (72≤Z≤83) using two theoretical models. These calculations are based on the Distorted Plane Wave Born Approximation for electron impact and the shellwise local plasma approximation for the proton impact, combined with relativistic calculations of these deep subshells wave functions and binding energies. We analyze the L-shell ionization of W, Au, and Bi and the M-shell of Hf, Ta, W, Re, Os, Pt, Au, Pb, and Bi. Present values are compared with available experimental data from the literature, with disparate agreement. The convergence of proton and electron impact cross-sections at high-impact velocities is also discussed.

Inner-shell ionization cross sections of atoms by positron impact

The relativistic binary-encounter-Bethe model with Wannier-type threshold law is employed to obtain the inner-shell ionization cross sections of multi-electron atoms (Ni, Cu, Y, Ag, Au, Yb, Ta, and Pb) for positron impact energies from the thresholds up to 105 keV. There is good agreement between the present calculations and the experimental data. The constant in the acceleration term derived from the Wannier law is determined to be 0.2 and 0.5 for the K- and L-shells, respectively.

Efficacy of Ni2+ on modification the structure, ultrasonic, optical, and radiation shielding behaviors of potassium lead borate glasses

This paper presents the method of preparing (60 − x) B2O3–20 K2O–20 PbO–x NiO, coded as (NiO x), and x = (0–10 mol%) glass systems fabricated through the melt-quench technique. The prepared glass was characterized through X-ray diffraction spectra (XRD); the mechanical behavior of the glass samples was investigated using the ultrasonic technique, Fourier transform infrared (FTIR) spectra, the optical reflectance R(λ), refractive index (n), optical conductivity (σopt), the dispersion parameters of the studied samples were deduced using Wemple and Di-Domenico models. The results obtained were reported in detail. One of the fundamental parameters used to evaluate the interaction of radiation with shielding material was the mass attenuation coefficient (μm), which was obtained using Phy/X software and PHITS code program. It was used to calculate radiation interaction parameters, e.g., linear (μL) attenuation coefficient, effective atomic number (Zeff), half value layer HVL, mean free path (MFP) and the average atomic cross section, σt. Comparing the shielding behavior of the glass samples revealed that (NiO 10) glass demonstrated the highest μm and μL compared to the other samples. The maximum μm values equal 48.13, 48.73, 49.42, 50.59, and 51.08 cm2/g for (NiO 0) to (NiO 10), recorded at 0.015 MeV, respectively. This study shows that increasing the amount of NiO in the preferred glass samples leads to achieving high-performance radiation shielding materials.Graphical abstract

Characterization of Polish-Induced Gouges on Single Crystal Sapphire Substrates

Single-crystal sapphire is known to be among the hardest insulators. Its mechanical properties and chemical inertness make it a challenging material to polish for the atomic-level surface smoothness required for its applications. Mechanical polish with diamond abrasives renders high removal rates but creates unacceptable levels of polish-induced gouges. Chemical mechanical polish on the other hand results in atomic smoothness but is a slow process. Hence, a combination of the two is used in the industry. In this work, we have attempted to characterize gouging and subsurface damage using atomic force microscopy, X-ray diffraction, and cross-section transmission electron microscopy on C-plane and A-plane sapphire induced by diamond abrasive mechanical polish and chemical mechanical polish with colloidal silica.

Theoretical Calculation of Gamma-Ray and Neutron Shielding Properties for CsPbBr3-Polypropylene Composite Material

The impact of CsPbBr3, known for its high atomic number and cross section with neutrons, on the gamma-ray and neutron shielding properties of CsPbBr3-polypropylene (PP) composite material was investigated in this study. Critical shielding parameters, including linear attenuation coefficient μ, mass attenuation coefficient μm, half-value thickness, tenth-value layer, and mean free path (MFP), were calculated using Phy-X/PSD software. Additionally, two types of gamma-ray buildup factors, i.e., exposure buildup factor and energy absorption buildup factor, were computed within the range of 0.015 to 15 MeV for depths up to 40 MFP. Furthermore, the neutron shielding ability was evaluated by determining the neutron total effective removal cross section. The results demonstrate that the incorporation of CsPbBr3 enhances the gamma-ray and neutron shielding characteristics of the CsPbBr3-PP composite material.

Relativistic calculations of energy levels, lifetimes, transition parameters, and electron impact excitation cross sections for Kr XIX

In this study, we present a detailed analysis of atomic properties for Kr XIX, specifically focusing on the lowest 128 fine-structure levels originating from the 3s23p6, 3s23p53d, 3s3p63d and 3s23p43d2 configurations. We report energy levels, lifetimes, wavelengths, weighted oscillator strengths, and transition probabilities for multipole transition types (E1, E2, M1, and M2). To achieve this, we employed the GRASP2018 code, which implements the fully relativistic multiconfigurational Dirac–Hartree–Fock method and accounts for Breit interaction and quantum electrodynamic effects. We performed another set of calculations using the many-body perturbation theory implemented in the flexible atomic code (FAC). By comparing the results obtained from GRASP2018 and FAC, we established the accuracy and consistency of our calculations. Furthermore, using the relativistic distorted wave theory, we studied electron impact excitation of all transitions to upper levels from the ground and metastable levels and reported excitation cross sections for incident electron energies up to 5 keV. To enhance the practical utility of our findings, we also provided analytical fittings of these cross sections and excitation rate coefficients for their applications in plasma modeling. This work contributes to the atomic properties and excitation cross sections of Kr XIX, addressing a marked gap in the available atomic data.

Enhancement of Gamma-Ray and Neutron Shielding Properties of TeO2-Li2O-ZnO-Nb2O5 Glass System with the Addition of Sm2O3

Radiation shielding glass is widely used, as it protects people from ionizing radiation while allowing for the observation of irradiated areas. However, the performance of even the best-performing tellurite glass for radiation shielding still falls short compared to traditional radiation shielding materials. The effect of Sm2O3, with a high atomic number and cross section with neutron, on the gamma-ray and neutron shielding properties of a 75TeO2-5Li2O-10ZnO-(10-x)Nb2O5-(x)Sm2O3 glass system is studied in this work. Some critical shielding parameters, including linear attenuation coefficients, half-value thickness, tenth-value layer, and mean free path (MFP), have been calculated with the software Phy-X/PSD. Two kinds of gamma-ray buildup factors, the exposure buildup factor and the energy absorption buildup factor, have been calculated in the range of 0.015 to 15 MeV for depths up to 40 MFP. What’s more, their neutron shielding ability has been evaluated by calculating the neutron total effective removal cross section. It is shown that Sm2O3 promotes the gamma-ray and neutron shielding performance of the 75TeO2-5Li2O-10ZnO-10Nb2O5 glass system. The results indicate that the addition of Sm2O3 can be helpful for the radiation shielding performance of tellurite glass, which provides a practical way for designing glass with ideal shielding properties.

Gamma-ray shielding effectiveness, thermal, and dielectric properties of filler-reinforced high-density polyethylene/boron carbide composites

The present research prepared samples of pure high-density polyethylene (HDPE)/boron carbide reinforced with iron dioxide, aluminum dioxide, iron, and aluminum. The effectiveness of the prepared samples as a shielding material against gamma-rays and their thermal and dielectric properties have been evaluated. The shielding characteristics of the prepared composites were investigated theoretically using the Phy-X/PSD program and experimentally for gamma-rays emitted from 131Cs and 60Co radioactive isotopes. The shielding evaluation included the mass attenuation coefficient (μ/ρ), half value layer (HVL), mean free path (MFP), atomic and electronic cross-sections (σa&σe), effective atomic number and electron density (Zeff &Neff), and exposure build-up factor (EBF). The EBF peaks of samples containing Fe and Fe2O3 are 103 times lower than pure HDPE. The results indicate that samples C2 and C3 have a higher ability to protect against gamma radiation than that of the other investigated samples. X-ray diffractometer (XRD) spectrum shows that adding B4C, Fe, Fe2O3, Al, and Al2O3 to HDPE caused an increase in its full width at half maximum (FWHM) value and a decrease in its average crystallite diameters (D) at its primary characteristic scattering angle of 21.49°. Adding multiple types of fillers to HDPE results in a minor shift in the melting temperature of the hosting matrix as proved from differential scanning calorimetry (DSC) data. The composite of HDPE/B4C/Al2O3 60/10/30 demonstrated the most significant values of dielectric parameters in comparison with the other composites, in good accord with the XRD results. The ac conductivity relied on the dopant type in the hosting matrix; the highest value was observed for HDPE/B4C/Al2O3 composite.

Gamma-ray, fast neutron and charged particle shielding performance of 15Li2O-25BaO-(40-x)B2O3-20P2O5-xDy2O3 glass system

Gamma-ray, fast neutron and charged particle shielding characteristics of Dy3＋ activated glasses with composition 15Li2O-25BaO-(40-x)B2O3-20P2O5-xDy2O3 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%) are analyzed in a wide incident energy for the first time. For gamma-ray shielding analysis, mass attenuation coefficient (MAC), mass energy absorption coefficient (μen), linear attenuation coefficient (LAC), mean free path (MFP), half-value layer (HVL), atomic cross-section (ACS), electronic cross-section (ECS), effective atomic number (Zeff), equivalent atomic number (Zeq), effective conductivity (Ceff), effective electron density (Neff), buildup factors (EABF and EBF), and kinetic energy released per unit mass of the absorbing material (KERMA) are calculated by using Phy-X/PSD and PAGEX softwares. For fast neutrons, fast neutron removal cross-section (FNRCS) is computed for all glass samples. For charged particle shielding analysis, mass stopping power (MSP), projected range (Rp), radiation yield (Ry), Zeff and Neff are computed using SRIM, ESTAR and PAGEX softwares. It is found that the glasses with increasing Dy3＋ have higher shielding potential. This suggests that the LBPDy1.0 sample has a potential use as shielding material for various applied fields.

RADIATION BEHAVIOR IN BIOLOGICAL COMPOUND: EXPLORING MASS ATTENUATION AND EFFECTIVE ATOMIC NUMBERS FOR GAMMA-RAY INTERACTION

This study involved the measurement of mass attenuation coefficients (μ/ρ) for fatty acids across a range of photon energies (from 122 keV to 1330 keV). These measurements were conducted through transmission experiments employing collimated beams generated by 57Co, 133Ba, 22Na 137Cs, 54Mn, and 60Co sources, each producing beams with a diameter of 0.52 cm. The detection of attenuated radiation was achieved using a NaI (Tl) scintillation detector with an energy resolution of 8.2% at 663 keV. The obtained experimental values of (μ/ρ) were subsequently used to calculate the atomic cross-sections (σa), electronic crosssections (σe), effective atomic numbers (Zeff), and electron densities (Neff). Notably, the study revealed that (μ/ρ), σa, and σe exhibited an initial decrease with increasing photon energy, stabilizing at higher energy levels. In contrast, Zeff and Neff remained relatively constant with changing energy levels. In addition, the research acknowledged that deviations in experimental results for radiological parameters may be influenced by the physical and chemical surroundings of the substances under investigation. Encouragingly, the experimental findings were found to be consistent with values from the WinXCom database, affirming their accuracy and reliability. These outcomes contribute to a deeper understanding of the photon interaction characteristics of these biological substances across diverse energy spectra.

XUV Absorption Spectroscopy and Photoconversion of a Tin-Oxo Cage Photoresist.

Extreme ultraviolet lithography has recently been introduced in high-volume production of integrated circuits for manufacturing the smallest features in high-end computer chips. Hybrid organic/inorganic materials are considered as the next generation of photoresists for this technology, but detailed knowledge about the response of such materials to the ionizing radiation used (13.5 nm, 92 eV) is still scarce. In the present work, we use broadband high-harmonic radiation in the energy range 22-70 eV for absorption spectroscopy and photobleaching (that is, the decrease of absorbance) of thin films of an n-butyltin oxo-cage, a representative of the class of metal-based EUV photoresist. The shape of the absorption spectrum in the range 22-92 eV matches well with the spectrum predicted using tabulated atomic cross sections. The photobleaching results are consistent with loss of the butyl side groups due to the breaking of Sn-C bonds following photoionization. Bleaching is strongest in the low-energy range (<40 eV), where the absorption is largely due to the carbon atoms in the organic groups. At higher energies (42-70 eV), absorption is dominated by the tin atoms, and since these remain in the film after photoconversion, the absorption change in this region is smaller. It is estimated that after prolonged irradiation (up to ∼3 J cm-2 in the range 22-40 eV) about 70% of the hydrocarbon groups are removed from the film. The rate of bleaching is high at the beginning of exposure, but it rapidly decreases with increasing conversion. We rationalize this using density functional theory calculations: the first Sn-C bonds are efficiently cleaved (quantum yield Φ ≈ 0.9), because the highest occupied molecular orbitals (HOMOs) (from which an electron is removed after photoionization) are located on Sn-C sigma bonds. In the photoproducts, the HOMO is localized on tin atoms that have lost their hydrocarbon group (formally reduced to the Sn(II) oxidation state), and holes formed on those tin atoms lead to less efficient cleavage reactions. Our results reveal the primary reaction steps following excitation with ionizing radiation of tin-oxo cages. Our methodology represents a systematic approach of studying and quantitatively assessing the performance of new photoresists and as such enables the development of future EUV photoresists.

ERCS24: An updated version of the ERCS08 program for calculations of the cross sections for atomic electron removal based on the ECPSSR theory and its variants

ERCS24: An updated version of the ERCS08 program for calculations of the cross sections for atomic electron removal based on the ECPSSR theory and its variants

Generalized binary-encounter-Bethe model for electron impact ionization of atoms

A generalized binary-encounter-Bethe (GBEB) model is proposed to calculate the partial ionization cross sections of all shells. The present model improves the original version of Kim et al (2000 Phys. Rev.A 62 052710) by incorporating a physically constructed effective charge felt by the ejected electron in the empirical factor, which prevents the selection of specific factors for different shells. A generalized relativistic binary-encounter-Bethe (BEB) formula is also proposed and applied to different inner shells of C, Al, Fe, Ar, Ag, Xe, Sn, Pb, and Bi atoms for impact energies from the thresholds up to 106 keV. The present model improves the partial ionization cross sections in the low-energy region compared to other relativistic BEB models. The GBEB partial and total ionization cross sections of the Xe atom are compared with the original BEB results. The present calculations, combined with the contribution from the direct multiple ionization, show good agreement with the experimental measurements in the intermediate- and high-energy ranges. We conclude that the present GBEB model, without any fitting parameters and ad hoc corrections, improves the BEB prediction of partial and total ionization cross sections for a good variety of atomic targets.