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A coherent soft x-ray Compton source driven by a density modulated electron beam is investigated. The density modulation is attained by an inverse free electron laser prebuncher, which offers strong energy modulation at the relevant beam energies for Compton scattering in an shallow-angle oblique scattering geometry using relatively low laser beam power. In particular, we study the case of a 101.7 MeV electron beam produced by a state-of-the-art high brightness accelerator beamline. Calculations show that 1 0 11 coherent soft x-ray photons per second can be generated in an ultra-narrow relative bandwidth of 0.002% from a 250 pC microbunched electron bunch colliding with a 23 mJ laser pulse at 10 kHz. [ABSTRACT FROM AUTHOR]

Copper-doped lithium calcium fluorophosphate glasses in the compositional system (60− x)P 2 O 5 ·20LiF·20CaF 2 · x CuO (x = 0−3 mol%) were prepared using the conventional melt quenching technique. X-ray diffraction confirmed the amorphous, non-crystalline phase of the glasses. Optical absorption spectra indicated the presence of additional broad visible-NIR absorption bands upon CuO doping, attributed to distorted Cu2+ ions. Possible overlaps from Jahn-Teller distorted sites or clustering into nanodomains may contribute to band broadening. The direct optical bandgap was found to reduce from 3.89 eV to 1.17 eV with increasing CuO content. The study of physical parameters showed almost linear variation in density (2.62–2.95 g/cm3) and molar volume (40.45–35.29 cm3/mol) with incremental CuO substitution, explained by changes in structural packing efficiency and formation of Cu–O complexes. FTIR spectra revealed vibrations corresponding to phosphate structural groups. The simulation of radiation shielding parameters displayed steady improvements with higher CuO fractions, which were related to enhanced photon interactions via photoelectric absorption and Compton scattering. • Copper-doped lithium calcium fluorophosphate glasses were prepared via melt quenching. • X-ray confirms the amorphous nature and IR spectra revealed vibrations corresponding to phosphate groups of the samples. • Increasing CuO contents reduced the direct optical bandgap from 3.89 eV to 1.17 eV. • Density and molar volume varied linearly with CuO substitution due to Cu–O complex formation. • The obtained data enhances the gamma-ray attenuation parameters of the P 2 O 5 –LiF–CaF 2 system. [ABSTRACT FROM AUTHOR]

• Light can also arise the phenomenon of shock wave in the context of a special Lorentz violation model, just like the shock wave in acoustic. • Making a correction to the quantum relation of photons so that the energy and momentum of photons are finite in any cases, such as the energy or momentum of spontaneous and synchrotron radiation in a cyclotron maser, and the energy and momentum obtained by photons in inverse Compton scattering, rather than be infinite as predicted by the Lorentz model. The possibility of the breaking of Lorentz symmetry has been discussed in many models of quantum gravity. In this paper we follow the Lorentz violation model in Ref. [14] (i.e., our previous work) to discuss the Doppler frequency shift of photons and the Compton scattering process between photons and electrons, pointing out that following the idea in Ref. [14] we have to modify the usual quantum relation of photons in the Doppler effect. But due to the current limited information and knowledge, we could not yet determine the specific expression for the correction coefficient in the modified quantum relation of photons. However, the phenomenon called spontaneous radiation in a cyclotron maser give us an opportunity to see what the expression for this correction coefficient might look like. Therefor, under some necessary constraints, we construct a very concise expression for this correction coefficient through the discussion of different cases. And then we use this expression to analyze the wavelength of radiation in the cyclotron maser, which tends to a limited value at v → c, rather than to 0 as predicted by the Lorentz model. And the inverse Compton scattering phenomenon is also discussed and we find that there is a limit to the maximum energy that can be obtained by photons in the collision between extremely relativistic particles and low-energy photons, which conclusion is also very different from that obtained from the Lorentz model, in which the energy that can be obtained by the photon tends to be infinite as the velocity of particle is close to c. This paper still follows the purpose in Ref. [14] that the energy and momentum of particles (i.e., any particles, including photons) cannot be infinite, otherwise it will make some physical scenarios invalid. When the parameter Q characterizing the degree of deviation from the Lorentz model is equal to 0, all the results and conclusions in this paper will return to the case as in the Lorentz model, so this paper also provides us with a possible experimental scheme to determine the value of Q in Ref. [14] , although it still requires extremely high experimental energy. [ABSTRACT FROM AUTHOR]

• Deduced Compton profiles (CPs) of SmCo 5 using LCAO and KKR schemes and 661.65 keV γ-rays. • Discussed bonding and CPs to check viability of exchange and correlation energies. • Analyzed available experimental magnetic CP (MCP) using our SPR-KKR computations. • Split experimental MCP for site-specific spin-momentum of Co, Sm and diffused e-. • Unique trial to resolve issue of spin-moments at Sm-4f and Co using MCPs and DFT. Looking at the limitations of neutron spectroscopy in exploring properties of rare earth hard magnet SmCo 5 , inelastic scattering for charge and magnetic Compton profiles are attempted. The experimental momentum densities using 661.65 keV γ-ray energy are compared with the theoretical Compton profiles (CPs) deduced using linear combination of atomic orbitals (LCAO) with different exchange and correlation potentials and also spin polarized relativistic Korringa-Kohn-Rostoker (SPR-KKR) calculations. The anisotropies in the computed CPs, along the principal directions, show high momentum densities along the c-axis [00.1] of SmCo 5 than [10.0] and [11.0] directions. An overall better agreement of CP computed using LCAO-GGA and that from experiment is observed which shows more appropriateness of GGA-PBE scheme for the exchange and correlation energies for SmCo 5. The small value of charge transfer from Sm → Co and positive value of overlap Mulliken population dictate dominance of covalent bonding in SmCo 5. Moreover, available experimental data on c-axis oriented magnetic CP (MCP) of SmCo 5 have been compared with the present SPR-KKR calculations. It is seen that present SPR-KKR based MCP is in resemblance with the available experimental MCP. A decomposition of experimental MCP in to its constituent profiles depict that the spin momentum of Co and Sm are aligned anti-parallel while the diffuse contribution aligns opposite to the absolute spin moment. Comparison of amplitude and direction of site specific spin moments in SmCo 5 is made with the present SPR-KKR and available experimental and theoretical data. [ABSTRACT FROM AUTHOR]

This study presents an innovative approach utilizing gamma scattering techniques to precisely determine the composition percentage in a two-component oxide compound. The experiment involved a 241Am gamma-ray source emitting 59.54 keV radiation and a Si(Li) detector to capture Rayleigh and Compton scattering signals from oxide powder samples. These samples were meticulously prepared by blending Pb 3 O 4 and ZnO, with Pb 3 O 4 proportions ranging from 0% to 100%. To ensure accuracy, eleven standard samples were employed to generate standard curves for the Rayleigh-Compton ratio. The key finding of this research was the calculation of composition percentages for the four samples under investigation, derived from experimental data and the standard curve. Validation against reference materials revealed a minimal relative deviation of approximately 1.0% when estimating the Pb 3 O 4 ratio, showcasing the precision and potential applicability of this method in material science and analysis. • Standard binary oxide mixtures are prepared with varying ratios of ZnO and Pb 3 O 4. • Si(Li) detector records scattering signals from oxide powder samples. • The standard R/C curve is established to determine the composition percentages. • Three different methods are used to calculate the Z eff from the composition. • The results show the applicability of the R/C ratio for determining compositions. [ABSTRACT FROM AUTHOR]

Thomson scattering sources are known for generating quasi-monochromatic, high-brightness, and polarization-tunable X-rays, which are widely applied in fields such as fluorescence imaging, magnetic circular dichroism, and nuclear physics. In this paper, we present an experimental demonstration of polarization control at the Tsinghua Thomson scattering X-ray source (TTX) by adjusting the laser polarization. A specially designed Compton polarimeter is employed to effectively analyze the Degree of Linear Polarization (DoLP) of the X-rays produced at the TTX. Our results indicate that the DoLP of X-rays within a collecting angle of 1 / (3 γ) , where γ is the Lorentz factor of the relativistic electron, closely matches the DoLP of the laser. Furthermore, we demonstrate that the X-ray polarization can be continuously modulated from linear polarization to circular polarization by adjusting the laser polarization, which can significantly enhance the functionality and applicability of Thomson Scattering sources for scientific research. [ABSTRACT FROM AUTHOR]

Recent studies of positron emission tomography (PET) devices have shown that the detection of polarization-correlated annihilation quanta can potentially reduce the background and creation of false lines of response (LORs) leading to improved image quality. We developed a novel PET demonstrator system, capable of measuring correlated gamma photons with single-layer Compton polarimeters to explore the potential of the method. We tested the system using sources with clinically relevant activities at the University Hospital Centre Zagreb. Here we present, for the first time, the images of two Ge-68 line sources, reconstructed solely from the correlated annihilation events. The spatial resolution at two different diameters is determined and compared to the one obtained from events with photoelectric interaction. [ABSTRACT FROM AUTHOR]

A novel design for energy-selective imaging of high-flux gamma rays in the multi-MeV range is presented. The proposed system is based on gamma-to-electron conversion and energy-selective imaging of the electrons. The main components of the system include a low-Z foil that converts MeV gamma-ray photons into electrons through Compton scattering, and a double-bend beam transport system that performs energy selection and point-to-point imaging for the electrons. The image of the energy-selected electrons can be used to obtain spatial information for incident gamma rays of interest energy, enabling energy-selective imaging of broad-spectrum gamma-ray beams. Design considerations and optimizations are detailed. Monte Carlo simulations are conducted to evaluate the performance in energy-selective imaging of broad-spectrum gamma-ray beams. The energy resolution for 4.44 MeV gamma-ray achieves 0.41 MeV (FWHM) with a quantum efficiency of 2.5 × 10−6 e/γ, and the spatial resolution is approximately 1 mm and 2.5 mm within a 60 × 60 mm field of view in the horizontal (x) and vertical (y) directions, respectively. • A novel design for gamma-to-electron energy-selective imaging of high-flux gamma rays in the multi-MeV range is presented. • The energy resolution for 4.44 MeV gamma-ray achieves 0.41 MeV (FWHM) with a quantum efficiency of 2.5 × 10−6 e/γ. • The spatial resolution is approximately 1 mm within a 60 × 60 mm field of view. [ABSTRACT FROM AUTHOR]

A Bayesian peak identification method based on physical model had been proposed in this study to perform qualitative analysis for the low count rate gamma spectrum under short-time measurement. Based on the prior knowledge about gamma detection, the distribution of energy deposited in the detector near the region of interest of a target peak through photoelectric effect, Compton scattering and multiple scattering had been analyzed and approximated using three elementary components, then, the distribution of each component after convolution had been studied, and at last, a probabilistic mixture model had been proposed to directly describe the distribution of measured energy within region of interest. When the data measurement has been completed, a Gibbs sampler was used to estimate the posterior distribution of model parameters to discriminate the existence of target peaks. The numerical and physical experiments were performed to verify the effectiveness of the parameter estimation algorithm and the performance of the proposed identification method. The numerical experiments showed the identification precision is proportional to counts and peak-to-total ratio, when the peak-to-total ratio is greater than 0.5, the proposed method could identify the peak with a probability greater than 50% given 50 observations. The physical experiment used a NaI(Tl) detector to measure 137Cs, 60Co and 152Eu sources in a laboratory environment at different equivalent distances, the peak identification precision had been tested for the proposed method, and the experiments proved that the probabilistic model is a good approximation to the physical process, and the proposed identification method outperformed the conventional method under short-time measurement conditions. [ABSTRACT FROM AUTHOR]

The objective of this research is to examine the effectiveness of gamma and neutron shielding, as well as to investigate the behavior of charged particles in glass compositions with the formula xBaO:5SnO 2 :10Na 2 O:10CaO:10Li 2 O: (65-x)SiO 2. These glass compositions will be created using the melt quenching technique (MQT). The findings indicated that the physical characteristics, such as density and molar volume, exhibited a comparable pattern. The gamma-ray shielding capacity of the glass system was assessed by comparing it with theoretical, simulation, and experimental values obtained using WinXCom, PHITS (Particle and Heavy Ion Transport Code System) Monte Carlo simulation, and Compton scattering technique (CST), respectively. The results revealed that the total attenuation (μ m), effective atomic number (Z eff), and electron density (N el) exhibited a consistent increase with higher BaO contents. Additionally, this increase led to a decrease in scattering energy within the Compton energy range. The half-value layer (HVL) exhibited superior shielding characteristics compared to alternative substances. Furthermore, the addition of more BaO atoms in the glass structure results in an increased ability of the material to stop the motion of charged particles with larger mass. Conversely, lower concentrations of BaO demonstrate an efficient barrier against fast neutrons. The simulation revealed that BaO can be utilized as an additive in glass materials to enhance their radiation shielding properties in environments with high levels of radiation. • Study of the gamma shielding properties and the behavior of charged particles and neutrons in the BaO glasses. • 137Cs was used for radiation shielding properties investigation. • The experimental values of shielding properties are comparable to WinXCom and PHIST simulations. • Replacing of BaO in the host glass can enhance the shielding properties of the glass. [ABSTRACT FROM AUTHOR]

This study aims to assess the efficacy of low energy gamma-ray based instrumentation for inspecting the wall thickness of metallic pipes in industrial situations. The primary motivation behind this work is to explore the feasibility of using a Monte Carlo approach, specifically FLUKA simulations, for radiation-based industrial applications. To achieve this objective, laboratory experiments and FLUKA simulations were conducted using 59.5 keV gamma-rays and a NaI(Tl) scintillation detector. The purpose was to detect changes in pipe wall thickness due to erosion and corrosion, enabling timely intervention to prevent any negative consequences. The ability, scoring commands and geometry design of the FLUKA Monte Carlo code were validated in this study by comparing the computed values of gamma-ray scattered/transmitted intensity with experimental data. Regression lines were derived from the computed and experimental data for scattered and transmitted intensity, providing valuable information for pipe wall inspection. The technique exhibited high sensitivity to changes in the wall thickness of metallic pipes, with a detection capability of 1 mm. However, for higher wall thickness, the sensitivity of the low-energy gamma-ray technique decreased due to the influence of overlying scattering/absorption components in the obtained spectra. The maximum sensitivity limit was found to be for a wall thickness of ∼8 mm for metallic pipes. The excellent agreement between simulation results and actual laboratory methods validates FLUKA's high efficacy in checking the condition of industrial pipelines. • Simulations of scattering and transmission measurements for pipe wall thickness. • Validation of FLUKA code with experimental data for pipeline industry. • FLUKA as an alternative to forecast the performance of any new inspection system. • Technique is sensitive enough to detect the thinning (∼1 mm) of metallic wall. [ABSTRACT FROM AUTHOR]

Basing on the slant Compton scattering of 10640 nm photons from a 100 W CO 2 laser on 3.5 GeV electrons from the Shanghai Light Source, the Shanghai Laser Electron Gamma Source (SLEGS) produces gamma-ray in the energy range of 0.66 MeV–21.7 MeV and flux of 105–107 photons/s. A Gamma Modulation System (GMS) composed of the collimators, attenuator, beam spot imaging(MiniPIX) and flux monitor(LaBr 3 detector) was developed to ensure producing bandwidth-variable quasi-monochromatic gamma-ray with a variable-flux at same time. Using the GMS, variable-flux quasi-monochromatic gamma-ray beams with a best bandwidth of 10% in the 90 ∘ slant-scattering and 4% in back-scattering were obtained respectively. We report on the performance of the GMS and results of gamma-ray beam modulating measurement with GMS at SLEGS. • SLEGS is a medium energy resolution slant-scattering beamline. • This article provides beam parameters for users on SLEGS. • The Gamma Modulation System(GMS) is effective in modulating gamma-ray beams. • Using the GMS, 4%–10% energy resolution can be obtained. • Flux of 105-107 photons/s can be obtained with 5 W laser power. [ABSTRACT FROM AUTHOR]

The release of radioactive gas into the atmosphere can diffuse into large volumes of air downwind from the point of release. The extent of radioactivity can cover thousands of cubic meters of air. For such large volumes, the weather models used to predict the down-wind distribution of the plume and the radiation transport models used to predict the radiation reaching ground-level from the plume can take tens of hours of computer time on multi-node institutional High-Performance Computing facilities. In this paper we focus on the radiation transport aspect of plume modeling. We describe a phenomenological method for approximating the amounts of radiation that reach ground level from large volumes of a static radioactive plume that can be calculated on a stand-alone personal computer in much shorter computation times than those usually needed for such large volume evaluations. We refer to this method as the Density Scaling Approximation (DSA). Its ability to approximate ground-level count rates of large plumes comes from using a small-plume volume with a scaled-up value of air density to simulate the same number of scatterings that occur during transport in larger plume volumes at normal air density. We demonstrate the DSA by using a 100 m-diameter air-filled hemispherical dome geometry with a uniform volumetric activity of 135Xe gas throughout the air-filled volume. The DSA for a larger dome diameter is obtained by evaluating the 100 m dome with an air density scaled up by the linear ratio of the larger diameter to the 100 m diameter. We find that this approximation works well for dome diameters up to 1200 m – the largest diameter studied and a size more than sufficient for accounting for all the radiation from 135Xe. Moreover, most of our DSA results can be calculated over 500 times faster than corresponding full-sized geometry with normal air density. To help evaluate the accuracy of the DSA and gain insight into how well it can reproduce different regions of the spectra, we use three, easily understood regions of interest to compare the DSA results to the full-sized geometry at normal air density results. These regions are the full-energy peak, the region of single-Compton scattering, and the region of multiple-Compton scattering. We show how the dominance of the Compton scattering mechanism determines this division and thus provides insight into how Compton scattering is manifested in spectra from photon scattering through air in general, and how well the DSA approximation works. [ABSTRACT FROM AUTHOR]

The backscatter X-ray system makes an image by detecting scattered particles from an object in the opposite direction by Compton scattering. This system has the advantage of detecting drugs or explosives composed of organic substances. In this study, we developed a backscatter X-ray detection system. The 6-ch DAQ system is able to store acquired data for 50 μs as 8 bytes and the 6-ch high voltage power supply board provides adjustable power from 0 to 1600 V. Using this detection system, we varied the tube voltage from 80 to 160 kV and observed backscatter X-ray images of two plastic phantoms at 160 kV. The results indicate a need to optimize the speed of the collimator and data acquisition time of the DAQ system to improve image quality. The backscatter X-ray imaging technology exhibits high scalability, making it applicable not only to security screening but also for medical and industrial purposes. [ABSTRACT FROM AUTHOR]

A polarimeter was constructed to measure the longitudinal polarization of a spin-polarized electron beam at 5 and 7 MeV. The polarimeter takes advantage of Compton scattering between circularly polarized bremsstrahlung photons produced by a longitudinally polarized electron beam striking a copper radiator and the spin-polarized electrons orbiting the iron atoms of an analyzing magnet. This so-called Compton transmission polarimeter is compact and relatively inexpensive compared to Mott-scattering polarimeters because no spin manipulator is required. This work presents the design of the radiator, analyzing magnet, photon detector assembly, and data acquisition system of the Compton transmission polarimeter as well as beam commissioning results performed at the Upgraded Injector Test Facility at Jefferson Lab. [ABSTRACT FROM AUTHOR]

In positron annihilation, exploration of the polarization correlations of the emerging gamma quanta has gained interest, since they offer a possibility to improve signal-to-background in medical imaging using positron emission tomography. The annihilation quanta, which are predicted to be in an entangled state, have orthogonal polarizations and this property may be exploited to discriminate them from two uncorrelated gamma photons contributing to the background. Recent experimental studies of polarization correlations of the annihilation quanta after a prior Compton scattering of one of them, had rather different conclusions regarding the strength of the correlation after the scattering, showing its puzzling nature. The scattering was described as a decoherence process. In the present work, we perform for the first time, a study of the polarization correlations of annihilation quanta after decoherence via Compton scattering in the angular range 0 ∘ − 50 ∘ using single-layer gamma ray polarimeters. In addition, we compare the measured polarization correlations after Compton scattering at 30 ∘ with an active and a passive scatterer element. The measured azimuthal correlation of back-to-back annihilation quanta is consistent with the Pryce-Ward formulation, as confirmed by Monte Carlo simulations. Further, the results indicate that the correlation, expressed in terms of the polarimetric modulation factor, shows no significant difference at small scattering angles (0 ∘ − 30 ∘) compared to the correlation measured for direct photons, while a moderate indication of a lower modulation is observed for 50 ∘ scattering angle. The measured modulation is larger at all scattering angles than the one expected from the simulation of orthogonally polarized, independent annihilation quanta. [ABSTRACT FROM AUTHOR]

The conflict between the production capacity and demand for medical radioisotopes has become more prominent. In addition, for some new types of medical radioisotopes, neutron, and proton-induced reactions are not the best way to generate them with high specific activity. The research status of medical radioisotopes is introduced, then the gamma facility and potential new medical radioisotope candidates based on photonuclear reaction are widely surveyed. The production of medical radioisotope 186 g Re is simulated based on the Laser Compton Scattering (LCS) gamma source and bremsstrahlung gamma source. It is found that the next generation quasi-monochromatic, high-flux LCS gamma source can produce medical radioisotope 186 g Re with less than 0.05% 188Re impurity with around 400 mb cross section. Meanwhile, the bremsstrahlung gamma source can produce around 200 MBq/g specific activity medical radioisotope 186 g Re with realistic electron intensity 3.125 mA. This study and simulations show that photonuclear reaction can be regarded as an alternative route for producing medical radioisotopes. • Study on photonuclear method for high-specific-activity medical isotopes. • Provided a wide survey of potential gamma transmutation medical radioisotopes. • Explored strengths of quasi-monoenergetic and bremsstrahlung γ for 186gRe production. [ABSTRACT FROM AUTHOR]

Linear combination of atomic orbitals (LCAO) and full potential linearised augmented plane wave (FP-LAPW) approximations have been utilized to discuss the electronic properties for different form of binary manganese oxides viz. MnO, β-MnO 2 , α-Mn 2 O 3 and Mn 3 O 4. Spin dependent energy bands and density of states (DOS) were computed using FP-LAPW-mBJ approximation. A significant band gap in both spin up and spin down channels for MnO, β-MnO 2 and Mn 3 O 4 reflects their semiconducting nature, while α-Mn 2 O 3 depicts the half metallic character. The Mulliken's charge reorganization on formation of oxides and Compton profiles (CPs) are also calculated using LCAO based pure and hybrid density functional theory. Mulliken analysis show that MnO, α-Mn 2 O 3 and Mn 3 O 4 have higher ionic character than that of natural β-MnO 2. Theoretical CPs for β-MnO 2 were validated by CP measurements using 100 mCi 241Am Compton spectrometer. It is shown that hybrid DFT (B3LYP) approximation is a better choice to evaluate electronic response, etc. Interdependence of energy bands (FP-LAPW-mBJ) and anisotropic CPs are also discussed. • Various properties of binary manganese oxides MnO, β-MnO 2 , α-Mn 2 O 3 and Mn 3 O 4 are studied. • mBJ potential depicts semiconducting nature of MnO, β-MnO 2 and Mn 3 O 4, whereas α-Mn 2 O 3 shows half metallicity. • Mulliken population reports an increase in the ionicity in order β-MnO 2.→Mn 3 O 4 →α-Mn 2 O 3 →MnO. • First ever LCAO based Compton profiles of β-MnO 2 are validated using 241Am Compton spectrometer. • Hybrid B3LYP is suggested to evaluate electronic response for β-MnO 2 and other properties more accurately. [ABSTRACT FROM AUTHOR]

Total, whole-atom, individual and integrated Compton scattering cross sections and Compton energy absorption scattering cross sections are evaluated for light elements, such as, H, C, N, O, P, and Ca, with relativistic impulse approximation methods. Most of the phantom materials composed of these elements, which are the basic constituents of biological soft-tissue and attenuation through them, provides potential source of information. Compton scattering cross-sections for few biological materials, such as, H 2 O, C 2 H 4 , C 8 H 8 , C 5 H 8 O 2 , C 6 H 11 NO, C 16 H 14 O 3 , C 55 H 102 O 6 , [Ca 3 (PO 4)] 3 Ca (OH) 2 of medical interest, have been evaluated with the use of double differential scattering cross-section based on impulse approximation. Utilized these values to evaluate the Compton energy absorption cross sections and Compton component of mass energy absorption coefficients (cm2/g) in the energy region from 0.005 to 10 MeV. The derived results are compared with the theoretical tabulations. • Evaluation of double differential scattering cross-section based on impulse approximation. • Total, whole-atom, individual and integrated Compton scattering cross sections. • Compton energy absorption scattering cross sections. • Compton scattering cross-sections for few biological materials. • Compton component of mass energy absorption coefficients. [ABSTRACT FROM AUTHOR]

This research explored the mechanical, physical, and ionizing radiation shielding properties of 10PbO–10Na 2 O-(80-x)B 2 O 3 -xBaO glass samples, where x = 10, 15, 20, and 25. The conventional melt-quench technique was employed to prepare the samples. The elastic moduli were investigated using the Makishima–Mackenzie model. At the same time, the radiation shielding properties involved a comprehensive analysis of the effective atomic number, linear attenuation and mass attenuation coefficients, half-value and tenth-value layers, radiation protection efficiency, and transmission factors, as well as the buildup factors for different mean-free paths (mfp). The impact of BaO (mol%) on the parameters mentioned above was investigated across a range of photon energies (0.015–15 MeV). In addition, the effect of BaO on the physical and mechanical properties of current glasses was studied. The addition of BaO showed an inverse impact on mechanical and physical properties, gradually reducing the glass's stability. In contrast, adding BaO to the compound enhanced photon attenuation ability, which means the sample with 25% BaO had the optimum capacity for radiation shielding amongst all the prepared samples. Moreover, the results demonstrated the complex interplay of Compton scattering, pair production, and the photoelectric effect, influencing the attention of photons. This work provides beneficial intuition into designing and optimizing glass-based radiation shielding materials. • We used the melt-quench technique to fabricate four 10PbO–10Na2O-(80-x)B2O3-xBaO glass samples, where x = 10, 15, 20, and 25. • The effect of BaO as additives was examined by investigating physical, mechanical, and radiation shielding features. • Comprehensive radiation shielding properties were studied. • Based on obtained results, the B55Ba25 sample has the highest shielding properties, which nominate using it in the shielding application. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive investigation of borate-based glasses doped with BaO, assessing their physical, structural, optical, and radiation shielding properties through experimental and theoretical analyses. XRD patterns reveal the amorphous nature of the prepared glass samples. Density and molar volume values, and FTIR spectra indicate the impact of BaO concentration on the glass matrix, affecting structural properties. Thermal analysis via TGA/DSC reveals improved thermal properties with the substitution of B 2 O 3 with BaO. UV–visible absorption spectroscopy shows a decrease in energy band gap with rising BaO content, suggesting potential non-bridging oxygen formation. Mass attenuation coefficient (μ m) values exhibit an exponential decay trend with photon energy, influenced by photoelectric absorption, Compton scattering, and pair creation. The glasses prepared had, in general, a better μ m values compared to that of concretes and other glass compositions containing barium oxide. Experimental and theoretical (XCOM) results for mean free path (MFP) and half-value layer (HVL) demonstrate close agreement, validating the accuracy of the experimental data. Both MFP and HVL increase with energy and decrease with BaO addition, emphasizing the potential for these glasses in radiation shielding applications. • Borate based glass samples of the composition (70-x)B 2 O 3 –20Bi 2 O 3 –5ZnO–5WO 3 -xBaO; x = 0, 5, 10, 15 and 20 mol% have been successfully prepared by melt-quenching process. • The addition of BaO in the glass system improves its density, thermal and gamma radiation shielding properties. • The study elucidates structural modifications of borate glasses imparted by the doping of BaO. • Non-toxic and environmentally friendly nature, along with effective shielding behavior, of our prepared glass samples makes it a practical solution for gamma shielding applications. [ABSTRACT FROM AUTHOR]

The production, application, and/or measurement of polarised X-/gamma rays are key to the fields of synchrotron science and X-/gamma-ray astronomy. The design, development and optimisation of experimental equipment utilised in these fields typically relies on the use of Monte Carlo radiation transport modelling toolkits such as Geant4. In this work the Geant4 "G4LowEPPhysics" electromagnetic physics constructor has been reconfigured to offer a best set of electromagnetic physics models for studies exploring the transport of low energy polarised X-/gamma rays. An overview of the physics models implemented in "G4LowEPPhysics", and it's experimental validation against Compton X-ray polarimetry measurements of the BL38B1 beamline at the SPring-8 synchrotron (Sayo, Japan) is reported. "G4LowEPPhysics" is shown to be able to reproduce the experimental results obtained at the BL38B1 beamline (SPring-8) to within a level of accuracy on the same order as Geant4's X-/gamma ray interaction cross-sectional data uncertainty (approximately ± 5 %). [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the radiation protection capabilities of glass specimens with the composition xBaO: 1.5Dy 2 O 3 : 25ZnO: 5Al 2 O 3 : 30B 2 O 3 : (x-38.5)SiO 2 by varying x = 10 (Ba10) to 35 (Ba35) mol% of BaO concentrations. The glass specimens were fabricated using the melt-quenching technique. The results revealed that the physical and optical properties, such as density (ρ), molar volume (V m), and refractive index (RI), had a similar trend. The % transmission result of glass specimens indicates higher transparency than those of commercial and x-ray windows. The experimental values of total attenuation (μ m) in this study used the Compton scattering technique. The obtained results were then compared with theoretical calculation obtained from the WinXCom program and the PHITS (Particle and Heavy Ion Transport Code System) Monte Carlo simulation. The results indicated the values of μ m , effective atomic number (Z eff), and electron density (N eff) increase with the rise in BaO content. However, these values decrease at higher energy levels. The observed trends align with the theoretical predictions of the WinXCom program and the obtained results from the PHITS Monte Carlo simulation. The half-value layer (HVL) showed better shielding properties than both standard radiation shielding glass and other materials. Additionally, an examination of energy absorption (EABF) and exposure buildup factors (EBF) revealed a distinct advantage associated with the incorporation of BaO atoms. This advantageous effect was observed in the reduction of photon scattering events, further enhancing the overall efficacy of the shielding properties in the glass specimens under study. • High-transparency borosilicate glasses was developed as nuclear radiation protection material. • 137Cs used for radiation shielding properties investigation via the Compton scattering technique. • Total attenuation experimental values compared to WinXCom and PHITS Monte Carlo simulation. • Replacing of BaO in glass matrix can enhance shielding properties of the glass. [ABSTRACT FROM AUTHOR]

Automatic identification and quantification of γ -emitting radionuclides, taking into account spectral deformations due to γ -interactions in radioactive source surroundings, is a challenging task in the nuclear field. In that context, this paper presents a Machine Learning approach based on autoencoder that can learn a model for the spectral signatures of γ -emitters with variability. Training and test datasets were obtained by means of simulated γ -spectra computed with the Geant4 simulation code according to increasing material thicknesses (steel, lead). A novel hybrid unmixing algorithm combining a pretrained autoencoder is studied for joint estimation of spectral signatures and counting in the case of mixtures of four radionuclides (57Co, 60Co, 133Ba, 137Cs). The investigations were carried out to account for spectral deformations due to attenuation, Compton scattering and fluorescence at high and low statistics. This study demonstrates the validity of this novel hybrid approach combining Machine Learning and Maximum Likelihood for the automatic full-spectrum analysis of γ -spectra. • Hybrid γ -spectra unmixing algorithm combining Machine Learning and Maximum Likelihood. • Modeling of spectral signature deformations by autoencoder with limited data. • Geant4 simulations of spectral deformations due to physical effects. • Full-spectrum unmixing using autoencoder as a generative model of γ -spectra. • Joint estimation of spectral signatures and mixing weights for all radionuclides. [ABSTRACT FROM AUTHOR]

In this study, albedo parameters are experimentally measured to determine radiation scattering features of some thermoluminescent dosimetry materials (TLD 100, TLD 100h, TLD 200 and TLD 400). In experimental setup, it was used scattering angle of 168°, 59.54 keV gamma rays and HPGe detector. The effective atomic numbers of the investigated materials were determined from the coherent to Compton scattering intensity ratio. Also, the mass attenuation coefficient, the mass energy absorption coefficient and kerma relative to air and ICRU tissue were calculated for the TLD materials. It was observed that TLD 100h is the best tissue equivalent material among other TLD materials and best reflects 59.54 keV gamma rays. • The effective atomic numbers of some thermoluminescent dosimetry materials were obtained from scattering ratios. • The effective atomic number and albedo parameters are obtained for 59.54 keV photon energy. • TLD 100h is the material that best reflects 59.54 keV gamma rays. [ABSTRACT FROM AUTHOR]

The gamma-radiation shielding capabilities of a Ni 0.2 Mg x Zn 0.8-x Fe 2 O 4 nanocrystal, synthesized using the sol-gel auto-ignition process, were described in the present investigation. The synthesized materials were analyzed using different techniques such as XRD, UV–Vis, FTIR, FE-SEM, and EDS to investigate their structural, optical, and functional group morphological properties, and elemental analysis. Additionally, utilizing various gamma-ray sources and a NaI (Tl) scintillation detector, we investigated the gamma-ray shielding parameters for the prepared materials. The cubic spinel structure of all produced Nanoferrites is clear from X-ray diffractograms, which show no contaminated phases. Pellets of nanocrystalline spinel ferrites have been exposed to gamma radiation from various sources by varying the intensity of the radiation dose. Utilizing Phy-X/PSD Software, a comparative analysis of the mass and linear attenuation coefficients, mean free path, half value layer, tenth value layer, effective atomic number, and effective electron density for synthesized spinel ferrites is performed at 122–1330 keV. Using the geometric progression (G-P) fitting technique, the gamma-ray energy absorption build-up factor (EABF) for four selected ferrites is explored at incident photon energy levels ranging from 0.015 to 15 MeV. It is found that the Compton scattering process is mostly responsible for the EABF maximum in an intermediate region. K1 has a higher EABF value than other ferrites, which is largely determined by the crystallite size effect and the chemical composition of the material. There is a good agreement between the theoretical and experimental results. Among the studied samples, sample K1 and K4 have superior gamma-ray and fast neutron attenuation capabilities respectively than its counterparts. The current study offers a thorough examination of the chosen iron oxides in the context of gamma and neutron radiation. • The values of μ m , μ, Z eff , λ, HVL, TVL were determined experimentally using NaI (Tl) detector. • Experimental results have been supported with Phy-X/PSD Software values. • The energy absorption buildup factor have been calculated using G.P. fitting method. • The values of macroscopic removal cross-sections for neutrons were determined. • Measured data in mixed neutron-gamma radiation field are useful in nuclear medicine application. [ABSTRACT FROM AUTHOR]

The Southern European Thomson back-scattering source for Applied Research (STAR) is a high-energy photon facility located on the campus of the University of Calabria (UniCal). The facility was designed for its first phase to operate with an electron and photon energy up to 85 MeV and 140 keV respectively. For the second phase of the project the energy of the electrons, and thereby the photons, would be increased up to 150 MeV and 350 keV respectively. The Italian Institute for Nuclear Physics (INFN) was awarded the project for installing, testing, and commissioning the energy upgrade of the electron beamline. In this article, we will outline the progress of this upgrade. In particular the completion of the site acceptance test of the RF system and the IT infrastructure combined with the control system software. [ABSTRACT FROM AUTHOR]

Researchers have been searching for different methods to determine the effective atomic number of materials for many years. Therefore, there are many methods in the literature to determine the effective atomic number theoretically or experimentally. While theoretical methods neglect some parameters, such as the momentum transfer parameter, photon energy, or scattering angle, experimental methods have incommodious processes. The main goal of this study is to provide a practical simulation method that is both as realistic as experimental results and as easy as theoretical methods. The method considers all these parameters compared to other theoretical methods and transfers them to the virtual environment. In this study, Rayleigh and Compton scattering peaks of 60 pure elements (in the range 20< Z <80) were determined. Rayleigh and Compton peak ratios were correlated with their atomic numbers. The proposed method is available for any energy or scattering angle. Six different compounds (WC, W 65 Cu 35 , SnAg, Fe 54 Co 17 Ni 29 , Pd 94 Cr 6 , Cu 60 Zn 40) were selected from different atomic number regions (such as low, medium, and high regions). It is important to note that any material (compound or mixture) could be selected. Validation of the method has been performed via different methods commonly used in the literature. It is observed that the results of this method are in good agreement with other methods in the literature. We are expecting that the proposed method will provide great convenience and guidance to researchers in this area. • A Monte Carlo simulation method of the R/C scattering ratio were proposed to determine the effective atomic number. • The scattering spectra were measured for about sixty different pure elements with atomic numbers between 20 and 80. • The ratios of the R/C scattering peaks were correlated with their atomic numbers. • The proposed method was tested on six different compounds. • The validation of the proposed method was confirmed with the theoretical results. [ABSTRACT FROM AUTHOR]

The gamma-ray shielding properties for the xPbO‧50B 2 O 3 ‧(50-x)V 2 O 5 glass systems (where x varied between 20 and 49 mol%) were investigated. The photon attenuation factors were determined using Phy-X/PSD software to evaluate the influence of PbO on the radiation shielding ability of the glass. The mass attenuation coefficient (MAC) increased with the addition of PbO. We discussed the effects of photoelectric effect, Compton scattering and pair production on the MAC values at different energy regions. The highest half value layer (HVL) for the investigated borovanadate glasses was reported at 284 keV and lie within the range of 0.5067 and 0.931 cm. The sample containing the highest content of PbO (49 mol%) had the lowest HVL, which indicates that it is the most effective radiation shield among the tested borovanadate glasses. The tenth value layer (TVL) results revealed that the shielding ability for the borovanadate glasses improved when the percentage of PbO increased from 20 to 49 mol%. The least TVL values of the samples with 20 and 49 mol% of PbO were 1.682 cm at 284 keV and 2.432 cm at 347 keV. [ABSTRACT FROM AUTHOR]

• Transmission of scattered x-ray through breast tissue phantoms was evaluated. • X-ray spectrum model and breast phantom composition were experimentally validated. • Three approaches: experiment, analytical calculation, and Monte Carlo simulation. • The transmission curves from all three methods matched reasonably well. • The quantitative results paved the base for future work on Compton scatter imaging. To explore the potential of utilizing Compton scattered x-ray photons for imaging applications, it is critical to accurately evaluate scattered x-ray transmission properties of targeted tissue materials. In this study, scattered x-ray transmission of breast tissue equivalent phantoms was evaluated. Firstly, two validations were carried out using a primary x-ray beam at 80 kVp with both experimental measurement (ion chamber with narrow-beam setup) and analytical calculation (Spektr toolkit). The tungsten-anode x-ray spectrum model was thus validated by measuring and calculating the transmission through increasing thickness of 1100 Aluminum filters. Similarly, the composition models of breast tissue equivalent phantoms (CIRS, 012A) were validated by measuring and calculating x-ray transmission for three different breast compositions (BR30/70, BR50/50, and BR70/30). Following validation, transmission properties of Compton scattered x-ray photons were measured with a GOS based linear array detector at the 90° angle from the primary beam. The same study was performed through three independent approaches: experimental measurement, analytical calculation, and Monte Carlo simulation (GEANT4). For all three methods, the scattered x-ray photon transmission as functions of phantom thickness were determined and fit into exponential functions. The transmission curves from all three methods matched reasonably well, with a maximum difference of 6.3% for the estimated effective attenuation coefficients of the BR50/50 phantom. The relative difference among the three methods of estimated attenuation is under 3.5%. As an initial step to develop a novel Compton scatter-based breast imaging system, the quantitative results from this study paved a fundamental base for future work. [ABSTRACT FROM AUTHOR]

• A new photon and neutron hybrid transmutation method for Cs-135, Cs-137, and I-129. • A two-step approach in which (γ,n) transmutation is followed by (n,γ) transmutation. • (n,γ) transmutation is a result of (γ,n) transmutation, therefore, cost-effective. This work is concerned with transmutation of the highly toxic radioactive Cs-135 and Cs-137, which are extremely difficult to transmute in the conventional neutron fields, together with I-129. A novel strategy of photon and neutron hybrid transmutation has been proposed for a CsI target. An optimized laser-Compton scattering (LCS) source is used to generate energetic gamma-rays, which are then directed to central CsI target for photonuclear (γ,n) transmutation. Energetic neutrons resulting from the (γ,n) reactions are scattered through moderator into a surrounding CsI blanket targets where they undergo (n,γ) transmutation. In this study, design parameters such as LCS spectrum, target dimensions and configurations have been optimized to enhance the effectiveness of the hybrid transmutation method. In addition, the CsI target configuration has also been optimized to remove heat deposited in the central target. From the results, it has been concluded that the hybrid transmutation has promising applications for the radioactive waste management. [ABSTRACT FROM AUTHOR]

Compton scatter imaging (CSI) is a promising, noninvasive imaging technique; however, it is limited by its poor utilization of X-rays and its bad image signal-to-noise ratio (SNR). In this work, a novel method combining push-broom CSI with coded-aperture imaging was devised to improve the utilization of backscattered X-rays and the image SNR. Firstly, the principles of coded-aperture push-broom CSI are illustrated, and its various applications are discussed. Then, simulations of a point source and a line source are performed to validate its feasibility. It was discovered that the inherent coding noise trends for the mask and the antimask were the opposite of each other. Therefore, these coding noises could be offset by averaging the two. Furthermore, a system prototype was built to scan objects, such as point phantoms, line phantoms, character phantoms of "IHEP", and other typical samples. Compared with traditional push-broom CSI, this novel system obtained a better backscatter image with lower X-ray power and at a farther distance. This feature is important for system miniaturization and radiation dose reduction. Although optimizations should be considered in the future, this approach demonstrates useful application potential. • We devise a novel method of coded-aperture push-broom Compton scatter imaging. • It improves the utilization of backscattered X-rays and the image SNR. • It shows a potential for system miniaturization and radiation dose reduction. • Noises could be offset mostly by averaging results of mask and antimask. • Simulations and experiments support the method well. [ABSTRACT FROM AUTHOR]

The scintillation properties of cesium-zirconium hexachloride (Cs 2 ZrCl 6) were investigated by γ-ray spectrometry and the Compton Coincidence Technique. The tested cylindrical sample had 20 mm diameter and 12 mm height. The crystal shows a high light output of 40 900 photons per MeV as measured by a spectroscopy type photomultiplier with 20 μs pulse integration time under γ-ray excitation at room temperature. A small deviation from linear response as a function of energy deposited in γ-ray absorption or Compton scattering processes, combined with a high light yield, results in good energy resolution equal to 4.3 % at 662 keV and 2.3 % at 2.6 MeV. Due to long lasting scintillation decay the sample properties were studied at different shaping time constants in an analogue spectroscopy chain or using different integration time gates when employing a digital analyzer. [ABSTRACT FROM AUTHOR]

With the rapid development of inverse Compton scattering gamma-ray sources, highly polarized gamma rays play a significant role in fundamental nuclear physics research based on nuclear resonance fluorescence (NRF). To meet the requirements of those applications, especially for guiding experiments and optimizing detection systems, a Monte Carlo simulation method for linearly polarized gamma-ray NRF is developed and implemented in the general-purpose toolkit Geant4. To validate the effectiveness of this method, simulations are compared with both theoretical and experimental results and are found to agree well with both. As a typical application of the linearly polarized gamma-ray NRF technique, a gamma-ray polarization measurement method is proposed in the energy region from hundreds of keV to several MeV, and its feasibility is analyzed based on the developed simulation method. Compared with the conventional Compton scattering method, the analyzing power of the NRF method is improved about 3.7-fold by using a 28 Si target, and reaches a value of more than 0.99 at a reasonable data acquisition time. [ABSTRACT FROM AUTHOR]

Radiation is used in many applications such as medicine, therapy, industry but it also has some disadvantages or hazards. Therefore, the knowledge of how radiation interacts with matter becomes very important at different photon energies. In the present study, Compton mass attenuation coefficients of different types of materials were investigated via Klein-Nishina formula in the energy range 0.284–15 MeV. Different methods were used to determine Compton mass attenuation coefficients of the materials. The results were compared with each other in terms of the methods. According to the results, Klein-Nishina electronic cross-sections and Compton mass attenuation coefficients of the studied materials were decreased with increasing γ-ray energy like the elements. In addition, the results were compared with possible results from literature as the mean result of the study. A good agreement was observed for Zn, Sn, Te, Ba, W and Bi elements (Diff. ≤ 6.25%) at 1.173 MeV photon energy. Best agreement was also observed for ZnS and CaCO 3 compounds (0.14% ≤ Diff. ≤ 22.18%) at 4 and 1.332 MeV photon energies respectively. The reported data should be useful when the gamma rays into these materials especially in Compton scattering energy region. • CMACs of important materials were determined using Klein-Nishina theory. • Different methods were used to calculate CMACs. • The methods were especially performed at Compton scattering energy region. [ABSTRACT FROM AUTHOR]

Compton scattering measurements using 59.54 keV γ-rays have been reported for sesquioxides Ga 2 O 3 and In 2 O 3. To precisely compare the experimental and theoretical momentum densities, different exchange and correlation potentials within density functional theory and its hybridisation with Hartree-Fock (PBESOL0 and HSE06) have been considered. χ2 fitting analysis depicts HSE06 as a better choice for both sesquioxides. Present band structures, density of states and UV–vis measurements unambiguously support the use of HSE06 for such oxides and resolves issues related to appropriateness of exchange and correlation potentials. Higher covalent character in Ga 2 O 3 than In 2 O 3 using Mulliken's population is well explained by equal-valence-electron-density scaled CPs. Most prominent and firstly reported features in band structures of In 2 O 3 are presence of parabolic trapping centres at Γ, H and N points with three direct band gaps of similar energy (3.37 eV), which may lead to its higher luminescence properties including potential applications in thermoluminescence dosimeters. [ABSTRACT FROM AUTHOR]

The Latin American Giant Observatory (LAGO) is a ground-based observatory studying solar or high-energy astrophysics transient events. LAGO takes advantage of its distributed network of Water Cherenkov Detectors (WCDs) in Latin America as a tool to measure the secondary particle flux reaching the ground. These secondary particles are produced during the interaction between the modulated cosmic rays flux and the atmosphere. The LAGO WCDs are sensitive to secondary charged particles, high energy photons through pair creation and Compton scattering, and even neutrons thanks to, e.g., the deuteration of protons in the water volume. The pulse shape generated by these particles depends on several factors, such as the detector geometry, the water purity, the sensor response, or the reflectivity and diffusivity of the inner coating. Due to the decentralized nature of LAGO, these properties are different for each node. Additionally, the pulse shape depends on the convolution between the response of the central photomultiplier (PMT) to individual photons and the time distribution of the Cherenkov photons reaching the PMT. Typically, a WCD gives pulses with a sharp rise time (∼ 10 ns) and a longer decay time (∼ 70 ns). In this work, the WCD data used is acquired using the original LAGO data-acquisition system that digitizes pulses at a sampling rate of 40 MHz and 10 bits resolution on time windows of 400 ns. Here, we apply unsupervised machine learning techniques to find patterns in the WCDs data and subsequently create groups, through clustering, that can be used to provide particle separation. We use data acquired from an individual WCD, showing that density-based clustering algorithms are suitable for automatic particle separation producing good candidate groups. Improved separation would help LAGO to reconstruct in situ the properties of primary cosmic rays flux. These results open the possibility to deploy machine learning-based models in our distributed detection network for onboard data analysis as an operative prototype, allowing detectors to be installed at very remote sites. [ABSTRACT FROM AUTHOR]

We introduce the concept of a morphism from the set of Butson Hadamard matrices over k th roots of unity to the set of Butson matrices over ℓ th roots of unity. Tensor products give many examples of morphisms in which k divides ℓ. More interesting are constructions where k does not divide ℓ. Examples where this occurs include Turyn's construction of real Hadamard matrices from Butson matrices over the 4th roots and the work of Compton, Craigen and de Launey on 'unreal' Butson matrices over the 6th roots. We give a unified treatment of these constructions in terms of the eigenvalues and minimal polynomials of associated Butson matrices. We produce a new family of morphisms from sets of mutually unbiased bases constructed by Gow. We also classify all morphisms from the set of n × n Butson matrices over k th roots of unity to the set of 2 n × 2 n Butson matrices over ℓ th roots of unity where ℓ < k. [ABSTRACT FROM AUTHOR]

Different kinds of nanoparticles have been widely studied for biomedical purposes, including applications like dose enhancement in radiotherapy treatments and contrast agent in radiological studies. Recent work suggests that gold nanoparticles can be used as contrast agents in K-edge imaging and X-ray Fluorescence Computed Tomography, mainly due to their high K-edge energy value and good biocompatibility. However, the gold X-ray fluorescence (XRF) signal obtained in these procedures is relatively week when compared with Compton or bremsstrahlung radiation emitted in the surrounding tissues, mainly because it is not possible to achieve large gold nanoparticles concentrations within biological tissues added to the XRF is attenuated by other tissues when leaving the patient body. This work presents a feasibility study on implementation of FLUKA, PENELOPE and MCNP6 Monte Carlo codes to model the detection of gold XRF emitted by a small volume containing different gold concentrations and located at different depths in a tissue-equivalent phantom. Results indicate that there is good agreement between PENELOPE and FLUKA for gold Kα and Kβ lines estimations when highly symmetric simulation scenario and kilovoltage X-ray beam were used, achieving differences lower than 2%; however, differences up to 6 times were observed between FLUKA and MCNP6 under the same conditions. In addition, remarkable differences were obtained when megavoltage X-ray beam was used, being up to 11 times between PENELOPE and FLUKA and up to 4 times between FLUKA and MCNP6 for gold Kα and Kβ lines estimations. In this regard, a suitable normalization method was proposed and implemented to perform cross-comparisons of XRF estimations obtained from the Monte Carlo codes. By means of the proposed method, FLUKA, PENELOPE and MCNP6 can be successfully implemented to assess which configuration (gold concentration and target volume depth) leads to a better detection of gold XRF, despite differences in XRF estimation between the codes. • FLUKA, PENELOPE and MCNP6 codes were used for gold XRF estimation. • Scenarios representing small tumor volumes marked with gold were studied. • X-ray beams for Radiology and Radiotherapy energy ranges were investigated. • FLUKA, PENELOPE and MCNP6 estimations of gold XRF do not agree with each other. • A normalization method was proposed for cross-comparison of Monte Carlo estimations. [ABSTRACT FROM AUTHOR]

Many PET scanner detectors use LSO or LYSO as their scintillation crystals. Since natural lutetium contains 2.6% radioactive 176Lu, which decays β− followed by the emission of three gamma rays or internal conversion electrons, its intrinsic radioactivity needs to be considered. This work compares the energy spectrum obtained with Monte Carlo simulations of ionizing radiation transport using the 176Lu ion source defined in GATE v8.1, for different LYSO crystal sizes with experimental and analytical data. In addition, we performed a set of simulations of 88, 202 and 307 keV monoenergetic photons, the gamma rays of the isomeric transitions of the 176Hf excited states, to quantify the Compton scattered photons interacting in or escaping the crystal. Even though the optical transport effects were not simulated, the results show a very good agreement with analytical and experimental data and support the accuracy for modeling the intrinsic radioactivity of LSO/LYSO crystals with GATE. [ABSTRACT FROM AUTHOR]

• Spin, orbital, and element specific magnetic hysteresis curve of Tb 12 Co 88 film was measured by using magnetic Compton scattering. • The orbital and spin moments are opposite directions. Similarly, the Tb and Co moments have opposite directions. • The temperature dependence of magnetic Compton profile shows the temperature should control the net magnetic moment because those fluctuations are suppressed at lower temperature. Tb-Co perpendicular magnetization films are mother materials for perpendicular magnetic recording media. Since the magnetic recording technique is based on magnetic switching of a material, investigating a magnetic the response of the material to a magnetic field is important. The magnetic response of the entire system is the net of each microscopic response of the spin magnetic moment and orbital magnetic moment of the elements. Herein we study the magnetization processes of the spin, orbital, and the element-specific magnetic moments by measuring the magnetic field dependence of the magnetic Compton profile of a Tb 12 Co 88 film. The spin and orbital magnetic moments have opposite orientations. Similarly, Tb and Co magnetic moments have opposite directions. When the total magnetic moment reverses, the orientation of spin and orbital magnetization as well as Tb and Co reverse. Decreasing the temperature, the fluctuation of the magnetic moment of Tb in the perpendicular direction decreases. So the cancelation between the Tb and Co moments reduces total magnetic moment. [ABSTRACT FROM AUTHOR]

The role of excess Ni in Ni 2+x Mn 1−x Sn (x = 0.05, 0.1) Heusler alloys has been reported using temperature dependent magnetic Compton spectroscopy. The experimental Compton profiles from magnetic electrons have been analyzed to quantify the contribution of Mn 3d electrons, Ni sites and sp-electrons in building-up the total spin moments. The experimentally deduced spin momentum densities, total and element-specific spin moments are examined using theoretical investigations within the spin polarized relativistic Korringa-Kohn-Rostoker method. The build-up of spin moments has been explored in terms of total and projected density of states. Site-dependent Ni magnetic moment is also discussed. Heisenberg exchange coupling parameters are also computed to study the change in Ruderman-Kittel-Kasuya-Yosida type exchange interaction on increasing Ni concentration in the Ni-Mn-Sn system. [ABSTRACT FROM AUTHOR]

A Compton suppression system (CSS), which plays an important role in γ-ray diagnostics, has been developed to acquire the γ-ray emission spectra generated in the HL-2A tokamak plasma. It takes advantages of the anti-coincidence method of two branches of γ-ray signals, one is from a high purity germanium (HPGe) detector, and the other from several bismuth germinate (BGO) detectors, to output the suppressed spectra. In the present paper, a Geant4 simulation, together with its subsequent data processing which took accidental coincidences into account, was performed to study the detection efficiencies of the CSS for γ-rays with energies between 0.2 and 13 MeV. Calculation results showed that there were small detection efficiency differences between the unsuppressed and suppressed spectra when HPGe count rates were smaller than 105 cps, and the area ratios of additional peaks to their corresponding full energy peaks were not associated with HPGe count rates. Based on the calculation results, the empirical formulas of detection efficiencies of the CSS were put forward. Finally, after the experimental verification of the empirical formulas, a suppressed γ-ray spectrum acquired by the CSS during 2018 HL-2A experiment campaign was unfolded using the detection efficiencies. This work makes it possible for the analyses of the γ-ray emission spectra generated from the HL-2A tokamak. • The detection efficiencies of the Compton suppression system at the HL-2A tokamak have been calculated using Geant4. • The detection efficiency calculations with Geant4 have taken accidental coincidences into account. • The empirical formulas of detection efficiencies of the Compton suppression system have been put forward. [ABSTRACT FROM AUTHOR]

Considered an important hydrological and geomorphological agent, fire can cause physical, chemical and biological changes in the soil. Besides wildfire, the study of fire effects is also related to traditional agriculture. This study presents the characterization and analysis of soil samples submitted to burn simulation with the objective to build a temperature prediction model in order to determine the maximum temperature reached by real soil burn samples. For this purpose, surface soil samples (0–2.5 cm) classified as Haplic Cambisol were collected from a native forest area close to the studied field. The temperature of the simulation samples ranged from 50 to 750 °C. Moreover, a real burn set of samples were measured for temperature prediction using the proposed model. The characterization and quantification of the chemical elements present in the soil were done by Energy Dispersive X-ray Fluorescence (EDXRF) measurements. Plots with Fe concentration and with the Rayleigh and Compton scattering data versus temperature were constructed. The Fe/Rh and Fe/RhC ratios resulted in relative deviations ranging from 14% to 22% using univariate analysis. Multivariate analysis was also applied through partial least squares regression (PLSR) method in four different spectrum regions. The best result was obtained for the model using the spectrum scattering region with r2 = 0.90 and relative deviation ranging from 8% to 25% for the predicted temperature. The use of local multivariate PLSR models improved the results when compared to the univariate regression results. • EDXRF data from soil measured after a prescribed fire was applied for maximum temperature prediction. • Modeling with Fe concentration and X-ray scattering conducted to reliable results. • Maximum temperature in prescribed real burn were estimated post-fire. [ABSTRACT FROM AUTHOR]

The total mass attenuation coefficients (μ/ρ) of oxide dispersion strengthened (ODS) steels have been investigated by using Geant4 simulation toolkit at energies ranging from 0.01 MeV to 100 GeV. Moreover, Geant4 is applied to further study on the partial mass attenuation coefficient of three main interactions including photoelectric effect, compton scattering, gamma conversion between incident photon and ODS steels. Then molecular cross-section (σ m) and mean free path (λ) are obtained by the total mass attenuation coefficients. The results obtained by Geant4 are compared with those obtained by experiments and XCOM program and these results agree with each other very well. It is concluded that Geant4 Monte Carlo toolkit is a powerful tool in studying interaction of photons in material and energies. The shielding parameters of ODS steels presented in this paper can be very useful for the potential nuclear application and other industries in future. • The μ/ρ of ODS steels have been studied by Geant4 at energies from 0.01 MeV to 100 GeV. • The results gained by Geant4 agree with those gained by experiments and XCOM well. • The partial μ/ρ of three main interactions between photon and ODS steels are studied. [ABSTRACT FROM AUTHOR]

We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/ c polarised μ + and μ − beams of the CERN SPS impinging on a liquid hydrogen target. We determine the dependence of the average of the measured μ + and μ − cross sections for deeply virtual Compton scattering on the squared four-momentum transfer t from the initial to the final proton. The slope B of the t -dependence is fitted with a single exponential function, which yields B = (4.3 ± 0.6 stat | sys − 0.3 + 0.1) (GeV / c) − 2. This result can be converted into a transverse extension of partons in the proton, 〈 r ⊥ 2 〉 = (0.58 ± 0.04 stat | sys − 0.02 + 0.01 ± 0.04 model) fm. For this measurement, the average virtuality of the photon mediating the interaction is 〈 Q 2 〉 = 1.8 (GeV/ c) 2 and the average value of the Bjorken variable is 〈 x Bj 〉 = 0.056. [ABSTRACT FROM AUTHOR]

Due to the discrepancies of gamma-induced Displacement per Atom (DPA) cross sections among different calculations, the present work identifies the sources of the discrepancies and recommends the computation of displacement cross sections induced by photons, including the stopping power for electrons and positrons, the differential scattering cross sections, and the gamma-matter interactions. The production of electrons and positrons and the corresponding gamma-induced damage cross sections computed with the above methods are validated against Monte Carlo simulations. The damage cross section for Photoelectric Effect (PE) is negligible for incident photon energy higher than 2 MeV. Above 2 MeV, the percentage of atomic displacement for Compton Scattering (CS) decreases with incident energy, while that for Pair Production (PP) increases and becomes more important than CS above 10 MeV. In the PP, it is recommended to differently treat positrons and electrons for damage calculations because positrons produce 68–77% of DPA induced by electrons. 9.8 × 10−10 DPA/year gamma-induced displacement is obtained in the heavy reflector of PERLE experiment using the recommended damage cross sections. Neglecting the influence of moderator on photon flux in reflector, 8.1 × 10−4 DPA/year gamma-induced displacement damage is found in the reflector of Evolutionary Pressurized Reactor (EPR). [ABSTRACT FROM AUTHOR]

The trace-metal composition of sediments provides important information on (past) environmental conditions, such as bottom water oxygenation, marine productivity, sediment provenance, and pollution. Whereas major and minor elements are often routinely analyzed using X-Ray Fluorescence (XRF) core scanning, analysis of trace metals with the same method is not yet established as a routine procedure. Here, we used a recently developed state-of-the-art XRF detector with a core scanner (Avaatech) to examine the optimal settings for analyzing a suite of trace metals (V, Cr, Ni, Cu, Zn, Mo, and U). Settings were optimized for fast analyses of sediment cores by extensive testing of primary energy settings, filters, and exposure times on two eastern Mediterranean Sea sapropel layers that archive episodes of past sea-floor anoxia. We reveal the following most advantageous (i.e., optimized for analytical accuracy and time efficiency) settings: (1) V, Cr, Ni at 20 kV with aluminum primary beam filter, (2) Cu, Zn, and U at 30 kV with 'thick' (125 μm) palladium primary beam filter, and (3) Mo at 50 kV with copper primary beam filter. For these trace elements, generally, ≥30 s of measurement are required for obtaining reliable data. Synthetic mixtures show that matrix effects, which are inherent to XRF analyses, are of particular importance for V. A correction for these matrix effects on V (e.g., using Compton scattering) may be necessary for samples with a large variability in carbonate content. XRF core-scanning measurements on synthetically, laminated sediments show that trace metals with contrasting atomic weights and related XRF penetration depths (V and Mo) can be determined at sub-mm resolution. We show that intensity results from the new XRF detector can be converted into concentrations using multivariate log-ratio calibration, allowing a fast quantitative prediction of sedimentary trace metal content using XRF core scanning. [ABSTRACT FROM AUTHOR]

Abstract The influence from uncertainty on light output calibration was studied experimentally for neutron energy spectra up to 300 MeV obtained by an unfolding method using a liquid organic scintillator. The neutrons were generated from the interactions of 100 and 290 MeV/u 28Si ion beams on thick silicon targets at a 75° direction with respect to the beam axis. The light output calibration determined by using Compton edges of γ-rays from 60Co and 241Am-Be sources was used for the unfolding method. The uncertainty of the calibration points at the Compton edges was estimated to be within 3%. Two calibration lines which connected the 3% larger light output point of the Compton edge of the γ-ray from 60Co and that the 3% lower light output point of that from 241Am-Be and vice versa were examined for influence on variation of calibration line. The unfolded spectra using the two calibration lines were compared with one using the calibration line connecting light output points of Compton edges from both γ-ray sources. The comparison indicates the uncertainty of calibration line influences the neutron light output spectrum within order of several %. The all unfolded spectra generally reproduced one by the time-of-flight (TOF) method in the same experiment. The difference between TOF and unfolded spectra were 17 and 8% for 100 and 290 MeV/u data, at maximum. [ABSTRACT FROM AUTHOR]