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In this work we study the high-energy Higgs boson phenomenology associated to the non-metricity scale ΛQ at the LHC. Non-metricity is present in more generic non-Riemannian geometries describing gravity beyond General Relativity and exhibits nice features in astronomy and cosmology, and it can be analysed perturbatively. Using effective field theory tools, we calculate the new physics contributions to the one-loop H → γγ and gg → H processes and, together with previous bounds from Compton scattering, we obtain relevant constraints and correlations in the model's parameter space. This can help us take a step further, and no longer associate gravitational effects uniquely to astronomical phenomena, and to start analysing these effects by means of high energy experiments. In turn, this could also help us get a better grasp at quantum phenomena associated to gravity. [ABSTRACT FROM AUTHOR]

Much of the structure of cosmological correlators is controlled by their singularities, which in turn are fixed in terms of flat-space scattering amplitudes. An important challenge is to interpolate between the singular limits to determine the full correlators at arbitrary kinematics. This is particularly relevant because the singularities of correlators are not directly observable, but can only be accessed by analytic continuation. In this paper, we study rational correlators — including those of gauge fields, gravitons, and the inflaton — whose only singularities at tree level are poles and whose behavior away from these poles is strongly constrained by unitarity and locality. We describe how unitarity translates into a set of cutting rules that consistent correlators must satisfy, and explain how this can be used to bootstrap correlators given information about their singularities. We also derive recursion relations that allow the iterative construction of more complicated correlators from simpler building blocks. In flat space, all energy singularities are simple poles, so that the combination of unitarity constraints and recursion relations provides an efficient way to bootstrap the full correlators. In many cases, these flat-space correlators can then be transformed into their more complex de Sitter counterparts. As an example of this procedure, we derive the correlator associated to graviton Compton scattering in de Sitter space, though the methods are much more widely applicable. [ABSTRACT FROM AUTHOR]

We report on numerical calculations in which a multi-petawatt γ-ray beam is generated using a novel configuration based on fully structured light irradiating an overdense plasma waveguide. We analyze how the relativistic laser pulse efficiently confines and accelerates plasma electrons to GeV-scale energies and drives a quasi-static field that induces magneto-bremsstrahlung radiation. Multiphoton Compton scattering of electrons in the intense part of the laser also occurs although the radiated energy-density is comparatively lower. The emitted γ-rays carry orbital angular momentum, are highly collimated, and account for upwards of 15% of the incident field energy in one particular case. A comparison of the laser-to-particle angular momentum and energy transfer efficiencies is made between the cases of irradiation by a circularly polarized Laguerre–Gauss mode and one type of full Poincaré beam, and it is found that the latter yields an order-of-magnitude enhancement. The essential characteristics of the interaction are validated with three-dimensional particle-in-cell simulations that include quantum electrodynamical effects. [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present work, we examined the impact of Fe2O3 on the mechanical and photon shielding characteristics of lead-phosphoaluminate glasses. Due to water corrosion, the use of lead-phosphosilicate glasses may be limited.The addition of Fe2O3 significantly improves its water resistance. The radiation and mechanical of 20PbO – 45P2O5 − 15 Al2O3– ( 20 - x ) Na2O- x Fe2O3glass system doped with x Fe2O3reflect the originality of this article. The molar volume of these samples is declining whereas the density is an increment. Ultrasonic velocity and elastic modulus were found to be enhanced. The shielding parameters were established using the Phy-X / PSD. The mace attenuation coefficient is the highest in the sample with the maximum Fe2O3 content. The (Zeff) and (Neff) values decreased and then increased slowly at lower energy. Because of the Compton scattering interaction, the (Zeq)-value decreases as the energy and Fe2O3content increase. Small deviations from the glass samples are observed at higher energy levels to decrease the value (ΣR). Finally, the increment of Fe2O3 in prepared glasses increases the γ-radiation & neutronattenuation rate. [ABSTRACT FROM AUTHOR]

The positions of the figurative points on the triangular Gibbs phase diagram for the process of high-temperature synthesis of solid solutions LiyNi2−yO2 were determined for the first time using a combination of x-ray diffraction (XRD) and Compton scattering methods. The trajectory of the figurative point is built according to experimental data for temperatures of 650 and 750 °C. The ratios of the phases in equilibrium are found. It was established that, when the structure goes from rock salt to layered structures, the composition of the reagent mixture changes nonmonotonically: with an increase in the degree of ordering of the solid solution lattice, the sum molecular weight of the solid reagents increases. It has been shown experimentally that the combined use of XRD and Compton scattering makes it possible to carry out physicochemical analysis of the process and predict the final product. [ABSTRACT FROM AUTHOR]

One of the major problems for the determination of the distance between two metal plates based on Compton scattering is complicated calculations. This method needs to consider many parameters and relations between them. The accuracy of the method strongly depends on the thicknesses and materials of the plates. As a result, the device must be calibrated for all possible different plate thicknesses so that by knowing some input conditions and using complex interpolation methods, the count recorded in the detector can be converted to a distance between two plates. In this condition, employing artificial neural networks can be a powerful alternative for the difficult calibration and analytical interpolation procedure. In this paper, an artificial neural network consisting of a three-layer perceptron was developed and trained for identifying the distance between steel and aluminum plates with thicknesses ranging from 1 to 10 mm. In the proposed method, a Cs-137 gamma-ray source with an activity of 35 μCi was used. [ABSTRACT FROM AUTHOR]

Dual-energy computed tomography (DECT) acquires two x-ray projection datasets with different x-ray energy spectra, performs material-specific image reconstruction based on the energy-dependent non-linear integral model, and provides more accurate quantification of attenuation coefficients than single energy spectrum CT. In the diagnostic energy range, x-ray energy-dependent attenuation is mainly caused by photoelectric absorption and Compton scattering. Theoretically, these two physical components of the x-ray attenuation mechanism can be determined from two projection datasets with distinct energy spectra. Practically, the solution of the non-linear integral equation is complicated due to spectral uncertainty, detector sensitivity, and data noise. Conventional multivariable optimization methods are prone to local minima. In this paper, we develop a new method for DECT image reconstruction in the projection domain. This method combines an analytic solution of a polynomial equation and a univariate optimization to solve the polychromatic non-linear integral equation. The polynomial equation of an odd order has a unique real solution with sufficient accuracy for image reconstruction, and the univariate optimization can achieve the global optimal solution, allowing accurate and stable projection decomposition for DECT. Numerical and physical phantom experiments are performed to demonstrate the effectiveness of the method in comparison with the state-of-the-art projection decomposition methods. As a result, the univariate optimization method yields a quality improvement of 15% for image reconstruction and substantial reduction of the computational time, as compared to the multivariable optimization methods. [ABSTRACT FROM AUTHOR]

The exclusive photoproduction off nucleon of a large invariant mass lepton pair in the backward region specified by the small Mandelstam variable - u is discussed in the framework of collinear QCD factorization. The amplitude is factorized in terms of photon-to-nucleon Transition Distribution Amplitudes (TDAs). These new non-perturbative objects, complementary to the "photon-inside-the-nucleon PDF", lead to a tomographic picture of the nucleon's photon content after Fourier transforming to the impact parameter space. This allows to address the question of where in the transverse plane the nucleon emits a photon. A simplistic model-estimate of photon-to-nucleon TDAs is used to estimate the magnitude of the corresponding cross sections. The background due to the electromagnetic Bethe–Heitler process is shown to be negligible in the kinematical regime of interest. [ABSTRACT FROM AUTHOR]

Copyright of Journal of University of Anbar for Pure Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We present a temporal and spectral study of the blazar PKS 0208−512, using recent flaring activity from 2019 November to 2020 May, as detected by the Fermi Large Area Telescope. The contemporaneous X-ray and optical/ultraviolet observations from the Swift X-Ray Telescope and UltraViolet and Optical Telescope are also used. During the activity state, the 2-d binned γ-ray light curve shows multiple peaks indicating subflares. To understand the possible physical mechanisms behind flux enhancement, we divided the activity state of the source into several flux states and carried out detailed temporal and spectral studies. The timing analysis of light curves suggests that peaks of subflares have rise and decay times of the order of days, with the flux doubling time ∼ 2 d. The 2-d binned γ-ray light curve shows double-lognormal flux distribution. The broad-band spectral energy distribution (SED) for three selected flux states can be well fitted under synchrotron, synchrotron self-Compton and external Compton emission mechanisms. We obtained the physical parameters of the jet by SED modelling and their confidence intervals through χ2-statistics. Our SED modelling results suggest that during the quiescent state, the γ-ray spectrum can be explained by considering the external Compton scattering of infrared photons from the dusty torus. However, γ-ray spectra corresponding to flares demand additional target photons from the broad-line region (BLR) along with infrared. These suggest that, during flares, the emission region is close to the edge of the BLR, while for the quiescent state, the emission region is away from the BLR. The best-fitting results suggest that a marginal increase in the magnetic field during the flaring episode can result in flux enhancement. This is possibly associated with the efficiency of particle acceleration during flaring states compared with the quiescent state. [ABSTRACT FROM AUTHOR]

Relativistic Fe K emission lines from accretion discs and from disc winds encode key information about black holes, and their accretion and feedback mechanisms. We show that these two processes can in principle produce indistinguishable line profiles, such that they cannot be disentangled spectrally. We argue that it is likely that in many cases both processes contribute to the net line profile, and their relative contributions cannot be constrained purely by Fe K spectroscopy. In almost all studies of Fe K emission to date, a single process (either disc reflection or wind Compton scattering) is assumed to dominate the total line profile. We demonstrate that fitting a single process emission model (pure reflection or pure wind) to a hybrid line profile results in large systematic biases in the estimates of key parameters, such as mass outflow rate and spin. We discuss various strategies to mitigate this effect, such as including high-energy data covering the Compton hump, and the implications for future X-ray missions. [ABSTRACT FROM AUTHOR]

The performance of Li+ ion batteries (LIBs) is hindered by steep Li+ ion concentration gradients in the electrodes. Although thick electrodes (≥300 µm) have the potential for reducing the proportion of inactive components inside LIBs and increasing battery energy density, the Li+ ion concentration gradient problem is exacerbated. Most understanding of Li+ ion diffusion in the electrodes is based on computational modeling because of the low atomic number (Z) of Li. There are few experimental methods to visualize Li+ ion concentration distribution of the electrode within a battery of typical configurations, for example, coin cells with stainless steel casing. Here, for the first time, an interrupted in situ correlative imaging technique is developed, combining novel, full‐field X‐ray Compton scattering imaging with X‐ray computed tomography that allows 3D pixel‐by‐pixel mapping of both Li+ stoichiometry and electrode microstructure of a LiNi0.8Mn0.1Co0.1O2 cathode to correlate the chemical and physical properties of the electrode inside a working coin cell battery. An electrode microstructure containing vertically oriented pore arrays and a density gradient is fabricated. It is shown how the designed electrode microstructure improves Li+ ion diffusivity, homogenizes Li+ ion concentration through the ultra‐thick electrode (1 mm), and improves utilization of electrode active materials. [ABSTRACT FROM AUTHOR]

In the second part of this paper we derive the final formulas for calculating the azimuthal average of the frequency redistribution functions (RF), for direction, and polarization for Compton scattering in plane stationary media. The azimuthal averages of the most singular term of the RF are expressed in terms of elliptical integrals of the first kind. Examples of averaging are given. [ABSTRACT FROM AUTHOR]

Changes in the internal state of a high-power capacitor during progressive charge–discharge cycling were measured non-destructively using high-energy synchrotron X-ray Compton scattering. The stacked structure of a laminated capacitor was clearly indicated by a Compton scattered X-ray intensity analysis and a line shape (S-parameter) analysis of a Compton scattered X-ray energy spectrum. Moreover, apparent differences in the progress of charge and discharge cycles were observed in the correlation between Compton scattered X-ray intensities and S-parameters obtained from the center and edge positions within the in-plane of the electrode. This difference in the correlation was obtained from the shifting of the stacked structure at the edge position, induced by the drift of the electrolyte material within the capacitor cells. [ABSTRACT FROM AUTHOR]

This research has studied in the effectiveness of steel slag and stone dust for the radiation shielding of concrete blocks. Compton scattering techniques were used to derive experimental value at energy of 662 keV. Phy-x/PSD software was used to derive theoretical values in an energy range of 15-1.5x104 keV. Compression testing was used to analyze the physical properties of concrete blocks for 28 days' age. The results showed that SCB2, SCB3, and SCB4 had better radiation shielding ability than SCB1 in energy range of 10-100 keV. At an energy of more than 100 keV, the radiation shielding efficiency of SCBs was very similar. The results indicated that steel slag can improve the radiation shielding efficiency of the concrete blocks in an energy range of 10-100 keV. In addition, the results of strength and tensile strength for SCBs decreased with increasing steel slag volume. Whereas surface of samples had smoother due to stone dust can bond better with concrete than steel slag. However, SCBs samples had a quality in engineering standards that samples can be used in the construction. [ABSTRACT FROM AUTHOR]

We demonstrate that in a nonuniform plasma, the parametric decay instabilities of kinetic Alfvén waves could be quantitatively and qualitatively different from that in a uniform plasma. Specifically, the decay rate via ion Compton scattering is found to be enhanced, typically, by an order of magnitude. Furthermore, the parity of the decay kinetic Alfvén wave spectrum is broken, leading to finite net wave momentum transfer and, consequently, significant convective plasma transport with implications for confinement improvement. That localized absolutely unstable eigenmodes may be excited by a mode-converted pump wave is also presented. [ABSTRACT FROM AUTHOR]

The interaction between an ultrastrong laser and a cone-like target is an efficient approach to generate high-power radiations such as attosecond pulses and terahertz waves. The objective is to study the γ -ray generation under this configuration with the help of 2D particle-in-cell simulations. It is deciphered that electrons experience three stages, including injection, acceleration and scattering, to emit high-energy photons via nonlinear Compton scattering (NCS). These spatial-separated attosecond γ -ray pulses own high peak brilliance (>1022 photons/(s·mm2·mrad2·0.1%BW)) and high energy (6 MeV) under the case of normalized laser intensity a 0 = 30 (I = 2 × 10 21   W / cm 2) . In addition, the cone target turns out to be an order of magnitude more efficient in energy transfer compared to a planar one. [ABSTRACT FROM AUTHOR]

We present the results of our study of the transient X-ray pulsar GRO J2058+42 in a wide energy range in a state with a luminosity erg s . We have found that the pulse profile of the source, along with the pulse fraction, changed significantly in comparison with the previous NuSTAR observations performed when the pulsar was brighter approximately by a factor of 10. The position of the cyclotron line at keV in a narrow phase interval is consistent with the observations in the high state. Spectral analysis has shown that at high luminosities erg s the spectrum has a shape typical of accreting pulsars, whereas a two-component model should be used to describe the spectrum when the luminosity drops approximately by an order of magnitude, to erg s . This behavior fits into the model in which the low-energy part of the spectrum is formed in a hot spot, while the high-energy one is formed as a result of resonant Compton scattering by the infalling matter in the accretion channel above the neutron star surface. [ABSTRACT FROM AUTHOR]

Obtaining directional information is required in many applications such as nuclear homeland security, contamination mapping after a nuclear incident and radiological events, or during the decontamination work. However, many directional radiation detectors are based on directional shielding, made of lead or tungsten collimators, introducing two main drawbacks. The first is the size and weight, making those detectors too heavy and irrelevant for utilization in handheld devices, drone mapping, or space applications. The second drawback is the limited field of view (FOV), which requires multiple detectors to cover the whole required FOV or machinery to rotate the detector’s narrow FOV detector. We propose a novel $4\pi $ directional detector based on a segmented hollow cubic detector, which uses the Compton effect interactions with no heavy collimators. The symmetrical cubical design provides both higher efficiency and $4\pi $ detection ability. Instead of the traditional two types of detectors (scatterer and absorber) structure, we use the same type of detector, based on Gd3Al2Ga3O12 (GAGG) (Ce) scintillator coupled to silicon photomultiplier. An additional advantage of the proposed detector is obtained by locating the photon sensors inside the detector, behind the scintillators, which improves the radiation hardness required for space applications. Furthermore, such an arrangement flattens the temperature variation across the detector, providing better gain stability. The main advantage of the proposed detector is an efficient $4\pi $ radiation detection for high-energy gamma rays without the use of heavy collimators. [ABSTRACT FROM AUTHOR]

The new scheme of the energy measurement of the extremely high energy electron beam with the inverse Compton scattering between electrons and microwave photons requires the precise calculation of the interaction cross section of electrons and microwave photons in a resonant cavity. In the local space of the cavity, the electromagnetic field is expressed by Bessel functions. Although Bessel functions can form a complete set of orthogonal basis, it is difficult to quantify them directly as fundamental wave functions. Fortunately, with the Fourier expansion of Bessel functions, the local electromagnetic field can be considered as the superposition of a series of plane waves. Therefore, with corresponding corrections of the cross section formula of the classical Compton scattering, the cross section of the linear or nonlinear microwave Compton scattering in the local space can be described accurately. As an important application of our results in astrophysics, corresponding ground verification devices can be designed to perform experimental verifications on the prediction of the Sunyaev–Zeldovich (SZ) effect of the cosmic microwave background radiation. Our results could also provide a new way to generate wave sources with strong practical value, such as the terahertz waves, the ultra-violet (EUV) waves, or the mid-infrared beams. [ABSTRACT FROM AUTHOR]

A new approach to determine the elements carbon, hydrogen, nitrogen and oxygen (CHNO) in polymers by wavelength-dispersive X-ray fluorescence analysis (WDXRF) in combination with partial least squares (PLS) regression was explored. The quantification of CHNO was achieved by using the Rayleigh and Compton scattering spectra of an Rh X-ray tube from 84 different polymers. Concealed differences of the corresponding scattering spectra could be utilized to quantify CHNO in a multivariate manner. It was shown that the developed model was capable of determining these commonly non-measurable matrix elements in polymers using WDXRF. Furthermore, the influence of spectral resolution, which is given by the collimator and the crystal, on the prediction of CHNO was explored in this study. It was found that minimal spectral resolution led to the most accurate CHNO predictions. Information about matrix composition could be used to improve so-called semi-quantitative XRF methods based on fundamental parameters (FP) for the analysis of plastics, soil or other samples with high organic content. [ABSTRACT FROM AUTHOR]

Most thickness measurement techniques using X-ray radiation are unsuitable in field processes involving fast-moving organic films. Herein, we propose a Compton scattering X-ray radiation method, which probes the light elements in organic materials, and a new simple, non-destructive, and non-contact calibration-free real-time film thickness measurement technique by setting up a bench-top X-ray thickness measurement system simulating a field process dealing with thin flexible organic films. The use of X-ray fluorescence and Compton scattering X-ray radiation reflectance signals from films in close contact with a roller produced accurate thickness measurements. In a high-thickness range, the contribution of X-ray fluorescence is negligible, whereas that of Compton scattering is negligible in a low-thickness range. X-ray fluorescence and Compton scattering show good correlations with the organic film thickness (R2 = 0.997 and 0.999 for X-ray fluorescence and Compton scattering, respectively, in the thickness range 0–0.5 mm). Although the sensitivity of X-ray fluorescence is approximately 4.6 times higher than that of Compton scattering, Compton scattering signals are useful for thick films (e.g., thicker than ca. 1–5 mm under our present experiment conditions). Thus, successful calibration-free thickness monitoring is possible for fast-moving films, as demonstrated in our experiments.

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]

High energy X-rays (115.56 keV) were used to measure the HIPed interface of F82H steel. The X-ray energy spectra of the samples were analyzed focusing on W and Ta fluorescence X-rays, Compton scattering and elastic scattering X-rays. The results suggest the presence of SiOx and TaOx at the HIP interface and the accumulation of W near the HIP interface. These results indicate that high-energy X-ray spectrum analysis can be a non-destructive testing technique (NDT) to evaluate precipitates at the HIP interface of F82H steel.

Background: Magnetoelectric multipoles, which break both space-inversion and time-reversal symmetries, play an important role in the magnetoelectric response of a material. Motivated by uncovering the underlying fundamental physics of the magnetoelectric multipoles and the possible technological applications of magnetoelectric materials, understanding as well as detecting such magnetoelectric multipoles has become an active area of research in condensed matter physics. Here we employ the well-established Compton scattering effect as a possible probe for the magnetoelectric toroidal moments in LiNiPO4. Methods: We employ combined theoretical and experimental techniques to compute as well as detect the antisymmetric Compton profile in LiNiPO4. For the theoretical investigation we use density functional theory to compute the anti-symmetric part of the Compton profile for the magnetic and structural ground state of LiNiPO4. For the experimental verification, we measure the Compton signals for a single magnetoelectric domain sample of LiNiPO4, and then again for the same sample with its magnetoelectric domain reversed. We then take the difference between these two measured signals to extract the antisymmetric Compton profile in LiNiPO4. Results: Our theoretical calculations indicate an antisymmetric Compton profile in the direction of the ty toroidal moment in momentum space, with the computed antisymmetric profile around four orders of magnitude smaller than the total profile. The difference signal that we measure is consistent with the computed profile, but of the same order of magnitude as the statistical errors and systematic uncertainties of the experiment. Conclusions: While the weak difference signal in the measurements prevents an unambiguous determination of the antisymmetric Compton profile in LiNiPO4, our results motivate further theoretical work to understand the factors that influence the size of the antisymmetric Compton profile, and to identify materials exhibiting larger effects.

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]

In this paper, we present the generalities of the Compton interaction process; we analyse the different paradigms of Inverse Compton Sources, implemented or in commissioning phase at various facilities, or proposed as future projects. We present an overview of the state of the art, with a discussion of the most demanding challenges.

We analyzed the unexposed to the sky (outFOV) region of the MOS2 detector on board XMM-Newton covering 15 yr of data amounting to 255 Ms. We show convincing evidence that the origin of the unfocused background in XMM-Newton is due to energetic protons, electrons, and hard X-ray photons. Galactic cosmic rays are the main contributors as shown by the tight correlation (2.6% of total scatter) with the 1 GeV proton data of the SOHO EPHIN detector. Tight correlations are found with a proxy of the Chandra background rate, revealing the common source of background for detectors in similar orbits, and with the data of the EPIC Radiation Monitor, only when excluding Solar energetic particle events. The entrance to the outer electron belts is associated with a sudden increase in the outFOV MOS2 rate and a spectral change. These facts support the fact that MeV electrons can generate an unfocused background signal. The correlation between MOS2 outFOV data and the SOHO EPHIN data reveals a term constant in time and isotropic, similar to the one found in the study of the pn data. The most plausible origin of this component is hard unfocused X-ray photons of the cosmic X-ray background Compton scattering in the detector as supported by the strength of the signal in the two detectors with different thicknesses. Based on this physical understanding, a particle radiation monitor on board the Advanced Telescope for High Energy Astrophysics has been proposed and it is currently under study. It will be able to track different species with the necessary accuracy and precision to guarantee the challenging requirement of 2% reproducibility of the background. [ABSTRACT FROM AUTHOR]

Purpose: Compared to energy integration, photon‐counting x‐ray detection facilitates the spectral channelization (energy binning) in spectral CT and thus offers the opportunity to implement data acquisition via sophisticated schemes, for example, gapping or interleaving in spectral channels. In this article, we report our investigation of the performance of material decomposition based spectral imaging in photon‐counting CT implemented in such data acquisition schemes, and their comparison with the benchmark scheme and other schemes without spectral gapping or interleaving. Materials and methods: Using a deliberately designed anthropomorphic head phantom that mimics the intracranial soft tissues and bony structures, a simulation study is carried out with the focus on two‐material decomposition based spectral imaging in photon‐counting computed tomography (CT), under both ideal and realistic detector spectral responses. The projection data are acquired in four spectral channels, and then are sorted to implement the schemes of gapping ((ch1, ch3); (ch2, ch4); (ch1, ch4)) and interleaving ((ch1, ch3) + (ch2, ch4); (ch1, ch4) + (ch2, ch3); ((ch1 + ch3), (ch2 + ch4)); ((ch1 + ch4), (ch2 + ch3))) in spectral channels, in addition to the benchmark scheme ((ch1 + ch2), (ch3 + ch4)) and other conventional schemes (ch1, ch2), (ch2, ch3) and (ch3, ch4), where "ch" denotes channel, "+" denote addition, and (·,·) the operation of material decomposition and image reconstruction. Using the contrast‐to‐noise ratio between targeted regions of interest as the figure of merit, we study the performance of spectral imaging (material specific and virtual monochromatic) associated with these spectral channelization schemes. Results: Under ideal detector spectral response, the scheme (ch1, ch4) outperforms the benchmark scheme ((ch1 + ch2), (ch3 + ch4)) and others in gapped and/or interleaved spectral channelization in material specific imaging, while the interleaved scheme (ch1, ch4) + (ch2, ch3) performs the best in virtual monochromatic imaging. Notably, only about half x‐ray dose is utilized in the scheme (ch1, ch4) for image formation. Under realistic detector spectral response, the difference in imaging performance over all spectral channelization schemes diminishes, along with degradation in each scheme's individual performance. The results suggest that (i) different strategy in spectral channelization may have to be exercised in material specific imaging and virtual monochromatic imaging, respectively, and (ii) the spectral distortion in realistic detector's response due to charge‐sharing, Compton scattering, and fluorescent escaping should be mitigated as much as possible. Conclusion: The spectral channelization schemes and associated imaging performance reported herein are novel and thus informative to the community, which may further the understanding of physical fundamentals and design principles for material decomposition based spectral imaging in photon‐counting CT and other x‐ray related imaging modalities. [ABSTRACT FROM AUTHOR]

The Gamma Factory (GF) is an ambitious proposal, currently explored within the CERN Physics Beyond Colliders program, for a source of photons with energies up to ≈400 MeV and photon fluxes (up to ≈1017 photons s−1) exceeding those of the currently available gamma sources by orders of magnitude. The high‐energy (secondary) photons are produced via resonant scattering of the primary laser photons by highly relativistic partially‐stripped ions circulating in the accelerator. The secondary photons are emitted in a narrow cone and the energy of the beam can be monochromatized, down to 10−3–10−6 level, via collimation, at the expense of the photon flux. This paper surveys the new opportunities that may be afforded by the GF in nuclear physics and related fields. [ABSTRACT FROM AUTHOR]