Compton Scattering Research Articles

Artificial Neural Networks Based Method for Measuring the Distance between Two Metal Plates Using Compton Scattering

Artificial Neural Networks Based Method for Measuring the Distance between Two Metal Plates Using Compton Scattering

Analysis of Physics Learning Difficulties in The Topic of Quantum Phenomena of Madrasah Aliyah Students in Indragiri Hulu

This study aims to analysis the learning difficulties experienced by class XII students in studying physics, quantum phenomena. For this purpose, we have surveyed 180 class XII students of MAN 1 Indragiri Hulu, Riau, Indonesia, as respondents. The survey was conducted by evaluating the respondents’ formative test results on quantum phenomena in the last three years and followed by interviews. Data analysis techniques were descriptive statistic as a quantitative analysis and interactive model as a qualitative analysis. Based on the analysis of the formative test data, it was found that 58% of respondents had learning difficulties in the very high category. Judging from understanding the concept of quantum phenomena which includes sub-topics: Black Body Radiation, Wien Shift Law, Photon Energy, Photoelectric Effects, Compton Effects, and X-Rays, the results of data analysis show that respondents’ mastery is below 30%. Meanwhile, based on interviews that have been conducted with some randomly selected respondents, it was found that the factors of respondents’ learning difficulties on the topic of Quantum Phenomena include: the topic is abstract, the teacher does not use engaging media and supports understanding, and the teacher’s teaching style is less variety.

A light tracker based on scintillating fibers with SiPM readout

We have developed a novel light tracker based on plastic scintillating fiber arrays readout with Silicon Photomultipliers (SiPMs). The tracker consists of multiple planes, with the fibers in each plane oriented perpendicularly to those in the adjacent plane, in order to allow 3D track reconstruction. The fibers in each plane have round cross sections, with a diameter of 500μm, and are arranged in two staggered layers in a close-packed configuration. The fibers are readout by means of SiPM arrays with a 250μm strip pitch placed at one of their ends. Scintillating fibers allow a reduced material budget while providing a good spatial resolution and a fast response. This design is therefore suitable to track low-energy particles, such as the lowest energy cosmic rays or the electrons produced in Compton scatterings of gamma rays with energies down to 100 keV. We have built a detector prototype, equipped with Hamamatsu 128-channel SiPM arrays, readout with 32-channel PETIROC2A front-end ASICs. These ASICs are controlled by a custom data acquisition system board equipped with Xilinx Kintex-7 FPGA with self-triggering capabilities. The prototype has been tested with particle beams, cosmic rays and radioactive sources. The tracker design will be presented and performance of the prototype will be discussed.

A study on radiation interactions, dose enhancement, and hydrolysis with metallic nanoparticles irradiated by 6 megavoltage X-rays: Geant4 Monte Carlo simulation

Nanoparticles (NPs) have been suggested to increase cancer radiotherapy efficiency. However, a fulfillment of knowledge on mechanisms of radiation dose enhancement by NPs is needed. The aim of present study was to evaluate the enhancement of radiation effects by metal NPs at physical and chemical levels. Geant4-DNA Monte Carlo simulation was used for assessment of radiation interaction processes, radiation dose effect and the produced hydrolysis byproducts following 6 MV X-rays. According to the results NPs of this study may be divided in three categories: low dose enhancers (TiO2NP, Fe3O4NP, GeNP), medium dose enhancers (BiNP, AgNP) and high dose enhancers (GNP, PtNP). It found that mass density of NPs may be the most effective feature on DER. Higher radiation enhancement efficiencies by GNP, PtNP may be produced due to the induced high energetic photoelectrons and Compton electrons and also the produced free radicals.

Neural network-based classification of X-ray fluorescence spectra of artists’ pigments: an approach leveraging a synthetic dataset created using the fundamental parameters method

X-ray fluorescence (XRF) spectroscopy is an analytical technique used to identify chemical elements that has found widespread use in the cultural heritage sector to characterise artists' materials including the pigments in paintings. It generates a spectrum with characteristic emission lines relating to the elements present, which is interpreted by an expert to understand the materials therein. Convolutional neural networks (CNNs) are an effective method for automating such classification tasks—an increasingly important feature as XRF datasets continue to grow in size—but they require large libraries that capture the natural variation of each class for training. As an alternative to having to acquire such a large library of XRF spectra of artists' materials a physical model, the Fundamental Parameters (FP) method, was used to generate a synthetic dataset of XRF spectra representative of pigments typically encountered in Renaissance paintings that could then be used to train a neural network. The synthetic spectra generated—modelled as single layers of individual pigments—had characteristic element lines closely matching those found in real XRF spectra. However, as the method did not incorporate effects from the X-ray source, the synthetic spectra lacked the continuum and Rayleigh and Compton scatter peaks. Nevertheless, the network trained on the synthetic dataset achieved 100% accuracy when tested on synthetic XRF data. Whilst this initial network only attained 55% accuracy when tested on real XRF spectra obtained from reference samples, applying transfer learning using a small quantity of such real XRF spectra increased the accuracy to 96%. Due to these promising results, the network was also tested on select data acquired during macro XRF (MA-XRF) scanning of a painting to challenge the model with noisier spectra Although only tested on spectra from relatively simple paint passages, the results obtained suggest that the FP method can be used to create accurate synthetic XRF spectra of individual artists' pigments, free from X-ray tube effects, on which a classification model could be trained for application to real XRF data and that the method has potential to be extended to deal with more complex paint mixtures and stratigraphies.

Non-Destructive Analysis of a High-Power Capacitor Using High-Energy X-ray Compton Scattering

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.

Radiation Interaction Characteristics of Solutions of La(NO3)3.6H2O and Sm(NO3)3.6H2O in Acetone Using Compton Scattering Technique

This work deals with the evaluation of interaction cross sections, effective atomic number, and effective electron density at gamma photon energies, not available from standard radioisotopes. The Compton scattering technique is used to obtain the required gamma energies within a specific range of energies from 241.8 to 401.8 keV to perform the radiation measurements. Radiation interaction parameters of some inorganic compounds (high-Z rare-earth nitrate hexahydrate), namely, Lanthanum(III) nitrate hexahydrate [La(NO3)3.6H2O] and Samarium(III) nitrate hexahydrate [Sm(NO3)3.6H2O], soluble in low-Z organic solvent (acetone) are evaluated. Six scattering angles are chosen to obtain six (not available from standard radioisotopes) Compton scattered energies to perform narrow-beam transmission experiments. An NaI(Tl) scintillation detector is used to detect the transmitted flux from the different solutions in various proportions. Photon interaction parameters useful in vast basic and applied fields are evaluated. The present measured results, obtained from the Compton scattered technique, are found to be in good agreement with the computed values of radiation interaction parameters obtained from the WinXCom program. The present data on rare-earth solutions have definite scientific importance in nuclear and radiation physics and fill in the gap of nonavailability of such data for radiation workers at these specific energies.

Quantitative assessment of a beam hole scatter correction in industrial computed tomography

Abstract In industrial Computed Tomography (CT), scattered radiation causes a loss of quality of the reconstructed 3D volume. Scatter is caused by photon-matter interaction, whereby a photon is deflected from its initial propagation direction. The most prominent contributor to scattered radiation in the scope of photon energies occurring in industrial CT is Compton Scattering. With the used Beam Hole Array (BHA) technology for scatter correction, scatter intensities are determined by subtracting the primary intensities, which are gathered behind small apertures from the total intensities, which are gathered in the absence of the apertures. Intensities measured behind the apertures are assumed to be scatter free, since the transversal components of the radiation are strongly reduced. The scatter correction is performed by subtracting scatter intensities from primary intensities in the projection image. Improvements are evaluated for a newly developed test specimen considering image quality metrics and dimensional accuracy. The contrast could be improved especially for small structures. Cupping artifacts that express as systematic offset of grey values rising with the penetration length were reduced. Measurement deviations towards tactile references were decreased.

Compton Scattering in Plane Media: Polarization of Radiation and Azimuthal Independence. II. Results of Calculations

Compton Scattering in Plane Media: Polarization of Radiation and Azimuthal Independence. II. Results of Calculations

Depth resolved pencil beam radiography using AI — a proof of principle study

Aims: clinical radiographic imaging is seated upon the principle of differential keV photon transmission through an object. At clinical x-ray energies the scattering of photons causes signal noise and is utilized solely for transmission measurements. However, scatter — particularly Compton scatter, is characterizable. In this work we hypothesized that modern radiation sources and detectors paired with deep learning techniques can use scattered photon information constructively to resolve superimposed attenuators in planar x-ray imaging. Methods: we simulated a monoenergetic x-ray imaging system consisting of a pencil beam x-ray source directed at an imaging target positioned in front of a high spatial- and energy-resolution detector array. The setup maximizes information capture of transmitted photons by measuring off-axis scatter location and energy. The signal was analyzed by a convolutional neural network, and a description of scattering material along the axis of the beam was derived. The system was virtually designed/tested using Monte Carlo processing of simple phantoms consisting of 10 pseudo-randomly stacked air/bone/water materials, and the network was trained by solving a classification problem. RESULTS: from our simulations we were able to resolve traversed material depth information to a high degree, within our simple imaging task. The average accuracy of the material identification along the beam was 0.91 ± 0.01, with slightly higher accuracy towards the entrance/exit peripheral surfaces of the object. The average sensitivity and specificity was 0.91 and 0.95, respectively. Conclusions: our work provides proof of principle that deep learning techniques can be used to analyze scattered photon patterns which can constructively contribute to the information content in radiography, here used to infer depth information in a traditional 2D planar setup. This principle, and our results, demonstrate that there is information in Compton scattered photons, and this may provide a basis for further development. The work was limited by simple testing scenarios and without yet integrating complexities or optimizations. The ability to scale performance to the clinic remains unexplored and requires further study.

Development of a Density Gauge for Measuring Water and Mud Density based on a Radioactive Technique

The density or concentration of mud is one of the key variables in studying cohesive sediments, due to being accumulated through settlement and consolidation, as well as resuspended through erosion. This indicates that the proper measurement of sediment density is important. Therefore, this study aims to evaluate the accuracy of density measurement by using the gamma-ray attenuation method as a non-intrusive technique. For Compton Scattering, gamma-ray attenuation was effectively independent of mineralogy, subsequently depending on only the electron density of the material, which is directly related to the bulk density of the mixture. Based on the results, the advantages of utilizing the nucleonic density gauge indicated that the technique was non-intrusive and very flexible for many experimental arrangements, as well as the high accuracy of measurements with errors less than 1%.

PVP-Modified Multifunctional Bi2WO6 Nanosheets for Enhanced CT Imaging and Cancer Radiotherapy.

Malignant tumors are one of the main causes of human death. The clinical treatment of malignant tumors is usually surgery, chemotherapy, radiotherapy, and so forth. Radiotherapy, as a traditional and effective treatment method for cancer, is widely used in clinical practice, but the radiation resistance of tumor cells and the toxic side effects to normal cells are still the Achilles heel of radiotherapy. Multifunctional inorganic high-atom nanomaterials are expected to enhance the effect of tumor radiotherapy. Tungsten and bismuth, which contain elements with high atomic coefficients, have strong X-ray energy attenuation capability. We synthesized Bi2WO6 nanosheets (NSs) using a hydrothermal synthesis method and modified polyvinylpyrrolidone (PVP) on their surface to make them more stable. PVP–Bi2WO6 NSs have a variety of effects after absorbing X-rays (such as the photoelectric effect and Compton effect) and release a variety of particles such as photoelectrons, Compton electrons, auger electrons, and so forth, which can react with organic molecules or water in cells, generate a large number of free radicals, and promote cell apoptosis, thereby improving the effect of radiotherapy. We show through γ-H2AX and DCFH-DA probe analysis experiments that PVP–Bi2WO6 NSs can effectively increase cell DNA damage and reactive oxygen species formation under X-ray irradiation. Clone formation analysis showed that PVP–Bi2WO6 NSs can effectively suppress cell colony formation under X-ray irradiation. These versatile functions endow PVP–Bi2WO6 NSs with enhanced radiotherapy efficacy in animal models. In addition, PVP–Bi2WO6 NSs can also be used as contrast agents for X-ray computed tomography (CT) imaging with obvious effects. Therefore, PVP–Bi2WO6 NSs can be used as CT imaging contrast agents and tumor radiotherapy sensitizers and have potential medical applications.

Gamma-Ray Bursts Afterglow Physics and the VHE Domain

Afterglow radiation in gamma-ray bursts (GRB), extending from the radio band to GeV energies, is produced as a result of the interaction between the relativistic jet and the ambient medium. Although in general the origin of the emission is robustly identified as synchrotron radiation from the shock-accelerated electrons, many aspects remain poorly constrained, such as the role of inverse Compton emission, the particle acceleration mechanism, the properties of the environment and of the GRB jet itself. The extension of the afterglow emission into the TeV band has been discussed and theorized for years, but has eluded for a long time the observations. Recently, the Cherenkov telescopes, MAGIC and H.E.S.S., have unequivocally proven that afterglow radiation is also produced above 100 GeV, up to at least a few TeV. The accessibility of the TeV spectral window will largely improve with the upcoming facility CTA (the Cherenkov Telescope Array). In this review article, we first revise the current model for afterglow emission in GRBs, its limitations and open issues. Then, we describe the recent detections of very high energy emission from GRBs and the origin of this radiation. Implications on the understanding of afterglow radiation and constraints on the physics of the involved processes will be deeply investigated, demonstrating how future observations, especially by the CTA Observatory, are expected to give a key contribution in improving our comprehension of such elusive sources.

From Alignment Laser to 3D Structures: Determining Structures of GPCRs in a Compact X‐ray Light Source

The Compact X‐ray Light Source (CXLS) at Arizona State University produces diffraction patterns with intense X‐ray by Inverse Compton Scattering (ICS). In ICS, a photon acquires energy from an electron to produce an X‐ray. With this system, we can study G‐Protein Coupled Receptors (GPCRs), which are peripheral membrane proteins targeted by 60% of FDA approved drugs. When GPCRs are activated, a series of reaction can occur. For example, opening and closing of ion channels, activation or deactivation of enzymes, and protein hydrolysis. The structural characterization of GPCRs can lead to optimization of drug development, by assessing a better targeting mechanism that will lead to fewer side‐effects and better drug biding. We conducted a laser alignment in the CXLS using a YAG screen, which is a fluorescent screen that helps determine the size and intensity of the beam. Furthermore, we provide the crystallization process of GPCRs using Lipidic Cubic Phase (LCP) and describe its potential for structure determination using the CXLS and CXFEL.

A High-Energy and High-Intensity Inverse Compton Scattering Source Based on CompactLight Technology

An inverse Compton scattering source based on the CompactLight injector and capable of producing MeV gamma-rays with a brilliance several orders of magnitude larger than existing sources is proposed. The CompactLight injector can operate at a bunch repetition rate of 1 kHz, with trains of 50 bunches and a bunch spacing of 5 ns, giving a maximum total flux of 8.62 × 1011 photons/s. For a normalised emittance of 0.3 mm mrad, an average brilliance of 1.85 × 1014 photons/(s mm2 mrad2 0.1%BW) could be obtained. A 1 kW colliding laser was considered, corresponding to a laser pulse energy of 50 mJ. Given the electron beam energy up to 300 MeV provided by the CompactLight photoinjector, a maximum photon energy of 2 MeV is obtained. Simulations of inverse Compton scattering were performed using the RF-Track particle tracking software. Parametric scans were used to derive the electron and laser spot sizes maximising the total flux. The accelerator optic components were also determined from the final focus design, which was optimised for a micrometer-level electron beam size at the interaction point. Given a maximum total flux in the order of 1012 photons/s and a maximum output photon energy in the MeV range, the proposed source could be used for various applications, including X-ray imaging.

Effect of thulium boro-tellurite glass system on radiation shielding parameters

This article reports the influence of thulium oxide on gamma shielding parameters of (B2O3)0.2-x (TeO2)0.5 (Bi2O3)0.3 (Tm2O3)x glass system. The mass attenuation coefficient has been obtained by the WinXCom program, whereas the effective atomic number and the electron density have been calculated from a comprehensive and consistent set of formulas. Appreciable variations have been observed for all parameters by varying the chemical composition of the glass and the gamma photon energy. The theoretical results have shown that the addition of the rare-earth oxide, Tm2O3 into the glass system as the dopant attenuates more gamma irradiation and improves the radiation shielding properties of the glass system. The interactions between the photons and the glass materials have been explained by the Photoelectric Effect, Compton Scattering and Pair Production.

Redefinition of De-Broglie Wavelength Associated with Material Particle

The objective of the work is to reveal the Association of special theory of relativity with De-Broglie wavelength of a particle. It shows that wave nature of a particle is always associated with it’s relativistic properties. The phenomena of interference, diffraction and polarization of light can only be explained on the basis of wave theory of light. These phenomena show that light possesses wave nature. However, certain phenomena like photoelectric effect, Compton effect and discrete emission and absorption of radiation can only be explained on the basis of quantum theory. According to this theory , light propagates in a small packets or quanta and behave like corpuscles or particle. This shows that light possesses particle nature. thus, we can say that light possesses dual nature. The matter also possesses the same dual nature. In order to have wave nature, the particle must satisfy the equation Where m denotes the mass of particle when it is moving with certain velocity. h=6.62×10-34 is the plank’s constant. C is the velocity of light in free space. This shows that wavelength of a material Particle depends on mass. When mathematical operation is done on above equation, it give complete quantitative properties about the wave nature of a particle.

Математическая модель поглощения энергии излучения многослойной структурой и решение сеточным методом

When studying the radiation effect on microcircuits, the problem arises of calculating the absorbed energy. Often it comes down to determining the radiation resistance of microcircuits. However, in some cases it is necessary to determine the distribution of temperature and voltage in the chip housings. To do this, it is necessary to get an accurate picture of how the radiation energy was absorbed in each layer, depending on the coordinate. The paper considers the solution of this problem by the grid method, which allows us to calculate the energy absorption at each point of the multilayer structure. To do this, the placement of the chip in a three-dimensional coordinate system is considered, its multilayer structure is divided into nodes, in each of which the absorbed dose is calculated. The presented mathematical model describes the processes of absorption and attenuation of the intensity of the energy flow of -quanta. The model takes into account the processes associated with the transfer of energy between the regions for the photoelectric effect and the Compton effect. The proposed method is implemented programmatically, and the paper presents the results of calculating the absorbed dose in each layer of a multilayer structure. The advantage of the developed model and the method of its solution is to obtain the dose value at each point of the multilayer structure depending on the coordinates.

Relativistic theory to Compton effect for spectroscopic detector

We report here a theoretical proof of the limiting value of the velocity of target/particle responsible for various photon–electron interactions in the Compton scattering experiment which may be carried out in various applications such as gamma-ray spectroscopy. Compton scattering deals with the collision of photons with a target particle where both energy and momentum are transferred to the particle while the photon moves with reduced energy and a change of momentum. Here, the changed energy of a photon depends on the angle between the incident axis and scattered photon (θ), the rest mass of the electron, and the frequency of the photon before the collision. However, when some initial velocity is provided to an electron that is at rest initially, then in such cases, the particle obeys limiting value on velocity for a particular energetic photon to follow Compton scattering. In such cases, the changed frequency of photons also depends on the initial and final velocity of nonstationary electrons during a collision, including the angle (φ′) between the recoil electron and incident axis. Here, we have presented the derivations to calculate the recoil velocity of the nonstationary electron. These terms are the accurate solution of the Compton shift. We have tried to calculate the upper limit or limiting values of the initial velocity of the target particle in Compton scattering. Further, we have computationally demonstrated that there is a dependence of scattered photon frequency on initial velocity of target particle (u) and mass of the target particle (m) at a higher scattering angle. Finally, numerical simulations were carried out with particles such as an electron, pion (+/-, 0) to verify the greater degree of accuracy of the particles in spectroscopic detectors such as gamma-ray spectroscopy and other high energy spectroscopic techniques.

Measurement of Compton Scattering at MAMI for the Extraction of the Electric and Magnetic Polarizabilities of the Proton

A precise measurement of the differential cross sections dσ/dΩ and the linearly polarized photon beam asymmetry Σ_{3} for Compton scattering on the proton below pion threshold has been performed with a tagged photon beam and almost 4π detector at the Mainz Microtron. The incident photons were produced by the recently upgraded Glasgow-Mainz photon tagging facility and impinged on a cryogenic liquid hydrogen target, with the scattered photons detected in the Crystal Ball/TAPS setup. Using the highest statistics Compton scattering data ever measured on the proton along with two effective field theories (both covariant baryon and heavy-baryon) and one fixed-t dispersion relation model, constraining the fits with the Baldin sum rule, we have obtained the proton electric and magnetic polarizabilities with unprecedented precision: α_{E1}=10.99±0.16±0.47±0.17±0.34, β_{M1}=3.14±0.21±0.24±0.20±0.35; in units of 10^{-4} fm^{3} where the errors are statistical, systematic, spin polarizability dependent, and model dependent.