المؤلفون: XIONG Chao, WANG Xin, WANG Xinjie, WU Hexi

المصدر: He jishu, Vol 47, Iss 4, Pp 040201-040201 (2024)

مصطلحات موضوعية: gpu, airborne gamma-ray spectra, threshold denoising, Nuclear engineering. Atomic power, TK9001-9401

الوصف: BackgroundThe volume of aviation gamma spectrum data is immense. If only a central processing unit (CPU) is used for data post-processing, it would be constrained by computational efficiency.PurposeThis study aims to propose a CUDA-based graphics processing unit (GPU) parallel solution that optimally accelerates the denoising of airborne gamma-ray spectral data using wavelet transformation.MethodsFirst, the impact of different block sizes on computational time was tested to determine the optimal block size for processing airborne gamma-ray spectral data. Subsequently, a GPU, instead of a CPU, was used to calculate the acceleration ratio for handling airborne gamma-ray spectral data of different volumes, and wavelet basis functions were used for those with the same data volume. Finally, by introducing white noise to the experimentally measured airborne gamma-ray spectral data, the signal-to-noise ratio of denoised data was calculated to optimize the threshold denoising method suitable for parallel acceleration of the GPU.ResultsThe optimal two-dimensional block sizes for denoising airborne gamma-ray spectral data are 64×64 and 128×128. Among the wavelet basis functions, those that achieved a total time acceleration ratio exceeding 100 compared to CPU processing account for 80%, while those that reached an acceleration ratio exceeding 90 constitute 91%. The coif5 function achieves an acceleration ratio of 353 times whilst the acceleration ratio of the threshold denoising function approaches 570.ConclusionsAll wavelet functions exhibit insufficient denoising effects at low signal-to-noise ratios and excessive denoising effects at high signal-to-noise ratios. Significant denoising can be achieved using hard thresholding of coif5, soft thresholding of coif1, and improved thresholding of bior3.7.

وصف الملف: electronic resource

العلاقة: http://www.hjs.sinap.ac.cn/thesisDetails#10.11889/j.0253-3219.2024.hjs.47.040201&lang=zhTest; https://doaj.org/toc/0253-3219Test

الوصول الحر: https://doaj.org/article/412b0164f5ec4b49879273ef3733d7acTest

المؤلفون: Jutila, Henri, Greenlees, Paul, Torvela, Tiina, Muikku, Maarit

المساهمون: Helsinki Institute of Physics

مصطلحات موضوعية: Geant4 simulation, Low-energy gamma-ray spectra, Lung counting, Voxel phantom, 114 Physical sciences

الوصف: A Geant4 simulation package has been developed to investigate and test detector configurations for lung counting applications. The objective of this study was to measure radiation emitted from the human body and to make a qualitative comparison of the results of the simulation with an experiment. Experimental data were measured from a plastic phantom with a set of lungs containing 241Am activity. For comparison, simulations in which 241Am activity was uniformly distributed inside the lungs of the ICRP adult reference computational phantom were made. The attenuation of photons by the chest wall was simulated and from this photopeak ef-ficiency and photon transmission were calculated as a function of photon energy. The transmission of 59.5 keV gamma rays, characteristic of the decay of 241Am, was determined from the computational phantom as a function of the angular position of the detector. It was found that the simulated detector response corresponds well with that from an experiment. The simulated count rate below 100 keV was 10.0(7) % greater compared to the experimental measurement. It was observed that 58.3(4) % of photons are attenuated for energies below 100 keV by the chest wall. In the simulation, the transmission of 59.5 keV gamma rays varied from 13.8(2) % to 38.0(4) % as a function of the angular position of the detector. The results obtained from the simulations show a satisfactory agreement with experimental data and the package can be used in the development of future body counting applications and enables optimization of the detection geometry. ; Peer reviewed

وصف الملف: application/pdf

العلاقة: Jutila , H , Greenlees , P , Torvela , T & Muikku , M 2023 , ' Technical note : Simulation of lung counting applications using Geant4 ' , Physica Medica , vol. 108 , 102573 . https://doi.org/10.1016/j.ejmp.2023.102573Test; 85151300167; c6795e22-dc8e-4ca8-8d6e-01aea0b41f95; http://hdl.handle.net/10138/358336Test; 000969199500001

الإتاحة: http://hdl.handle.net/10138/358336Test

المؤلفون: V. A. Plujko, O. M. Gorbachenko, K. M. Solodovnyk, V. M. Petrenko

المصدر: Âderna Fìzika ta Energetika, Vol 22, Iss 3, Pp 221-229 (2021)

مصطلحات موضوعية: nuclear reaction 113cd(n, {xγ}), thermal neutrons, average gamma-ray spectra evaluation. calculations by empire and talys codes, scaling approximation., Atomic physics. Constitution and properties of matter, QC170-197

الوصف: The average gamma-ray spectrum of 114Cd after thermal neutron capture in 113Cd was evaluated in units of mb/MeV. Two approaches are considered for estimation of the average gamma-ray spectrum with normalization of the experimental data: mean spectra for all gamma-energies were found by averaging frequency polygon for experimental data histogram, and mean spectra were estimated as the combination of theoretical values at low gamma-ray energies and averaging experimental data in high-energy range. The experimental spectra were evaluated from the gamma-intensities presented by Mheemeed et al. [A. Mheemeed et al. Nucl. Phys. A 412 (1984) 113] and Belgya et al. [T. Belgya et al. EPJ Web of Conf. 146 (2017) 05009]. They were normalized to the average theoretical spectrum which was calculated using EMPIRE and TALYS codes. The procedure of normalization of the high-energy part of the spectrum was described. Estimated gamma-spectra for 113Cd(n, {xγ}) reaction induced by thermal neutrons were presented.

وصف الملف: electronic resource

العلاقة: http://jnpae.kinr.kiev.ua/22.3/html/22.3.0221.htmlTest; https://doaj.org/toc/1818-331XTest; https://doaj.org/toc/2074-0565Test

الوصول الحر: https://doaj.org/article/daea9baaefa34f779371ab71d7cfe98dTest

المؤلفون: A. T. Gheith, M. A. El-Sarraf, I. E. Hasan, N. L. Helal, R. A. Rizk, Amal A. El-Sawy, A. El-Sayed Abdo

المصدر: Âderna Fìzika ta Energetika, Vol 21, Iss 4, Pp 361-368 (2020)

مصطلحات موضوعية: biological shield, composite, neutron and gamma-ray spectra, attenuation parameters, mcnp code., Atomic physics. Constitution and properties of matter, QC170-197

الوصف: This work is dedicated to figuring out robust epoxy/magnetite/boron carbide (EP/Mag/B4C) composite for radiation attenuation at multiple applications related to nuclear installations, as well as restoration mortar for cracking developed in concrete biological shields. The mechanical properties (flexural, compressive, and impact strengths) and the physical properties (water absorption, porosity, and dry bulk density), each, have been performed to label the composite integrity for practical application. In practice, attenuation properties have been performed by using a collimated beam emitted from spontaneous fission 252Cf (100 μg) neutron source and neutron gamma spectrometer with stilbene scintillator. The pulse shape discrimination technique which would come of the zero cross over method was used to measure the fast neutron and gamma-ray spectra. Thermal neutron fluxes have been measured by using the thermal neutron detection system and the BF-3 detector. The attenuation parameters: precisely, macroscopic effective removal cross-sections ΣR (cm-1), macroscopic cross-sections Σ (cm-1), and total attenuation coefficients μ (cm-1) of fast and thermal neutrons and total gamma-rays respectively were evaluated using the attenuation relations. Also, the MCNP5 code and MERCSF-N program have been used to compute the parameters theoretically. When applicable, measured and calculated results were compared, and it tells us a comprehensive agreement.

وصف الملف: electronic resource

العلاقة: http://jnpae.kinr.kiev.ua/21.4/Articles_PDF/jnpae-2020-21-0361-Gheith.pdfTest; https://doaj.org/toc/1818-331XTest; https://doaj.org/toc/2074-0565Test

الوصول الحر: https://doaj.org/article/a4fca083ac124291a2466ddaf359526cTest

المساهمون: Sterbentz, James

المصدر: Conference: 13th International Symposium on Reactor Dosimetry,Akersloot, Netherlands,05/25/2008,05/30/2008

وصف الملف: Medium: ED

الوصول الحر: http://www.osti.gov/scitech/servlets/purl/950994Test

المساهمون: Antolak, A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)]

المصدر: Physics Procedia; 66; C

وصف الملف: Medium: ED; Size: p. 226-231

الوصول الحر: http://www.osti.gov/scitech/servlets/purl/1214671Test

المؤلفون: Henri Jutila, Paul Greenlees, Tiina Torvela, Maarit Muikku

المساهمون: Helsinki Institute of Physics

مصطلحات موضوعية: lung counting, Biophysics, Geant4 simulation, General Physics and Astronomy, General Medicine, gammasäteily, 114 Physical sciences, Lung counting, mittausmenetelmät, radioaktiiviset aineet, voxel phantom, säteilyannokset, säteilyfysiikka, ilmaisimet, Low-energy gamma-ray spectra, low-energy gamma-ray spectra, Radiology, Nuclear Medicine and imaging, simulointi, Voxel phantom, keuhkot

الوصف: A Geant4 simulation package has been developed to investigate and test detector configurations for lung counting applications. The objective of this study was to measure radiation emitted from the human body and to make a qualitative comparison of the results of the simulation with an experiment. Experimental data were measured from a plastic phantom with a set of lungs containing 241Am activity. For comparison, simulations in which 241Am activity was uniformly distributed inside the lungs of the ICRP adult reference computational phantom were made. The attenuation of photons by the chest wall was simulated and from this photopeak ef-ficiency and photon transmission were calculated as a function of photon energy. The transmission of 59.5 keV gamma rays, characteristic of the decay of 241Am, was determined from the computational phantom as a function of the angular position of the detector. It was found that the simulated detector response corresponds well with that from an experiment. The simulated count rate below 100 keV was 10.0(7) % greater compared to the experimental measurement. It was observed that 58.3(4) % of photons are attenuated for energies below 100 keV by the chest wall. In the simulation, the transmission of 59.5 keV gamma rays varied from 13.8(2) % to 38.0(4) % as a function of the angular position of the detector. The results obtained from the simulations show a satisfactory agreement with experimental data and the package can be used in the development of future body counting applications and enables optimization of the detection geometry.

وصف الملف: application/pdf; fulltext

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::58f90fb9dc69adeb703a524abdeb56bcTest
http://urn.fi/URN:NBN:fi:jyu-202304042389Test

المؤلفون: Marrone, S., Colonna, Nicola, Krticka, M., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Alvarez Pol, Héctor, Alvarez Velarde, Francisco, Andrzejewski, Józef, Audouin, Ludmila, Berthoumieux, Eric, Capdevila Paramio, Roser, Poch, Agustí, Pretel Sánchez, Carme

المساهمون: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. CTTC - Centre Tecnològic de la Transferència de Calor

مصطلحات موضوعية: Àrees temàtiques de la UPC::Física, Àrees temàtiques de la UPC::Física::Física de partícules, Àrees temàtiques de la UPC::Física::Física de partícules::Fotons, Photons, Nuclear physics, Monte Carlo method, Intelligent systems, Monte Carlo methods, Resonance, Ultraviolet spectroscopy, Experimental apparatus, Gamma ray spectra, Liquid scintillator detectors, Model calculations, Neutron capture, Nuclear level densities, Strength function, Gamma rays, Fotons, Física nuclear, Montecarlo, Mètode de

الوصف: The Photon Strength Function of 152Sm has been investigated at nTOF by studying the ¿-ray spectra from resonance neutron capture of 151Sm. The experimental apparatus consisted of two C6D6 liquid scintillator detectors. The measured spectra were compared with the predictions of the DICEBOX code, for different assumptions on the Photon Stregth Functions and on the Nuclear Level Density. For a meaningful comparison, the model calculations were filtered through a detailed software replica of the experimental apparatus, performed by means of three different Monte Carlo simulations. Preliminary results indicate that a reasonable reproduction of the experimental ¿-ray spectrum is obtained by postulating the presence of a Scissors Resonance. Some hints on the most suitable models, developed in the most recent studies of the Photon Strength Functions and Nuclear Level Density, are also obtained. © 2007 Sissa Medialab Srl. All rights reserved. ; Postprint (published version)

وصف الملف: 14 p.

العلاقة: https://pos.sissa.it/044/019/pdfTest; info:eu-repo/grantAgreement/MICINN/1PE/ FPA2011-28770-C03-03; Marrone, S., Colonna, N., Krticka, M., Calviño, F., Cortes, G., Alvarez-Pol, H., Alvarez-Velarde, F., Andrzejewski, J., Audouin, L., Berthoumieux, E., Capdevila, R., Poch, A., Pretel, C. Study of the photon strength function of 152SM in resonance neutron capture at n-TOF. A: Workshop on Photon Strength Functions and Related Topics. "PSF 2007: Proceedings of the Workshop on Photon Strength Functions and Related Topics, vol 44: Prague, Czech Republic: June 17-20, 2007". PoS - Proceedings of Science, 2018, p. 1-14.; http://hdl.handle.net/2117/126684Test

الإتاحة: http://hdl.handle.net/2117/126684Test

المؤلفون: Zhao L, Zhou Y, Shi Z, Ni Z, Wang M, Liu Y, Huang J

المصدر: Nature Photonics, 17(4)

مصطلحات موضوعية: Gamma-ray spectroscopy, High quality single crystals, Metal halides, Spectra's, IS performance, Higher yield, Yield growth, Bromine compounds, Perovskite, Defect density, Gamma ray spectrometers, Gamma ray spectra, Lead compounds, Low defect densities, Single crystals, Ultraviolet spectroscopy, Halide perovskites, Mixed solvent, Cesium compounds, Hole mobility

الوصف: Metal halide perovskites are promising candidates for room-temperature gamma-ray spectrum detectors; however, it is hard to grow high-quality single crystals that are performance competitive with existing materials. Here we report the growth of centimetre-sized formamidinium-caesium lead bromide (FACsPbBr3) single crystals at high yield from low-purity (98%) precursors using a solution method. The introduction of formamidinium into CsPbBr3 reduces defect density in crystals by eliminating the phase transition upon cooling from growth temperature to room temperature. A mixed solvent is applied to match the solubility slopes of CsPbBr3 and FAPbBr3, resulting in successful incorporation of caesium into FAPbBr3 at FA:Cs ratios from 0 to 1. As-grown FACsPbBr3 exhibits a high resistivity of 9.5 × 109 Ω cm, balanced hole and electron mobility-lifetime products of (2.2–3.2) × 10−3 cm2 V−1, and a record low deep trap density of 5.6 × 1010 cm−3, yielding a high charge collection efficiency of 84% under gamma-rays. FACsPbBr3 spectrum detectors achieve an energy resolution of 2.9% for 662 keV 137Cs γ-rays. Over 65% of the FACsPbBr3 crystals exhibit good γ-ray spectral performance. FACsPbBr3 single crystals show excellent stability under large biases of up to 1,000 V and no degradation of spectrum performance after seven months.

العلاقة: https://doi.org/10.17615/evdq-nn25Test; https://cdr.lib.unc.edu/downloads/qr46rb64w?file=thumbnailTest; https://cdr.lib.unc.edu/downloads/qr46rb64wTest

الإتاحة: https://doi.org/10.17615/evdq-nn25Test
https://cdr.lib.unc.edu/downloads/qr46rb64w?file=thumbnailTest
https://cdr.lib.unc.edu/downloads/qr46rb64wTest

المؤلفون: Hyoung-Koo Lee, P.K. Bhowmik, Shaikat M. Galib, Ashish V. Avachat

المصدر: Nuclear Engineering and Technology, Vol 53, Iss 12, Pp 4072-4079 (2021)

مصطلحات موضوعية: Artificial neural network, Real-time processing, Computer science, 020209 energy, Radioisotope identification, Gamma ray spectra, 02 engineering and technology, Machine learning, computer.software_genre, Convolutional neural network, Nuclear security, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, 0202 electrical engineering, electronic engineering, information engineering, Nuclear threat detection, Gamma-ray spectroscopy, business.industry, Deep learning, TK9001-9401, Identification (information), Nuclear Energy and Engineering, Metric (mathematics), Nuclear engineering. Atomic power, Alternating decision tree, Artificial intelligence, F1 score, business, computer

الوصف: This article presents a study on the state-of-the-art methods for automated radioactive material detection and identification, using gamma-ray spectra and modern machine learning methods. The recent developments inspired this in deep learning algorithms, and the proposed method provided better performance than the current state-of-the-art models. Machine learning models such as: fully connected, recurrent, convolutional, and gradient boosted decision trees, are applied under a wide variety of testing conditions, and their advantage and disadvantage are discussed. Furthermore, a hybrid model is developed by combining the fully-connected and convolutional neural network, which shows the best performance among the different machine learning models. These improvements are represented by the model's test performance metric (i.e., F1 score) of 93.33% with an improvement of 2%–12% than the state-of-the-art model at various conditions. The experimental results show that fusion of classical neural networks and modern deep learning architecture is a suitable choice for interpreting gamma spectra data where real-time and remote detection is necessary.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4774abff06aa47af78cc82be3341fb92Test
https://doi.org/10.1016/j.net.2021.06.020Test