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Becker SM, Franz TE, Morris TC, Mullins B. Field Testing of Gamma-Spectroscopy Method for Soil Water Content Estimation in an Agricultural Field. SENSORS (BASEL, SWITZERLAND) 2024; 24:2223. [PMID: 38610435 PMCID: PMC11014223 DOI: 10.3390/s24072223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/25/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024]
Abstract
Gamma-ray spectroscopy (GRS) enables continuous estimation of soil water content (SWC) at the subfield scale with a noninvasive sensor. Hydrological applications, including hyper-resolution land surface models and precision agricultural decision making, could benefit greatly from such SWC information, but a gap exists between established theory and accurate estimation of SWC from GRS in the field. In response, we conducted a robust three-year field validation study at a well-instrumented agricultural site in Nebraska, United States. The study involved 27 gravimetric water content sampling campaigns in maize and soybean and 40K specific activity (Bq kg-1) measurements from a stationary GRS sensor. Our analysis showed that the current method for biomass water content correction is appropriate for our maize and soybean field but that the ratio of soil mass attenuation to water mass attenuation used in the theoretical equation must be adjusted to satisfactorily describe the field data. We propose a calibration equation with two free parameters: the theoretical 40K intensity in dry soil and a, which creates an "effective" mass attenuation ratio. Based on statistical analyses of our data set, we recommend calibrating the GRS sensor for SWC estimation using 10 profiles within the footprint and 5 calibration sampling campaigns to achieve a cross-validation root mean square error below 0.035 g g-1.
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Affiliation(s)
- Sophia M. Becker
- School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68503, USA; (T.E.F.); (T.C.M.)
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2
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Bi H, Zhang Y, Wu B, Yuan D, Feng X, Shi Y. Study on reconstruction and analytical method of seawater radioactive gamma spectrum. Appl Radiat Isot 2023; 198:110853. [PMID: 37216724 DOI: 10.1016/j.apradiso.2023.110853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/16/2023] [Accepted: 05/11/2023] [Indexed: 05/24/2023]
Abstract
Gamma detector detection technology based on NaI(Tl) scintillation crystal has become a popular research topic and has been applied in the field of marine radioactive environment automatic monitoring because of its advantages of low power consumption, low cost and strong environmental adaptability. However, insufficient energy resolution of the NaI(Tl) detector and great Compton scattering in the low-energy region caused by the abundance of natural radionuclides in seawater hinder the automatic analysis of radionuclides in seawater. This study adopts the combination of theoretical derivation, simulation experiment, water tank test and seawater field test, establishing an effective and feasible spectrum reconstruction method. The measured spectrum in seawater is regarded as the output signal formed by the convolution of the incident spectrum and the detector response function. The acceleration factor p is introduced to construct the Boosted-WNNLS deconvolution algorithm, which is used to iteratively reconstruct the spectrum. The analysis results of the simulation test, water tank test and field test meet the radionuclide analysis speed and accuracy requirements for the in-situ automatic monitoring of seawater radioactivity. The spectrum reconstruction method in this study converts the physical problem of insufficient detection accuracy of spectrometer in the practical application into a mathematical problem of deconvolution solution, restores the original radiation information in seawater, and improves the resolution of the seawater gamma spectrum.
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Affiliation(s)
- Haijie Bi
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Techno1ogy, National Engineering and Technological Research Center of Marine Monitoring Equipment, No 37 Miaoling Road, 266061, Qingdao, China
| | - Yingying Zhang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Techno1ogy, National Engineering and Technological Research Center of Marine Monitoring Equipment, No 37 Miaoling Road, 266061, Qingdao, China.
| | - Bingwei Wu
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Techno1ogy, National Engineering and Technological Research Center of Marine Monitoring Equipment, No 37 Miaoling Road, 266061, Qingdao, China
| | - Da Yuan
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Techno1ogy, National Engineering and Technological Research Center of Marine Monitoring Equipment, No 37 Miaoling Road, 266061, Qingdao, China.
| | - Xiandong Feng
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Techno1ogy, National Engineering and Technological Research Center of Marine Monitoring Equipment, No 37 Miaoling Road, 266061, Qingdao, China
| | - Yan Shi
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Techno1ogy, National Engineering and Technological Research Center of Marine Monitoring Equipment, No 37 Miaoling Road, 266061, Qingdao, China
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Han SY, Maeng S, Lee HY, Lee SH. Preliminary study on the detection efficiency and estimation of minimum detectable activity for a NaI(Tl)-based seawater monitoring system. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 218:106222. [PMID: 32174443 DOI: 10.1016/j.jenvrad.2020.106222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
To monitor radioactivity levels in seawater Korea Institute of Nuclear Safety has installed and been operating 18 NaI(Tl)-based gamma detectors around the Korean peninsula. This study was conducted to estimate the detector efficiency and MDA of 137Cs in seawater for measurement situations. For this purpose, experiments in the air and a water tank, and Monte Carlo simulations were performed using a seawater radioactivity monitor system with 3 in. × 3 in. NaI(Tl) scintillation detector. In the geometry reliability assessment using certified reference materials in a disc source, the validity of simulations was obtained by comparing measurement and Monte Carlo simulation results. The FWHM of the seawater radioactivity monitor were obtained from the results of the water tank measurement for applying a Gaussian Energy Broadening (GEB) option to Monte Carlo N-Particle (MCNP) radiation transport code. In addition, the detection efficiency of 40K in the water tank was measured and compared with the Monte Carlo simulation results in order to estimate the MDA and the detection efficiency of the seawater radioactivity monitoring system. For the based condition of water tank, 40K concentration in water tank was controlled to 10.13±0.18 Bq/L, similar to that of real marine. In laboratory water tank experiments, the detection efficiency of the radioactivity monitor for 40K was measured at 0.184±0.005 cps/(Bq/L), the Monte Carlo simulations showed the similar result of 0.182±0.002 cps/(Bq/L), and the detection efficiency of 137Cs was estimated to be 0.224±0.009 cps/(Bq/L) from the simulations. For 3h measurement in the water tank based condition, the MDA of 137Cs was estimated to be 0.077±0.003 Bq/L. Future research will include detailed studies for detector sizes and seawater salinities.
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Affiliation(s)
- Seung Yeon Han
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea; Korea Institute of Nuclear Safety, Daejeon, 34142, Republic of Korea
| | - Seongjin Maeng
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea.
| | - Hae Young Lee
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea; Radiation Science Research Institute, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Sang Hoon Lee
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea; Radiation Science Research Institute, Kyungpook National University, Daegu, 41566, Republic of Korea
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4
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Eleftheriou G, Pappa FΚ, Maragos N, Tsabaris C. Continuous monitoring of multiple submarine springs by means of gamma-ray spectrometry. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 216:106180. [PMID: 32217197 DOI: 10.1016/j.jenvrad.2020.106180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 01/24/2020] [Accepted: 01/25/2020] [Indexed: 06/10/2023]
Abstract
The measurement of radiotracers is recognized as a major tool for the investigation and characterization of submarine groundwater discharges, while the use of underwater gamma-ray spectrometry has been proved a robust solution for the qualitative and quantitative determination of radionuclides in the aquatic environment. The capability of online continuous monitoring of submarine springs by means of gamma-ray spectrometry for direct estimation of SGD velocity and discharge is presented. The quantification of SGD flux rate is based on radon progenies time-series provided by two spectrometers placed above the seabed and near the water surface respectively, coupled with water level and meteorological data. The proposed methodology has been applied for a 5-month period in a coastal karstic system where multiple submarine springs occur at Anavalos-Kiveri, Greece. The estimated flux rates derived from the measured activities revealed significant SGD temporal variations with the mean discharge of 12 m3 s-1 being compatible with previous measurements. The advantages and limitations of direct SGD estimation via underwater gamma-ray monitoring are also discussed.
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Affiliation(s)
- Georgios Eleftheriou
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR-19013, Anavyssos, Greece.
| | - Filothei Κ Pappa
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR-19013, Anavyssos, Greece
| | - Nikos Maragos
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR-19013, Anavyssos, Greece
| | - Christos Tsabaris
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR-19013, Anavyssos, Greece
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5
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Chuong HD, Hung NQ, My Le NT, Nguyen VH, Thanh TT. Validation of gamma scanning method for optimizing NaI(Tl) detector model in Monte Carlo simulation. Appl Radiat Isot 2019; 149:1-8. [PMID: 31003039 DOI: 10.1016/j.apradiso.2019.04.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 03/07/2019] [Accepted: 04/05/2019] [Indexed: 10/27/2022]
Abstract
The aim of this study is the validation of gamma scanning method for optimizing NaI(Tl) detector model in Monte Carlo simulation. The experimental procedure involved: scanning on front and lateral surfaces of the detector with collimated low-energy photon beam; calibrating the efficiency with energies between 31-1408 keV for point sources at distances of 0 cm and 30 cm from source to the detector. The Monte Carlo code used for the simulations was MCNP6. The diameter and the length of crystal were determined according to the measured results of gamma scanning with a collimated 241Am radioactive source. The distance from window to crystal was estimated using transmission measurement recorded on a second detector. The density of reflector was adjusted to obtain the match between measured and simulated values of efficiency ratio of 81 and 31 keV from a 133Ba radioactive source. The optimized model was applied in Monte Carlo simulations to determine the efficiency and energy spectrum response function of NaI(Tl) detector for point source measurements in two configurations. Good agreement was obtained between measured and simulated results.
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Affiliation(s)
- Huynh Dinh Chuong
- Nuclear Technique Laboratory, University of Science, VNU-HCM, Viet Nam
| | - Nguyen Quoc Hung
- Department of Nuclear Physics, Faculty of Physics and Engineering Physics, University of Science, VNU-HCM, Viet Nam
| | - Nguyen Thi My Le
- Department of Nuclear Physics, Faculty of Physics and Engineering Physics, University of Science, VNU-HCM, Viet Nam; Faculty of Applied Sciences, Ho Chi Minh City University of Technology and Education, Viet Nam
| | - Vo Hoang Nguyen
- Department of Nuclear Physics, Faculty of Physics and Engineering Physics, University of Science, VNU-HCM, Viet Nam
| | - Tran Thien Thanh
- Nuclear Technique Laboratory, University of Science, VNU-HCM, Viet Nam; Department of Nuclear Physics, Faculty of Physics and Engineering Physics, University of Science, VNU-HCM, Viet Nam.
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6
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Tsabaris C, Androulakaki E, Alexakis S, Patiris D. An in-situ gamma-ray spectrometer for the deep ocean. Appl Radiat Isot 2018; 142:120-127. [DOI: 10.1016/j.apradiso.2018.08.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/29/2018] [Accepted: 08/30/2018] [Indexed: 11/30/2022]
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7
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Baldoncini M, Albéri M, Bottardi C, Chiarelli E, Raptis KGC, Strati V, Mantovani F. Investigating the potentialities of Monte Carlo simulation for assessing soil water content via proximal gamma-ray spectroscopy. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 192:105-116. [PMID: 29909224 DOI: 10.1016/j.jenvrad.2018.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/22/2018] [Accepted: 06/02/2018] [Indexed: 06/08/2023]
Abstract
Proximal gamma-ray spectroscopy recently emerged as a promising technique for non-stop monitoring of soil water content with possible applications in the field of precision farming. The potentialities of the method are investigated by means of Monte Carlo simulations applied to the reconstruction of gamma-ray spectra collected by a NaI scintillation detector permanently installed at an agricultural experimental site. A two steps simulation strategy based on a geometrical translational invariance is developed. The strengths of this approach are the reduction of computational time with respect to a direct source-detector simulation, the reconstruction of 40K, 232Th and 238U fundamental spectra, the customization in relation to different experimental scenarios and the investigation of effects due to individual variables for sensitivity studies. The reliability of the simulation is effectively validated against an experimental measurement with known soil water content and radionuclides abundances. The relation between soil water content and gamma signal is theoretically derived and applied to a Monte Carlo synthetic calibration performed with the specific soil composition of the experimental site. Ready to use general formulae and simulated coefficients for the estimation of soil water content are also provided adopting standard soil compositions. Linear regressions between input and output soil water contents, inferred from simulated 40K and 208Tl gamma signals, provide excellent results demonstrating the capability of the proposed method in estimating soil water content with an average uncertainty <1%.
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Affiliation(s)
- Marica Baldoncini
- INFN, Legnaro National Laboratories, Viale dell'Università 2, 35020, Legnaro, Padua, Italy; Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy.
| | - Matteo Albéri
- INFN, Legnaro National Laboratories, Viale dell'Università 2, 35020, Legnaro, Padua, Italy; Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy
| | - Carlo Bottardi
- Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy; INFN, Ferrara Section, Via Saragat 1, 44121, Ferrara, Italy
| | - Enrico Chiarelli
- INFN, Legnaro National Laboratories, Viale dell'Università 2, 35020, Legnaro, Padua, Italy; Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy
| | - Kassandra Giulia Cristina Raptis
- INFN, Legnaro National Laboratories, Viale dell'Università 2, 35020, Legnaro, Padua, Italy; Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy
| | - Virginia Strati
- Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy; INFN, Ferrara Section, Via Saragat 1, 44121, Ferrara, Italy
| | - Fabio Mantovani
- Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy; INFN, Ferrara Section, Via Saragat 1, 44121, Ferrara, Italy
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8
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In situ measurement of radioactive contamination of bottom sediments. Appl Radiat Isot 2018; 139:114-120. [DOI: 10.1016/j.apradiso.2018.04.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 11/17/2022]
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9
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González ER, Mainardi RT, Grad GB, Bonzi EV. A methodology to determine natural radioactivity by γ spectrometry without using calibrated standard samples. Appl Radiat Isot 2017; 125:48-52. [DOI: 10.1016/j.apradiso.2017.03.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 03/22/2017] [Indexed: 11/30/2022]
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10
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Androulakaki EG, Tsabaris C, Eleftheriou G, Kokkoris M, Patiris DL, Pappa FK, Vlastou R. Efficiency calibration for in situ γ-ray measurements on the seabed using Monte Carlo simulations: Application in two different marine environments. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 164:47-59. [PMID: 27420593 DOI: 10.1016/j.jenvrad.2016.06.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 06/02/2016] [Accepted: 06/20/2016] [Indexed: 06/06/2023]
Abstract
A new approach for calibrating an in situ detection system for measurements in marine sediments has been developed. The efficiency calibration was deduced on full spectral range by Monte Carlo simulations (MCNP5 code) considering a close detector-seabed geometry set-up. Moreover, the influence of the detection efficiency with respect to the variations of the sediment geological characteristics was studied through Monte Carlo simulations. The results of the theoretical approach were compared with experimental calculations in two different real test cases, yielding a satisfactory agreement (up to 10% and 20% for sites 1 and 2 respectively) in the energy range from 351 keV to 2614 keV. For the experimental measurements, the in situ detection system KATERINA was deployed both in the seawater and on the seabed in two different marine environments. The experimental determinations of the detection efficiency were performed by utilizing the acquired data of the deployments, along with additional necessary laboratory measurements. The adopted approach and the obtained results are discussed.
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Affiliation(s)
- E G Androulakaki
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR 19013, Anavyssos, Greece; National Technical University of Athens, Department of Physics, Zografou Campus, GR 15780, Athens, Greece.
| | - C Tsabaris
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR 19013, Anavyssos, Greece
| | - G Eleftheriou
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR 19013, Anavyssos, Greece; National Technical University of Athens, Department of Physics, Zografou Campus, GR 15780, Athens, Greece
| | - M Kokkoris
- National Technical University of Athens, Department of Physics, Zografou Campus, GR 15780, Athens, Greece
| | - D L Patiris
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR 19013, Anavyssos, Greece
| | - F K Pappa
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, GR 19013, Anavyssos, Greece; National Technical University of Athens, Department of Physics, Zografou Campus, GR 15780, Athens, Greece
| | - R Vlastou
- National Technical University of Athens, Department of Physics, Zografou Campus, GR 15780, Athens, Greece
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11
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Androulakaki E, Kokkoris M, Tsabaris C, Eleftheriou G, Patiris D, Pappa F, Vlastou R. In situ γ-ray spectrometry in the marine environment using full spectrum analysis for natural radionuclides. Appl Radiat Isot 2016; 114:76-86. [DOI: 10.1016/j.apradiso.2016.05.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 10/21/2022]
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12
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Abdollahnejad H, Vosoughi N, Zare MR. Design and fabrication of an in situ gamma radioactivity measurement system for marine environment and its calibration with Monte Carlo method. Appl Radiat Isot 2016; 114:87-91. [PMID: 27213808 DOI: 10.1016/j.apradiso.2016.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 05/04/2016] [Accepted: 05/13/2016] [Indexed: 11/27/2022]
Abstract
Simulation, design and fabrication of a sealing enclosure is carried out for a NaI(Tl) 2″×2″ detector, to be used as in situ gamma radioactivity measurement system in marine environment. Effect of sealing enclosure on performance of the system in laboratory and marine environment (distinct tank with 10m(3) volume) were studied using point sources. The marine volumetric efficiency for radiation with 1461keV energy (from (40)K) is measured with KCl volumetric liquid source diluted in distinct tank. The experimental and simulated efficiency values agreed well. Marine volumetric efficiency calibration curve is calculated for 60keV to 1461keV energy with Monte Carlo method. This curve indicates that efficiency increasing rapidly up to 140.5keV but then drops exponentially.
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Affiliation(s)
- Hamed Abdollahnejad
- Faculty of Energy Engineering, Sharif University of Technology, P.O. Box 8639-11365, Tehran, Iran.
| | - Naser Vosoughi
- Faculty of Energy Engineering, Sharif University of Technology, P.O. Box 8639-11365, Tehran, Iran
| | - Mohammad Reza Zare
- Faculty of Physics, University of Isfahan, P.O. Box 81746-73441, Isfahan, Iran
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13
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Cinelli G, Tositti L, Mostacci D, Baré J. Calibration with MCNP of NaI detector for the determination of natural radioactivity levels in the field. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 155-156:31-37. [PMID: 26913974 DOI: 10.1016/j.jenvrad.2016.02.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 02/08/2016] [Accepted: 02/10/2016] [Indexed: 06/05/2023]
Abstract
In view of assessing natural radioactivity with on-site quantitative gamma spectrometry, efficiency calibration of NaI(Tl) detectors is investigated. A calibration based on Monte Carlo simulation of detector response is proposed, to render reliable quantitative analysis practicable in field campaigns. The method is developed with reference to contact geometry, in which measurements are taken placing the NaI(Tl) probe directly against the solid source to be analyzed. The Monte Carlo code used for the simulations was MCNP. Experimental verification of the calibration goodness is obtained by comparison with appropriate standards, as reported. On-site measurements yield a quick quantitative assessment of natural radioactivity levels present ((40)K, (238)U and (232)Th). On-site gamma spectrometry can prove particularly useful insofar as it provides information on materials from which samples cannot be taken.
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Affiliation(s)
- Giorgia Cinelli
- European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Nuclear Security Unit, Via Enrico Fermi 2749, 21027 Ispra VA, Italy.
| | - Laura Tositti
- Department of Chemistry «Giacomo Ciamician», Alma Mater Studiorum University of Bologna, Via Selmi 2, 40126 Bologna, Italy
| | - Domiziano Mostacci
- Laboratory of Nuclear Engineering, Alma Mater Studiorum-University of Bologna, Via dei Colli 16, 40136 Bologna, Italy
| | - Jonathan Baré
- Laboratoire de Physique des Radiations, Institut Supérieur Industriel de Bruxelles, H.-E. Paul-Henri Spaak, Rue Royale, 150, 1000 Bruxelles, Belgium
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14
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Seabed radioactivity based on in situ measurements and Monte Carlo simulations. Appl Radiat Isot 2015; 101:83-92. [DOI: 10.1016/j.apradiso.2015.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 12/22/2014] [Accepted: 03/13/2015] [Indexed: 11/23/2022]
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15
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Monte Carlo simulation of a NaI(Tl) detector for in situ radioactivity measurements in the marine environment. Appl Radiat Isot 2015; 98:44-8. [DOI: 10.1016/j.apradiso.2015.01.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 12/18/2014] [Accepted: 01/07/2015] [Indexed: 11/21/2022]
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16
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Radioactivity measurements in the aquatic environment using in-situ and laboratory gamma-ray spectrometry. Appl Radiat Isot 2013; 82:268-78. [DOI: 10.1016/j.apradiso.2013.08.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 07/25/2013] [Accepted: 08/16/2013] [Indexed: 11/19/2022]
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17
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Casanovas R, Morant JJ, Salvadó M. Implementation of gamma-ray spectrometry in two real-time water monitors using NaI(Tl) scintillation detectors. Appl Radiat Isot 2013; 80:49-55. [PMID: 23827508 DOI: 10.1016/j.apradiso.2013.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 05/30/2013] [Accepted: 06/04/2013] [Indexed: 10/26/2022]
Abstract
In this study, the implementation of gamma-ray spectrometry in two real-time water monitors using 2 in. × 2 in. NaI(Tl) scintillation detectors is described. These monitors collect the water from the river through a pump and it is analyzed in a vessel, which is shielded with Pb. The full calibration of the monitors was performed experimentally, except for the efficiency curve, which was set using validated Monte Carlo simulations with the EGS5 code system. After the calibration, the monitors permitted the identification and quantification of the involved isotopes in a possible radioactive increment and made it possible to discard possible leaks in the nuclear plants. As an example, a radiological increment during rain is used to show the advantages of gamma-ray spectrometry. To study the capabilities of the monitor, the minimum detectable activity concentrations for (131)I, (137)Cs and (40)K are presented for different integration times.
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Affiliation(s)
- R Casanovas
- Unitat de Física Mèdica, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, ES-43201 Reus (Tarragona), Spain.
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18
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Ahmadi M, Mir Ahmadpour P, Rabbani M. Designing of an online system for radiocaesium measurements in the marine environment. Appl Radiat Isot 2011; 69:1079-83. [PMID: 21388816 DOI: 10.1016/j.apradiso.2010.11.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 10/31/2010] [Accepted: 11/23/2010] [Indexed: 10/18/2022]
Abstract
An online radiocaesium measuring system (ORMS) is designed to determine the environmental radiocaesium contamination of sea water near the Bushehr Nuclear Power Plant (BNPP). The System consists of a 400-liter, spherical stainless steel water tank, including three aluminum (0.5mm) enclosure NaI (TI) detectors, which each are located in 120° phase angle with size (6×3in.) to confirm each other. Responses of detectors to gamma radiations were calculated, using Monte Carlo code MCNP.4C. Moreover, delay time of each response and the dead time of the whole system to be considered due to designing decisions were calculated.
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Affiliation(s)
- M Ahmadi
- Development of Reactors and Accelerators Research School, Nuclear Science and Technology Institute, Tehran, Iran
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Bagatelas C, Tsabaris C, Kokkoris M, Papadopoulos CT, Vlastou R. Determination of marine gamma activity and study of the minimum detectable activity (MDA) in 4pi geometry based on Monte Carlo simulation. ENVIRONMENTAL MONITORING AND ASSESSMENT 2010; 165:159-168. [PMID: 19421884 DOI: 10.1007/s10661-009-0935-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 04/18/2009] [Indexed: 05/27/2023]
Abstract
Monte Carlo simulations were performed using the GEANT4 code for the investigation of gamma-ray absorption in water in different spherical geometries and of the efficiency of a NaI(Tl) detector for different radionuclides in the aquatic environment. In order to test the reliability of these simulations, experimental values of the NaI(Tl) detector efficiency were deduced and seem to be in good agreement with the simulated ones. In addition, using the simulated efficiency, an algorithm was developed to determine the minimum detectable activity in becquerels per cubic meter in situ as a function of energy for typical freshwater and seawater spectra.
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Affiliation(s)
- C Bagatelas
- Institute of Oceanography, Hellenic Centre for Marine Research, Anavyssos, Greece
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Rahman MS, Cho G, Kang BS. Deconvolution of gamma-ray spectra obtained with NAI(Tl) detector in a water tank. RADIATION PROTECTION DOSIMETRY 2009; 135:203-210. [PMID: 19502359 DOI: 10.1093/rpd/ncp102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Maximum-likelihood fitting by the expectation maximization deconvolution method is presented to analyse gamma-ray spectra recorded using an NaI(Tl) detector for a water monitoring system. The applicability of the method was tested by deconvolving measured spectra taken using an industry standard 3'' x 3'' cylindrical NaI(Tl) detector in a model water tank with several calibration sources. The results show significant removal of the Compton continuum counts and efficient transfer of the counts into the corresponding photo-peaks. The peak-to-total count ratio and the number of counts in the photo-peaks in the deconvolved spectra increased approximately 4.67 and 5.29 times, respectively, compared with those of measured spectra taken using an NaI(Tl) scintillation detector in the case of (137)Cs.
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Affiliation(s)
- M Sohelur Rahman
- Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea
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Tsabaris C, Bagatelas C, Dakladas T, Papadopoulos C, Vlastou R, Chronis G. An autonomous in situ detection system for radioactivity measurements in the marine environment. Appl Radiat Isot 2008; 66:1419-26. [DOI: 10.1016/j.apradiso.2008.02.064] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Accepted: 02/10/2008] [Indexed: 10/22/2022]
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