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Qiao Y, Zhao W, Hei H, Han Y, Wang Q, Fang K, Zhang S. Optimization design of the portable cylindrical water injection multilayer neutron spectrometer. Appl Radiat Isot 2023; 201:111010. [PMID: 37678071 DOI: 10.1016/j.apradiso.2023.111010] [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: 03/03/2023] [Revised: 07/22/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023]
Abstract
The currently widely used multi-sphere neutron spectrometers still have many drawbacks, including complex design and processing, the need for multiple moderating spheres, high costs, large volumes, and complicated measurement procedures. This work proposes the portable cylindrical water injection multilayer neutron spectrometer (CWNS) as a promising alternative based on water pumping injection. The structure of CWNS consists of a central thermal neutron detector and a surrounding 6-layer of coaxial cylindrical water bags with varying diameters. During non-measurement periods, this CWNS is convenient to carry due to the absence of the need to inject moderating water. To optimize the CWNS design, we employed FLUKA simulation software to study and refine various parameters, including the thickness of the water bag, the material composition of the water bag, and the parameters of the supporting column. We finally achieved an optimized design. Specifically, the water bag of the CWNS is constructed using a 0.3 mm thick polyethylene film. The supporting column for the water bag is made of aluminum, providing stability and support to the overall structure. These optimized design parameters determine the specific size and configuration of the CWNS. The CWNS offers the benefits of convenient carrying, simplified processing, cost-effectiveness, and straightforward measurement. It has a promising potential use for the directional neutron dose monitoring.
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Affiliation(s)
- Yujie Qiao
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Weijia Zhao
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Huimin Hei
- The Fourth Research and Design Engineering Corporation of CNNC, Shijiazhuang, 050000, China
| | - Yafei Han
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Qiang Wang
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Kaihong Fang
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Shuo Zhang
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou, 730000, China.
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Li C, Zhou H, Liu H, Sun T, Fan H, Yang J, Xiao W. Neutron spectrometry of D 2O-moderated 252Cf with Bonner sphere spectrometer. Appl Radiat Isot 2023; 197:110824. [PMID: 37075588 DOI: 10.1016/j.apradiso.2023.110824] [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: 09/30/2022] [Revised: 02/28/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
For neutron spectrometry of the D2O-moderated 252Cf source with a Bonner sphere spectrometer (BSS), it is difficult to use the large and heavy shadow cone to correct the neutron scattering effect. To overcome this problem, Monte Carlo (MC) simulation method was applied to calculate the neutron scattering ratio and to establish the BSS response functions. The simulated response functions were verified by experimental measurements in reference mono-energetic neutron fields. MC simulation based scattering-correction was validated by measurement of 252Cf neutron field. The measured and simulated values of the neutron scattering ratio were very close with relative errors within ±6%. Finally, the neutron spectrum and the spectrum averaged conversion coefficients of the D2O-moderated 252Cf were measured using BSS after scattering-correction by MC simulation, and the results agreed with the values recommended by ISO 8529-1:2021. It shows that the MC simulation can be a useful substitute to shadow cones method for neutron scattering-correction.
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Affiliation(s)
- Chongwei Li
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Hongzhao Zhou
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Haixia Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing, China.
| | - Tao Sun
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Haijun Fan
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Jun Yang
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Wuyun Xiao
- State Key Laboratory of NBC Protection for Civilian, Beijing, China.
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3
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Paterson LC, Yonkeu A, Ali F, Priest ND, Boreham DR, Seymour CB, Norton F, Richardson RB. Relative Biological Effectiveness and Non-Poissonian Distribution of Dicentric Chromosome Aberrations following Californium-252 Neutron Exposures of Human Peripheral Blood Lymphocytes. Radiat Res 2021; 195:211-217. [PMID: 33400791 DOI: 10.1667/rr15528.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 10/30/2020] [Indexed: 11/03/2022]
Abstract
Cells exposed to fast neutrons often exhibit a non-Poisson distribution of chromosome aberrations due to the high ionization density of the secondary reaction products. However, it is unknown whether lymphocytes exposed to californium-252 (252Cf) spectrum neutrons, of mean energy 2.1 MeV, demonstrate this same dispersion effect at low doses. Furthermore, there is no consensus regarding the relative biological effectiveness (RBE) of 252Cf neutrons. Dicentric and ring chromosome formations were assessed in human peripheral blood lymphocytes irradiated at doses of 12-135 mGy. The number of aberrations observed were tested for adherence to a Poisson distribution and the maximum low-dose relative biological effectiveness (RBEM) was also assessed. When 252Cf-irradiated lymphocytes were examined along with previously published cesium-137 (137Cs) data, RBEM values of 15.0 ± 2.2 and 25.7 ± 3.8 were found for the neutron-plus-photon and neutron-only dose components, respectively. Four of the five dose points were found to exhibit the expected, or close to the expected non-Poisson over-dispersion of aberrations. Thus, even at low doses of 252Cf fast neutrons, when sufficient lymphocyte nuclei are scored, chromosome aberration clustering can be observed.
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Affiliation(s)
- Laura C Paterson
- Canadian Nuclear Laboratories, Chalk River, Canada.,McGill University, Montreal, Canada
| | - Andre Yonkeu
- Canadian Nuclear Laboratories, Chalk River, Canada
| | - Fawaz Ali
- Canadian Nuclear Laboratories, Chalk River, Canada
| | | | - Douglas R Boreham
- McMaster University, Hamilton, Canada.,Northern Ontario School of Medicine, Sudbury, Canada
| | | | | | - Richard B Richardson
- Canadian Nuclear Laboratories, Chalk River, Canada.,McGill University, Montreal, Canada
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Application of the Reduced-Fitting Method to determine neutron scattering. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2020.109207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Seydaliev M, Dubeau J, Ali F. SINGLE ANODE TRIPLE GEM TISSUE EQUIVALENT PROPORTIONAL COUNTER AS THE BASIS FOR A PERSONAL NEUTRON DOSIMETER. RADIATION PROTECTION DOSIMETRY 2017; 174:337-347. [PMID: 27574327 DOI: 10.1093/rpd/ncw193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 04/22/2016] [Indexed: 06/06/2023]
Abstract
This paper reports on a tissue-equivalent proportional counter (TEPC) based on a triple gas electron multiplier structure, with a single pad readout, as a basis for a personal neutron dosimeter. Its dosimetric response was studied using the 252Cf neutron source at the Health Physics Generator Facility of the Canadian Nuclear Laboratories. Measured lineal energy spectra were found to be in agreement with numerical simulations performed with Monte Carlo N-Particle eXtended (MCNPX). Both simulations and measurements showed that the mean pathlength of secondary charged particles in the TEPC gas was best represented by the thickness of the drift region of the device. It was determined that the Cauchy Theorem, used to calculate the mean chord length in spherical and cylindrical TEPCs, overestimated the simulated mean chord length by nearly a factor of two. Important operational characteristics of the device were investigated, including gas gain, sensitivity and dosimetric response, as functions of tissue-equivalent gas pressure. This work demonstrates that the proposed design can serve as the basis for a personal neutron dosimeter device, which would satisfy the angular dosimetric response criteria of the personal dosimeter standard IEC61526.
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Affiliation(s)
- M Seydaliev
- Canadian Nuclear Laboratories, Chalk River, Ontario K0J 1J0, Canada
| | - J Dubeau
- DETEC, Gatineau, Quebec J8T 4J1, Canada
| | - F Ali
- Canadian Nuclear Laboratories, Chalk River, Ontario K0J 1J0, Canada
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Seydaliev M, Dubeau J, Hakmana Witharana SS. 2-D GEM-BASED TEPC FOR NEUTRON PROTECTION DOSIMETRY. CNL NUCLEAR REVIEW 2016. [DOI: 10.12943/cnr.2016.00012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Mazrou H, Nedjar A, Seguini T. Neutron spectrum measurements at a radial beam port of the NUR research reactor using a Bonner spheres spectrometer. Appl Radiat Isot 2016; 114:63-70. [PMID: 27203706 DOI: 10.1016/j.apradiso.2016.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 05/02/2016] [Accepted: 05/10/2016] [Indexed: 10/21/2022]
Abstract
This paper describes the measurement campaign held around the neutron radiography (NR) facility of the Algerian 1MW NUR research reactor. The main objective of this work is to characterize accurately the neutron beam provided at one of the radial channels of the NUR research reactor taking benefit of the acquired CRNA Bonner spheres spectrometer (BSS). The specific objective was to improve the image quality of the NR facility. The spectrometric system in use is based on a central spherical (3)He thermal neutron proportional counter combined with high density polyethylene spheres of different diameters ranging from 3 to 12in. This counting system has good gamma ray discrimination and is able to cover an energy range from thermal to 20MeV. The measurements were performed at the sample distance of 0.6m from the beam port and at a height of 1.2m from the facility floor. During the BSS measurements, the reactor was operating at low power (100W) to avoid large dead times, pulse pileup and high level radiation exposures, in particular, during spheres handling. Thereafter, the neutron spectrum at the sample position was unfolded by means of GRAVEL and MAXED computer codes. The thermal, epithermal and fast neutron fluxes, the total neutron flux, the mean energy and the Cadmium ratio (RCd) were provided. A sensitivity analysis was performed taking into account various defaults spectra and ultimately a different response functions in the unfolding procedure. Overall, from the obtained results it reveals, unexpectedly, that the measured neutron spectrum at the sample position of the neutron radiography of the NUR reactor is being harder with a predominance of fast neutrons (>100keV) by about 60%. Finally, those results were compared to previous and more recent measurements obtained by activation foils detectors. The agreement was fairly good highlighting thereby the consistency of our findings.
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Affiliation(s)
- H Mazrou
- Division de Physique Radiologique - Centre de Recherche Nucléaire d'Alger (CRNA), 02 Boulevard Frantz - Fanon, B.P. 399, Alger-RP, 16000, Algeria.
| | - A Nedjar
- Division de Physique et des Applications Nucléaires - Centre de Recherche Nucléaire de Draria (CRND), Route de Sebala, B.P. 43, Alger, Draria 16050, Algeria
| | - T Seguini
- Division de Physique et des Applications Nucléaires - Centre de Recherche Nucléaire de Draria (CRND), Route de Sebala, B.P. 43, Alger, Draria 16050, Algeria
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