{"title":"Conceptual design of sandwich walls for shielding against secondary neutrons using MC simulations with FLUKA","authors":"Redona Bexheti , Mimoza Ristova","doi":"10.1016/j.apradiso.2024.111525","DOIUrl":null,"url":null,"abstract":"<div><div>FLUKA Monte-Carlo transport code was employed to evaluate the secondary neutron spectra emerging from spherical sandwich shielding configurations composed of concrete and soil, similar to that used at the particle therapy facility MedAustron. This study provides a comparative analysis of neutron spectra attenuated by a concrete-soil-concrete (CSC) sandwich wall shielding configuration versus a full concrete wall design (CCC). Furthermore, we enhanced the shielding performance of the CSC configuration by adding an additional concrete layer (CCSC) to achieve results comparable to the CCC shielding. Two scenarios were tested for shielding performance: (1) primary protons at 100 MeV, and (2) primary carbon ions (C-ions) at 190 MeV/u. Our simulations with primary protons of 100 MeV showed that adding additional internal concrete wall to the CSC configuration, therefore designing the CCSC configuration, the RP performance becomes slightly improved – the HE-peak drops from (1.43 ± 0.11)10<sup>−11</sup> to (5.62 ± 0.3)10<sup>−12</sup>, about 2.5 times. Still, the HE-peak of the exiting neutron spectrum from CCC -(6.29 ± 1.87) 10<sup>−13</sup> is about 9 times lower than that exiting CCSC - (5.62 ± 0.3) 10<sup>−12</sup>.</div><div>Our simulations with primary C-ions showed that by placing an additional internal concrete wall to the CSC configuration (CCSC) the RP performance becomes slightly improved – the exiting HE peak can be further attenuated from (6.92 ± 0.40)10<sup>−9</sup> for CSC to (3.79 ± 0.15)10<sup>−9</sup>, becoming comparable to the one exiting the CCC configuration, (0.92 ± 0.04)10<sup>−9</sup>, only 4 times higher. Future research should be focused on improvements of the RP performance of the CCSC, by increasing the soil layer thickness and taking into consideration the humidity (water content) in the soil and concrete and also improve the number of primaries to 10<sup>9</sup> or even 10<sup>10</sup> for better statistical outcome.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"214 ","pages":"Article 111525"},"PeriodicalIF":1.6000,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Radiation and Isotopes","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0969804324003531","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
Abstract
FLUKA Monte-Carlo transport code was employed to evaluate the secondary neutron spectra emerging from spherical sandwich shielding configurations composed of concrete and soil, similar to that used at the particle therapy facility MedAustron. This study provides a comparative analysis of neutron spectra attenuated by a concrete-soil-concrete (CSC) sandwich wall shielding configuration versus a full concrete wall design (CCC). Furthermore, we enhanced the shielding performance of the CSC configuration by adding an additional concrete layer (CCSC) to achieve results comparable to the CCC shielding. Two scenarios were tested for shielding performance: (1) primary protons at 100 MeV, and (2) primary carbon ions (C-ions) at 190 MeV/u. Our simulations with primary protons of 100 MeV showed that adding additional internal concrete wall to the CSC configuration, therefore designing the CCSC configuration, the RP performance becomes slightly improved – the HE-peak drops from (1.43 ± 0.11)10−11 to (5.62 ± 0.3)10−12, about 2.5 times. Still, the HE-peak of the exiting neutron spectrum from CCC -(6.29 ± 1.87) 10−13 is about 9 times lower than that exiting CCSC - (5.62 ± 0.3) 10−12.
Our simulations with primary C-ions showed that by placing an additional internal concrete wall to the CSC configuration (CCSC) the RP performance becomes slightly improved – the exiting HE peak can be further attenuated from (6.92 ± 0.40)10−9 for CSC to (3.79 ± 0.15)10−9, becoming comparable to the one exiting the CCC configuration, (0.92 ± 0.04)10−9, only 4 times higher. Future research should be focused on improvements of the RP performance of the CCSC, by increasing the soil layer thickness and taking into consideration the humidity (water content) in the soil and concrete and also improve the number of primaries to 109 or even 1010 for better statistical outcome.
期刊介绍:
Applied Radiation and Isotopes provides a high quality medium for the publication of substantial, original and scientific and technological papers on the development and peaceful application of nuclear, radiation and radionuclide techniques in chemistry, physics, biochemistry, biology, medicine, security, engineering and in the earth, planetary and environmental sciences, all including dosimetry. Nuclear techniques are defined in the broadest sense and both experimental and theoretical papers are welcome. They include the development and use of α- and β-particles, X-rays and γ-rays, neutrons and other nuclear particles and radiations from all sources, including radionuclides, synchrotron sources, cyclotrons and reactors and from the natural environment.
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