Dimitris Mavrikis, Tatiana Siarafera, E. Ntalla, A. Markopoulos, A. Ioannidou, A. Savidou
The present work concerns the development of a technique for activity determination of 68Ge/68Ga and 57Co disused radioactive sources. This technique aims to determine the activity of these sources by measuring and Monte Carlo simulation using the MCNPX code. Therefore, efficiency calibrations of the 3 x 3 NaI(Tl) detector for specific source geometries were carried out. Spectrums for two types of disused radioactive sources were collected for different measurement times. The characteristic gamma rays of a flood source containing 57Co and a line source containing 68Ge/68Ga, were used. In case of 68Ge/68Ga, the annihilation peak of 511 keV was also used considering the disused radioactive sources as a positron emitter. Sources of the mentioned types with certified nominal activities were used to validate MCNPX models. For the 57Co source, 15 minutes measuring time was adequate for activity determination, and 2 hours measuring time provided adequate sensitivity, at the level of general clearance. For 68Ge/68Ga line source, 15 minutes measurement was adequate for activity determination by using the 511 keV from the annihilation of 1899.1 keV positrons.
{"title":"Measurement technique for characterization and recording of spent 57Co and 68Ge/68Ga sealed radioactive sources","authors":"Dimitris Mavrikis, Tatiana Siarafera, E. Ntalla, A. Markopoulos, A. Ioannidou, A. Savidou","doi":"10.2298/ntrp2301053m","DOIUrl":"https://doi.org/10.2298/ntrp2301053m","url":null,"abstract":"The present work concerns the development of a technique for activity determination of 68Ge/68Ga and 57Co disused radioactive sources. This technique aims to determine the activity of these sources by measuring and Monte Carlo simulation using the MCNPX code. Therefore, efficiency calibrations of the 3 x 3 NaI(Tl) detector for specific source geometries were carried out. Spectrums for two types of disused radioactive sources were collected for different measurement times. The characteristic gamma rays of a flood source containing 57Co and a line source containing 68Ge/68Ga, were used. In case of 68Ge/68Ga, the annihilation peak of 511 keV was also used considering the disused radioactive sources as a positron emitter. Sources of the mentioned types with certified nominal activities were used to validate MCNPX models. For the 57Co source, 15 minutes measuring time was adequate for activity determination, and 2 hours measuring time provided adequate sensitivity, at the level of general clearance. For 68Ge/68Ga line source, 15 minutes measurement was adequate for activity determination by using the 511 keV from the annihilation of 1899.1 keV positrons.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68551267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Kartalović, Uroš Kovačević, Dušan P. Nikezić, Alija Jusić
The study considers the impact of the environmental contamination by the electromagnetic radiation of electron beam generator and high-energy radioactive source on the memory components. Electron beam generator can be used for injecting particle energy into the plasma of the fusion system based on a Marx generator, while radioactive source as a simulator of high-energy ionizing radiation that can be caused by the neutron-induced activation of plasma surrounding structures or released from deuterium-tritium fusion reaction. The effects of gamma radiation of high-energy radioactive source and electric field of the electron beam generator on EPROM and EEPROM semiconductor computer memory, were investigated. An older memory types were deliberately chosen for the reason that their more robust construction will better protect them from the effects of ionizing and non-ionizing radiation. The results obtained under well-controlled conditions show a high degree of non-resistance of the semiconductor technology to the expected electromagnetic pollution of the electron beam generator and high-energy radioactive source. This conclusion raises doubts on the possibility of simultaneous application of electron beam generator, consequently fusion system and nanotechnologies with the increasing need for miniaturization of electronic components.
{"title":"Influence of electromagnetic pollution of the electron beam generator and high-energy radioactive source on the memory components","authors":"N. Kartalović, Uroš Kovačević, Dušan P. Nikezić, Alija Jusić","doi":"10.2298/ntrp2301010k","DOIUrl":"https://doi.org/10.2298/ntrp2301010k","url":null,"abstract":"The study considers the impact of the environmental contamination by the electromagnetic radiation of electron beam generator and high-energy radioactive source on the memory components. Electron beam generator can be used for injecting particle energy into the plasma of the fusion system based on a Marx generator, while radioactive source as a simulator of high-energy ionizing radiation that can be caused by the neutron-induced activation of plasma surrounding structures or released from deuterium-tritium fusion reaction. The effects of gamma radiation of high-energy radioactive source and electric field of the electron beam generator on EPROM and EEPROM semiconductor computer memory, were investigated. An older memory types were deliberately chosen for the reason that their more robust construction will better protect them from the effects of ionizing and non-ionizing radiation. The results obtained under well-controlled conditions show a high degree of non-resistance of the semiconductor technology to the expected electromagnetic pollution of the electron beam generator and high-energy radioactive source. This conclusion raises doubts on the possibility of simultaneous application of electron beam generator, consequently fusion system and nanotechnologies with the increasing need for miniaturization of electronic components.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68550673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Vuong, H. Chuong, Lam Nhat, H. Tam, T. Thanh, V. Minh, Le Hung, P. Ho, C. Tao
This study is aimed at assessing radiation hazards associated with natural radioactivity in common building materials used in Ho Chi Minh City, Vietnam. Thirty-six samples from eighteen types of building materials were collected to measure activity concentrations using the gross alpha/beta counting system and gamma-ray spectrometry. The gross alpha and gross beta activity concentrations ranged from 94.7 ? 31.3 to 1045.1 ? 112.3 Bqkg-1 and 104.9 ? 4.7 to 834.4 ? 37.1 Bqkg-1, respectively. In addition, the activity concentrations of 226Ra, 232Th, and 40K were also determined, which ranged from 4.1 ? 0.1 to 53.5 ? 0.4 Bqkg-1, 5.7 ? 0.1 to 83.6 ? 0.8 Bqkg-1, and 14.9 ? 0.8 to 664.9 ? 10.6 Bqkg-1, respectively. The indices including radium equivalent activity, external and internal radiation hazard, gamma and alpha indices, activity utilization index, and annual effective dose, were calculated to evaluate the radiological hazards of natural radioactivity. The results showed that these indices were below the recommended safety limits for most investigated samples except six brick samples, whose activity utilization indexes are slightly higher than the safety limit. Even so, all annual effective doses of the samples were found to be below the world average.
{"title":"Assessing radiation hazards associated with natural radioactivity in building materials in Ho Chi Minh City, Vietnam","authors":"L. Vuong, H. Chuong, Lam Nhat, H. Tam, T. Thanh, V. Minh, Le Hung, P. Ho, C. Tao","doi":"10.2298/ntrp2301030v","DOIUrl":"https://doi.org/10.2298/ntrp2301030v","url":null,"abstract":"This study is aimed at assessing radiation hazards associated with natural radioactivity in common building materials used in Ho Chi Minh City, Vietnam. Thirty-six samples from eighteen types of building materials were collected to measure activity concentrations using the gross alpha/beta counting system and gamma-ray spectrometry. The gross alpha and gross beta activity concentrations ranged from 94.7 ? 31.3 to 1045.1 ? 112.3 Bqkg-1 and 104.9 ? 4.7 to 834.4 ? 37.1 Bqkg-1, respectively. In addition, the activity concentrations of 226Ra, 232Th, and 40K were also determined, which ranged from 4.1 ? 0.1 to 53.5 ? 0.4 Bqkg-1, 5.7 ? 0.1 to 83.6 ? 0.8 Bqkg-1, and 14.9 ? 0.8 to 664.9 ? 10.6 Bqkg-1, respectively. The indices including radium equivalent activity, external and internal radiation hazard, gamma and alpha indices, activity utilization index, and annual effective dose, were calculated to evaluate the radiological hazards of natural radioactivity. The results showed that these indices were below the recommended safety limits for most investigated samples except six brick samples, whose activity utilization indexes are slightly higher than the safety limit. Even so, all annual effective doses of the samples were found to be below the world average.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68551019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanja Jevtić, M. Sreckovic, N. Mitrović, Katarina Zarubica, V. Zarubica, A. Janićijević, Z. Stević
Aromatic plants and laser beam wavelength in the red range of visible spectra (623.8 nm), most commonly used for treating plant species, were selected. As there is not much information in the references, it is necessary to set a scale with qualitative and partially quantitative evaluations of the results. Specimens of thyme seed (Thymus vulgaris) were selected as aromatic plants for studying the effect of low-power lasers on plant development, and continuous He-Ne laser, with irradiation times in the range of minutes.
{"title":"Influence of gaseous laser in continuous-wave and pulse regimes on biomaterial characteristics","authors":"Sanja Jevtić, M. Sreckovic, N. Mitrović, Katarina Zarubica, V. Zarubica, A. Janićijević, Z. Stević","doi":"10.2298/ntrp2301059j","DOIUrl":"https://doi.org/10.2298/ntrp2301059j","url":null,"abstract":"Aromatic plants and laser beam wavelength in the red range of visible spectra (623.8 nm), most commonly used for treating plant species, were selected. As there is not much information in the references, it is necessary to set a scale with qualitative and partially quantitative evaluations of the results. Specimens of thyme seed (Thymus vulgaris) were selected as aromatic plants for studying the effect of low-power lasers on plant development, and continuous He-Ne laser, with irradiation times in the range of minutes.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68551296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Changli Luo, Wuyuan Li, Bo Yang, Youwu Su, Yang Li, Shakhboz Khasanova, W. Mao, Xuebo Liu, Weiwei Yan, Zongqiang Li
Heavy-ion radiotherapy is currently recognized as the most advanced particle therapy method and is being vigorously promoted and applied worldwide. This method can rapidly generate radiation and induce radioactivity during treatment. However, the induced radioactivity, which is the primary source of exposure for medical staff, does not disappear following therapeutic application in the treatment room. In this study, we investigated the characteristics, dose rate distribution, and impact of this induced radioactivity on medical staff in the treatment room (uniform scanning mode) at Gansu Wuwei Tumor Hospital using experimental measurement and Monte Carlo simulation. We found that the exposure dose experienced by medical staff is predominantly related to the irradiated patients for single irradiation and the irradiated beam delivery system for long-term irradiation. The half-lives of the main radionuclides ranged from a few minutes to tens of minutes for single irradiation and from tens of days to hundreds of days for long-term irradiation. The primary radionuclide contributors are 15O, 11C, 176Ta, and 177W. We also estimated the personal dose experienced by the medical staff in the treatment room in relation to their working patterns. The results showed that the maximum annual exposure dose of medical staff in the horizontal treatment direction under the current model was 0.728 mSv. We hypothesized that an appropriate increase in the patient's treatment could reduce the annual exposure dose of medical staff to 0.650 mSv without changing the total treatment time per day. Finally, some suggestions were made to reduce the exposure of medical staff to unwanted radiation.
{"title":"Study on occupational exposure of medical staff caused by induced radioactivity in the treatment room of medical heavy-ion facility","authors":"Changli Luo, Wuyuan Li, Bo Yang, Youwu Su, Yang Li, Shakhboz Khasanova, W. Mao, Xuebo Liu, Weiwei Yan, Zongqiang Li","doi":"10.2298/ntrp2301039l","DOIUrl":"https://doi.org/10.2298/ntrp2301039l","url":null,"abstract":"Heavy-ion radiotherapy is currently recognized as the most advanced particle therapy method and is being vigorously promoted and applied worldwide. This method can rapidly generate radiation and induce radioactivity during treatment. However, the induced radioactivity, which is the primary source of exposure for medical staff, does not disappear following therapeutic application in the treatment room. In this study, we investigated the characteristics, dose rate distribution, and impact of this induced radioactivity on medical staff in the treatment room (uniform scanning mode) at Gansu Wuwei Tumor Hospital using experimental measurement and Monte Carlo simulation. We found that the exposure dose experienced by medical staff is predominantly related to the irradiated patients for single irradiation and the irradiated beam delivery system for long-term irradiation. The half-lives of the main radionuclides ranged from a few minutes to tens of minutes for single irradiation and from tens of days to hundreds of days for long-term irradiation. The primary radionuclide contributors are 15O, 11C, 176Ta, and 177W. We also estimated the personal dose experienced by the medical staff in the treatment room in relation to their working patterns. The results showed that the maximum annual exposure dose of medical staff in the horizontal treatment direction under the current model was 0.728 mSv. We hypothesized that an appropriate increase in the patient's treatment could reduce the annual exposure dose of medical staff to 0.650 mSv without changing the total treatment time per day. Finally, some suggestions were made to reduce the exposure of medical staff to unwanted radiation.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68551041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Zuhair, W. Luthfi, Andika Dwijayanto, A. Rohanda, S. Suwoto
Thorium, in this case, 232Th has a higher thermal neutron capture cross-section than 238U, which means that more fertile isotopes can be transmuted and could lead to higher fissile isotope 233U. In addition, 233U has a good performance in the thermal spectrum. Theoretically, a nuclear reactor using thorium fuel can also last longer than one using uranium fuel. The use of TRISO duplex fuel is predicted to produce better neutronic behavior in a pebble bed reactor. This work aims to study the kinetic parameters of a pebble bed reactor with TRISO duplex fuel. The configuration of the TRISO duplex fuel pebble consists of an inner region filled with UO2 TRISO particles and an outer region filled with ThO2 TRISO particles surrounded by a graphite matrix of fuel pebble. Three configurations with volume fraction of UO2-ThO2 were considered in this study: 80-20 %, 75-25 %, and 70-30 %. The HTR-10 reactor was chosen as a reactor model because its geometry and material specifications are known. A series of calculations were conducted using the Monte Carlo transport code MCNP6 and ENDF/B-VII.1 nuclear data library. The calculation results were then analyzed to investigate the effect of UO2 and ThO2 compositions in TRISO duplex fuel on the kinetic parameters of the pebble bed reactor with various TRISO packing fractions of 1-50 %. It can be concluded that the utilization of TRISO duplex fuel in a pebble bed reactor could significantly affect the core multiplication factor and kinetic parameters caused by an increase in Th content. On the other hand, the TRISO packing fraction is taking part in neutron moderation since a lower packing fraction means higher moderation for fueled pebble.
{"title":"Study on kinetic parameters of pebble bed reactor with TRISO duplex fuel","authors":"Z. Zuhair, W. Luthfi, Andika Dwijayanto, A. Rohanda, S. Suwoto","doi":"10.2298/ntrp2301001z","DOIUrl":"https://doi.org/10.2298/ntrp2301001z","url":null,"abstract":"Thorium, in this case, 232Th has a higher thermal neutron capture cross-section than 238U, which means that more fertile isotopes can be transmuted and could lead to higher fissile isotope 233U. In addition, 233U has a good performance in the thermal spectrum. Theoretically, a nuclear reactor using thorium fuel can also last longer than one using uranium fuel. The use of TRISO duplex fuel is predicted to produce better neutronic behavior in a pebble bed reactor. This work aims to study the kinetic parameters of a pebble bed reactor with TRISO duplex fuel. The configuration of the TRISO duplex fuel pebble consists of an inner region filled with UO2 TRISO particles and an outer region filled with ThO2 TRISO particles surrounded by a graphite matrix of fuel pebble. Three configurations with volume fraction of UO2-ThO2 were considered in this study: 80-20 %, 75-25 %, and 70-30 %. The HTR-10 reactor was chosen as a reactor model because its geometry and material specifications are known. A series of calculations were conducted using the Monte Carlo transport code MCNP6 and ENDF/B-VII.1 nuclear data library. The calculation results were then analyzed to investigate the effect of UO2 and ThO2 compositions in TRISO duplex fuel on the kinetic parameters of the pebble bed reactor with various TRISO packing fractions of 1-50 %. It can be concluded that the utilization of TRISO duplex fuel in a pebble bed reactor could significantly affect the core multiplication factor and kinetic parameters caused by an increase in Th content. On the other hand, the TRISO packing fraction is taking part in neutron moderation since a lower packing fraction means higher moderation for fueled pebble.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68550602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Measurements of 238U, 232Th, and 40K activity concentrations in some commonly used medicinal plant parts have been performed for radiation hazard assessment and as baseline data for health risk monitoring in South Africa and other countries. The mean activity of 238U, 232Th, and 40K was found to be 43.3 Bqkg-1, 33.7 Bqkg-1, and 180 Bqkg-1 in Sclerocarya birrea; 85.0 Bqkg-1, 75.3 Bqkg-1, and 316.7 Bqkg-1 in Cymbopogon citratus; 47.3 Bqkg-1, 37.0 Bqkg-1, and 773.3 Bqkg-1 in Neorautanenia ficifolia; 25.7 Bqkg-1, 30.0 Bqkg-1, and 510 Bqkg-1 in Kigelia africana, respectively. The estimated annual effective dose due to ingestion ranged from 0.013 mSv (Kigelia africana) to 0.032 mSv (Cymbopogon citratus), well within recommended limits for the members of the public. Although the values revealed no hazards from a radiological point of view, it represents a valuable database for regulatory functions.
{"title":"Activity concentrations of 238U, 232Th, and 40K radionuclides in some south African medicinal herbs and their effective ingestion doses","authors":"B. Adeleye, N. Chetty","doi":"10.2298/ntrp2301048a","DOIUrl":"https://doi.org/10.2298/ntrp2301048a","url":null,"abstract":"Measurements of 238U, 232Th, and 40K activity concentrations in some commonly used medicinal plant parts have been performed for radiation hazard assessment and as baseline data for health risk monitoring in South Africa and other countries. The mean activity of 238U, 232Th, and 40K was found to be 43.3 Bqkg-1, 33.7 Bqkg-1, and 180 Bqkg-1 in Sclerocarya birrea; 85.0 Bqkg-1, 75.3 Bqkg-1, and 316.7 Bqkg-1 in Cymbopogon citratus; 47.3 Bqkg-1, 37.0 Bqkg-1, and 773.3 Bqkg-1 in Neorautanenia ficifolia; 25.7 Bqkg-1, 30.0 Bqkg-1, and 510 Bqkg-1 in Kigelia africana, respectively. The estimated annual effective dose due to ingestion ranged from 0.013 mSv (Kigelia africana) to 0.032 mSv (Cymbopogon citratus), well within recommended limits for the members of the public. Although the values revealed no hazards from a radiological point of view, it represents a valuable database for regulatory functions.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68551131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper considers the possibility of improving the technical characteristics of gas surge arresters for the co-ordination of insulation at low voltage, medium voltage and high voltage levels. The idea for improving the characteristics of a gas surge arrester is based on the application of the radioactive source 241Am in the area of the surge arrester cathode. Intensive ionization with alpha particles significantly increases the number of free electrons in the space between electrodes, which shortens the time of their transition to initial electrons. This changes the Paschen curve of the gas surge arrester, narrows and flattens its impulse characteristic and reduces the stochasticity of the response of the gas surge arrester. All this results in a significant improvement in the characteristics of the gas surge arrester at all voltage levels. This improvement is particularly noticeable in the case of low voltage surge arresters. The paper is basically theoretical-experimental research. The experiments were performed under well-controlled laboratory conditions. The combined measurement uncertainty of all measurements was acceptable.
{"title":"Influence of ionizing radiation on the stochasticity of overvoltage protection at low, medium, and high voltage levels in gas surge arresters","authors":"Alija Jusić, D. Lazarevic, I. Turkovic","doi":"10.2298/ntrp2301018j","DOIUrl":"https://doi.org/10.2298/ntrp2301018j","url":null,"abstract":"The paper considers the possibility of improving the technical characteristics of gas surge arresters for the co-ordination of insulation at low voltage, medium voltage and high voltage levels. The idea for improving the characteristics of a gas surge arrester is based on the application of the radioactive source 241Am in the area of the surge arrester cathode. Intensive ionization with alpha particles significantly increases the number of free electrons in the space between electrodes, which shortens the time of their transition to initial electrons. This changes the Paschen curve of the gas surge arrester, narrows and flattens its impulse characteristic and reduces the stochasticity of the response of the gas surge arrester. All this results in a significant improvement in the characteristics of the gas surge arrester at all voltage levels. This improvement is particularly noticeable in the case of low voltage surge arresters. The paper is basically theoretical-experimental research. The experiments were performed under well-controlled laboratory conditions. The combined measurement uncertainty of all measurements was acceptable.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68550731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Radon is a radioactive noble gas, recognized as a carcinogenic agent, being affected by degree of ventilation. The aim of this preliminary study was to determine the concentration of indoor radon gas in schools, to estimate the main factors affecting their radon concentration levels and to analyze the effective dose received by students in Duhok schools. Therefore, the concentrations of radon were measured in 28 classrooms, from 13 schools located in Duhok city, using both RAD7 and Corentium monitor, from January 15-30, 2021. In all schools indoor radon was measured in four different scenarios of closed, natural and mechanical ventilation then, radon reduction rate between each case was calculated. In addition to that, exposure to annual effective dose of radon, for each different degree of ventilation, was evaluated. Furthermore, effects of building floors were studied. Results showed that maximum radon concentration, 121 Bqm-3, was recorded in closed ventilation, while minimum, 15 Bqm-3, was recorded in mechanical ventilation. Radon reduction rate in a mechanical ventilation is relatively large 81%. Also, results demonstrate that indoor radon levels at first floor, in all schools under study, were considerably greater than those at second and third floor (p < 0.05). The annual effective dose of all studied schools at 4 different cases of ventilation were found less than the worldwide average radiation dose of 3-10 mSv. So, it is not required to take any action to minimize the level of radon in schools under study.
{"title":"Indoor radon monitoring in various ventilation degree in some schools of Duhok City, Iraq","authors":"W. Alhamdi","doi":"10.2298/ntrp2301064a","DOIUrl":"https://doi.org/10.2298/ntrp2301064a","url":null,"abstract":"Radon is a radioactive noble gas, recognized as a carcinogenic agent, being affected by degree of ventilation. The aim of this preliminary study was to determine the concentration of indoor radon gas in schools, to estimate the main factors affecting their radon concentration levels and to analyze the effective dose received by students in Duhok schools. Therefore, the concentrations of radon were measured in 28 classrooms, from 13 schools located in Duhok city, using both RAD7 and Corentium monitor, from January 15-30, 2021. In all schools indoor radon was measured in four different scenarios of closed, natural and mechanical ventilation then, radon reduction rate between each case was calculated. In addition to that, exposure to annual effective dose of radon, for each different degree of ventilation, was evaluated. Furthermore, effects of building floors were studied. Results showed that maximum radon concentration, 121 Bqm-3, was recorded in closed ventilation, while minimum, 15 Bqm-3, was recorded in mechanical ventilation. Radon reduction rate in a mechanical ventilation is relatively large 81%. Also, results demonstrate that indoor radon levels at first floor, in all schools under study, were considerably greater than those at second and third floor (p < 0.05). The annual effective dose of all studied schools at 4 different cases of ventilation were found less than the worldwide average radiation dose of 3-10 mSv. So, it is not required to take any action to minimize the level of radon in schools under study.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68551367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Gloginjić, M. Erich, Ž. Mravik, B. Vrban, Š. Čerba, J. Lüley, V. Filová, K. Katovský, Ondej Stastný, J. Burian, S. Petrović
Due to its unique material properties, such as extreme hardness and radiation resistance, silicon carbide has been used as an important construction material for environments with extreme conditions, like those present in nuclear reactors. As such, it is constantly exposed to energetic particles (e.g., neutrons) and consequently subjected to gradual crystal lattice degradation. In this article, the 6H-SiC crystal damage has been simulated by the implantation of 4 MeV C3+ ions in the (0001) axial direction of a single 6H-SiC crystal to the ion fluences of 1.359 1015 cm-2, 6.740 1015 cm-2, and 2.02 1016 cm-2. These implanted samples were subsequently analyzed by Rutherford and elastic backscattering spectrometry in the channeling orientation (RBS/C & EBS/C) by the usage of 1 MeV protons. Obtained spectra were analyzed by channeling simulation phenomenological computer code (CSIM) to obtain quantitative crystal damage depth profiles. The difference between the positions of damage profile maxima obtained by CSIM code and one simulated with stopping and range of ions in matter (SRIM), a Monte Carlo based computer code focused on ion implantation simulation in random crystal direction only, is about 10%. Therefore, due to small profile depth shifts, the usage of the iterative procedure for calculating crystal damage depth profiles is proposed. It was shown that profiles obtained by iterative procedure show very good agreement with the ones obtained with CSIM code. Additionally, with the introduction of channeling to random energy loss ratio the energy to depth profile scale conversion, the agreement with CSIM profiles becomes excellent.
{"title":"Comparative study of the MeV ion channeling implantation induced damage in 6H-SiC by the iterative procedure and phenomenological CSIM computer code","authors":"M. Gloginjić, M. Erich, Ž. Mravik, B. Vrban, Š. Čerba, J. Lüley, V. Filová, K. Katovský, Ondej Stastný, J. Burian, S. Petrović","doi":"10.2298/ntrp2202128g","DOIUrl":"https://doi.org/10.2298/ntrp2202128g","url":null,"abstract":"Due to its unique material properties, such as extreme hardness and radiation resistance, silicon carbide has been used as an important construction material for environments with extreme conditions, like those present in nuclear reactors. As such, it is constantly exposed to energetic particles (e.g., neutrons) and consequently subjected to gradual crystal lattice degradation. In this article, the 6H-SiC crystal damage has been simulated by the implantation of 4 MeV C3+ ions in the (0001) axial direction of a single 6H-SiC crystal to the ion fluences of 1.359 1015 cm-2, 6.740 1015 cm-2, and 2.02 1016 cm-2. These implanted samples were subsequently analyzed by Rutherford and elastic backscattering spectrometry in the channeling orientation (RBS/C & EBS/C) by the usage of 1 MeV protons. Obtained spectra were analyzed by channeling simulation phenomenological computer code (CSIM) to obtain quantitative crystal damage depth profiles. The difference between the positions of damage profile maxima obtained by CSIM code and one simulated with stopping and range of ions in matter (SRIM), a Monte Carlo based computer code focused on ion implantation simulation in random crystal direction only, is about 10%. Therefore, due to small profile depth shifts, the usage of the iterative procedure for calculating crystal damage depth profiles is proposed. It was shown that profiles obtained by iterative procedure show very good agreement with the ones obtained with CSIM code. Additionally, with the introduction of channeling to random energy loss ratio the energy to depth profile scale conversion, the agreement with CSIM profiles becomes excellent.","PeriodicalId":49734,"journal":{"name":"Nuclear Technology & Radiation Protection","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68548754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：