A prompt gamma-neutron activation analysis(PGNAA) system was developed to detect the iron content of iron ore concentrate. Because of the self-absorption effect of gamma-rays and neutrons, and the interference of chlo...A prompt gamma-neutron activation analysis(PGNAA) system was developed to detect the iron content of iron ore concentrate. Because of the self-absorption effect of gamma-rays and neutrons, and the interference of chlorine in the neutron field, the linear relationship between the iron analytical coefficient and total iron content was poor, increasing the error in the quantitative analysis. To solve this problem, gamma-ray self-absorption compensation and a neutron field correction algorithm were proposed, and the experimental results have been corrected using this algorithm. The results show that the linear relationship between the iron analytical coefficient and total iron content was considerably improved after the correction. The linear correlation coefficients reached 0.99 or more.展开更多
In this paper,computational methods are used to optimize the design of a prompt-gamma neutron activation analysis(PGNAA) system on China Advanced Research Reactor(CARR).Approaches are adopted for obtaining accurate ne...In this paper,computational methods are used to optimize the design of a prompt-gamma neutron activation analysis(PGNAA) system on China Advanced Research Reactor(CARR).Approaches are adopted for obtaining accurate neutron beam parameter and saving the computing time.For the radiation shielding design,the optimizing factors include the cost,weight,volume,machining convenience and background radiation at the detector position.Low background spectrum and high sensitivity are expected.The simulation results,and experiences from international PGNAA community,were used in the design of the CARR PGNAA system.展开更多
Prompt gamma neutron activation analysis (PGNAA) is a non-destructive online measurement nuclear analysis method. With its unique advantages, it has been widely used in online analysis of industrial materials such as ...Prompt gamma neutron activation analysis (PGNAA) is a non-destructive online measurement nuclear analysis method. With its unique advantages, it has been widely used in online analysis of industrial materials such as coal, cement, and minerals in recent years. </span><span style="font-family:Verdana;">However, there are many kinds of literature on PGNAA in the field of industrial materials detection, and there are still a few concluding articles. To this end,</span><span style="font-family:Verdana;"> based on the principle of PGNAA online analysis, the status quo and development of the real-time online detection of industrial material components in the field are reviewed and discussed by consulting a large number of domestic and foreign PGNAA related literature and data, to facilitate the reference of relevant scientific researchers.展开更多
The history,the major achievements in both methodology and applications,the current trends and future perspectives of neutron activation analysis (NAA) in China are briefly described.
This paper introduces the principles, instrumentation, implementation, and industrial applications of an on- line thermal neutron prompt- gamma element analysis system (using a 252Cf neutron source, Am- Be neutron sou...This paper introduces the principles, instrumentation, implementation, and industrial applications of an on- line thermal neutron prompt- gamma element analysis system (using a 252Cf neutron source, Am- Be neutron source, or neutron generator). The energy resolution of the system at the H prompt- gamma full- energy photopeak (2.22325 MeV) is 3.6 keV. The concentration measurement error of A12O3, Fe2O3, CaO and SiO2 is ±0.3%,±0.1%.±0.4% and ±0.4%, respectively.The system has been tested on- site at both the Shandong and the Zhengzhou Aluminum Works. Our preliminary on- site measurements confirm that the stability, reliability, measurement range, and accuracy of the system can meet the requirements of the aluminum production process. Facilitation of this measurement at aluminum plants is expected to reduce plant costs by over 3 million dollars annually through reduced energy consumption, more rapid qualification of pulps being mixed during the production process, and in reduced labor costs.展开更多
A prompt gamma neutron activation analysis system with a 252Cf neutron source for on-line cement analysis has been simulated with the MCNP code.The results indicate that the optimum arrangement is a Bi shield of 20-mm...A prompt gamma neutron activation analysis system with a 252Cf neutron source for on-line cement analysis has been simulated with the MCNP code.The results indicate that the optimum arrangement is a Bi shield of 20-mm thickness,a polyethylene moderator of 50-mm thickness,a source-to-sample distance of 70 mm,and cement samples of 1200 mm×600 mm×170 mm.To absorb thermal neutrons and suppress low-energy γ-rays,the optimum-sized sheets are 150 mm×7 mm Cd,and 150 mm×15 mm Pb.展开更多
The distribution characteristics of the neutron field in cement was simulated using the MCNP code to comply with the requirements of an online Prompt Gamma Neutron Activation Analysis system.Simulation results showed ...The distribution characteristics of the neutron field in cement was simulated using the MCNP code to comply with the requirements of an online Prompt Gamma Neutron Activation Analysis system.Simulation results showed that the neutron relative flux proportion reduced with increasing cement thickness.When the cement thickness remains unchanged,the reduced proportion of thermal neutrons increases to a small extent,but the epithermal, intermediate,and fast neutrons will decrease according to the geometric progression.H element in the cement mainly affects the reduction of fast neutrons and other single-substance elements,e.g.,O,Ca,56Fe,Si,and Al.It also slows down the reduction of the fast neutrons via inelastic scattering.O contributes more than other elements in the reduction of fast neutrons.Changing the H content affects the thermal,epithermal,intermediate,and fast neutrons, while changing the Ca,Fe,and Si contents only influences the thermal,epithermal,and intermediate neutrons;hence, there is little effect on the reduction of fast neutrons.展开更多
The response of a 14 MeV neutron-based prompt gamma neutron activation analysis (PGNAA) system,i.e.the prompt gamma-rays count rate and the average thermal neutron flux,is studied with a large concrete sample and with...The response of a 14 MeV neutron-based prompt gamma neutron activation analysis (PGNAA) system,i.e.the prompt gamma-rays count rate and the average thermal neutron flux,is studied with a large concrete sample and with a homogeneous large sample,which is made of polyethylene and metal with various concentrations of hydrogen and cadmium using the MCNP-5 (Monte Carlo N-Particle) code.The average thermal neutron flux is determined by the analysis of the prompt gamma-rays using the thermal neutron activation of hydrogen in the sample,and the thermal and fast neutron activation of carbon graphite irradiation chamber of the PGNAA-system.Our results demonstrated that the graphite irradiation chamber of the PGNAA-system fairly operates,and is useful to estimate the average thermal neutron flux of large samples with various compositions irradiated by 14 MeV neutrons.展开更多
基金supported by the National Key Scientific Instrument and Equipment Development Projects(No.2012YQ240121)Liaoning science and technology project(No.2017220010)Changchun Science and Technology Bureau Local Company and College(University,Institution)Cooperation Projects(No.17DY023)
文摘A prompt gamma-neutron activation analysis(PGNAA) system was developed to detect the iron content of iron ore concentrate. Because of the self-absorption effect of gamma-rays and neutrons, and the interference of chlorine in the neutron field, the linear relationship between the iron analytical coefficient and total iron content was poor, increasing the error in the quantitative analysis. To solve this problem, gamma-ray self-absorption compensation and a neutron field correction algorithm were proposed, and the experimental results have been corrected using this algorithm. The results show that the linear relationship between the iron analytical coefficient and total iron content was considerably improved after the correction. The linear correlation coefficients reached 0.99 or more.
基金Supported by National Natural Science Foundation of China(No.10805077)
文摘In this paper,computational methods are used to optimize the design of a prompt-gamma neutron activation analysis(PGNAA) system on China Advanced Research Reactor(CARR).Approaches are adopted for obtaining accurate neutron beam parameter and saving the computing time.For the radiation shielding design,the optimizing factors include the cost,weight,volume,machining convenience and background radiation at the detector position.Low background spectrum and high sensitivity are expected.The simulation results,and experiences from international PGNAA community,were used in the design of the CARR PGNAA system.
文摘Prompt gamma neutron activation analysis (PGNAA) is a non-destructive online measurement nuclear analysis method. With its unique advantages, it has been widely used in online analysis of industrial materials such as coal, cement, and minerals in recent years. </span><span style="font-family:Verdana;">However, there are many kinds of literature on PGNAA in the field of industrial materials detection, and there are still a few concluding articles. To this end,</span><span style="font-family:Verdana;"> based on the principle of PGNAA online analysis, the status quo and development of the real-time online detection of industrial material components in the field are reviewed and discussed by consulting a large number of domestic and foreign PGNAA related literature and data, to facilitate the reference of relevant scientific researchers.
文摘The history,the major achievements in both methodology and applications,the current trends and future perspectives of neutron activation analysis (NAA) in China are briefly described.
文摘This paper introduces the principles, instrumentation, implementation, and industrial applications of an on- line thermal neutron prompt- gamma element analysis system (using a 252Cf neutron source, Am- Be neutron source, or neutron generator). The energy resolution of the system at the H prompt- gamma full- energy photopeak (2.22325 MeV) is 3.6 keV. The concentration measurement error of A12O3, Fe2O3, CaO and SiO2 is ±0.3%,±0.1%.±0.4% and ±0.4%, respectively.The system has been tested on- site at both the Shandong and the Zhengzhou Aluminum Works. Our preliminary on- site measurements confirm that the stability, reliability, measurement range, and accuracy of the system can meet the requirements of the aluminum production process. Facilitation of this measurement at aluminum plants is expected to reduce plant costs by over 3 million dollars annually through reduced energy consumption, more rapid qualification of pulps being mixed during the production process, and in reduced labor costs.
基金Supported by NSFC(40974065)National Innovation Method(2008IM021500)+1 种基金National Key Technology R & D Program(2008BAC44B04)Province Key Technology R & D Program(2008SZ0148,2008GZ0197,2008GZ0040)
文摘A prompt gamma neutron activation analysis system with a 252Cf neutron source for on-line cement analysis has been simulated with the MCNP code.The results indicate that the optimum arrangement is a Bi shield of 20-mm thickness,a polyethylene moderator of 50-mm thickness,a source-to-sample distance of 70 mm,and cement samples of 1200 mm×600 mm×170 mm.To absorb thermal neutrons and suppress low-energy γ-rays,the optimum-sized sheets are 150 mm×7 mm Cd,and 150 mm×15 mm Pb.
基金Supported by National Natural Science Foundation for Distinguished Young Scholar(41025015)NSFC(40974065,11105132)+3 种基金Province Key Technology R&D Program(2011FZ0055)National High Technology Research and Development Program of China(2012AA063501)the Basic Research for Application of Sichuan Province(2012JY0109)China Postdoctoral Science Foundation(2012M520245)
文摘The distribution characteristics of the neutron field in cement was simulated using the MCNP code to comply with the requirements of an online Prompt Gamma Neutron Activation Analysis system.Simulation results showed that the neutron relative flux proportion reduced with increasing cement thickness.When the cement thickness remains unchanged,the reduced proportion of thermal neutrons increases to a small extent,but the epithermal, intermediate,and fast neutrons will decrease according to the geometric progression.H element in the cement mainly affects the reduction of fast neutrons and other single-substance elements,e.g.,O,Ca,56Fe,Si,and Al.It also slows down the reduction of the fast neutrons via inelastic scattering.O contributes more than other elements in the reduction of fast neutrons.Changing the H content affects the thermal,epithermal,intermediate,and fast neutrons, while changing the Ca,Fe,and Si contents only influences the thermal,epithermal,and intermediate neutrons;hence, there is little effect on the reduction of fast neutrons.
基金Supported by National Natural Science Foundation of China (No. 10675084)the Forschungszentrum Jülich GmbH, Germany
文摘The response of a 14 MeV neutron-based prompt gamma neutron activation analysis (PGNAA) system,i.e.the prompt gamma-rays count rate and the average thermal neutron flux,is studied with a large concrete sample and with a homogeneous large sample,which is made of polyethylene and metal with various concentrations of hydrogen and cadmium using the MCNP-5 (Monte Carlo N-Particle) code.The average thermal neutron flux is determined by the analysis of the prompt gamma-rays using the thermal neutron activation of hydrogen in the sample,and the thermal and fast neutron activation of carbon graphite irradiation chamber of the PGNAA-system.Our results demonstrated that the graphite irradiation chamber of the PGNAA-system fairly operates,and is useful to estimate the average thermal neutron flux of large samples with various compositions irradiated by 14 MeV neutrons.
