As a key part of the diagnosis system in the International Thermonuclear Experimental Reactor(ITER),the neutron flux monitor(NFM),which measures the neutron intensity of the fusion reaction,is a Counting-Campbelling s...As a key part of the diagnosis system in the International Thermonuclear Experimental Reactor(ITER),the neutron flux monitor(NFM),which measures the neutron intensity of the fusion reaction,is a Counting-Campbelling system with a large dynamic counting range.A dynamic linear calibration method is proposed in this paper to solve the problem of cross-over between the different counting and Campbelling channels,and improve the accuracy of the cross-calibration for long-term operation.The experimental results show that the NFM system with the dynamic linear calibration system can obtain the neutron flux of the fusion reactor in real time and realize the seamless measurement area connection between the two channels.展开更多
Neutron flux monitor （NFM） as an important diagnostic sub-system in ITER （international thermonuclear experimental reactor） provides a global neutron source intensity, fusion power and neutron flux in real time. T...Neutron flux monitor （NFM） as an important diagnostic sub-system in ITER （international thermonuclear experimental reactor） provides a global neutron source intensity, fusion power and neutron flux in real time. Three types of neutron flux monitor assemblies with different sensitivities and shielding materials have been designed. Through MCNP （Mante-Carlo neutral particle transport code） calculations, this extended system of NFM can detect the neutron flux in a range of 10^4 n/（cm^2.s） to 10^14 n/（cm^2.s）. It is capable of providing accurate neutron yield measurements for all operational modes encountered in the ITER experiments including the in-situ calibration. Combining both the counting mode and Campbelling （MSV; Mean Square Voltage） mode in the signal processing units, the requirement of the dynamic range （107） for these NFMs and time resolution （1 ms） can be met. Based on a uncertainty analysis, the estimated absolute measurement accuracies of the total fusion neutron yield can reach the required 10% level in both the early stage of the DD-phase and the DD-phase, the absolute measurement accuracy full power DT operation mode. In the advanced would be better than 20%.展开更多
Absolutely calibrated measurements of the neutron yields which need to cover both D-D and D-T phase of the international thermal-nuclear experimental reactor （ITER） are important for the evaluation of fusion power a...Absolutely calibrated measurements of the neutron yields which need to cover both D-D and D-T phase of the international thermal-nuclear experimental reactor （ITER） are important for the evaluation of fusion power and fusion gain Q in D-D and D-T operations. This paper describes the in-situ calibration techniques and methods, the neutron sources including ^252Cf and neutron generator for calibration, the preliminary accuracy assessment and the error analyses. In addition, some difficult problems regarding the in situ calibration for the neutron flux monitor （NFM） on ITER are presented and discussed.展开更多
A novel full-digital real-time neutron flux monitor(NFM) has been developed for thorium-based molten salt reactor(TMSR).The system is based on the highspeed,parallel,and pipeline processing of the field programmable g...A novel full-digital real-time neutron flux monitor(NFM) has been developed for thorium-based molten salt reactor(TMSR).The system is based on the highspeed,parallel,and pipeline processing of the field programmable gate array as well as the high-stability controller area network platform.A measurement range of 10~8 counts per second is achieved with a single fission chamber by utilizing the normalization of the count and Campbell algorithms.With the advantages of using the measurement range,system integrity,and real-time performance,digital NFM has been tested in the Xi'an pulsed reactor fission experiments and was found to exhibit superior experimental performance.展开更多
基金Supported by ITER Plan National Major Project(No.2008GB109000)
文摘As a key part of the diagnosis system in the International Thermonuclear Experimental Reactor(ITER),the neutron flux monitor(NFM),which measures the neutron intensity of the fusion reaction,is a Counting-Campbelling system with a large dynamic counting range.A dynamic linear calibration method is proposed in this paper to solve the problem of cross-over between the different counting and Campbelling channels,and improve the accuracy of the cross-calibration for long-term operation.The experimental results show that the NFM system with the dynamic linear calibration system can obtain the neutron flux of the fusion reactor in real time and realize the seamless measurement area connection between the two channels.
基金National Natural Science Foundation of China(Nos.10175021,10675124)
文摘Neutron flux monitor （NFM） as an important diagnostic sub-system in ITER （international thermonuclear experimental reactor） provides a global neutron source intensity, fusion power and neutron flux in real time. Three types of neutron flux monitor assemblies with different sensitivities and shielding materials have been designed. Through MCNP （Mante-Carlo neutral particle transport code） calculations, this extended system of NFM can detect the neutron flux in a range of 10^4 n/（cm^2.s） to 10^14 n/（cm^2.s）. It is capable of providing accurate neutron yield measurements for all operational modes encountered in the ITER experiments including the in-situ calibration. Combining both the counting mode and Campbelling （MSV; Mean Square Voltage） mode in the signal processing units, the requirement of the dynamic range （107） for these NFMs and time resolution （1 ms） can be met. Based on a uncertainty analysis, the estimated absolute measurement accuracies of the total fusion neutron yield can reach the required 10% level in both the early stage of the DD-phase and the DD-phase, the absolute measurement accuracy full power DT operation mode. In the advanced would be better than 20%.
基金National Natural Science Foundation of China(Nos.10175021,10675124)
文摘Absolutely calibrated measurements of the neutron yields which need to cover both D-D and D-T phase of the international thermal-nuclear experimental reactor （ITER） are important for the evaluation of fusion power and fusion gain Q in D-D and D-T operations. This paper describes the in-situ calibration techniques and methods, the neutron sources including ^252Cf and neutron generator for calibration, the preliminary accuracy assessment and the error analyses. In addition, some difficult problems regarding the in situ calibration for the neutron flux monitor （NFM） on ITER are presented and discussed.
基金supported by the National Natural Science Foundation of China(Nos.11375195 and 11575184)the National Magnetic Confinement Fusion Energy Development Research(No.2013GB104003)
文摘A novel full-digital real-time neutron flux monitor(NFM) has been developed for thorium-based molten salt reactor(TMSR).The system is based on the highspeed,parallel,and pipeline processing of the field programmable gate array as well as the high-stability controller area network platform.A measurement range of 10~8 counts per second is achieved with a single fission chamber by utilizing the normalization of the count and Campbell algorithms.With the advantages of using the measurement range,system integrity,and real-time performance,digital NFM has been tested in the Xi'an pulsed reactor fission experiments and was found to exhibit superior experimental performance.
