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
The prototype neutron flux monitor consists of a high purity ^(235)U fission chamber detector and a'blank'detector,which is a fissile material free detector with the same dimension as the fission chamber detec...The prototype neutron flux monitor consists of a high purity ^(235)U fission chamber detector and a'blank'detector,which is a fissile material free detector with the same dimension as the fission chamber detector to identify noise issues such as noise coming from gamma rays.The main parameters of the fission chamber assembly that have been measured in the laboratory are confirmed to approach the technological level of the International Thermonuclear Experimental Reactor(ITER)in the near future.This prototype neutron flux monitor will be further developed to become a neutron flux monitor suitable for the operation phase of D-D fusion on the ITER.展开更多
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The project supported by the National Natural Science Foundation of China(No.10175021)the Retraining Foundation of the Southwestern Institute of Physics for Talented Personnel
文摘The prototype neutron flux monitor consists of a high purity ^(235)U fission chamber detector and a'blank'detector,which is a fissile material free detector with the same dimension as the fission chamber detector to identify noise issues such as noise coming from gamma rays.The main parameters of the fission chamber assembly that have been measured in the laboratory are confirmed to approach the technological level of the International Thermonuclear Experimental Reactor(ITER)in the near future.This prototype neutron flux monitor will be further developed to become a neutron flux monitor suitable for the operation phase of D-D fusion on the ITER.
