Self-powered neutron detectors(SPNDs)play a critical role in monitoring the safety margins and overall health of reactors,directly affecting safe operation within the reactor.In this work,a novel fault identification ...Self-powered neutron detectors(SPNDs)play a critical role in monitoring the safety margins and overall health of reactors,directly affecting safe operation within the reactor.In this work,a novel fault identification method based on graph convolutional networks(GCN)and Stacking ensemble learning is proposed for SPNDs.The GCN is employed to extract the spatial neighborhood information of SPNDs at different positions,and residuals are obtained by nonlinear fitting of SPND signals.In order to completely extract the time-varying features from residual sequences,the Stacking fusion model,integrated with various algorithms,is developed and enables the identification of five conditions for SPNDs:normal,drift,bias,precision degradation,and complete failure.The results demonstrate that the integration of diverse base-learners in the GCN-Stacking model exhibits advantages over a single model as well as enhances the stability and reliability in fault identification.Additionally,the GCN-Stacking model maintains higher accuracy in identifying faults at different reactor power levels.展开更多
By introducing a thin p-type layer between the Schottky metal and n-GaN layer, this work presents a Schottky-pn junction diode(SPND) configuration for the GaN rectifier fabrication. Specific unipolar carrier conductio...By introducing a thin p-type layer between the Schottky metal and n-GaN layer, this work presents a Schottky-pn junction diode(SPND) configuration for the GaN rectifier fabrication. Specific unipolar carrier conduction characteristic is demonstrated by the verification of temperature-dependent current–voltage(I–V) tests and electroluminescence spectra.Meanwhile, apparently advantageous forward conduction properties as compared to the pn diode fabricated on the same wafer have been achieved, featuring a lower turn-on voltage of 0.82 V. Together with the analysis model established in the GaN SPND for a wide-range designable turn-on voltage, this work provides an alternative method to the GaN rectifier strategies besides the traditional solution.展开更多
基金the Industry-University Cooperation Project in Fujian Province University(No.2022H6020)。
文摘Self-powered neutron detectors(SPNDs)play a critical role in monitoring the safety margins and overall health of reactors,directly affecting safe operation within the reactor.In this work,a novel fault identification method based on graph convolutional networks(GCN)and Stacking ensemble learning is proposed for SPNDs.The GCN is employed to extract the spatial neighborhood information of SPNDs at different positions,and residuals are obtained by nonlinear fitting of SPND signals.In order to completely extract the time-varying features from residual sequences,the Stacking fusion model,integrated with various algorithms,is developed and enables the identification of five conditions for SPNDs:normal,drift,bias,precision degradation,and complete failure.The results demonstrate that the integration of diverse base-learners in the GCN-Stacking model exhibits advantages over a single model as well as enhances the stability and reliability in fault identification.Additionally,the GCN-Stacking model maintains higher accuracy in identifying faults at different reactor power levels.
基金supported by the National Natural Science Foundation of China (Grant Nos. U2141241, 62004099, 61921005,and 91850112)。
文摘By introducing a thin p-type layer between the Schottky metal and n-GaN layer, this work presents a Schottky-pn junction diode(SPND) configuration for the GaN rectifier fabrication. Specific unipolar carrier conduction characteristic is demonstrated by the verification of temperature-dependent current–voltage(I–V) tests and electroluminescence spectra.Meanwhile, apparently advantageous forward conduction properties as compared to the pn diode fabricated on the same wafer have been achieved, featuring a lower turn-on voltage of 0.82 V. Together with the analysis model established in the GaN SPND for a wide-range designable turn-on voltage, this work provides an alternative method to the GaN rectifier strategies besides the traditional solution.
