The energy-resolved neutron imaging spectrometer(ERNI)will be installed in 2022 according to the spectrometer construction plan of the China Spallation Neutron Source(CSNS).The instrument requires neutron detectors wi...The energy-resolved neutron imaging spectrometer(ERNI)will be installed in 2022 according to the spectrometer construction plan of the China Spallation Neutron Source(CSNS).The instrument requires neutron detectors with the coverage area of approximately 4 m^(2)in 5°-170°neutron diffraction angle.The neutron detection efficiency needs to be better than 40%at 1 A neutron wavelength.The spatial resolution should be better than 3 mm×50 mm in the horizontal and vertical directions respectively.We develop a one-dimensional scintillator neutron detector which is composed of the^(6)Li F/Zn S(Ag)scintillation screens,the wavelength-shifting fiber(WLSF)array,the silicon photomultipliers(Si PMs),and the self-designed application-specific integrated circuit(ASIC)readout electronics.The pixel size of the detector is designed as 3 mm×50 mm,and the neutron-sensitive area is 50 mm×200 mm.The performance of the detector prototype is measured using neutron beam 20#of the CSNS.The maximum counting rate of 247 k Hz,and the detection efficiency of63%at 1.59 A are obtained.The test results show that the performance of the detector fulfills the physical requirements of the ERNI under construction at the CSNS.展开更多
Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradi...Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradiation experiment.The hot pixels,random telegraph signal(RTS),mean dark signal,dark current and dark signal non-uniformity(DSNU)induced by Back-n are presented.The dark current is calculated according to the mean dark signal at various integration times.The single-particle displacement damage and transient response are also observed based on the online measurement data.The trends of hot pixels,mean dark signal,DSNU and RTS degradation are related to the integration time and irradiation fluence.The mean dark signal,dark current and DSNU2 are nearly linear with neutron irradiation fluence when nearly all the pixels do not reach saturation.In addition,the mechanisms of the displacement damage effects on the CCD are demonstrated by combining the experimental results and technology computer-aided design(TCAD)simulation.Radiation-induced traps in the space charge region of the CCD will act as generation/recombination centers of electron-hole pairs,leading to an increase in the dark signal.展开更多
A scintillator detector consisting of a LaBr_(3)(Ce)(0.5%)scintillator,a photomultiplier tube(PMT),and an oscilloscope were used to study the neutron sensitivities of the LaBr_(3)(Ce)scintillator at the China Spallati...A scintillator detector consisting of a LaBr_(3)(Ce)(0.5%)scintillator,a photomultiplier tube(PMT),and an oscilloscope were used to study the neutron sensitivities of the LaBr_(3)(Ce)scintillator at the China Spallation Neutron Source(CSNS)Back-n white neutron source in the double-bunch and single-bunch operation modes,respectively.Under the two operational modes,the relative neutron sensitivity curves of the LaBr_(3)(Ce)scintillator in the energy regions of 1–20 MeV and 0.5–20 MeV were obtained for the first time.In the energy range of 1–20 MeV,the two curves were nearly identical.However the relative neutron sensitivity uncertainties of the double-bunch experiment were higher than those of the single-bunch experiment.The above results indicated that the single-bunch experiment's neutron sensitivity curve has a lower minimum measurable energy than the double-bunch experiment.Above the minimum measurable energy of the double-bunch experiment,there is little difference between the measured relative neutron sensitivity curves of the single-bunch and double-bunch experiments of the LaBr_(3)(Ce)scintillator and those of other scintillators with a similar neutron response signal intensity.展开更多
Displacement damage induced by neutron irradiation in China Spallation Neutron Source(CSNS) is studied on bipolar transistors with lateral PNP, substrate PNP, and vertical NPN configurations, respectively. Comparison ...Displacement damage induced by neutron irradiation in China Spallation Neutron Source(CSNS) is studied on bipolar transistors with lateral PNP, substrate PNP, and vertical NPN configurations, respectively. Comparison of the effects on different type transistors is conducted based on displacement damage factor, and the differences are analyzed through minority carrier lifetime calculation and structure analysis. The influence of CSNS neutrons irradiation on the lateral PNP transistors is analyzed by the gate-controlled method, including the oxide charge accumulation, surface recombine velocity,and minority carrier lifetime. The results indicate that the total ionizing dose in CSNS neutron radiation environment is negligible in this study. The displacement damage factors based on 1-MeV equivalent neutron flux of different transistors are consistent between Xi’an pulse reactor(XAPR) and CSNS.展开更多
Silver indium cadmium(Ag–In–Cd) control rod is widely used in pressurized water reactor nuclear power plants,and it is continuously consumed in a high neutron flux environment. The mass ratio of ^(107)Ag in the Ag...Silver indium cadmium(Ag–In–Cd) control rod is widely used in pressurized water reactor nuclear power plants,and it is continuously consumed in a high neutron flux environment. The mass ratio of ^(107)Ag in the Ag–In–Cd control rod is 41.44%. To accurately calculate the consumption value of the control rod, a reliable neutron reaction cross section of the ^(107)Ag is required. Meanwhile,^(107)Ag is also an important weak r nucleus. Thus, the cross sections for neutron induced interactions with ^(107)Ag are very important both in nuclear energy and nuclear astrophysics. The(n, γ) cross section of ^(107)Ag has been measured in the energy range of 1–60 eV using a back streaming white neutron beam line at China spallation neutron source. The resonance parameters are extracted by an R-matrix code. All the cross section of ^(107)Ag and resonance parameters are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00010.展开更多
基金the National Natural Science Foundation of China(Grant Nos.11875273,U1832111,61964001,and 12275049)the Science Foundation of Guangdong Province of China(Grant No.2020B1515120025)+3 种基金the Neutron Physics Laboratory Funding of China Academy of Engineering Physics(Grant No.2018BC03)the General Project of Jiangxi Province Key Research and Development Program(Grant No.20212BBG73012)the Key Scientific Research Projects of Henan Higher Education Institutions(Grant Nos.23A490002 and 24A490001)the Engineering Research Center of Nuclear Technology Application(Grant No.HJSJYB2021-4)。
文摘The energy-resolved neutron imaging spectrometer(ERNI)will be installed in 2022 according to the spectrometer construction plan of the China Spallation Neutron Source(CSNS).The instrument requires neutron detectors with the coverage area of approximately 4 m^(2)in 5°-170°neutron diffraction angle.The neutron detection efficiency needs to be better than 40%at 1 A neutron wavelength.The spatial resolution should be better than 3 mm×50 mm in the horizontal and vertical directions respectively.We develop a one-dimensional scintillator neutron detector which is composed of the^(6)Li F/Zn S(Ag)scintillation screens,the wavelength-shifting fiber(WLSF)array,the silicon photomultipliers(Si PMs),and the self-designed application-specific integrated circuit(ASIC)readout electronics.The pixel size of the detector is designed as 3 mm×50 mm,and the neutron-sensitive area is 50 mm×200 mm.The performance of the detector prototype is measured using neutron beam 20#of the CSNS.The maximum counting rate of 247 k Hz,and the detection efficiency of63%at 1.59 A are obtained.The test results show that the performance of the detector fulfills the physical requirements of the ERNI under construction at the CSNS.
基金Project supported by the Foundation of State Key Laboratory of China(Grant Nos.SKLIPR1903Z,1803)the National Natural Science Foundation of China(Grant Nos.U2167208 and 11875223).
文摘Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradiation experiment.The hot pixels,random telegraph signal(RTS),mean dark signal,dark current and dark signal non-uniformity(DSNU)induced by Back-n are presented.The dark current is calculated according to the mean dark signal at various integration times.The single-particle displacement damage and transient response are also observed based on the online measurement data.The trends of hot pixels,mean dark signal,DSNU and RTS degradation are related to the integration time and irradiation fluence.The mean dark signal,dark current and DSNU2 are nearly linear with neutron irradiation fluence when nearly all the pixels do not reach saturation.In addition,the mechanisms of the displacement damage effects on the CCD are demonstrated by combining the experimental results and technology computer-aided design(TCAD)simulation.Radiation-induced traps in the space charge region of the CCD will act as generation/recombination centers of electron-hole pairs,leading to an increase in the dark signal.
基金Project supported by the National Natural Science Foundation of China(Grant No.11905196)。
文摘A scintillator detector consisting of a LaBr_(3)(Ce)(0.5%)scintillator,a photomultiplier tube(PMT),and an oscilloscope were used to study the neutron sensitivities of the LaBr_(3)(Ce)scintillator at the China Spallation Neutron Source(CSNS)Back-n white neutron source in the double-bunch and single-bunch operation modes,respectively.Under the two operational modes,the relative neutron sensitivity curves of the LaBr_(3)(Ce)scintillator in the energy regions of 1–20 MeV and 0.5–20 MeV were obtained for the first time.In the energy range of 1–20 MeV,the two curves were nearly identical.However the relative neutron sensitivity uncertainties of the double-bunch experiment were higher than those of the single-bunch experiment.The above results indicated that the single-bunch experiment's neutron sensitivity curve has a lower minimum measurable energy than the double-bunch experiment.Above the minimum measurable energy of the double-bunch experiment,there is little difference between the measured relative neutron sensitivity curves of the single-bunch and double-bunch experiments of the LaBr_(3)(Ce)scintillator and those of other scintillators with a similar neutron response signal intensity.
文摘Displacement damage induced by neutron irradiation in China Spallation Neutron Source(CSNS) is studied on bipolar transistors with lateral PNP, substrate PNP, and vertical NPN configurations, respectively. Comparison of the effects on different type transistors is conducted based on displacement damage factor, and the differences are analyzed through minority carrier lifetime calculation and structure analysis. The influence of CSNS neutrons irradiation on the lateral PNP transistors is analyzed by the gate-controlled method, including the oxide charge accumulation, surface recombine velocity,and minority carrier lifetime. The results indicate that the total ionizing dose in CSNS neutron radiation environment is negligible in this study. The displacement damage factors based on 1-MeV equivalent neutron flux of different transistors are consistent between Xi’an pulse reactor(XAPR) and CSNS.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11875311, 11905274, 1705156, U2032146, 11865010, 11765015, and 1160509)the Natural Science Foundation of Inner Mongolia, China (Grant Nos. 2019JQ01 and 2018MS01009)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB34030000)。
文摘Silver indium cadmium(Ag–In–Cd) control rod is widely used in pressurized water reactor nuclear power plants,and it is continuously consumed in a high neutron flux environment. The mass ratio of ^(107)Ag in the Ag–In–Cd control rod is 41.44%. To accurately calculate the consumption value of the control rod, a reliable neutron reaction cross section of the ^(107)Ag is required. Meanwhile,^(107)Ag is also an important weak r nucleus. Thus, the cross sections for neutron induced interactions with ^(107)Ag are very important both in nuclear energy and nuclear astrophysics. The(n, γ) cross section of ^(107)Ag has been measured in the energy range of 1–60 eV using a back streaming white neutron beam line at China spallation neutron source. The resonance parameters are extracted by an R-matrix code. All the cross section of ^(107)Ag and resonance parameters are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00010.
