Low-toxicity single crystal Sn S nanowires had been successfully synthesized by the catalystassistant chemical vapor deposition. Au nanoparticles were applied on the ITO surface as the catalysis, using Sn S powder and...Low-toxicity single crystal Sn S nanowires had been successfully synthesized by the catalystassistant chemical vapor deposition. Au nanoparticles were applied on the ITO surface as the catalysis, using Sn S powder and S powder as forerunners. The structure, morphology and optical properties of the prepared Sn S nanowires were characterized. The experimental results show the as-synthesized nanowires are single crystalline with a preferential orientation. The synthesized Sn S nanowires show strong absorption in the visible and nearinfrared spectral region, and the direct energy band gap of Sn S nanowires is 1.46 e V.展开更多
Background Each GECAM satellite payload contains 25 gamma-ray detectors(GRDs),which can detect gamma-rays and particles and can roughly localize the Gamma-Ray Bursts(GRBs).GRD was designed using lanthanum bromide(LaBr...Background Each GECAM satellite payload contains 25 gamma-ray detectors(GRDs),which can detect gamma-rays and particles and can roughly localize the Gamma-Ray Bursts(GRBs).GRD was designed using lanthanum bromide(LaBr3)crystal as the sensitive material with the rear end coupled with silicon photomultiplier(SiPM)array for readout.Purpose In aerospace engineering design of GRD,there are many key points to be studied.In this paper,we present the specific design scheme of GRD,the assembly and the performance test results of detectors.Methods Based on Monte Carlo simulation and experimental test results,the specific schematic design and assembling process of GRD were optimized.After being fully assembled,the GRDs were conducted performance tests by using radioactive source and also conducted random vibration tests.Result and conclusion The test results show that all satellite-borne GRDs have energy resolution<16%at 59.5 keV,meeting requirements of satellite in scientific performance.The random vibration test shows that GRD can maintain in a stable performance,which meets the requirement of spatial application.展开更多
Introduction The main physical objective of the GECAM satellite is to detect gamma-ray bursts,which is related to gravitational waves of double compact object mergers.The GECAM satellite also detects and investigates ...Introduction The main physical objective of the GECAM satellite is to detect gamma-ray bursts,which is related to gravitational waves of double compact object mergers.The GECAM satellite also detects and investigates various bursts of high-energy celestial bodies.Purposes and methods In this study,we designed,developed and calibrated the payload and launched it into orbit with GECAM satellite.The payload consists of the gamma ray detector(GRD,for detecting 4 keV–4 MeV X/γray),the charged particle detector(CPD,for detecting 150 keV–5 MeV charged particle),and the electronic box(EBOX).The all-sky field coverage is achieved via two 229-degree large-area satellites positioned 180 degrees apart and are on opposite sides of the geo-center.Each satellite is equipped with 25 GRDs and 8 CPDs;thus,the satellite can identify charged particle bursts in space.Gamma-ray detectors adopt lanthanum bromide crystal technology combined with silicon photomultipliers.This is the first time that this technology was used massively in space detectors.Conclusions The GECAM satellite can quickly determine the direction of gamma-ray bursts(positioning)via indexing and fitting method,while the transmit variability,energy spectrum and direction of the gamma-ray bursts guide subsequent observations through the Beidou-3 RDSS in quasi-real time.It will play an important role in the study of high energy celestial bursts.展开更多
Background The Gravitational wave highly energetic Electromagnetic Counterpart All-sky Monitor(GECAM)is dedicated to detecting gravitational wave gamma-ray bursts.It is capable of all-sky monitoring over and discoveri...Background The Gravitational wave highly energetic Electromagnetic Counterpart All-sky Monitor(GECAM)is dedicated to detecting gravitational wave gamma-ray bursts.It is capable of all-sky monitoring over and discovering gamma-ray bursts and new radiation phenomena.GECAM consists of two microsatellites,each equipped with 8 charged particle detectors(CPDs)and 25 gamma-ray detectors(GRDs).Purpose The CPD is used to measure charged particles in the space environment,monitor energy and flow intensity changes,and identify between gamma-ray bursts and space charged particle events in conjunction with GRD.Methods CPD uses plastic scintillator as the sensitive material for detection,silicon photomultiplier array as the optically readable device,and the inlaid Am-241 radioactive source as the onboard calibration means.Conclusion In this paper,we will present the working principle,physical design,functional implementation and preliminary performance test results of the CPD.As a result,the energy range of electron,gamma-ray detection efficiency and dead time are tested to be better than the indexes required through the ground calibration experiment.展开更多
Background The Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor(GECAM)consists of 2 microsatellites,each of which contains 25 GRD(LaBr3)detectors and 8 CPD(plastic scintillator)detectors.Meth...Background The Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor(GECAM)consists of 2 microsatellites,each of which contains 25 GRD(LaBr3)detectors and 8 CPD(plastic scintillator)detectors.Method silicon photomultiplier(SiPM)array is used to read each detector.The output signal of these detectors with SiPM array is very special and challenging to readout.In this study,a novel data acquisition(DAQ)algorithm for these detectors is designed and implemented,and the content of the output event packet is defined.Result and Conclusion The performances,including the event acquisition efficiency of this DAQ algorithm,are extensively verified through experimental tests.From the on-ground and in-flight tests,this algorithm has excellent performance despite the very limited resources and short development time of GECAM mission.展开更多
Background The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM)satellite developed a SiPM-based gamma-ray detector to monitor the gravitational wave-related GRBs and guide subsequent o...Background The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM)satellite developed a SiPM-based gamma-ray detector to monitor the gravitational wave-related GRBs and guide subsequent observations in other wavelengths of EM.Purpose As all the available SiPM devices belong to commercial grade,quality assurance tests need to be performed in accordance with the aerospace specifcations.Methods In the SiPM application of GECAM,quality assurance experiments were conducted.The mechanism of the failure of SiPM devices was analyzed during the development process.Result Based on the quality assurance test results,the fnal pass rate of SiPM array was 95%.Based on the failure analysis,it was found that a piece of SiPM had a leakage channel after longtime operation due to device defects.Conclusion According to the accumulated experience,in the reliability test of SiPM,it is necessary to pay special attention to test the impedance of each pin of SiPM to ground and confrm that the power switch state of SiPM is controllable.展开更多
Purpose The discovery of gravitational waves and gamma-ray bursts heralds the era of multi-messenger astronomy.With the adoption of two small satellites to achieve the all-sky monitoring of gamma-ray bursts,the gravit...Purpose The discovery of gravitational waves and gamma-ray bursts heralds the era of multi-messenger astronomy.With the adoption of two small satellites to achieve the all-sky monitoring of gamma-ray bursts,the gravitational wave highenergy electromagnetic counterpart all-sky monitor(GECAM)possesses a quasi-real-time early warning ability and plays an important role in positioning the sources of gravitational waves and in subsequent observations.Each satellite of GECAM was fitted with 253-inch-diameter gamma-ray detectors(GRD),covering an energy range of 8–2 MeV.GRDs have adopted silicon photomultiplier tubes(SiPM)in lieu of photomultiplier tubes(PMT)to adapt to the dimensional limitations of micro-satellites.Methods A unique 3-inch circular SiPM array was designed.In this design,646×6 mm chips were arranged evenly in a circular manner with the seams filled with reflecting films,thus achieving satisfactory uniformity of light collection.The integrated pre-amplifier circuit on the back of the SiPM array adopted two-level grouping and summing;further,it achieved a satisfactory signal-to-noise ratio.Two high-gain and low-gain channels were adopted to achieve a large dynamic range,and two independent power supply units were used,where each unit can be closed separately,thus improving reliability.Results Performance studies show that this SiPM array meets the requirements of GECAM.Conclusion A 3-inch SiPM array have been developed that uses grouped summation,reflective films,a circular arrangement,two groups of independent power supplies,high-and low-gain signals,differential signal output technologies,etc.This solution can be used not only for GECAM,but also as a general solution for SiPM-based scintillation detectors.展开更多
基金partially supported by the National Science Foundation of China(No.50902117,No.11104126 and No.50825101)the Natural Science Foundation of Fujian Province of China(Grant No.2009J01263)+1 种基金the National Basic Research Program of China(No.2012CB933103)Scientific and Technological Innovation Platform of Fujian Province(2006L2003)
文摘Low-toxicity single crystal Sn S nanowires had been successfully synthesized by the catalystassistant chemical vapor deposition. Au nanoparticles were applied on the ITO surface as the catalysis, using Sn S powder and S powder as forerunners. The structure, morphology and optical properties of the prepared Sn S nanowires were characterized. The experimental results show the as-synthesized nanowires are single crystalline with a preferential orientation. The synthesized Sn S nanowires show strong absorption in the visible and nearinfrared spectral region, and the direct energy band gap of Sn S nanowires is 1.46 e V.
基金financial support from industrial sponsors Aurubis AG(Germany)the Australian Research Council Linkage Program+5 种基金Boliden(Sweden)Metso Outotec Oyj(Finland)Nyrstar(Australia)Kazzinc LtdGlencore(Kazakhstan)Umicore NV(Belgium)are gratefully acknowledged。
基金This research was supported by the National Natural Science Foundation of China,Grant No.11775251the strategic leading science and technology program of Chinese Academy of Sciences(Grant No.XDA 15360100,XDA 15360102).
文摘Background Each GECAM satellite payload contains 25 gamma-ray detectors(GRDs),which can detect gamma-rays and particles and can roughly localize the Gamma-Ray Bursts(GRBs).GRD was designed using lanthanum bromide(LaBr3)crystal as the sensitive material with the rear end coupled with silicon photomultiplier(SiPM)array for readout.Purpose In aerospace engineering design of GRD,there are many key points to be studied.In this paper,we present the specific design scheme of GRD,the assembly and the performance test results of detectors.Methods Based on Monte Carlo simulation and experimental test results,the specific schematic design and assembling process of GRD were optimized.After being fully assembled,the GRDs were conducted performance tests by using radioactive source and also conducted random vibration tests.Result and conclusion The test results show that all satellite-borne GRDs have energy resolution<16%at 59.5 keV,meeting requirements of satellite in scientific performance.The random vibration test shows that GRD can maintain in a stable performance,which meets the requirement of spatial application.
基金This project is supported by National Natural Science Foundation of China(12173038)the strategic leading science and technology program(XDA 15360100,XDA 15360102)of the Chinese Academy of Sciences.
文摘Introduction The main physical objective of the GECAM satellite is to detect gamma-ray bursts,which is related to gravitational waves of double compact object mergers.The GECAM satellite also detects and investigates various bursts of high-energy celestial bodies.Purposes and methods In this study,we designed,developed and calibrated the payload and launched it into orbit with GECAM satellite.The payload consists of the gamma ray detector(GRD,for detecting 4 keV–4 MeV X/γray),the charged particle detector(CPD,for detecting 150 keV–5 MeV charged particle),and the electronic box(EBOX).The all-sky field coverage is achieved via two 229-degree large-area satellites positioned 180 degrees apart and are on opposite sides of the geo-center.Each satellite is equipped with 25 GRDs and 8 CPDs;thus,the satellite can identify charged particle bursts in space.Gamma-ray detectors adopt lanthanum bromide crystal technology combined with silicon photomultipliers.This is the first time that this technology was used massively in space detectors.Conclusions The GECAM satellite can quickly determine the direction of gamma-ray bursts(positioning)via indexing and fitting method,while the transmit variability,energy spectrum and direction of the gamma-ray bursts guide subsequent observations through the Beidou-3 RDSS in quasi-real time.It will play an important role in the study of high energy celestial bursts.
基金This research was supported by the“Strategic Priority Research Program”of the Chinese Academy of Sciences,Grant No.XDA 15360102.
文摘Background The Gravitational wave highly energetic Electromagnetic Counterpart All-sky Monitor(GECAM)is dedicated to detecting gravitational wave gamma-ray bursts.It is capable of all-sky monitoring over and discovering gamma-ray bursts and new radiation phenomena.GECAM consists of two microsatellites,each equipped with 8 charged particle detectors(CPDs)and 25 gamma-ray detectors(GRDs).Purpose The CPD is used to measure charged particles in the space environment,monitor energy and flow intensity changes,and identify between gamma-ray bursts and space charged particle events in conjunction with GRD.Methods CPD uses plastic scintillator as the sensitive material for detection,silicon photomultiplier array as the optically readable device,and the inlaid Am-241 radioactive source as the onboard calibration means.Conclusion In this paper,we will present the working principle,physical design,functional implementation and preliminary performance test results of the CPD.As a result,the energy range of electron,gamma-ray detection efficiency and dead time are tested to be better than the indexes required through the ground calibration experiment.
基金The authors would like to thank all colleagues for helpful suggestions and comments.This study was supported by the National Natural Science Foundation of China(Grant No.11803039 and 12173038)the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(Grant No.XDA 15360100 and XDA 15360102).
文摘Background The Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor(GECAM)consists of 2 microsatellites,each of which contains 25 GRD(LaBr3)detectors and 8 CPD(plastic scintillator)detectors.Method silicon photomultiplier(SiPM)array is used to read each detector.The output signal of these detectors with SiPM array is very special and challenging to readout.In this study,a novel data acquisition(DAQ)algorithm for these detectors is designed and implemented,and the content of the output event packet is defined.Result and Conclusion The performances,including the event acquisition efficiency of this DAQ algorithm,are extensively verified through experimental tests.From the on-ground and in-flight tests,this algorithm has excellent performance despite the very limited resources and short development time of GECAM mission.
基金This research is supported by the Strategic Priority Research Program of Chinese Academy of Sciences,Grant No.XDA15360102.
文摘Background The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM)satellite developed a SiPM-based gamma-ray detector to monitor the gravitational wave-related GRBs and guide subsequent observations in other wavelengths of EM.Purpose As all the available SiPM devices belong to commercial grade,quality assurance tests need to be performed in accordance with the aerospace specifcations.Methods In the SiPM application of GECAM,quality assurance experiments were conducted.The mechanism of the failure of SiPM devices was analyzed during the development process.Result Based on the quality assurance test results,the fnal pass rate of SiPM array was 95%.Based on the failure analysis,it was found that a piece of SiPM had a leakage channel after longtime operation due to device defects.Conclusion According to the accumulated experience,in the reliability test of SiPM,it is necessary to pay special attention to test the impedance of each pin of SiPM to ground and confrm that the power switch state of SiPM is controllable.
基金This research was supported by the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDBSSW-SLH012)the National Natural Science Foundation of China(11775251,11775252)the strategic leading science and technology program of Chinese Academy of Sciences(XDA 15360100,XDA 15360102).
文摘Purpose The discovery of gravitational waves and gamma-ray bursts heralds the era of multi-messenger astronomy.With the adoption of two small satellites to achieve the all-sky monitoring of gamma-ray bursts,the gravitational wave highenergy electromagnetic counterpart all-sky monitor(GECAM)possesses a quasi-real-time early warning ability and plays an important role in positioning the sources of gravitational waves and in subsequent observations.Each satellite of GECAM was fitted with 253-inch-diameter gamma-ray detectors(GRD),covering an energy range of 8–2 MeV.GRDs have adopted silicon photomultiplier tubes(SiPM)in lieu of photomultiplier tubes(PMT)to adapt to the dimensional limitations of micro-satellites.Methods A unique 3-inch circular SiPM array was designed.In this design,646×6 mm chips were arranged evenly in a circular manner with the seams filled with reflecting films,thus achieving satisfactory uniformity of light collection.The integrated pre-amplifier circuit on the back of the SiPM array adopted two-level grouping and summing;further,it achieved a satisfactory signal-to-noise ratio.Two high-gain and low-gain channels were adopted to achieve a large dynamic range,and two independent power supply units were used,where each unit can be closed separately,thus improving reliability.Results Performance studies show that this SiPM array meets the requirements of GECAM.Conclusion A 3-inch SiPM array have been developed that uses grouped summation,reflective films,a circular arrangement,two groups of independent power supplies,high-and low-gain signals,differential signal output technologies,etc.This solution can be used not only for GECAM,but also as a general solution for SiPM-based scintillation detectors.
