This paper presents a review of the position-sensitive detector(PSD) sensor, covering different types of PSD and recent works related to this field. Furthermore, it explains the theoretical concepts and provides infor...This paper presents a review of the position-sensitive detector(PSD) sensor, covering different types of PSD and recent works related to this field. Furthermore, it explains the theoretical concepts and provides information about its structure and principles of operation. Moreover, it includes the main information about the available commercial PSDs from different companies, along with a comparison between the common modules. The PSD features include high position resolution, fast response, and a wide dynamic range. These features make it suitable for various fields and applications, such as imaging, spectrometry, spectroscopy and others.展开更多
Ultraviolet position-sensitive detectors(PSDs)are expected to undergo harsh environments,such as high temperatures,for a wide variety of applications in military,civilian,and aerospace.However,no report on relevant PS...Ultraviolet position-sensitive detectors(PSDs)are expected to undergo harsh environments,such as high temperatures,for a wide variety of applications in military,civilian,and aerospace.However,no report on relevant PSDs operating at high temperatures can be found up to now.Herein,we design a new 2D/3D graphitic carbon nitride(g-C_(3)N_(4))/gallium nitride(GaN)hybrid heterojunction to construct the ultraviolet high-temperature-resistant PSD.The g-C_(3)N_(4)/GaN PSD exhibits a high position sensitivity of 355 mV mm^(-1),a rise/fall response time of 1.7/2.3 ms,and a nonlinearity of 0.5%at room temperature.The ultralow formation energy of-0.917 eV atom^(-1)has been obtained via the thermodynamic phase stability calculations,which endows g-C_(3)N_(4)with robust stability against heat.By merits of the strong built-in electric field of the 2D/3D hybrid heterojunction and robust thermo-stability of g-C_(3)N_(4),the g-C_(3)N_(4)/GaN PSD delivers an excellent position sensitivity and angle detection nonlinearity of 315 mV mm^(-1)and 1.4%,respectively,with high repeatability at a high temperature up to 700 K,outperforming most of the other counterparts and even commercial silicon-based devices.This work unveils the high-temperature PSD,and pioneers a new path to constructing g-C_(3)N_(4)-based harsh-environment-tolerant optoelectronic devices.展开更多
A foil–microchannel plate(MCP)detector,which uses electrostatic lenses and possesses both good position and timing resolutions,has been designed and simulated for beam diagnostics and mass measurements at the next-ge...A foil–microchannel plate(MCP)detector,which uses electrostatic lenses and possesses both good position and timing resolutions,has been designed and simulated for beam diagnostics and mass measurements at the next-generation heavy-ion-beam facility HIAF in China.Characterized by low energy loss and good performances of timing and position measurements,it would be located at focal planes in fragment separator HFRS for position monitoring,beam turning,Bq measurement,and trajectory reconstruction.Moreover,it will benefit the building-up of a magnetic-rigidity–energy-loss–time-offlight(BqDETOF)method at HFRS for high-precision in-flight particle identification of radioactive isotope beams on an event-by-event basis.Most importantly,the detector can be utilized for in-ring TOF and position measurements,beam-line TOF measurements at two achromatic foci,and position measurements at a dispersive focus of HFRS,thus making it possible to use two complementary mass measurement methods[isochronous mass spectrometry at the storage ring SRing and magnetic-rigidity–time-of-flight(BqTOF)at the beam-line HFRS]in one single experimental run.展开更多
A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels.Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software ...A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels.Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software is developed using LabVIEW, and the offline Compton imaging codes are written in C++. The prototype has been successfully calibrated, and its capabilities for source detection, spectroscopy, and Compton imaging have been demonstrated using a Cs-137 source.The angular resolution of the 662 keV line is 36° FWHM for the simple back-projection method and 9.6° FWHM for the MLEM reconstruction method. The system is ready to be extended to 11-by-11 pixels in the future, and a better imaging quality can be expected due to the better relative position resolution.展开更多
In this paper, we propose a new method for position-sensitive measurement of beta surface contamination. With a position-sensitive detector of enlarged sensitive detection area, accurate information of the contaminati...In this paper, we propose a new method for position-sensitive measurement of beta surface contamination. With a position-sensitive detector of enlarged sensitive detection area, accurate information of the contamination distribution can be obtained. The positionsensitive detection is based on a large-area plastic scintillator and the wavelength shifting(WLS) fibers and adopts the ‘‘light center of gravity'' method. Optical transmission of the detector is simulated with a preliminary detector model, and feasibility of the detector design and measurement method is evaluated using an experiment system.The simulation and experiment results at different beta-ray incident points on the scintillator surface show that there is a polynomial relationship between the average amplitude ratio of the output pulses from the two parallel WLS fibers in the same fiber layer and the relative distance from the incident point to the WLS fiber.展开更多
Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the application...Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the applications of flexible PSDs have been limited.Therefore,we presented a flexible broadband PSD based on a WS_(2)/Si heterostructure for the first time.A scalable sputtering method was used to deposit WS_(2)thin films onto the etched ultrathin crystalline Si surface.The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450-1350 nm,with a high position sensitivity of~539.8 mV·mm^(−1)and a fast response of 2.3μs,thanks to the strong light absorption,the built-in electrical field at the WS_(2)/Si interface,and facilitated transport.Furthermore,mechanical-bending tests revealed that after 200 mechanical-bending cycles,the WS_(2)/Si PSDs have excellent mechanical flexibility,stability,and durability,demonstrating the great potential in wearable PSDs with competitive performance.展开更多
Two-dimensional(2D)materials have attracted great attention in optoelectronics because of their unique structure,optical and electrical properties.Designing high-performance photodetectors and implementing their appli...Two-dimensional(2D)materials have attracted great attention in optoelectronics because of their unique structure,optical and electrical properties.Designing high-performance photodetectors and implementing their applications are eager to promote the development of 2D materials.Position-sensitive detector(PSD)is an optical inspection device for the precise measurements of position,distance,angle,and other relevant physical variables.It is a widely used component in the fields of tracking,aerospace,nanorobotics,and so forth.Essentially,PSD is also a photodetector based on the lateral photovoltaic effect(LPE).This article reviews recent progress in high-performance PSD based on 2D materials.The high-sensitive photodetectors and LPE involved in 2D photodetectors are firstly discussed.Then,we introduce the research progress of PSD based on 2D materials and analyze the carrier dynamics in different device structures.Finally,we summarize the functionalities and applications of PSD based on 2D materials,and highlight the challenges and opportunities in this research area.展开更多
Motion tracking has attracted great attention in the fields of real-time tracking,nanorobotics,and targeted therapy.For achieving more accurate motion tracking,the highly sensitive position-sensitive detector(PSD)is d...Motion tracking has attracted great attention in the fields of real-time tracking,nanorobotics,and targeted therapy.For achieving more accurate motion tracking,the highly sensitive position-sensitive detector(PSD)is desirable.Here,we demonstrate a meliorated PSD based on graphene-Si heterojunction for motion tracking.The position sensitivity of PSD was improved by employing surface engineering of graphene.Through modulating the transport property of graphene,nearly 20-fold increase of sensitivity was achieved under weak light,and at the same time,the detection limit power was reduced to^2 nW.A motion tracking system was developed based on the improved PSD,and human arm swing was tracked,which demonstrated high sensitivity and real-time tracking capabilities of the PSD.In addition,the PSD can support up to^10 kHz high-frequency tracking.This work provides a new strategy for improving the performance of PSD,and promotes the development of two-dimensional materials in novel optoelectronic devices.展开更多
Monoclinic Ga2O3(β-Ga2O3)is a promising material for achieving solar-blind photodetection because of its unique characteristics,including its high breakdown electric field,radiation hardness,thermal and chemical stab...Monoclinic Ga2O3(β-Ga2O3)is a promising material for achieving solar-blind photodetection because of its unique characteristics,including its high breakdown electric field,radiation hardness,thermal and chemical stabilities,and intrinsic visible/solar-blind properties.Until now,several studies have investigated the development of high-performanceβ-Ga2O3 solar-blind photodetectors.However,these photodetectors can only detect the light intensity but not the light position.In this work,fourquadrant position-sensitive detectors(4Q-PSDs)were developed and demonstrated based onβ-Ga2O3.4Q-PSDs,comprising four identical metal-semiconductor-metal-structured photodetector components,demonstrate high uniformity,large signal-tonoise ratio,good ultraviolet/visible rejection ratio,and fast response/recovery time.Subsequently,the position of the illumination beam can be determined by analyzing the output signals of the four photodetector components.This work may indicate the promising application potential of the Ga2O3-based photodetectors in the fields of positioning,aligning,and monitoring the solarblind beams.展开更多
As a typical two-dimensional material,graphitic carbon nitride(g-CN)has attracted great interest because of its distinctive electronic,optical,and catalytic properties.However,the absence of a feasible route toward la...As a typical two-dimensional material,graphitic carbon nitride(g-CN)has attracted great interest because of its distinctive electronic,optical,and catalytic properties.However,the absence of a feasible route toward large-area and high-quality films hinders its development in optoelectronics.Herein,high-quality g-CN films have been grown on Si substrate via a vapor-phase transport-assisted condensation method.The g-CN/Si heterojunction shows an obvious response to ultraviolet–visible-near infrared photons with a responsivity of 133 A·W−1,which is two orders of magnitude higher than the best value ever reported for g-CN photodetectors.A position-sensitive detector(PSD)has been developed using the lateral photovoltaic effect of the g-CN/Si heterojunction.The PSD shows a wide response spectrum ranging from 300 to 1,100 nm,and a position sensitivity and rise/decay time of 395 mV·mm−1 and 3.1/50μs,respectively.Moreover,the application of the g-CN/Si heterojunction photodetector in trajectory tracking and acoustic detection has been realized for the first time.This work unveils the potential of g-CN for large-area photodetectors,and prospects for their applications in trajectory tracking and acoustic detection.展开更多
Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance...Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance and differences in electrode structures,the nonlinearity of PSD becomes increasingly severe as the photosensitive surface moves from the center toward the edges of the four electrodes.To address this issue,a PSD nonlinearity correction algorithm is proposed.The algorithm utilizes the particle swarm optimization(PSO)algorithm to determine the optimal weights and thresholds,providing better initial parameters for the back propagation(BP)neural network.The BP neural network then iterates continuously until the error conditions are met,completing the correction process.Furthermore,a PSD nonlinearity correction system was developed,and the influence of different spot sizes on PSD positioning accuracy was simulated based on the current equation under the Gaussian spot model.This validated the robustness of the correction algorithm under varying spot sizes.The results demonstrate that the overall optimized error is reduced by 84.51%,and for spot sizes smaller than 1 mm,the error reduction exceeds 93.89%.This method not only meets the measurement accuracy requirements but also extends the measurement range of PSD.展开更多
A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of p...A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out（FIFO） memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.展开更多
A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of positio...A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of position measurement,which is used to correct the momentum spread,thus reducing the uncertainty inthe mass determination.The detector comprises a cylindrical reference cavity and elliptical position-sensitive cavity,which uses an offset beam-pipe to create a relation between the Schottky power and horizontal position.The uncertaintyin the power response can be improved by minimizing free parameters inside the power equation,providing asecond-order correction for the position determination.This requires a large dispersion and momentum spread to effectivelycharacterize the SCD acceptance,which simulations show is achieved when using^(76)Zn as a reference isotope.A key parameter to minimize is uncertainty of the impedance map,which relates power to position in the ellipticalcavity.We find that an uncertainty in impedance of 0.3Ωresults in a precision equal to that of the current massmeasurement method.Additionally,measuring momentum with the SCD enables the removal of other detectorsfrom the beam-line,which drastically reduces the yield of high-Z beams via charge-change interactions.展开更多
We developed a time-of-flight(TOF)detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory.Compared to the previous design,the developed TOF detector emplo...We developed a time-of-flight(TOF)detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory.Compared to the previous design,the developed TOF detector employed modified electrodes,and its static electric and magnetic fields were reduced.We improved the detection efficiency and stability of operation.Its specification and design were finally fixed for mass measurements.We also developed a position-sensitive detector based on the principles of the TOF detector.This study utilized larger microchannel plate(MCP)detectors than those of the prototype.By improving acceptance,we demonstrated the performance of the position-sensitive detector with very low material thickness.展开更多
文摘This paper presents a review of the position-sensitive detector(PSD) sensor, covering different types of PSD and recent works related to this field. Furthermore, it explains the theoretical concepts and provides information about its structure and principles of operation. Moreover, it includes the main information about the available commercial PSDs from different companies, along with a comparison between the common modules. The PSD features include high position resolution, fast response, and a wide dynamic range. These features make it suitable for various fields and applications, such as imaging, spectrometry, spectroscopy and others.
基金financially supported by the National Natural Science Foundation of China(No.61804136,U1804155,11974317,62027816,12074348,and U2004168)Henan Science Fund for Distinguished Young Scholars(No.212300410020)+2 种基金Natural Science Foundation of Henan Province(No.212300410020 and 212300410078)Key Project of Henan Higher Education(No.21A140001)the Zhengzhou University Physics Discipline Improvement Program and China Postdoctoral Science Foundation(No.2018M630829 and 2019 T120630)
文摘Ultraviolet position-sensitive detectors(PSDs)are expected to undergo harsh environments,such as high temperatures,for a wide variety of applications in military,civilian,and aerospace.However,no report on relevant PSDs operating at high temperatures can be found up to now.Herein,we design a new 2D/3D graphitic carbon nitride(g-C_(3)N_(4))/gallium nitride(GaN)hybrid heterojunction to construct the ultraviolet high-temperature-resistant PSD.The g-C_(3)N_(4)/GaN PSD exhibits a high position sensitivity of 355 mV mm^(-1),a rise/fall response time of 1.7/2.3 ms,and a nonlinearity of 0.5%at room temperature.The ultralow formation energy of-0.917 eV atom^(-1)has been obtained via the thermodynamic phase stability calculations,which endows g-C_(3)N_(4)with robust stability against heat.By merits of the strong built-in electric field of the 2D/3D hybrid heterojunction and robust thermo-stability of g-C_(3)N_(4),the g-C_(3)N_(4)/GaN PSD delivers an excellent position sensitivity and angle detection nonlinearity of 315 mV mm^(-1)and 1.4%,respectively,with high repeatability at a high temperature up to 700 K,outperforming most of the other counterparts and even commercial silicon-based devices.This work unveils the high-temperature PSD,and pioneers a new path to constructing g-C_(3)N_(4)-based harsh-environment-tolerant optoelectronic devices.
基金supported by the National Natural Science Foundation of China(Nos.11605248,11605249,11605267,and 11805032.)
文摘A foil–microchannel plate(MCP)detector,which uses electrostatic lenses and possesses both good position and timing resolutions,has been designed and simulated for beam diagnostics and mass measurements at the next-generation heavy-ion-beam facility HIAF in China.Characterized by low energy loss and good performances of timing and position measurements,it would be located at focal planes in fragment separator HFRS for position monitoring,beam turning,Bq measurement,and trajectory reconstruction.Moreover,it will benefit the building-up of a magnetic-rigidity–energy-loss–time-offlight(BqDETOF)method at HFRS for high-precision in-flight particle identification of radioactive isotope beams on an event-by-event basis.Most importantly,the detector can be utilized for in-ring TOF and position measurements,beam-line TOF measurements at two achromatic foci,and position measurements at a dispersive focus of HFRS,thus making it possible to use two complementary mass measurement methods[isochronous mass spectrometry at the storage ring SRing and magnetic-rigidity–time-of-flight(BqTOF)at the beam-line HFRS]in one single experimental run.
文摘A Compton camera prototype has been developed using a pixelated CZT detector with 4-by-4 pixels.Signals of the detector are read out by a VASTAT ASIC that is controlled by a self-developed DAQ board. The DAQ software is developed using LabVIEW, and the offline Compton imaging codes are written in C++. The prototype has been successfully calibrated, and its capabilities for source detection, spectroscopy, and Compton imaging have been demonstrated using a Cs-137 source.The angular resolution of the 662 keV line is 36° FWHM for the simple back-projection method and 9.6° FWHM for the MLEM reconstruction method. The system is ready to be extended to 11-by-11 pixels in the future, and a better imaging quality can be expected due to the better relative position resolution.
基金supported by the Technology and Industry for National Defense(No.HK.FA1001-1)
文摘In this paper, we propose a new method for position-sensitive measurement of beta surface contamination. With a position-sensitive detector of enlarged sensitive detection area, accurate information of the contamination distribution can be obtained. The positionsensitive detection is based on a large-area plastic scintillator and the wavelength shifting(WLS) fibers and adopts the ‘‘light center of gravity'' method. Optical transmission of the detector is simulated with a preliminary detector model, and feasibility of the detector design and measurement method is evaluated using an experiment system.The simulation and experiment results at different beta-ray incident points on the scintillator surface show that there is a polynomial relationship between the average amplitude ratio of the output pulses from the two parallel WLS fibers in the same fiber layer and the relative distance from the incident point to the WLS fiber.
基金supported by the National Natural Science Foundation of China(No.51972341)the Shandong Natural Science Foundation,China(No.ZR2020MA069).
文摘Si-based optical position-sensitive detectors(PSDs)have stimulated the interest of researchers due to their wide range of practical applications.However,due to the rigidity and fragility of Si crystals,the applications of flexible PSDs have been limited.Therefore,we presented a flexible broadband PSD based on a WS_(2)/Si heterostructure for the first time.A scalable sputtering method was used to deposit WS_(2)thin films onto the etched ultrathin crystalline Si surface.The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450-1350 nm,with a high position sensitivity of~539.8 mV·mm^(−1)and a fast response of 2.3μs,thanks to the strong light absorption,the built-in electrical field at the WS_(2)/Si interface,and facilitated transport.Furthermore,mechanical-bending tests revealed that after 200 mechanical-bending cycles,the WS_(2)/Si PSDs have excellent mechanical flexibility,stability,and durability,demonstrating the great potential in wearable PSDs with competitive performance.
基金the National Natural Science Foundation of China(Nos.61927808,61774034,and 11704068)the National Key Research and Development Program of China(No.2017YFA0205700)China Postdoctoral Science Foundation(No.2018M632197).
文摘Two-dimensional(2D)materials have attracted great attention in optoelectronics because of their unique structure,optical and electrical properties.Designing high-performance photodetectors and implementing their applications are eager to promote the development of 2D materials.Position-sensitive detector(PSD)is an optical inspection device for the precise measurements of position,distance,angle,and other relevant physical variables.It is a widely used component in the fields of tracking,aerospace,nanorobotics,and so forth.Essentially,PSD is also a photodetector based on the lateral photovoltaic effect(LPE).This article reviews recent progress in high-performance PSD based on 2D materials.The high-sensitive photodetectors and LPE involved in 2D photodetectors are firstly discussed.Then,we introduce the research progress of PSD based on 2D materials and analyze the carrier dynamics in different device structures.Finally,we summarize the functionalities and applications of PSD based on 2D materials,and highlight the challenges and opportunities in this research area.
基金China Postdoctoral Science Foundation,Grant/Award Number:2018M632197Funding of Natural Science Research Projects in Colleges and Universities of Jiangsu Province,Grant/Award Number:18KJD140003+3 种基金National Natural Science Foundation of China,Grant/Award Numbers:11704068,61774034the Fundamental Research Funds for the Central Universities,Grant/Award Number:2242019R20025The National Key Research and Development Program of China,Grant/Award Number:2017YFA0205700the Strategic Priority Research Program of Chinese Academy of Sciences,Grant/Award Number:XDB30000000。
文摘Motion tracking has attracted great attention in the fields of real-time tracking,nanorobotics,and targeted therapy.For achieving more accurate motion tracking,the highly sensitive position-sensitive detector(PSD)is desirable.Here,we demonstrate a meliorated PSD based on graphene-Si heterojunction for motion tracking.The position sensitivity of PSD was improved by employing surface engineering of graphene.Through modulating the transport property of graphene,nearly 20-fold increase of sensitivity was achieved under weak light,and at the same time,the detection limit power was reduced to^2 nW.A motion tracking system was developed based on the improved PSD,and human arm swing was tracked,which demonstrated high sensitivity and real-time tracking capabilities of the PSD.In addition,the PSD can support up to^10 kHz high-frequency tracking.This work provides a new strategy for improving the performance of PSD,and promotes the development of two-dimensional materials in novel optoelectronic devices.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFB0406500)the National Natural Science Foundation of China(Grant Nos.61804136,U1804155,and U1604263)the China Postdoctoral Science Foundation(Grant Nos.2018M630829,and 2019T120630)。
文摘Monoclinic Ga2O3(β-Ga2O3)is a promising material for achieving solar-blind photodetection because of its unique characteristics,including its high breakdown electric field,radiation hardness,thermal and chemical stabilities,and intrinsic visible/solar-blind properties.Until now,several studies have investigated the development of high-performanceβ-Ga2O3 solar-blind photodetectors.However,these photodetectors can only detect the light intensity but not the light position.In this work,fourquadrant position-sensitive detectors(4Q-PSDs)were developed and demonstrated based onβ-Ga2O3.4Q-PSDs,comprising four identical metal-semiconductor-metal-structured photodetector components,demonstrate high uniformity,large signal-tonoise ratio,good ultraviolet/visible rejection ratio,and fast response/recovery time.Subsequently,the position of the illumination beam can be determined by analyzing the output signals of the four photodetector components.This work may indicate the promising application potential of the Ga2O3-based photodetectors in the fields of positioning,aligning,and monitoring the solarblind beams.
基金This work was financially supported by Henan Center for Outstanding Overseas Scientists(No.GZS201903)the National Natural Science Foundation of China(Nos.61804136,11974317,and 62027816)+2 种基金Henan Science Fund for Distinguished Young Scholars(No.212300410020)Key Project of Henan Higher Education(No.21A140001)the Zhengzhou University Physics Discipline Improvement Program.
文摘As a typical two-dimensional material,graphitic carbon nitride(g-CN)has attracted great interest because of its distinctive electronic,optical,and catalytic properties.However,the absence of a feasible route toward large-area and high-quality films hinders its development in optoelectronics.Herein,high-quality g-CN films have been grown on Si substrate via a vapor-phase transport-assisted condensation method.The g-CN/Si heterojunction shows an obvious response to ultraviolet–visible-near infrared photons with a responsivity of 133 A·W−1,which is two orders of magnitude higher than the best value ever reported for g-CN photodetectors.A position-sensitive detector(PSD)has been developed using the lateral photovoltaic effect of the g-CN/Si heterojunction.The PSD shows a wide response spectrum ranging from 300 to 1,100 nm,and a position sensitivity and rise/decay time of 395 mV·mm−1 and 3.1/50μs,respectively.Moreover,the application of the g-CN/Si heterojunction photodetector in trajectory tracking and acoustic detection has been realized for the first time.This work unveils the potential of g-CN for large-area photodetectors,and prospects for their applications in trajectory tracking and acoustic detection.
基金Supported by the National Natural Science Foundation of China(U1831133)Open Fund of Key Laboratory of Space Active Optoelectronics Technology,Chinese Academy of Sciences(2021ZDKF4)。
文摘Position-sensitive detector(PSD)is widely used in precision measurement fields such as flatness detection,auto-collimator systems,and degrees of freedom testing.However,due to factors such as uneven surface resistance and differences in electrode structures,the nonlinearity of PSD becomes increasingly severe as the photosensitive surface moves from the center toward the edges of the four electrodes.To address this issue,a PSD nonlinearity correction algorithm is proposed.The algorithm utilizes the particle swarm optimization(PSO)algorithm to determine the optimal weights and thresholds,providing better initial parameters for the back propagation(BP)neural network.The BP neural network then iterates continuously until the error conditions are met,completing the correction process.Furthermore,a PSD nonlinearity correction system was developed,and the influence of different spot sizes on PSD positioning accuracy was simulated based on the current equation under the Gaussian spot model.This validated the robustness of the correction algorithm under varying spot sizes.The results demonstrate that the overall optimized error is reduced by 84.51%,and for spot sizes smaller than 1 mm,the error reduction exceeds 93.89%.This method not only meets the measurement accuracy requirements but also extends the measurement range of PSD.
基金National Natural Science Foundation of China (Nos. 10134010 and 10004010)
文摘A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out（FIFO） memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.
基金support from the State of Hesse within the Research Cluster ELEMENTS(project ID 500/10.006)。
文摘A position-sensitive Schottky Cavity Doublet(SCD)was developed to enhance the accuracy of isochronousmass measurement at the Rare Radio-Isotope Ring(R3)at RIBF-RIKEN,Japan.The aim is to increase theaccuracy of position measurement,which is used to correct the momentum spread,thus reducing the uncertainty inthe mass determination.The detector comprises a cylindrical reference cavity and elliptical position-sensitive cavity,which uses an offset beam-pipe to create a relation between the Schottky power and horizontal position.The uncertaintyin the power response can be improved by minimizing free parameters inside the power equation,providing asecond-order correction for the position determination.This requires a large dispersion and momentum spread to effectivelycharacterize the SCD acceptance,which simulations show is achieved when using^(76)Zn as a reference isotope.A key parameter to minimize is uncertainty of the impedance map,which relates power to position in the ellipticalcavity.We find that an uncertainty in impedance of 0.3Ωresults in a precision equal to that of the current massmeasurement method.Additionally,measuring momentum with the SCD enables the removal of other detectorsfrom the beam-line,which drastically reduces the yield of high-Z beams via charge-change interactions.
基金Supported by the Research Project with Heavy Ions at QST-HIMAC(21H296)JSPS KAKENHI(JP18H03695,JP19K14730,JP21H04461)。
文摘We developed a time-of-flight(TOF)detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory.Compared to the previous design,the developed TOF detector employed modified electrodes,and its static electric and magnetic fields were reduced.We improved the detection efficiency and stability of operation.Its specification and design were finally fixed for mass measurements.We also developed a position-sensitive detector based on the principles of the TOF detector.This study utilized larger microchannel plate(MCP)detectors than those of the prototype.By improving acceptance,we demonstrated the performance of the position-sensitive detector with very low material thickness.
