In recent years,there have been fewer missions to detect neutrons in low Earth orbits(LEO),and the data obtained have been extremely limited.Studying the distribution of the neutron energy spectrum in LEO satellites t...In recent years,there have been fewer missions to detect neutrons in low Earth orbits(LEO),and the data obtained have been extremely limited.Studying the distribution of the neutron energy spectrum in LEO satellites through detection can help solve three major scientific problems:the source of particles in the inner radiation belt,information on solar-accelerated particles,and the proportion of neutrons from different sources in near-Earth space.The detection efficiency and accuracy of neutrons are affected by charged and primary particles in the environment and secondary neutrons produced by the spacecraft itself,which has been a hot research topic.The neutron spectrometer developed in this study adopts two combinations of 15 silicon detectors in terms of detector type and arrangement,which are used for neutron detection via the nuclear reaction method and recoil proton method,respectively,in which a 27μm-thick^(6)LiF conversion layer is used for thermal neutron detection up to 0.4 eV and a 300μm-thick high-density polyethylene conversion layer is used for fast-neutron detection up to 14 MeV and below.The design of the detector set can also remove the influence of primary charged particles and secondary neutrons in the detection environment to a certain extent,thereby improving the accuracy of neutron detection.In this study,the neutron spectrometer hardware,firmware,software design,and basic performance of the front-end readout chip SKIROC2A were tested.The readout circuit of each channel baseline ADC code was less than 17;thus,the channel consistency was good.The RMS noise of the channel baseline was only 7.1 mV and exhibited good stability.The maximum number of events that could be processed per second is 75.The overall power consumption was 3 W,the weight was 792 g,and the volume was less than 1 dm^(3).Furthermore,the neutron spectrometer was tested for principle and detection efficiency using various neutron sources,such as ^(241)Am-Be neutron source,2.5 MeV neutron beam,and 14 MeV neutron beam,and the experiments were analyzed with corresponding simulations.The experimental data and simulation results were in good agreement and met the design requirements.The intrinsic detection efficiency of the probes used in the neutron spectrometer was 1.05%for 14 MeV fast neutrons.展开更多
Background Silicon PIN(Si-PIN)diode has been widely used in high-energy physics experiments.The next-generation experiments ask for a large amount of the Si-PIN diode arrays,leading to a requirement for the electronic...Background Silicon PIN(Si-PIN)diode has been widely used in high-energy physics experiments.The next-generation experiments ask for a large amount of the Si-PIN diode arrays,leading to a requirement for the electronics system with features of higher integration and lower power consumption than the traditional ones.Purpose The aim was to design and implement a prototype of multi-channel electronic system,which is based on the SKIROC2 ASIC.The system is also considered as the pre-research of the silicon–tungsten(Si-W)ECAL for CEPC.Methods The prototype is divided into two parts,so that it has the potentiality for the expansion of more readout channels.The front-end board(FEB),which carries a Si-PIN diode array and an ASIC of SKIROC2 on it,provides high voltage to the Si-PIN diodes and processes the signals as well.The FEB is configured by a data interface board(DIF)and sends data to the DIF,which then transfers data to PC via USB interface after packing process.Results The prototype electronics system has been implemented.The equivalent noise level of all the 64 channels is below 0.4 fC.The dynamic range is up to+3000 fC with an integral nonlinearity(INL)of 0.2%,and the gain non-uniformity is better than 5%.The energy resolution with 59 keV X-rays from 241Am is about 13.3%(in RMS),while the signal-to-noise ratio(SNR)reaches about 10.9 for minimum ionizing particles(MIPs).Conclusion In this paper,a SKIROC2-based prototype electronics system for Si-PIN array,as well as the performance test,has been presented.The system has features of high integration,low noise,and high dynamic range.The SKIROC2,as well as the design concept of the electronics system,can be applied to the preliminary prototype Si-W ECAL of CEPC.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.42225405 and U2106202)。
文摘In recent years,there have been fewer missions to detect neutrons in low Earth orbits(LEO),and the data obtained have been extremely limited.Studying the distribution of the neutron energy spectrum in LEO satellites through detection can help solve three major scientific problems:the source of particles in the inner radiation belt,information on solar-accelerated particles,and the proportion of neutrons from different sources in near-Earth space.The detection efficiency and accuracy of neutrons are affected by charged and primary particles in the environment and secondary neutrons produced by the spacecraft itself,which has been a hot research topic.The neutron spectrometer developed in this study adopts two combinations of 15 silicon detectors in terms of detector type and arrangement,which are used for neutron detection via the nuclear reaction method and recoil proton method,respectively,in which a 27μm-thick^(6)LiF conversion layer is used for thermal neutron detection up to 0.4 eV and a 300μm-thick high-density polyethylene conversion layer is used for fast-neutron detection up to 14 MeV and below.The design of the detector set can also remove the influence of primary charged particles and secondary neutrons in the detection environment to a certain extent,thereby improving the accuracy of neutron detection.In this study,the neutron spectrometer hardware,firmware,software design,and basic performance of the front-end readout chip SKIROC2A were tested.The readout circuit of each channel baseline ADC code was less than 17;thus,the channel consistency was good.The RMS noise of the channel baseline was only 7.1 mV and exhibited good stability.The maximum number of events that could be processed per second is 75.The overall power consumption was 3 W,the weight was 792 g,and the volume was less than 1 dm^(3).Furthermore,the neutron spectrometer was tested for principle and detection efficiency using various neutron sources,such as ^(241)Am-Be neutron source,2.5 MeV neutron beam,and 14 MeV neutron beam,and the experiments were analyzed with corresponding simulations.The experimental data and simulation results were in good agreement and met the design requirements.The intrinsic detection efficiency of the probes used in the neutron spectrometer was 1.05%for 14 MeV fast neutrons.
基金This work was supported by National Natural Science Foun-dation of China(Grant No.11635007).
文摘Background Silicon PIN(Si-PIN)diode has been widely used in high-energy physics experiments.The next-generation experiments ask for a large amount of the Si-PIN diode arrays,leading to a requirement for the electronics system with features of higher integration and lower power consumption than the traditional ones.Purpose The aim was to design and implement a prototype of multi-channel electronic system,which is based on the SKIROC2 ASIC.The system is also considered as the pre-research of the silicon–tungsten(Si-W)ECAL for CEPC.Methods The prototype is divided into two parts,so that it has the potentiality for the expansion of more readout channels.The front-end board(FEB),which carries a Si-PIN diode array and an ASIC of SKIROC2 on it,provides high voltage to the Si-PIN diodes and processes the signals as well.The FEB is configured by a data interface board(DIF)and sends data to the DIF,which then transfers data to PC via USB interface after packing process.Results The prototype electronics system has been implemented.The equivalent noise level of all the 64 channels is below 0.4 fC.The dynamic range is up to+3000 fC with an integral nonlinearity(INL)of 0.2%,and the gain non-uniformity is better than 5%.The energy resolution with 59 keV X-rays from 241Am is about 13.3%(in RMS),while the signal-to-noise ratio(SNR)reaches about 10.9 for minimum ionizing particles(MIPs).Conclusion In this paper,a SKIROC2-based prototype electronics system for Si-PIN array,as well as the performance test,has been presented.The system has features of high integration,low noise,and high dynamic range.The SKIROC2,as well as the design concept of the electronics system,can be applied to the preliminary prototype Si-W ECAL of CEPC.
