The PICOSEC Micromegas(MM)is a precise timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and an MM amplifying structure.It features a two-stage amplification process th...The PICOSEC Micromegas(MM)is a precise timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and an MM amplifying structure.It features a two-stage amplification process that leads to a significant deterioration of non-uniformity when scaling up to larger areas.Since the performance of gaseous detectors is highly dependent on the choice of working gas,optimizing the gas mixture offers a promising solution to improve the uniformity performance.This paper addresses these challenges through a combined approach of simulation based on Garfield++and experimental studies.The simulation investigates the properties of different mixing fractions of gas mixtures and their impact on detector performance,including gain uniformity and time resolution.To verify the simulation results,experimental tests were conducted using a multi-channel PICOSEC MM prototype with different gas mixtures.The experimental results are consistent with the findings of the simulation,indicating that a higher concentration of neon significantly improves the detector’s gain uniformity.Furthermore,the influence of gas mixtures on time resolution was explored as a critical performance indicator.The study presented in this paper offers valuable insights for improving uniformity in large-area PICOSEC MM detectors and optimizing overall performance.展开更多
The study of the charge conjugation and parity(CP)violation of hyperon is the precision frontier for probing possible new CP violation sources beyond the standard model(SM).With the large number of quantum entangled h...The study of the charge conjugation and parity(CP)violation of hyperon is the precision frontier for probing possible new CP violation sources beyond the standard model(SM).With the large number of quantum entangled hyperonantihyperon pairs to be produced at Super Tau-Charm Facility(STCF),the CP asymmetry of hyperon is expected to be tested with a statistical sensitivity of 10^(−4) or even better.To cope with the statistical precision,the systematic effects from various aspects are critical and need to be studied in detail.In this paper,the sensitivity effects on the CP violation parameters associated with the detector resolution,including those of the position and momentum,are studied and discussed in detail.The results provide valuable guidance for the design of STCF detector.展开更多
A state-of-the-art detector array with a digital data acquisition system has been developed for charged-particle decay studies,includingβ-delayed protons,αdecay,and direct proton emissions from exotic proton-rich nu...A state-of-the-art detector array with a digital data acquisition system has been developed for charged-particle decay studies,includingβ-delayed protons,αdecay,and direct proton emissions from exotic proton-rich nuclei.The digital data acquisition system enables precise synchronization and processing of complex signals from various detectors,such as plastic scintillators,silicon detectors,and germaniumγdetectors.The system's performance was evaluated using theβdecay of^(32)Ar and its neighboring nuclei,produced via projectile fragmentation at the first Radioactive Ion Beam Line in Lanzhou(RIBLL1).Key measurements,including the half-life,charged-particle spectrum,andγ-ray spectrum,were obtained and compared with previous results for validation.Using the implantation–decay method,the isotopes of interest were implanted into two doublesided silicon strip detectors,where their subsequent decays were measured and correlated with preceding implantations using both position and time information.This detection system has potential for further applications,including the study ofβ-delayed charged-particle decay and direct proton emissions from even more exotic proton-rich nuclei.展开更多
This study presents a low-noise,high-rate front-end readout application-specific integrated circuit(ASIC)designed for the electromagnetic calorimeter(ECAL)of the Super Tau-Charm Facility(STCF).To address the high back...This study presents a low-noise,high-rate front-end readout application-specific integrated circuit(ASIC)designed for the electromagnetic calorimeter(ECAL)of the Super Tau-Charm Facility(STCF).To address the high background-count rate in the STCF ECAL,the temporal features of signals are analyzed node-by-node along the chain of the analog front-end circuit.Then,the system is optimized to mitigate the pile-up effects and elevate the count rate to megahertz levels.First,a charge-sensitive amplifier(CSA)with a fast reset path is developed,enabling quick resetting when the output reaches the maximum amplitude.This prevents the CSA from entering a pulse-dead zone owing to amplifier saturation caused by the pile-up.Second,a high-order shaper with baseline holder circuits is improved to enhance the anti-pile-up capability while maintaining an effective noise-filtering performance.Third,a high-speed peak-detection and hold circuit with an asynchronous first-input-first-output buffer function is proposed to hold and read the piled-up signals of the shaper.The ASIC is designed and manufactured using a standard commercial 1P6M 0.18μm mixed-signal CMOS process with a chip area of 2.4 mm×1.6 mm.The measurement results demonstrate a dynamic range of 4–500 fC with a nonlinearity error below 1.5%.For periodically distributed input signals,a count rate of 1.5 MHz/Ch is achieved with a peak time of 360 ns,resulting in an equivalent noise charge(ENC)of 2500 e^(-)-.The maximum count rate is 4 MHz/Ch at a peak time of 120 ns.At a peak time of 1.68μs with a 270 pF external capacitance,the minimum ENC is 1966 e^(-)-,and the noise slope is 3.08 e^(-)-∕pF.The timing resolution is better than 125 ps at an input charge of 200 fC.The power consumption is 35 mW/Ch.展开更多
基金supported by the National Natural Science Foundation of China(12125505).
文摘The PICOSEC Micromegas(MM)is a precise timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and an MM amplifying structure.It features a two-stage amplification process that leads to a significant deterioration of non-uniformity when scaling up to larger areas.Since the performance of gaseous detectors is highly dependent on the choice of working gas,optimizing the gas mixture offers a promising solution to improve the uniformity performance.This paper addresses these challenges through a combined approach of simulation based on Garfield++and experimental studies.The simulation investigates the properties of different mixing fractions of gas mixtures and their impact on detector performance,including gain uniformity and time resolution.To verify the simulation results,experimental tests were conducted using a multi-channel PICOSEC MM prototype with different gas mixtures.The experimental results are consistent with the findings of the simulation,indicating that a higher concentration of neon significantly improves the detector’s gain uniformity.Furthermore,the influence of gas mixtures on time resolution was explored as a critical performance indicator.The study presented in this paper offers valuable insights for improving uniformity in large-area PICOSEC MM detectors and optimizing overall performance.
基金supported by the National Key R&D Program of China(2022YFA1602200)the International Partnership Program of the Chinese Academy of Sciences(211134KYSB20200057).
文摘The study of the charge conjugation and parity(CP)violation of hyperon is the precision frontier for probing possible new CP violation sources beyond the standard model(SM).With the large number of quantum entangled hyperonantihyperon pairs to be produced at Super Tau-Charm Facility(STCF),the CP asymmetry of hyperon is expected to be tested with a statistical sensitivity of 10^(−4) or even better.To cope with the statistical precision,the systematic effects from various aspects are critical and need to be studied in detail.In this paper,the sensitivity effects on the CP violation parameters associated with the detector resolution,including those of the position and momentum,are studied and discussed in detail.The results provide valuable guidance for the design of STCF detector.
基金国际原子能机构IAEA CRP项目“基于LaBr3143-1001 keV相对效率法确定铀富集度方法研究(编号:CRPJ02020)”[IAEA CRP J02020 on"Study on the Method for Determining Uranium Enrichment Based on LaBr3143-1001 keV Relative Efficiency Method"]。
基金supported by the National Key Research and Development Project,China(No.2023YFA1606404)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34010300)+5 种基金the National Natural Science Foundation of China(Nos.12022501,12105329,12475127)the Guangdong Major Project of Basic and Applied Basic Research(No.2021B0301030006)the Research Program of Heavy Ion Science and Technology Key Laboratory,Institute of Modern Physics,Chinese Academy of Sciences(Nos.HIST2024KS04,HIST2024CO04)Longyuan Youth Innovation and Entrepreneurship Talent Project of Gansu Province(No.2024GZT04)State Key Laboratory of Nuclear Physics and Technology,Peking University(No.NPT2023KFY01)the Major Science and Technology Projects in Gansu Province(No.24GD13GA005)。
文摘A state-of-the-art detector array with a digital data acquisition system has been developed for charged-particle decay studies,includingβ-delayed protons,αdecay,and direct proton emissions from exotic proton-rich nuclei.The digital data acquisition system enables precise synchronization and processing of complex signals from various detectors,such as plastic scintillators,silicon detectors,and germaniumγdetectors.The system's performance was evaluated using theβdecay of^(32)Ar and its neighboring nuclei,produced via projectile fragmentation at the first Radioactive Ion Beam Line in Lanzhou(RIBLL1).Key measurements,including the half-life,charged-particle spectrum,andγ-ray spectrum,were obtained and compared with previous results for validation.Using the implantation–decay method,the isotopes of interest were implanted into two doublesided silicon strip detectors,where their subsequent decays were measured and correlated with preceding implantations using both position and time information.This detection system has potential for further applications,including the study ofβ-delayed charged-particle decay and direct proton emissions from even more exotic proton-rich nuclei.
基金supported by the National Natural Science Foundation of China(Nos.12375191,12275218,12341502,12105224,12205307)National Key Research and Development Program of China(No.2023YFE0206300,2023YFF0719600)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2024A1515012141)China Postdoctoral Science Foundation(No.2023M742850)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2021025)。
文摘This study presents a low-noise,high-rate front-end readout application-specific integrated circuit(ASIC)designed for the electromagnetic calorimeter(ECAL)of the Super Tau-Charm Facility(STCF).To address the high background-count rate in the STCF ECAL,the temporal features of signals are analyzed node-by-node along the chain of the analog front-end circuit.Then,the system is optimized to mitigate the pile-up effects and elevate the count rate to megahertz levels.First,a charge-sensitive amplifier(CSA)with a fast reset path is developed,enabling quick resetting when the output reaches the maximum amplitude.This prevents the CSA from entering a pulse-dead zone owing to amplifier saturation caused by the pile-up.Second,a high-order shaper with baseline holder circuits is improved to enhance the anti-pile-up capability while maintaining an effective noise-filtering performance.Third,a high-speed peak-detection and hold circuit with an asynchronous first-input-first-output buffer function is proposed to hold and read the piled-up signals of the shaper.The ASIC is designed and manufactured using a standard commercial 1P6M 0.18μm mixed-signal CMOS process with a chip area of 2.4 mm×1.6 mm.The measurement results demonstrate a dynamic range of 4–500 fC with a nonlinearity error below 1.5%.For periodically distributed input signals,a count rate of 1.5 MHz/Ch is achieved with a peak time of 360 ns,resulting in an equivalent noise charge(ENC)of 2500 e^(-)-.The maximum count rate is 4 MHz/Ch at a peak time of 120 ns.At a peak time of 1.68μs with a 270 pF external capacitance,the minimum ENC is 1966 e^(-)-,and the noise slope is 3.08 e^(-)-∕pF.The timing resolution is better than 125 ps at an input charge of 200 fC.The power consumption is 35 mW/Ch.
