Polymethyl methacrylate(PMMA)is an optically transparent thermoplastic with favorable processing conditions.In this study,a series of plastic scintillators are prepared via thermal polymerization,and the impact of PMM...Polymethyl methacrylate(PMMA)is an optically transparent thermoplastic with favorable processing conditions.In this study,a series of plastic scintillators are prepared via thermal polymerization,and the impact of PMMA content on their transparency and pulse shape discrimination(PSD)ability is investigated.The fabricated samples,comprising a polystyrene(PS)-PMMA matrix,30.0 wt%2,5-diphenyloxazole(PPO),and 0.2 wt%9,10-diphenylanthracene(DPA),exhibit high transparency with transmissivity ranging from 70.0 to 90.0%(above 415.0 nm)and demonstrate excellent n/γdiscrimination capability.Transparency increased with increasing PMMA content across the entire visible light spectrum.However,the PSD performance gradually deteriorated when the aromatic matrix was replaced with PMMA.The scintillator containing 20.0 wt%PMMA demonstrated the best stability concerning PSD properties and relative light yields.展开更多
Plastic scintillators(PSs)embedded with wavelength-shifting fibers are widely used in high-energy particle physics,such as in muon taggers,as well as in medical physics and other applications.In this study,a simulatio...Plastic scintillators(PSs)embedded with wavelength-shifting fibers are widely used in high-energy particle physics,such as in muon taggers,as well as in medical physics and other applications.In this study,a simulation package was built to evaluate the effects of the diameter and layout of optical fibers on the light yield with different configurations.The optimal optical configuration was designed based on simulations and validated using two PS prototypes under certain experimental condi-tions.A top veto tracker(TVT)for the JUNO-TAO experiment,comprising four layers of 160 strips of PS,was designed and evaluated.The threshold was evaluated when the muon tagging efficiency of a PS strip was>99%.The efficiency of three layer out of four layer of TVT is>99%,even with a tagging efficiency of a single strip as low as 97%,using a threshold of 10 photoelectrons and assuming a 40%silicon PM photon detection efficiency.展开更多
In this study,an online detector system based on plastic scintillators is designed to monitor the activity of tritiated water in the liquid effluents of nuclear power plants.The feasibility of the detector is verified...In this study,an online detector system based on plastic scintillators is designed to monitor the activity of tritiated water in the liquid effluents of nuclear power plants.The feasibility of the detector is verified via simulation on Geant4,and the optimal detector structure size is determined.A back-end electronics system is designed and an experimental measurement platform forβ-rays based on a ^(40)KCl solution is constructed.Thirteen ^(40)KC solutions with different activities ranging from 10 to4500 Bq/L are measured,and 1300 V is determined as the optimal operating high voltage of the photomultiplier tubes.A linear fit is performed in 10-min counts,and the maximum linear goodness of fit(R^(2))achieved is 0.9992.Long-term stability measurements are performed for two detectors,one filled with air and the other with a ^(40)KCl solution exhibiting an activity of 2000 Bq/L.The relative deviation of the counts of the detector system every 10 min is 0.998%when the ^(40)KCl solution is used,and the maximum Gaussian R^(2) of the counts is 0.9849.展开更多
Tritium,a radioactive nuclide discharged by nuclear power plants,poses challenges for removal.Continuous online monitoring of tritium in water is crucial for real-time radiation data,given its predominant existence in...Tritium,a radioactive nuclide discharged by nuclear power plants,poses challenges for removal.Continuous online monitoring of tritium in water is crucial for real-time radiation data,given its predominant existence in the environment as water.This paper presents the design,simulation,and development of a tritium monitoring device utilizing a plastic scintillation fiber(PSF)array.Experimental validation confirmed the device’s detection efficiency and minimum detectable activity.The recorded detection efficiency of the device is 1.6×10^(-3),which exceeds the theoretically simulated value of 4×10^(-4)by four times.Without shielding,the device can achieve a minimum detectable activity of 3165 Bq L^(-1)over a 1600-second measurement duration.According to simulation and experimental results,enhancing detection efficiency is possible by increasing the number and length of PSFs and implementing rigorous shielding measures.Additionally,reducing the diameter of PSFs can also improve detection efficiency.The minimum detectable activity of the device can be further reduced using the aforementioned methods.展开更多
This study presents the design and performance results for compact plastic scintillator strips using a wavelength shifting fiber(WLS-fiber)readout with dimensions of 0.1 m×0.02 m×2 m.This approach was evalua...This study presents the design and performance results for compact plastic scintillator strips using a wavelength shifting fiber(WLS-fiber)readout with dimensions of 0.1 m×0.02 m×2 m.This approach was evaluated as a candidate for a cosmic-ray muon detector for the Taishan Antineutrino Observatory(JUNO-TAO).The strips coupled with 3-inch photomultiplier tubes(PMTs)were measured and compared between the single-end and double-end readout options.Additionally,a strip using the double-end option coupling with a silicon photomultiplier(SiPM)was further evaluated and compared with the results obtained using PMTs.The performance of the strips was determined by a detailed survey along their length with a cosmicray muon after detailed characterization of the 3-inch PMTs and SiPMs.The proposed design employing a compact plastic scintillator strip with WLS-fiber coupling to a SiPM provides a good choice for cosmic-ray muon veto detectors,particularly when detector dimensions must be limited.展开更多
Fundamental characteristics of the plastic scintillating fiber (PSF) as a detector for electromagnetic radiation (X & γ) are obtained by GEANT4 detector simulation tool package. The detector response to radiation...Fundamental characteristics of the plastic scintillating fiber (PSF) as a detector for electromagnetic radiation (X & γ) are obtained by GEANT4 detector simulation tool package. The detector response to radiation with energy of 10~400 keV is found out. Energy deposition as well as detector efficiency (DE) of the PSF are studied. In order to make linear array of the PSF for imaging purpose, the optimum length of fiber is also estimated.展开更多
The photoelectric device of a scintillation dosimeter converts photons produced by radiation into an electrical signal.Its features directly determine the overall performance of the dosimeter.For a plastic scintillati...The photoelectric device of a scintillation dosimeter converts photons produced by radiation into an electrical signal.Its features directly determine the overall performance of the dosimeter.For a plastic scintillation fiber dosimeter(PSFD)with a current readout mode,systematic studies of the stability and light-dose response were performed for the photomultiplier tube(PMT),silicon photomultiplier(SiPM),avalanche photodiode(APD),and photodiode(PD).The temperature stability,long-term stability,repeatability,signal-to-noise ratio(SNR),and current dose response of the PSFD with the abovementioned photoelectric devices were studied using a pulsed LED light source and the Small Animal Radiation Therapy platform.An exponential relationship between the dark/ne current and temperature was obtained for all the devices.I is shown that the APD is the most sensitive device to temperature,with a current dependence on temperature reaching 6.5%C^(-1)at room temperature,whereas for the other devices this dependence is always<0:6%C^(-1).In terms of long-term stability,the net current of PD can change by up to 4%when working continuously for 8 h and 2%when working intermittently for 32 h,whereas for the other devices,the changes are all<1%.For the dose response,the PMT and SiPM exhibit excellent linear responses and SNRs within the range of 0.1-60 Gy/min For the PSFD with a current readout mode,the performance of the PMT and SiPM is concluded to be better than that of the other devices in the study.In particular,the SiPM,which has a compact size,low bias voltage,and antimagnetic interference,has great advantages for further applications.展开更多
Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation facilities.This microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with ...Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation facilities.This microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with minimized dead detection zones,monitoring the whole body,and conforming to the contamination limit prescribed by the regulatory authority.This system has the features for monitoring hands,feet,head,and faceβ/γusing contamination monitors and portal exit monitors.It can detect gamma sources at a dose rate of 10 n Gyh^(-1).The system is calibrated using b sources^(90)Sr/^(90)Y,^(204)Tl,and^(36)Cl,and the efficiency is found to be 29%,22%,and 18%,respectively.Theminimumdetectableβ/γcontaminationis0.15 Bqcm^(-2),which is significantly less than the minimum detection objectives on head,face,hands,and feet.展开更多
Currently,the liquid scintillation method is widely used to measure the activity of tritiated water in the primary circuit of nuclear power plants,which leads to the continuous production of radioactive waste during m...Currently,the liquid scintillation method is widely used to measure the activity of tritiated water in the primary circuit of nuclear power plants,which leads to the continuous production of radioactive waste during measurement.In addition,the real-time activity information of tritiated water cannot be obtained.To solve this problem,herein we present an online tritiated water measurement method based on plastic scintillators that used the optical transport process in the Geant 4 software toolkit to build a model of plastic scintillation detection for tritiated water.Through simulation,the basic geometric dimensions of the detector were determined.In this dimension,using one detector to measure for 3 h,when the tritiated water activity was 100 Bq/L,its resolution was 16%(16 Bq/L).In addition,calculations were performed for the presence of other background signals to obtain the minimum detectable concentration.展开更多
A digital pulse analysis system is an important diagnostic system in nuclear physics experimental research.In response to the demand for reflecting the particle state in a nuclear physics experiment,we have designed a...A digital pulse analysis system is an important diagnostic system in nuclear physics experimental research.In response to the demand for reflecting the particle state in a nuclear physics experiment,we have designed and developed a real-time digital pulse analysis system and applied it to the digital nuclear pulse waveform discrimination of different detectors in the HL-2M tokamak.The system is based on the peripheral component interconnect extensions for instrumentation(PXI)platform,while its software was written in LABVIEW.The key technologies involved in the system implementation include digital pulse analysis technology,digital discrimination technology,pulse height analysis technology,etc.The system has been applied to the plastic scintillator detector at the Neutron Source Lab of the University of Science and Technology of China.And the experimental results indicate that the system can discriminate between neutron(n)particles and gamma(γ)particles well when used to measure the plastic scintillator detector.展开更多
基金supported by the National Natural Science Foundation of China(No.12027813)the fund of National Innovation Center of Radiation Application of China(Nos.KFZC2020020501,KFZC2021010101).
文摘Polymethyl methacrylate(PMMA)is an optically transparent thermoplastic with favorable processing conditions.In this study,a series of plastic scintillators are prepared via thermal polymerization,and the impact of PMMA content on their transparency and pulse shape discrimination(PSD)ability is investigated.The fabricated samples,comprising a polystyrene(PS)-PMMA matrix,30.0 wt%2,5-diphenyloxazole(PPO),and 0.2 wt%9,10-diphenylanthracene(DPA),exhibit high transparency with transmissivity ranging from 70.0 to 90.0%(above 415.0 nm)and demonstrate excellent n/γdiscrimination capability.Transparency increased with increasing PMMA content across the entire visible light spectrum.However,the PSD performance gradually deteriorated when the aromatic matrix was replaced with PMMA.The scintillator containing 20.0 wt%PMMA demonstrated the best stability concerning PSD properties and relative light yields.
基金supported by the School of Physics at Sun Yat-sen University,China
文摘Plastic scintillators(PSs)embedded with wavelength-shifting fibers are widely used in high-energy particle physics,such as in muon taggers,as well as in medical physics and other applications.In this study,a simulation package was built to evaluate the effects of the diameter and layout of optical fibers on the light yield with different configurations.The optimal optical configuration was designed based on simulations and validated using two PS prototypes under certain experimental condi-tions.A top veto tracker(TVT)for the JUNO-TAO experiment,comprising four layers of 160 strips of PS,was designed and evaluated.The threshold was evaluated when the muon tagging efficiency of a PS strip was>99%.The efficiency of three layer out of four layer of TVT is>99%,even with a tagging efficiency of a single strip as low as 97%,using a threshold of 10 photoelectrons and assuming a 40%silicon PM photon detection efficiency.
基金supported by the National Natural Science Foundation of China (No. 12105029)。
文摘In this study,an online detector system based on plastic scintillators is designed to monitor the activity of tritiated water in the liquid effluents of nuclear power plants.The feasibility of the detector is verified via simulation on Geant4,and the optimal detector structure size is determined.A back-end electronics system is designed and an experimental measurement platform forβ-rays based on a ^(40)KCl solution is constructed.Thirteen ^(40)KC solutions with different activities ranging from 10 to4500 Bq/L are measured,and 1300 V is determined as the optimal operating high voltage of the photomultiplier tubes.A linear fit is performed in 10-min counts,and the maximum linear goodness of fit(R^(2))achieved is 0.9992.Long-term stability measurements are performed for two detectors,one filled with air and the other with a ^(40)KCl solution exhibiting an activity of 2000 Bq/L.The relative deviation of the counts of the detector system every 10 min is 0.998%when the ^(40)KCl solution is used,and the maximum Gaussian R^(2) of the counts is 0.9849.
基金supported by the Young Potential Program of the Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai Rising-Star Program,China(No.22YF1457800)the Chinese Academy of Sciences Youth Education Fund Program(No.E2292502)Gansu Major Scientific and Technological Special Project(No.23ZDGH001)。
文摘Tritium,a radioactive nuclide discharged by nuclear power plants,poses challenges for removal.Continuous online monitoring of tritium in water is crucial for real-time radiation data,given its predominant existence in the environment as water.This paper presents the design,simulation,and development of a tritium monitoring device utilizing a plastic scintillation fiber(PSF)array.Experimental validation confirmed the device’s detection efficiency and minimum detectable activity.The recorded detection efficiency of the device is 1.6×10^(-3),which exceeds the theoretically simulated value of 4×10^(-4)by four times.Without shielding,the device can achieve a minimum detectable activity of 3165 Bq L^(-1)over a 1600-second measurement duration.According to simulation and experimental results,enhancing detection efficiency is possible by increasing the number and length of PSFs and implementing rigorous shielding measures.Additionally,reducing the diameter of PSFs can also improve detection efficiency.The minimum detectable activity of the device can be further reduced using the aforementioned methods.
基金the National Natural Science Foundation of China(Nos.11875282,11475205 and 12022505)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA10011200)the Youth Innovation Promotion Association of CAS.
文摘This study presents the design and performance results for compact plastic scintillator strips using a wavelength shifting fiber(WLS-fiber)readout with dimensions of 0.1 m×0.02 m×2 m.This approach was evaluated as a candidate for a cosmic-ray muon detector for the Taishan Antineutrino Observatory(JUNO-TAO).The strips coupled with 3-inch photomultiplier tubes(PMTs)were measured and compared between the single-end and double-end readout options.Additionally,a strip using the double-end option coupling with a silicon photomultiplier(SiPM)was further evaluated and compared with the results obtained using PMTs.The performance of the strips was determined by a detailed survey along their length with a cosmicray muon after detailed characterization of the 3-inch PMTs and SiPMs.The proposed design employing a compact plastic scintillator strip with WLS-fiber coupling to a SiPM provides a good choice for cosmic-ray muon veto detectors,particularly when detector dimensions must be limited.
文摘Fundamental characteristics of the plastic scintillating fiber (PSF) as a detector for electromagnetic radiation (X & γ) are obtained by GEANT4 detector simulation tool package. The detector response to radiation with energy of 10~400 keV is found out. Energy deposition as well as detector efficiency (DE) of the PSF are studied. In order to make linear array of the PSF for imaging purpose, the optimum length of fiber is also estimated.
基金supported by the China Postdoctoral Science Foundation(No.2017M621818)the National Key Research and Development Project(Nos.2017YFF0206205 and2016YFB0501303)+1 种基金the National Natural Science Foundation of China(Nos.51873137 and 11705123)the Project of the State Key Laboratory of Radiation Medicine and Protection Soochow University(No.GZN1201801)。
文摘The photoelectric device of a scintillation dosimeter converts photons produced by radiation into an electrical signal.Its features directly determine the overall performance of the dosimeter.For a plastic scintillation fiber dosimeter(PSFD)with a current readout mode,systematic studies of the stability and light-dose response were performed for the photomultiplier tube(PMT),silicon photomultiplier(SiPM),avalanche photodiode(APD),and photodiode(PD).The temperature stability,long-term stability,repeatability,signal-to-noise ratio(SNR),and current dose response of the PSFD with the abovementioned photoelectric devices were studied using a pulsed LED light source and the Small Animal Radiation Therapy platform.An exponential relationship between the dark/ne current and temperature was obtained for all the devices.I is shown that the APD is the most sensitive device to temperature,with a current dependence on temperature reaching 6.5%C^(-1)at room temperature,whereas for the other devices this dependence is always<0:6%C^(-1).In terms of long-term stability,the net current of PD can change by up to 4%when working continuously for 8 h and 2%when working intermittently for 32 h,whereas for the other devices,the changes are all<1%.For the dose response,the PMT and SiPM exhibit excellent linear responses and SNRs within the range of 0.1-60 Gy/min For the PSFD with a current readout mode,the performance of the PMT and SiPM is concluded to be better than that of the other devices in the study.In particular,the SiPM,which has a compact size,low bias voltage,and antimagnetic interference,has great advantages for further applications.
文摘Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation facilities.This microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with minimized dead detection zones,monitoring the whole body,and conforming to the contamination limit prescribed by the regulatory authority.This system has the features for monitoring hands,feet,head,and faceβ/γusing contamination monitors and portal exit monitors.It can detect gamma sources at a dose rate of 10 n Gyh^(-1).The system is calibrated using b sources^(90)Sr/^(90)Y,^(204)Tl,and^(36)Cl,and the efficiency is found to be 29%,22%,and 18%,respectively.Theminimumdetectableβ/γcontaminationis0.15 Bqcm^(-2),which is significantly less than the minimum detection objectives on head,face,hands,and feet.
基金supported by the National Natural Science Foundation of China(No.12105029)。
文摘Currently,the liquid scintillation method is widely used to measure the activity of tritiated water in the primary circuit of nuclear power plants,which leads to the continuous production of radioactive waste during measurement.In addition,the real-time activity information of tritiated water cannot be obtained.To solve this problem,herein we present an online tritiated water measurement method based on plastic scintillators that used the optical transport process in the Geant 4 software toolkit to build a model of plastic scintillation detection for tritiated water.Through simulation,the basic geometric dimensions of the detector were determined.In this dimension,using one detector to measure for 3 h,when the tritiated water activity was 100 Bq/L,its resolution was 16%(16 Bq/L).In addition,calculations were performed for the presence of other background signals to obtain the minimum detectable concentration.
基金supported by National Natural Science Foundation of China (No. 1157518)
文摘A digital pulse analysis system is an important diagnostic system in nuclear physics experimental research.In response to the demand for reflecting the particle state in a nuclear physics experiment,we have designed and developed a real-time digital pulse analysis system and applied it to the digital nuclear pulse waveform discrimination of different detectors in the HL-2M tokamak.The system is based on the peripheral component interconnect extensions for instrumentation(PXI)platform,while its software was written in LABVIEW.The key technologies involved in the system implementation include digital pulse analysis technology,digital discrimination technology,pulse height analysis technology,etc.The system has been applied to the plastic scintillator detector at the Neutron Source Lab of the University of Science and Technology of China.And the experimental results indicate that the system can discriminate between neutron(n)particles and gamma(γ)particles well when used to measure the plastic scintillator detector.
