The neutron response function and detection efficiency of a spherical proton recoil proportional counter (SP) play key roles in precise measurement of neutron spectra of the interior materials.In this paper,the respon...The neutron response function and detection efficiency of a spherical proton recoil proportional counter (SP) play key roles in precise measurement of neutron spectra of the interior materials.In this paper,the response functions and detection efficiency of three SPs developed at CAEP are simulated by Geant4.The simulated spectra are compared with pulse-height spectra measured at 0.165,0.575,1.4,and 14.1 MeV of incident neutrons.And the calculated detector efficiencies agree within 5%with the data obtained by neutron activation.展开更多
A spherical tissue equivalent proportional counter(TEPC) for neutron monitoring has been developed. It was properly designed to produce a uniform electric field intensity around the anode wire. An internal ^(241)Am al...A spherical tissue equivalent proportional counter(TEPC) for neutron monitoring has been developed. It was properly designed to produce a uniform electric field intensity around the anode wire. An internal ^(241)Am alpha source was adopted for lineal energy calibration. The TEPC was characterized in terms of dose equivalent response in a standard ^(252)Cf neutron field, and was tested with 2.45 MeV neutrons. Microdosimetric spectra, frequency mean lineal energy and dose-average mean lineal energy of 2.45 MeV neutrons were obtained and compared with FLUKA Monte Carlo simulation results. The measurement and simulation results agreed well. The mean quality factor and dose equivalent values evaluated from the 2.45 MeV neutron measurement were in good agreement with the recommended effective quality factor and ambient dose equivalent H*(10),respectively. Preliminary results have proved the availability of the developed TEPC for neutron monitoring.展开更多
Neutron detection is used in a wide range of applications in nuclear physics,radiation protection,nuclear fuel cycle,reactor instrumentation,security and industrial measurement.Among the detectors used in this field,w...Neutron detection is used in a wide range of applications in nuclear physics,radiation protection,nuclear fuel cycle,reactor instrumentation,security and industrial measurement.Among the detectors used in this field,we notice the gas-filled 3He proportional counters which have been one of the main detecting tools for thermal and cold neutron detection for many years.This last characteristic has ensured that this detector is one of the best tools for thermal neutron flux measurements in a nuclear reactor control.In the instrumentation and detection laboratory of the Nuclear Research Center,of Birine,we are working toward the design and the development of this type of detectors,indeed,several prototypes of neutron detectors have been realized including the 3He proportional counters.Through this paper,we will present the experimental steps and the obtained results to carry out a 3He proportional counter prototype that was fully developed and tested in our laboratory.A comparison study was made between our detector and a commercial cylindrical 3He neutron detector which was considered in this work as a reference detector:LND252(3He)-PC.The results showed that the characteristics of the gas amplification and the counting plateau for the two counters reference LND 252(3He)-PC and our prototype was of the same order of scale.The experimental tests show that our developed prototype perfect fit with the standard International Electrotechnical Commission(IEC,www.iec.ch)in the operating principle,the technology adopted and obtained technical specifications.展开更多
Purpose Neutrons detection is of paramount importance in nuclear physics experiments,reactor physics,monitoring and control of nuclear reactors and in radiation protection.Among the neutron detectors used are Proporti...Purpose Neutrons detection is of paramount importance in nuclear physics experiments,reactor physics,monitoring and control of nuclear reactors and in radiation protection.Among the neutron detectors used are Proportional Counters(PC to BF3,boron deposition,3He),Our Detection and Measurements laboratory has embarked on a project to develop,design and build proportional counters with boron deposition mainly for gas filling,several prototypes of which have been produced.Method This work presents the Boron-10 Lined Proportional Counters(PC),developed and produced in the Detection and Measurements Department(DDM19).The PC was designed by adopting,for the electrodes,a stainless steel cathode 0.5 mm thick and a gold-plated tungsten anode with diameter of 25μm.The detectors are filled with an Ar-CH4 mixture(10%)at a pressure of 20 cmHg.The boron deposition is performed by the technique of electrophoresis.Result The results obtained using the DDM19 prototype PC(Detector produced in our Detection and Measurement laboratory,2019),show the advantage of electrophoresis as a better boron deposition technique,and the limitation of the surface mass of 10B to optimal values is around 0.5 at 0.6 mg/cm2.Conclusions The characteristics of the gas amplification in the mixture(Ar-CH4(CH410%)),were measured by different methods and compared with the values of the proportional reference counter LND232.The counting plates for the two reference meters LND232 and our DDM19 prototype from 200 to 300 V have slopes ranging from 6.5 to 10%/100 V,and gas amplification factors from 1436 to 1380,respectively.展开更多
文摘The neutron response function and detection efficiency of a spherical proton recoil proportional counter (SP) play key roles in precise measurement of neutron spectra of the interior materials.In this paper,the response functions and detection efficiency of three SPs developed at CAEP are simulated by Geant4.The simulated spectra are compared with pulse-height spectra measured at 0.165,0.575,1.4,and 14.1 MeV of incident neutrons.And the calculated detector efficiencies agree within 5%with the data obtained by neutron activation.
基金Supported by the Key Technology of Fusion Reactor Radiation Protection Foundation(No.2014GB112005)
文摘A spherical tissue equivalent proportional counter(TEPC) for neutron monitoring has been developed. It was properly designed to produce a uniform electric field intensity around the anode wire. An internal ^(241)Am alpha source was adopted for lineal energy calibration. The TEPC was characterized in terms of dose equivalent response in a standard ^(252)Cf neutron field, and was tested with 2.45 MeV neutrons. Microdosimetric spectra, frequency mean lineal energy and dose-average mean lineal energy of 2.45 MeV neutrons were obtained and compared with FLUKA Monte Carlo simulation results. The measurement and simulation results agreed well. The mean quality factor and dose equivalent values evaluated from the 2.45 MeV neutron measurement were in good agreement with the recommended effective quality factor and ambient dose equivalent H*(10),respectively. Preliminary results have proved the availability of the developed TEPC for neutron monitoring.
文摘Neutron detection is used in a wide range of applications in nuclear physics,radiation protection,nuclear fuel cycle,reactor instrumentation,security and industrial measurement.Among the detectors used in this field,we notice the gas-filled 3He proportional counters which have been one of the main detecting tools for thermal and cold neutron detection for many years.This last characteristic has ensured that this detector is one of the best tools for thermal neutron flux measurements in a nuclear reactor control.In the instrumentation and detection laboratory of the Nuclear Research Center,of Birine,we are working toward the design and the development of this type of detectors,indeed,several prototypes of neutron detectors have been realized including the 3He proportional counters.Through this paper,we will present the experimental steps and the obtained results to carry out a 3He proportional counter prototype that was fully developed and tested in our laboratory.A comparison study was made between our detector and a commercial cylindrical 3He neutron detector which was considered in this work as a reference detector:LND252(3He)-PC.The results showed that the characteristics of the gas amplification and the counting plateau for the two counters reference LND 252(3He)-PC and our prototype was of the same order of scale.The experimental tests show that our developed prototype perfect fit with the standard International Electrotechnical Commission(IEC,www.iec.ch)in the operating principle,the technology adopted and obtained technical specifications.
文摘Purpose Neutrons detection is of paramount importance in nuclear physics experiments,reactor physics,monitoring and control of nuclear reactors and in radiation protection.Among the neutron detectors used are Proportional Counters(PC to BF3,boron deposition,3He),Our Detection and Measurements laboratory has embarked on a project to develop,design and build proportional counters with boron deposition mainly for gas filling,several prototypes of which have been produced.Method This work presents the Boron-10 Lined Proportional Counters(PC),developed and produced in the Detection and Measurements Department(DDM19).The PC was designed by adopting,for the electrodes,a stainless steel cathode 0.5 mm thick and a gold-plated tungsten anode with diameter of 25μm.The detectors are filled with an Ar-CH4 mixture(10%)at a pressure of 20 cmHg.The boron deposition is performed by the technique of electrophoresis.Result The results obtained using the DDM19 prototype PC(Detector produced in our Detection and Measurement laboratory,2019),show the advantage of electrophoresis as a better boron deposition technique,and the limitation of the surface mass of 10B to optimal values is around 0.5 at 0.6 mg/cm2.Conclusions The characteristics of the gas amplification in the mixture(Ar-CH4(CH410%)),were measured by different methods and compared with the values of the proportional reference counter LND232.The counting plates for the two reference meters LND232 and our DDM19 prototype from 200 to 300 V have slopes ranging from 6.5 to 10%/100 V,and gas amplification factors from 1436 to 1380,respectively.
