The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides...The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.展开更多
Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, espe-cially for medium-heavy nuclide measurement. It is difficult for online discrimination of the nuclide of interest from...Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, espe-cially for medium-heavy nuclide measurement. It is difficult for online discrimination of the nuclide of interest from the interfering ones. In order to solve this problem, we developed a method to simulate the experimental spectra of medium-heavy nuclides in AMS measurements. The results obtained from this method are in good agreement with experimental values.展开更多
A single and dual parameter data acquisition, ion beam measurements and control system for accelerator mass spectrometry is described. The system hardware has been constructed with the advantage of the lower cost and ...A single and dual parameter data acquisition, ion beam measurements and control system for accelerator mass spectrometry is described. The system hardware has been constructed with the advantage of the lower cost and higher reliability. It is provided with varieties of functions such as selecting acquisition mode carrying out the multiple display, analyzing data and especially viewing isometric spectrum at different directions. It can also be used for ordinary nuclear spectrum system.展开更多
The concentration of the natural ultra-trace radionuclides CI and U in the uranium depended on the neutron flux.In this article,a method for measuring 36C1 and 236U in the same uranium mineral with accelerator mass sp...The concentration of the natural ultra-trace radionuclides CI and U in the uranium depended on the neutron flux.In this article,a method for measuring 36C1 and 236U in the same uranium mineral with accelerator mass spectrometry was developed in China Institute of Atomic Energy,providing a protocol of the potential application of 236U in uranium mining,environmental,and geological research.The two samples were from Guangxi and Shanxi province,China,and their ratios 36Cl/C1 and 236U/238U were measured.More experimental data conduced to understand the natural nuclides in the uranium mineral.We plan to conduct more efforts on the research.展开更多
36Cl is one of the most interesting nuclides in accelerator mass spectrometry (AMS) measurements. The application of 36Cl has been widely applied in various fields. All most all of 36Cl AMS measurements at natural iso...36Cl is one of the most interesting nuclides in accelerator mass spectrometry (AMS) measurements. The application of 36Cl has been widely applied in various fields. All most all of 36Cl AMS measurements at natural isotopic concentrations have yet been performed at tandem accelerator with 5 MV or higher terminal voltage. The measure improvement of 36Cl and other medium heavy isotopes performed at 3 MV in AMS facilities is one of the hottest topics in AMS measurements. In order to increase the suppression factor of 36S, the energy loss straggling and angular straggling of 36Cl and 36S ions in various counter gases (P10, isobutane and propane) were investigated. Some groundwater samples were measured with energy of 32 MeV, and the results were in good agreement with the result obtained with ion energy of 72 MeV. The results indicate that the approximate detection limit of 36Cl in 3 MV AMS facility is 36Cl/Cl=1×10-14 , and the uncertainty is 30% when the sample with isotopic ration 36Cl/Cl≈10-13.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12125509,12222514,11961141003,and 12005304)National Key Research and Development Project(No.2022YFA1602301)+1 种基金CAST Young Talent Support Planthe CNNC Science Fund for Talented Young Scholars Continuous support for basic scientific research projects。
文摘The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.
基金Supported by the National Natural Science Foundation of China (No.10175094) and the Science Foundation of Guangxi University (X022013)
文摘Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, espe-cially for medium-heavy nuclide measurement. It is difficult for online discrimination of the nuclide of interest from the interfering ones. In order to solve this problem, we developed a method to simulate the experimental spectra of medium-heavy nuclides in AMS measurements. The results obtained from this method are in good agreement with experimental values.
文摘A single and dual parameter data acquisition, ion beam measurements and control system for accelerator mass spectrometry is described. The system hardware has been constructed with the advantage of the lower cost and higher reliability. It is provided with varieties of functions such as selecting acquisition mode carrying out the multiple display, analyzing data and especially viewing isometric spectrum at different directions. It can also be used for ordinary nuclear spectrum system.
基金Supported by National Natural Science Foundation of China(No.41166002)Guangxi Natural Science Foundation(No.2012GXNSFBA053004)+1 种基金Scientific Research Foundation of Guangxi Higher Education(No.201102ZD001)Scientific Research Foundation ofGuangxi University(No.XBZ100773)
文摘The concentration of the natural ultra-trace radionuclides CI and U in the uranium depended on the neutron flux.In this article,a method for measuring 36C1 and 236U in the same uranium mineral with accelerator mass spectrometry was developed in China Institute of Atomic Energy,providing a protocol of the potential application of 236U in uranium mining,environmental,and geological research.The two samples were from Guangxi and Shanxi province,China,and their ratios 36Cl/C1 and 236U/238U were measured.More experimental data conduced to understand the natural nuclides in the uranium mineral.We plan to conduct more efforts on the research.
基金Supported by National Natural Science Foundation of China (10805010, 41166002, 11025313)the special funding for national outstanding young scientist (Contract No. 2011-135)Guangxi Natural Science Foundation (Contract No. 2011GXNSFC018016, 2012GXNSFFA060005)
文摘36Cl is one of the most interesting nuclides in accelerator mass spectrometry (AMS) measurements. The application of 36Cl has been widely applied in various fields. All most all of 36Cl AMS measurements at natural isotopic concentrations have yet been performed at tandem accelerator with 5 MV or higher terminal voltage. The measure improvement of 36Cl and other medium heavy isotopes performed at 3 MV in AMS facilities is one of the hottest topics in AMS measurements. In order to increase the suppression factor of 36S, the energy loss straggling and angular straggling of 36Cl and 36S ions in various counter gases (P10, isobutane and propane) were investigated. Some groundwater samples were measured with energy of 32 MeV, and the results were in good agreement with the result obtained with ion energy of 72 MeV. The results indicate that the approximate detection limit of 36Cl in 3 MV AMS facility is 36Cl/Cl=1×10-14 , and the uncertainty is 30% when the sample with isotopic ration 36Cl/Cl≈10-13.
