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HI—13串列加速器质谱测量中的粒子鉴别技术 总被引:1,自引:0,他引:1
着重介绍中国原子能科学研究院的HI-13串列加速器质谱计装置的粒子鉴别技术,该装置于1989年建成,到目前可以完成自然界中^10Be,^26Al、^36Cl与^129I的测定,测量灵敏度达到10^-13-10^-15,探测限度为10^5-10^7个原子。 相似文献
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在端电压为3 MV的AMS装置上实现36Cl及其他中重核素的高灵敏测量是AMS技术发展的重要方向之一。为进一步提高充气飞行时间探测方法中36S的压低能力,本文研究了36S和36Cl在P10、异丁烷和丙烷气体中的能量歧离和角度歧离。在32 MeV的入射能量下测量了几个地下水样品中36Cl的[JP2]含量,测量结果与72 MeV能量下的测量结果相符。测量结果表明,采用充气飞行时间探测方法在3 MV的串列加速器上测量36Cl时,探测限为36Cl/Cl≈10-14,当样品中36Cl/Cl≈10-13时测量不确定度为30%。 相似文献
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在利用回旋加速器质谱技术进行氚断代的测量中,工作气体是电解水样品时收集到的含氚氢气,并混入少许一定量的空气。空气中的微量~3He和样品中的~3H同时加速并被用作参考标准以监督加速器的束流变化。描述了利用金硅面垒探测器望远镜和铝吸收箔的组合来探测和鉴别~3H和~3He的实验方法和结果。 相似文献
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叙述了为提高单粒子微通道板探测器的性能和稳定性所采取的措施,在采用本底同时交替扣除法以后,探测效率可以达到95%以上,探测效率为50%时,单粒子微通道板探测器探测^14C的丰度灵敏度达到2×10^-15。 相似文献
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叙述了为提高SMCAMS单粒子微通道板探测器性能和稳定性所采取的措施。 相似文献
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The correlation between Al metabolism and senile dementia in animal has been studied by AMS(accelerator mass spectrometry).Three groups of laboratory rats were fed with normal food.food with high Al content,and with enriched Ca and Mg together with high Al,respectively for six to eight months.Mapping test was made to recored th degree of wisdom degeneration.Half of the rats were sacrificed and Al contents in various organs were measured by atomic absorption spectroscopy.The rest were injected with ^26Al,killed after 5,10,15,25,and 35d and ^26Al contents measured by AMS.The distribution of Al as well as the correlation among the accumulation of ^26Al,and the existed Al content and dementia was studied. 相似文献
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Simulation of experimental spectra for medium-heavy nuclides in accelerator mass spectrometry 总被引:1,自引:0,他引:1
WANG Hui-Juan GUAN Yong-Jin HE Ming RUAN Xiang-Dong DONG Ke-Jun LI Guo-Qiang Wu Shao-Yong WU Wei-Ming JIANG Shan 《核技术(英文版)》2005,16(5):273-277
Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, especially 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. 相似文献
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Xianggao Wang Shan Jiang Ming He Wei Wang Guozhu He Jie Gong Shaoyong Wu 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(13):2295-2299
236U is a long-lived radioactive isotope which is produced principally by thermal neutron capture on 235U. 236U may be potentially applied in geological research and nuclear safeguards. Accelerator mass spectrometry is presently the most sensitive technique for the measurement of 236U and a measurement method for long-lived heavy ion 236U has been developed. The set-up uses a dedicated injector and the newly proposed 208Pb16 molecular ions for the simulation of 236U ion transport. A sensitivity of lower than 10−10 has been achieved for the isotopic ratio 236U/238U in present work. 相似文献
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A.L. Hunt G.A. Petrucci P.R. Bierman R.C. Finkel 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,260(2):633-636
We report experiments designed to help optimize accelerator mass spectrometry (AMS) of 26Al (in the form of Al2O3) for geochronologic and geomorphologic applications. Analysis times are long and the precision of AMS are restricted by counting statistics for 26Al, which are in turn limited by the intensity of Al− beam currents. We show that ion beam currents are affected by the metal matrix in which Al2O3 is dispersed, by the matrix-to-Al2O3 mixing ratio, and for at least some matrices, such as Ag, by the depth to which the sample is packed in the AMS cathode. Typical instantaneous Al+7 currents (μA) produced by the LLNL CAMS Cs sputter ion source and measured in a Faraday cup after the accelerator are 2.26 for samples in Ag, 2.17 in Re, 2.00 in Nb, 1.92 in V and 1.73 in Mo. The AMS counting efficiency (Al− ions detected per Al atom loaded in the target) for a constant analysis time (900 s) and for equimolar mixtures of Al2O3 and matrix is in the range of 6 × 10−5–9 × 10−5 in the order Ag > Re > Nb > V > Mo. Additionally, we observed a correlation between the ion detection efficiency (Al ions detected per Al atoms loaded) and the matrix work function and inverse vaporization enthalpy of the matrix and beam current. Typical currents (μA) obtained with elemental Al are 13.3 for samples in no matrix, 3.23 in V, 3.14 in Nb, 3.07 in Re, 2.85 in Mo, 1.46 in Ag. The ion detection efficiency for elemental Al correlates strongly with matrix electron affinity. Thus, our data indicate that the current practice of mixing Al2O3 with Ag is reasonable until a means is found to produce cathodes of elemental Al. 相似文献