最新刊期
      卷 0 ， 期 0 ， 2020
      • Issue 8, (1996)
        摘要：The beam-foil experimental setup, data acquisition system and monochromator control system at institute of Modern Physics（EMP） were upgraded. This paper. presented beam-foil VUV Li-, Be-like spectra of 47MeV Ne4+ ions bombarding on carbon foil（39 μg/cm2）. The possibility of further improvement of the monochromator system by using of position sensitive detectors was also discussed.  
        关键词：Beam-foil spectroscopy system;Dais acquisition;Monochromator control system   
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        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：Discrimination of uranium materials is an important technical issue in arms control. This article introduces a method of detecting and discriminating the uranium materials, by means of gamma-ray measurements of the materials and based on the relation between the ratio of uranium-235/uranium-238 and the intensity ratio of the corresponding gamma-rays. The enrichment grade and the mass of the measured uranium materials can also be obtained.  
        关键词：Uranium materials;Discrimination;Enrichment grade;Gamma-rays   
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        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：The crystallographic and magnetic stricture of Ho2Fe13A14C, Ho2Fe13Ga4C2, Ho2Fe9Ga4Al4 and Ho2Fe9Ga6Al2 has been studied with a neutron triple-axis spectrometer at room temperature. The atomic fractional occupancies of Ga, Al and C as well as the atomic magnetic moments of Ho and Fe were obtained by the Rietveld analysis program. The magnetic structure of Ho2Fe9Ga6Al2 shows an easy-axis anisotropy, with the Fe magnetic moment being ferrimagnetically coupled to those of Ho. The Curie temperature of each sample was also determined.  
        关键词：Neutron diffraction;Crystallographic structure;Magnetic structure   
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        <引用本文> <批量引用> 8411977 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：At room temperature, the proton enhanced backscattering technique and scanning electron microscopy are used to study the behaviour of implanted helium in titanium forget with different manufacturing process and alumina with different purity. The result proves that adhesion of the titanium film Prepared by ion.beam enhanced deposition（BED） is superior to that of the film made by vaporization.The release mechanism of helium in titanitum target and alumina is different.Compared with the titanium target made by IBED,helium in alumina is difficult to form bubbles.For titanium target,the implanted He dose for blistering is 4×1017-7×1017He/cm2,and this dose is very close to the dose value that makes flabes.  
        关键词：Helium;Depth distribution;Titanium target;Sintered alumina;He bubbles   
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        <引用本文> <批量引用> 8411768 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：The accuracy of energy calibration can be improved through the analysis of detected products coming from decay of unstable particles in the measurement of particle correlations. This provides a good way to examine and improve energy calibration for the scintillation detectors, which are widely used in the study of middle and high energy nuclear reactions.  
        关键词：Energy calibration;Unstable particles;Relative velocity   
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        <引用本文> <批量引用> 8411784 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：An elaborate comparison is made between two methods, i.e. NAA （neutron activation analysis） and AFS （atomic fluorescence analysis）, for determining mercury in human hair on the basis of the authors’ experience. It is emphasised that in spite of advantages of NAA such as high sensitivity, accuracy and the multielementanalysis feasibility, AFS method seems more suitable for the determination of both organic and inorganic mercury in human hair samples under some conditions due to itS simplicity, rapidity and low cost.  
        关键词：NAA;AFS;Mercury;Human hair   
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        <引用本文> <批量引用> 8412079 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：The technique of artificial neural network has been used to identify the gamma spectra of explosives and ordinary organic materials irradiated by 14MeV neutrons. In this article, features of the network are described, and the results of recognition of gamma spectra are given.  
        关键词：Artificial neural network;Explosive;Organic materials;Gamma spectra   
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        <引用本文> <批量引用> 8411824 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：When using detectors with better efficiency but lower energy resolution such as NaI（Tl） for the thermal neutron capture prompt gamma-ray on-line analysis in a hostile environment, a method based on elemental standard spectra is more effective. The method includes acquisition of a standard spectra’s closure set, spectra fitting with the weighted-least square method, and calibration of the elemental relative sensitivity and the normalized parameters. With a NaI（Tl） detector and 252Cf neutron source, the NaCl solution was analyzed with a good precision.  
        关键词：Thermal neutron capture prompt gamma-ray analysis;Spectra’s fitting with weighted-least-square method;Elemental standard spectrum;NaCl solution   
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        <引用本文> <批量引用> 8411836 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：new method to monitor the surface contamination on some devices in hot cells is presented. According to the straight propagation of γ rays, their interaction with materials, and the pinhole imaging principle, a pinhole camera, made of 238U material, was developed. With this camera, both contaminations on the device and the device itself can be imaged. Overlapping of the two photos by a computer will give a new picture, which can tell both distribution and intensity of the contaminations. This method ensures a more direct and clear γ-contamination monitoring, and a less exposure dose to the monitoring workers.  
        关键词：Pinhole imaging;Pinhole camera;γ-ray contamination   
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        <引用本文> <批量引用> 8412103 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：The stopping powers of 1-6 MeV 7Li ions in C, Al, Cu, Ag, An and Pb have been determined with solid self-supported foils and transmission geometry. The relative error of the data is less than 6%. The obtained data are compared with those in available literatures and the TRIM-91 values, and the differences are discussed. The stopping powers in Ph for 1-6 MeV 7Li ions and those in C, Al, Cu, Ag and An for 4.7-6 MeV 7Li ions are reported for the first time.  
        关键词：Stopping power;￣7Li ions   
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        <引用本文> <批量引用> 8411850 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：With UV spectrophotometry, the dose effectS of residual activity S of thymidine irradiated by 20keV N+ ion beam and of based T released from the irradiated thymidine were studied. It was found that S was related to the irradiated sample’s weight, and that about 50% of the damaged dTR molecules was able to produce based T. The post-treatment of strong alkali or strong acid made this proportion be reduced to 23% and 41% respectively, which showed a tendency contrary to that tinder gamma-ray irradiation.  
        关键词：Ion beam;Thymidine;Irradiation damage   
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        <引用本文> <批量引用> 8411863 false
        发布时间：2021-04-09
      • Issue 8, (1996)
        摘要：The recoil-distance Doppler-shift （RDDS） methods is an accurate and direct method to measure lifetime of nuclear levels in 10-12-10-9s range. An apparatus based on the RDDS method was designed and tested. An in-beam experiment with the apparatus was first performed in China. Lifetimes were measured for the levels of 120Xe ground band and a few levels of 121Cs and 117I which are produced by bombardment on 93Nb target with 31p beam.  
        关键词：Recoil-distance Doppler-shift method;Nuclear level;Lifetime   
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        <引用本文> <批量引用> 8411873 false
        发布时间：2021-04-09
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