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1.
Angular distributions for the ~7(Li)(~6(Li),~7(Li))~6(Li) Li elastic-transfer reaction have been measured with the Q3D magnetic spectrograph at the HI-13 tandem accelerator of Beijing, China. The neutron spectroscopic factors of 7Li are derived by comparing the calculated differential cross sections, which are obtained through the distorted-wave Born approximation (DWBA) calculation, to the experimental data. And these spectroscopic factors are then used to deduce the direct capture cross sections in 6Li(n,γ)7 Li at energies of astrophysical relevance. 相似文献
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《中国原子能科学研究院年报(英文版)》2017,(0)
<正>In order to study the 58keV resonance in ~(25)Mg(p,γ)~(26)Al reaction,the measurement of the~(25)Mg(~7Li,~6 He)~(26) Al*_(6.364)reaction was carried out by using a 31.5 MeV ~7Li beam from the HI-13tandem accelerator,Beijing.The 200 enA 7Li beam impinged on ~(25)MgO,~(24)MgO and ~(12)C target, 相似文献
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《中国原子能科学研究院年报(英文版)》2016,(0)
正The baryon density can be deduced from the Wilkinson microwave anisotropy probe(WMAP),and the ~6Li and ~7Li abundance can then be computed by the standard Big Bang nucleosynthesis model~([1]).Surprisingly,the primordial ~7Li abundances of astronomical observations are only 相似文献
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《中国原子能科学研究院年报(英文版)》2017,(0)
<正>Due to the limit of the intensity and quality of the radioactive ion beam(RIB),it is a difficult task to extract the optical model potentials(OMPs)of halo nuclear systems directly from the elastic scattering measurement.In view of this fact,the transfer reaction was tried to be used as an alternative method to extract and stud- 相似文献
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《中国原子能科学研究院年报(英文版)》2017,(0)
<正>The ~6Li,~7Li abundance can be computed by the[standard Big Bang nucleosynthesis model[1].Surprisingly,the primordial ~7Li abundances of astronomical observations are only about 1/3of the model calculation,while the primordial ~6Li abundances observed by astronomical observa- 相似文献
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《中国原子能科学研究院年报(英文版)》2001,(1)
The isospin distribution of particles and fragments in collisions 96Ru 96Ru, 96Ru 96Zr, 96Zr 96Ru, and 96Zr 96Zr at beam energy 400 AMeV is studied with isospin dependent QMD model. We find the rapidity distribution of difference between neutron-proton number in neutron rich nucleus-nucleus collisions at intermediate energies is sensitive to the isospin dependent part of nuclear potential. The study of the N/Z ratio of nucleons, light charged particles (LCP) and intermediate mass fragments (IMF) shows that the isospin dependent part of nuclear potential drives IMF to be more isospin symmetric and emitted nucleons to be more neutron rich. We also study the time evolution of the isospin distribution 相似文献
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Mustafa Yi?it 《核技术(英文版)》2018,(4)
A cross section database on excitation functions of reactions produced by charged particles is essential for many areas of nuclear research. Particularly, accurate knowledge on nuclear cross sections for the cyclotron production of radioisotopes is very important for nuclear medicine. In the present paper, the cross section calculations for the production of~(43),~(34)Sc,~(45)Ti,~(51)Cr,~(54)Mn, and~(55) Fe radioisotopes were carried out by the use of ALICE/ASH code using the Fermi gas model, Kataria Ramamurthy Fermi gas model, and superfluid nuclear model for nuclear level density. Thereby, these model calculations were compared with the available measured data. 相似文献
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作为1990年全国总膳食调查的放射性物质部分,本文报道了组成我国膳食的各类食品中~(90)Sr、~(137)Cs、~(226)Ra、~(228)Ra、~(210)Pb 和~(210)Po 含量的测定结果;按调查所得膳食组成和食品中核素含量,估算了我国居民(成年男子)当前这些核素经食入所致年摄入量和待积有效剂量当量。结果表明,每年食入所致总待积有效剂量当量约为0.24 mSv,贡献较大的食品是蔬菜、水产品和谷类,贡献较大的核素为~(210)Pb、~(210)Po 和~(228)Ra。这些结果更新了我国膳食中这些核素的资料,补充了来自饮水的数据。文中还讨论了我国膳食组成的地区差异及其对居民摄入量和所致内照射剂量的影响。 相似文献
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《中国原子能科学研究院年报(英文版)》2017,(0)
<正>The optical model is one of the most fundamental theoretical models in nuclear reaction theory.The key point of the optical model is how to give the optical model potential.The global phenomenological optical model potential for ~6Li,~7Li,~8Li projectiles are obtained by simultaneously fitting the experimental data of the reaction cross sections and elastic scattering 相似文献
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《中国原子能科学研究院年报(英文版)》2016,(0)
正The angular distributions of the elastic scattering of weakly bound nuclear systems of~7Li+~(63)Cu were measured at energy around the Coulomb barrier,to extract and study the optical model potential(OMP)of this weakly bound system.For the weakly-bound nucleus ~7Li,there are large amount of elastic scattering data.However, 相似文献
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用中国原子能科学研究院HI-13串列加速器,高压倍加器和北京大学4.5MV静电加速器分别获得能量为10-12,14和18MeV的中子,了^176Hf(n,2n)和^185Re(n,2n)的反应堆面,并与现有的实验数据作了比较,初步搞清了分歧的主要原因和激发函数的走向。 相似文献
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《中国核科技报告》1999,(Z1)
Using a gridded ionization chamber, the differential cross sections for ~6Li(n,t)~4He reaction were measured at 3.67 and 4.42 MeV. The neutrons were produced with D(d,n)~3He reaction. Absolute neutron flux was determined through ~(238)U(n,f) and H(n,p) reaction. The result at 3.67 MeV is almost 90 degree symmetry but it is obviously forward peaked at 4.42 MeV in the center of mass system. 相似文献
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Photofission fragments mass yield for~(232)Th,~(234;238) U,~(237) Np, and~(239;240;242) Pu isotopes are investigated.The calculations are done using a developed approach based on Gorodisskiy's phenomenological formalism. The Gorodisskiy's method is developed to be applied for the neutron-induced fission. Here we revised it for application to photofission. The effect of emitted neutron prior to fission on the fission fragment mass yields has also been studied. The peak-to-valley ratio is extracted for the240 Pu isotope as a function of energy. Obtained results of the present formalism are compared with the available experimental data. Satisfactory agreement is achieved between the results of present approach and the experimental data. 相似文献
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用活化法测量相对于~(93)Nb(n,2n)~(92)Nb~m反应的~(179)Hf(n,2n)~(178)Hf~(m2)的反应截面和相对于~(27)Al(n,2n)~(24)Na反应的~(209)Bi(n,2n)~(208)Bi的反应截面。在中子能量为14.4 MeV处~(179)Hf(n,2n)~(178)Hf~(m2)反应的测量截面为(6.04±0.32)×10~(-31)m~2。在中子能量为14.6 MeV处~(209)Bi(n,2n)~(208)Bi反应的测量截面为(2279±173)×10~(31)m~2。在这些测量中,中子能量是用~(90)Zr(n,2n)~(89)Zr~(m+8)反应和~(93)Nb(n,2n)~(92)Nb~m反应的截面比法测定的。 相似文献
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本文报道武汉市空气中~(238)U、~(226)Ra、~(232)Th 放射性浓度的估算结果。空气中~(238)U、~(226)Ra、~(232)Th 的放射性浓度是根据地面空气中铀、镭、钍的主要天然来源是土壤粒子的再悬浮的假定,通过调查测量武汉市土壤中天然放射性核素含量和空气中含尘量,经计算后确定的。我们于1984年4—10月在武汉地区采集了60个土壤样品,调查测量了土壤中天然放射性核素含量,并根据在1981—1985年间采集的7346个空气粉尘样品测得的空气中含尘量,估算出武汉市空气中~(238)U、~(226)Ra 和~(232)Th 放射性浓度的五年平均值分别为24.0、18.9和28.7nBq/L。五年中以1983年的平均值最高,分别为30.4、23.9和36.2nBq/L。以1984和1985年的数据为例,空气中~(238)U、(226)Ra、~(232)Th 放射性浓度呈明显的季节性变化,两年中均以冬季为最高,夏季最低。在武汉市六个城区中,空气中~(238)U、~(226)Ra、~(232)Th 的放射性浓度,以青山区最高,武昌区最低。 相似文献
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本文介绍了用α谱仪同时测定人骨骼中~(228)Th、~(230)Th和~(232)Th含量的方法。样品用浓 HNO_3和 H_2O_3湿灰化,草酸钙共沉淀载带、CL-5208萃淋树脂和743阳离子交换树脂联合分离后,电沉积制源,在低温半导体α谱仪上测量。该方法对~(234)Th的全程回收率为95.0±1.7%,对铀和镭的去污系数分别为6.3×10~4和1.5×10~3,对~(228)Th、~(230)Th、~(232)Th 的探测下限分别为0.432、0.135和0.108Bq/kg(鲜重)。 相似文献