~(56)Fe(n,p)~(56)Mn反应截面的测量

在E_n=12.8—18.2兆电子伏能区,用活化法测量了~(56)Fe(n,p)~(56)Mn反应截面,在E_n=14.63±0.20兆电子伏处做了绝对测量,结果为108.0±2.9毫靶。中子通量用伴随粒子法测定。对T(d,n)~4He反应的中子角分布也作了测定。~(56)Mn的放射性用φ10×7.6厘米的Nal(Tl)闪烁谱仪测量,~(56)Mn特征γ射线的探测效率用4πβ-γ符合法测定的~(56)Mn标准源刻度。本文还对用伴随粒子法测量中子通量作了较详细的叙述。测量结果同国外数据作了比较,并做了简短讨论。     

14MeV中子反应截面的综合评价

文章叙述了14MeV中子反应截面综合评价的基本思想及数学处理方法。对~(56)Fe(n,p)~(56)Mn,~(27)Al(n,α)~(24)Na,~(63)Cu(n,2n)~(62)Cu,~(27)Al(n,p)~(27)Mg和~(41)K(n,p)~(41)Ar等五种反应截面进行综合评价,得到了较满意的结果。评价值分别为109.7,114.2,533.5,71.8和48.0mb,误差(1σ)分别为0.88%,1.1%,1.5%,2.6%和3.2%。     

Apollo-17月海玄武岩样品的中子活化分析

本文叙述利用60mg月岩样品测定包括14种稀土在内的36种元素的含量。称取20.00mg月岩样品密封于聚乙稀薄膜小袋里,利用原子能研究所游泳池式反应堆的水平孔道,由气动快速辐照装置,对样品、标准和国际标样W-1分别与C1监察器在中子通量为3×10~(12)n·cm~(-2)·s~(-1)处辐照5分钟,冷却5分钟后测定A1、Ti、V、Ca;冷却1小时后测定Dy、Mn;冷却10小时后测定Eu、Na;冷却30小时后测定Sm。将上述的20.00mg样品转移到小铝盒内,称取42.10mg的W-1标样装入小铝盒内与制备好的中、长寿命核素的标准包在一起,在堆的垂直孔道中中子通量为2×10~(13)n·cm~(-2)·s~(-1)处照射20小时;冷却5天、10天和20天后分别测定Na、La、Sm、Ho、Eu、Yb、Hf、Cr、Fe、Sc、Co、Lu和Tb。冷却50天后进行放化分离,然后测定Tm、Ta、Gd、Ce和Zn。第二次照射取月岩样42.10mg,W-1标样64.90mg和制备好的标准,在中子通量为2×10~(13)n·cm~(-2)·s~(-1)处辐照40小时,冷却12小时后取出。样品用1mlHClO_4 2ml     

14兆电子伏中子活化分析测定钢中的硅

利用14兆电子伏中子照射硅样品,产生~(23)Si(n,p)~(28)Al反应,通过测量~(28)Al的1.78兆电子伏γ射线,测定钢中的硅。由于基体铁的~(56)Fe(n,p)~(56)Mn干扰反应产生1.81兆电子伏γ射线与~(28)Al的γ射线重叠在一起。必须对结果加以修正。本文介绍了两种修正方法。在中子通量为3×10~7中子/厘米~2·秒的条件下,硅含量为0.4—0.09%时,分析精密度为±5—±9%,极限灵敏度为0.2—0.7毫克。活化分析的结果与化学分析的值符合得很好。     

人发样品中Sr、Zn、Cu、Br、As、Sb、Na、K、Mn的热中子活化分析

人发样品由于取样简单方便,易于保存,在地方病因研究和作为环境污染监测的指示器方面,已引起人们的兴趣。 我们利用短照射10分钟、冷却3小时后直接测定样品γ谱的方法,分析了人发样品中Sr、Zn、Cu、Br、As、Sb,Mn、K、Na等九个元素。本文讨论了分析的准确度和精密度。 1.实验方法     

中子活化分析法测定吉林陨石中微量镓

陨石中的Na、Mn等杂质元素,经中子活化后产生~(24)Na和~(56)Mn等核素,它们干扰Ga的测定,因此必须进行放化分离。实验步骤如下: 称取20mg陨石样品置于铝制照射筒中,与标准一起在中子通量约为1×10~(13)n·cm~(-2)·s~(-1)的反应堆中照射20小时,冷却1天后将样品置于高压溶样埚中(高压溶样埚中已置有200μg镓载体),加1ml浓HNO_3、5ml浓HF,摇匀后置于烘箱中烘2小时,温度180～200℃。取出后在冷水中冷却15分钟,再打开高压溶样埚,将溶液转入白金坩埚中,分别加2次1ml HClO_4,置于电炉上缓慢加热挥发除去SiF_4和HF,加热至近干,加1.5ml浓HCl,则生成清澈的黄色溶液,再加热至近干,然后用3ml 7N HCl清洗白金坩埚,转     

GSD水系沉积物标准参考样中一些元素的仪器光子活化分析

本文首次用仪器光子活化法测定了GSD-2、GSD-5和GSD-6三种标准参考样中的Ce、Cs、Fe、Mg、Mn、Na、Nb、Nd、Ni、Pb、Rb、Sr、Ti、Y、Zn、Zr等16种元素的含量。其中Nb、Ph、Ti、Y、Zr等5种元素中子活化法还未曾提供数据。测定采用相对法,利用Cu箔活化产生的~(64)Cu校正不同照射位置处光子通量。分析周期3—5天。结果表明69％以     

Nuclear Data Sheets Update for A=56

The 1992 version of Nuclear Data Sheets for A=56 had been evaluated on the nuclear reaction and decay experiments leading to ~(56)Ti, ~(56)V, ~(56)Cr, ~(56)Mn, ~(56)Fe, ~(56)Co basis of ~(56)Ni, ~(56)Cu and ~(56)Zn since the date of last evaluation, December 1991. The     

核纯石墨中微量杂质元素ICP/AES法测定的研究

对核纯石墨中十八个微量杂质元素Al,Ca,Cd,Co,Cr,Cu,Fe,In,Mg,Li,Mn,Mo,Ni,Pb,Sn,V,Y和Zn的测定进行了试验研究。方法测定下限0.01μg·g~(-1)～0.04μg·g~(-1),平均回收率为94.2％～107.3％,RSD(n=8)为0.82％～6.4％。采用硝酸加高     

核电用二氧化铀中杂质元素的色谱分离-ICP/AES法测定

应用237-季铵萃取树脂色谱分离技术,将核电用二氧化铀中铀与待测杂质元素在6.5mol/LHNO_3介质中定量分离后,用975型ICP直读光谱仪同时测定Al,Ba,Be,Ca,Cd,Co,Cr,Cu,Fe,Mg,Mn,Mo,Nb,Ni,Pb,Ru,Sb,Sn,Ta,Ti,V,Zn和Zr等23种杂质。取样300mg时,测定下限为0.003×10~(-6)～0.25×10~(-6);方法的加入回收率在95％～109％范围内,相对标准偏差小于10％。     

Stopping powers of Be,Al, Ti,V, Fe,Co, Ni,Cu, Zn,Mo, Rh,Ag, Sn,Ta, Pt and Au For 6.5 MeV protons

The stopping powers of Be, Al, Ti, V, Fe, Co, Ni, Cu, Zn, Mo, Rh, Ag, Sn, Ta, Pt and Au for 6.5 MeV have been measured using a surface barrier silicon detector. The accuracy of the results is ± 0.3%. The detail of the experimental procedures is described. The results have been compared with the Risø data and the Aarhus data of Andersen et al. The present results for Al, Cu and Ag agree very well with the Aarhus results at 6.5 MeV. The mean excitation energy has been extracted from the present results using the Bonderup shell correction, the Barkas correction and the Bloch correction. The parameters x and b which appear in the Bonderup shell correction and the Barkas correction have been newly determined as x = 1.358 and b = 1.3. The present mean excitation energy agrees very well with the I values obtained by other authors. It has been confirmed that the Bonderup shell correction is quantitatively correct for 6.5 MeV protons.     

Wavelengths,transition probabilities,and oscillator strengths for M-shell transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions

Wavelengths, transition probabilities, and oscillator strengths have been calculated for M-shell electric dipole transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions. The fully relativistic multiconfiguration Dirac–Fock method, taking quantum electrodynamical effects and the Breit correction into account, was used in the calculations. Calculated energy levels of M-shell excited states for Cu-, Zn-, Ga-, Ge-, and Se-like Au ions from the method were compared with available theoretical and experimental results, and good agreement with them was achieved.     

Gamma-Ray Production Cross Sections for Interactions of 14.8 MeV Neutrons with O,Na, Al,Cl, Cr,Fe, Ni,Cu and Pb

Production cross sections for 85 discrete γ-rays at 125° were measured with a Ge(Li) detector for interactions of 14.8 MeV neutrons with natural samples of O, Na, Al, Cl, Cr, Fe, Ni, Cu and Pb. The obtained cross sections were compared with the results of previous works. For O, Na, Al, Cr and Ni, the present results agree with the previous data measured with monoenergetic neutron sources; for Cl, Fe, Cu and Pb, the present results are larger than the previous data. In comparison between the present results shown by histograms of γ-ray energy and unfolded data, a considerable discrepancy is found from some of the previous data for Fe.     

Measurements of the total effective cross sections for resonance neutrons in Pd,Os, Ir,Mo, In,I, Ta,Th, U238

The results of calculations of the level constants in the elements Pd, Os, Ir, Mo, I, In, Ta, Th, U²³⁸ are presented; the cross sections for these elements have been published earlier. New measurements for the cross sections in Ir, Th, U²³⁸ are cited. The measurements were made with a mechanical-chopper spectrometer with a resolution of 0.08 sec/m in the energy region from 4.5 to 10,000 ev. The integrated and differential curves for the distribution of neutron widths in these elements are plotted.Presented at the International Conference on Nuclear Reactions in Amsterdam (June 1956).The authors take this opportunity to express their gratitude to U. Chi-Kwa and Suan Chi-Ling for their assistance in the mathematical analysis of the experimental results, G. M. Kukavadze for the mass-spectro-graphic analyses of the samples, V. N. Bovinoi and M. P. Anikinoi for providing the chemical analyses and A. I. Ermakov, N. S. Rezvyakov, G. V. Rukolaine and K. A. Trostinoi for help in building the analyzer and in carrying out the measurements.