海水中放射性核素238U、232Th、600Co、137Cs浓集实验

采用广东省环境辐射监测中心编制的操作规程《海水中γ核素浓集方法实施细则》分析了环境海水样品的γ放射性核素238U、232Th、60Co、137Cs,该方法的238U、232Th、60Co、137Cs的回收率分别为82.5%、79.3%、80.3%、91.3%;制样放置约90 d后测量238U的数据更准确。     

Gamma-ray emission probabilities of the fission products 144Ce144Pr, 106Rh, 95Zr

The fission products ¹⁴⁴Ce¹⁴⁴Pr, ¹⁰⁶Rh and ⁹⁵Zr play an important role in the burn-up determination of fuel elements by means of γ-ray spectrometry. One of the crucial quantities in this field is the absolute γ-ray emission probability (intensity) for which values available in literature have not the desirable accuracy of 1–2%.By using Ge(Li)-spectrometers of known efficiency and sources calibrated by 4πβ-γ-coincidence methods, we determined absolute γ-ray emission probabilities of ¹⁴⁴Ce¹⁴⁴Pr, ¹⁰⁶Rh and ⁹⁵Zr with an uncertainty of ±1% for the main γ-rays.     

Cross sections for K-shell ionization by 1H, 2H, 3He,and 4He ion impact

Cross section for K-shell ionization derived from experimental measurements with the light ions ¹H, ²H, ³He, and ⁴He are tabulated according to projectile energy and target atomic number.     

Sr树脂在气溶胶~(210)Pb、~(210)Bi和~(210)Po联合分析中的初步应用

气溶胶中~(210)Pb、~(210)Bi和~(210)Po的活度浓度处于不平衡状态,本工作对3种核素联合分析进行了方法设计,并采用标准溶液对方法进行了验证。方法验证了Sr树脂对Pb-Bi-Po的分离。依据三种核素的回收率~(210)Bi(约97%)~(210)Po(约93%)~(210)Pb(约89%)、PbSO_4中~(210)Bi的生长曲线及BiOCl的衰变曲线,可以确定Sr树脂对3种核素的分离效果较好。Sr树脂在气溶胶~(210)Pb、~(210)Bi和~(210)Po中的联合分析应用研究,可以应用于探究气溶胶中Pb-Bi-Po不平衡现象,为气溶胶分析提供技术方法。     

Cross section measurements of the 23Na(n, 2n)22Na, 58Ni(n, 2n)57Ni and 115In(n,n′)115mIn reactions

Cross sections for two high energy threshold reactions ²³Na(n, 2n)²²Na and ⁵⁸Ni(n, 2n)⁵⁷Ni were measured by the activation method in the neutron energy range from 14 to 18 MeV. Inelastic scattering cross section for ¹¹⁵In was measured in the threshold region, i.e. from 0.5 to 1.3 MeV. The results of measurements are compared with scarce and divergent earlier data.     

北京地区大气中7Be、137Cs和131I活度浓度分布规律初步研究

介绍了全面禁止核试验条约（CTBT）国际监测系统（IMS）北京核素台站和北京放射性核素实验室的大气气溶胶取样和测量过程;对核素台站和放射性核素实验室的大气气溶胶的长期监测数据进行了统计分析,得到了⁷Be、¹³⁷Cs和¹³¹I活度浓度的分布特点和规律,为深入研究大气中相关放射性核素浓度分布规律奠定了基础。     

Measured activation cross sections below 10 MeV for the 51V(n,p)51Ti and 51V(n, α)48Sc reactions

The activation method is used to measure cross sections for the ⁵¹V(n, p)⁵¹Ti reaction from E_n = 2.856 to 9.267 MeV and for the ⁵¹V(n, α)⁴⁸Sc reaction from 5.515 to 9.567 MeV. Both measurements utilize ENDF/B-V evaluated neutron-induced fission cross sections of ²³⁸U as a standard. The experimental results from this work are compared with corresponding ENDF/B-V evaluated cross sections for V and substantial differences are evident. The most significant difference is a tendency for the measured values to exceed evaluated ones by as much as 50% in the vicinity of 8 MeV.     

Multiple-models predictions for drip line nuclides in projectile fragmentation of 40,48Ca,58,64Ni,and 78,86Kr at 140 MeV/u

Modern rare isotope beam (RIB) factories will significantly enhance the production of extremely rare isotopes (ERI) at or near drip lines.As one of the most important methods employed in RIB factories,the production of ERIs in projectile fragmentation reactions should be theoretically improved to provide better guidance for experimental research.The cross-sections of ERIs produced in 140 MeV/u ^78;86Kr/^58;64Ni/^40;48Ca+ ⁹Be projectile fragmentation react...     

^161Tb低能γ射线发射几率的精确测量

利用4πβ-γ符合装置和低能光子谱仪精确测量了161Tb衰变γ射线的发射几率.对于25.7 keV、48.9 keV和74.6 keV的低能γ射线,测定结果分别为0.2327±0.0053、0.1700±0.0031和0.1001±0.0019.表明本测量结果的不确定度明显减小.     

K-shell X-ray cross-section ratios for 1H, 4He and 6Li projectiles on targets from fluorine to titanium

Experimental K X-ray emission ratios have been measured for nine elements ranging from F to Ti (9 ? Z₂ ? 22) using ¹H⁺, and ⁶Li⁺ projectiles. The experimental ratios are in fair agreement with theoretical predictions for the velocity range studied, $\text{?}{}_{\mathrm{k}}\text{\$}\text{?}\text{1}$.     

^6Li第二激发态中子—质子晕结构的首次实验证实

利用北京HI－13串列加速器次级束流线产生的能量为4．17AeV的^6He束对电荷交换反应^1H(^6He,^6Li)n的角分布进行了逆运动学的测量。实验结果与微观计算的比较表明：^6Li第二激发态和^6He的基态都具有晕结构。本工作首次实证了K.Arai等1995年提出的^6Li第二激发态具有中子－质子晕结构的理论预言。     

Effets de protection mutuelle dans les interactions238U235U et 238U239Pu

This study presents some results concerning mutual shielding calculations. ²³⁸U²³⁵U and ²³⁸U²³⁹Pu interactions were studied for the fissile isotope enrichments between 0 and 4%. The resolved cross sections of fissile isotopes were calculated for 20 and 1000°C.The study of the mutual shielding effect, in a heterogeneous cell of volume ratio 2, was performed for three fuel rod radii r = 0,2, 0,5 and 2 cm. A second study of the Doppler effect on the resonance overlap were performed on a homogeneous medium equivalent to the usual P.W.R. lattices. This effect was found to be appreciable.     

Fission spectrum averaged cross-section of 94Zr(n, α)91Sr

The fission spectrum averaged cross-section of ⁹⁴Zr(n, α)⁹¹Sr reaction was obtained by comparing that of ²⁷Al(n, α)²⁴Na reaction as reference. Highly enriched ⁹⁴ZrO₂ and ²⁷Al samples were irradiated with fast neutrons having a fission-like spectrum above about 5.6 MeV. After the neutron irradiation, the produced ⁹¹Sr was chemically separated from the irradiated sample. Gamma-rays from ⁹¹Sr and ²⁴Na were measured with a Ge(Li) detector. The obtained value is 5.37 ± 0.43 μb assuming the averaged cross-section of the reference reaction to be 0.61 mb.     

有临床应用意义的^188W／^188Re发生器的研制

对^188W/^188Re发生器的吸附条件及装柱工艺等进行了研究,确定了最佳的吸附条件及吸附容量等重要参数,制备了以酸性氧化铝为吸附剂的医用^188W/^188Re发生器（7．40GBq),可用生理盐水淋洗得到^188Re.^188Re的淋洗效率在3个月之内大于70％,^188W的漏穿率小于10^-4%,核纯度和放射化学纯度均大于99％。     

Na188ReO4、188Re-DTPA和188Re-MAG3的生物分布及排泄比较

为比较Na     

^237Np与^233Pa的分离与测定

采用多孔高硅氧玻璃作吸附柱，研究了在8mol/LNHO3介质中^237Np与子体^233Pa的分离和测定。研究结果表明，用H2SO4解吸^233Pa，能使^237Np与^233Pa定量分离。^237Np和^233Pa的放化回收率分别为99％－101％和99％－103％，方法的相对标准偏差分别为2％和3％。     

The Applications and Fabrication Methods of 90Sr/90Y Sources

The applications of ⁹⁰Sr/⁹⁰Y sources were reviewed on clinical medicine, thickness gauge, continuous energy supply for science and industry, reference source for contamination calibration. The application of each source proposes certain requirement for the source properties, and that could be realized by some corresponding preparation method. Different⁹⁰Sr/⁹⁰Y source preparation methods for each application were introduced, and the characteristics of them were contrasted.