无载体放射性同位素~(109)Cd的制备

放射性同位素~(109)Cd,半衰期453天,经过电子俘获衰变,放出22keV的Ag的KX射线和88keV的γ射线,适合作X荧光源,用于矿物、石油和各种材料的分析。~(109m)Ag又是一个有用的医用同位素,用于血管造影。 我们利用1.5米回旋加速器加速的 HD束流,照射Ag靶,通过~(109)Ag(d,2n)~(109)Cd反应产生~(109)Cd。用HBr体系的阴离子交换柱从热靶料液中分离出了无载体~(109)Cd,回收率达到99％。产品经γ能谱鉴定,无其它放射性杂质存在。用~(109)Cd产品溶液制成的X荧光源,已提供给北京大学、吉林大学、大庆油田等单位使     

用分子电镀法制备~(109)Cd X射线源

~(109)Cd X射线源是供油水分析仪测原油含水率用的。~(109)Cd的半寿命为453天,它的衰变子体~(109m)Ag发射22keV的X射线和88keV的γ射线,而能量为22keV的谱线的油水吸收系数相差较大,适用于油水分析仪测原油含水率。由于22keV的X谱线能量较低,为了尽量减少自吸收,要求源要薄而均匀,所以我们采用了电镀效率高、时间短,镀层薄而均匀、牢固的分子电镀法做源。测得源强为1×10~7/s。     

加速器生产~(109)Cd用Ag靶制备

Ag靶用于加速器生产109Cd,核反应为109Ag(p,n)109Cd。本工作采用电沉积法制备Ag靶。通过对影响电沉积Ag靶层质量及厚度的各种因素的实验,确定了Ag靶制备工艺条件如下:ρ(Ag )=20～50g/L,ρ(KNO3)=10～30g/L,?(NH4OH)=0.1～0.2。用此工艺条件,制备出质量厚度大于100mg/cm2、表面     

Measurement of the ~(107)Ag(n,2n)~(106m)Ag Reaction Cross Section

The measurement of the ~(107)Ag(n,2n)~(106m)Ag reaction cross sections in theneutron energy range 13.50～14.73 MeV were done by the activation method with     

电沉积法制备加速器生产109Cd用Ag靶

采用电沉积法对加速器生产109Cd所用Ag靶的制备工艺进行研究。实验研究了电沉积过程中影响Ag靶层质量及厚度的主要因素,确定了Ag靶制备工艺条件和工艺参数:ρ(Ag )=20~50 g/L,ρ(KNO3)=10~30 g/L,φ(NH4OH)=0.1~0.2;电流密度10~15 mA/cm2,电沉积时间2~3 h,室温。用此工艺条件制备出靶厚大于100 mg/cm2、表面光滑、镀层致密的Ag靶。     

HDEHP从含有大量Ag(Ⅰ)的硝酸溶液中萃取In(Ⅲ)

前言 ~(111)In是近年来很受人们注意的一种医用同位素。产生~(111)In的主要核反应有~(109)Ag(α,2n)~(111)In,~(111)Cd(p,n)~(111)In,~(111)Cd(d,2n)~(111)In。In(Ⅲ)的分离方法有HCl沉淀Ag(Ⅰ)法;阴离子交换法;甲基异丁基酮萃取法;把In(Ⅲ)转化为溴化物后,用异丙醚萃取,再用8M HCl反萃取等方法。用二(2-乙基己基)磷酸(HDEHP)萃取\n(Ⅲ)的报道尚未多见。     

实验测定~(116)Cd(n,2n)和~(115)In(n,p)反应截面

一、引言由于对~_(116)Cd(n,2n)反应的截面测量数据分歧较大,而关于~(115)In(n,p)反应,文献中也只报导了该反应的总截面,对亚稳态和基态的截面国内外报导得均很少,因此,我们通过实验来测定~(116)Cd(n,2n)和~(115)In(n,p)反应中产生的~(115m,g)Cd的截面和它们     

~(182)W(n,n′α)~(178)Hf~(m2)反应截面研究

对当前有关182W(n,n′α)178Hfm2反应截面的实验测量值和理论计算值相差100倍这一分歧进行了样品成分活化分析和仔细的理论分析。所得结果排除了实验所用样品存在Hf杂质影响这一推论。理论和实验值的分歧依然存在,可能原因是现有的理论计算程序还不能对高角动量激发态进行很好的理论预言     

Cross Section Measurements for ~(111)Cd(n,p)~(111m)Ag,~(106)Cd(n,2n)~(105)Cd,~(110)Cd(n,2n)~(109)Cd,~(116)Cd(n,2n)~(115m)Cd and ~(116)Cd(n,2n)~(115g)Cd Reactions

Activation cross sections for cadmium were measured in the neutron energy range from 13.40 MeV to 14.80 MeV using the T(d,n)~4He reaction as neutron source. The cross sections of ~(27)Al(n,α)~(24)Na reaction is used as standard one.     

直接测量~(109)Cd活度

~(100)Cd是一个重要的低能γ射线源和X射线源,其半衰期为462.6d。广泛地用于刻度半导体谱仪的效率和X射线荧光分析中作为X射线源。本文介绍了利用4πβ(PPC),4πβ(L,S)和4πe-γ符合法测量~(109)Cd活度的原理,并对几朴方法作了比较和讨论。     

Neutron Resonance Parameters of Silver-107 and Silver-109

Neutron transmission measurements were carried out on the separated isotopes of silver using the time-of-flight facility at the Japan Atomic Energy Research Institute electron linear accelerator. Neutrons were detected with the ⁶Li-glass detectors at 56 and 191 m. The samples used were metallic powder enriched to 98.2% for ¹⁰⁷Ag and 99.3% for ¹⁰⁹Ag. Transmission data were analyzed with the multi-level Breit-Wigner formula incorporated in a least squares fitting program. Resonance energies and neutron widths were determined for the large number of resolved resonances in the neutron energy region of 400 eV~7 keV. The s-wave strength functions and average level spacings were obtained to be; S₀= (0.43±0.05) × 10^?4, D₀ = 20±2 eV for ¹⁰⁷Ag and S₀= (0.45 ± 0.05) × 10^?4, D₀ = 20 ± 2eV for ¹⁰⁹Ag.     

~(109)Cdγ射线发射率的比对测量

一、序言~(109)Cd核素是用于低能范围刻度Ge探测器较理想的标准源。我们利用新建的薄窗闭端同轴Ge和平面高纯Ge探测器系统参加了中国计量科学院组织的~(109)Cd核素活度比对测量,随后又测量了BIPM组织的国际比对~(109)Cd标准溶液。我们的结果是比较好的,在误差范围内和国际比对结果较好的符合。     

放射性(~(110)Ag~m)Ag/TiO_2复合纳米微粒的研制

用钛酸四正丁酯水解法制备了纳米TiO2溶胶,并通过光化学沉积的方法制备Ag/TiO2复合纳米微粒。研究了浓度、pH值、乙醇等条件对复合物形成的影响,在此基础上用放射性的110Agm制备了放射性(110Agm)Ag/TiO2复合纳米微粒。实验结果表明在最佳反应条件下,用聚酰胺薄膜层析法测得约有93.6%的110Agm沉积在TiO2纳米微粒表面,放射性浓度为0.6MBq/mL;放置48小时后仍有93.0%的110Agm沉积在TiO2纳米微粒表面;经原子力显微镜测定,TiO2微粒和Ag/TiO2复合微粒的粒径分别为1—2nm和8—40nm。     

Measurement of ~(232)Th(n,2n)~(231)Th reaction cross-sections at neutron energies of 14.1 MeV and 14.8 MeV using neutron activation method

In this study, the activation cross-sections were measured for ~(232)Th(n,2n)~(231)Th reactions at neutron energies of 14.1 and 14.8 MeV, which were produced by a neutron generator through a T(d,n)~4He reaction. Induced gamma-ray activities were measured using a low background gamma ray spectrometer equipped with a high resolution HPGe detector. In the cross-section calculations, corrections were made regarding the effects of gamma-ray attenuation, dead-time, fluctuation of the neutron flux, and low energy neutrons. The measured cross-sections were compared with the literature data, evaluation data(ENDF-B/VII.1, JENDL-4.0 and CENDL-3.1), and the results of the model calculation(TALYS1.6).     

Measurement of the cross sections for the reactions Cr(n,2n)Cr, Zn(n,2n)Zn, Y(n,2n)Y and Zr(n,2n)Zr from 13.5 to 14.8 MeV

Cross section measurements for the reactions ⁵²Cr(n,2n)⁵¹Cr, ⁶⁶Zn(n,2n)⁶⁵Zn, ⁸⁹Y(n,2n)⁸⁸Y and ⁹⁶Zr(n,2n)⁹⁵Zr were carried out in the neutron energy range 13.47–14.79 MeV applying the activation technique. Neutrons were produced via the T(d,n)⁴He reaction, making use of the variation of neutron energy with the emission angle. The neutron fluences incident on the samples were determined relative to the well-evaluated cross section for the reaction ⁹³Nb(n,2n)^92mNb.

The induced γ-ray activities of the irradiated Zn, Zr and Y₂O₃ samples and their monitor foils were measured by means of a calibrated Ge(Li) γ-ray detector at the KFI, Debrecen. At the IRK, Vienna, relative γ-ray measurements using a high-purity Ge detector were combined with integral γ-ray counting by means of a NaI(TI) well-type detector on the Cr, Zn and Zr foils of highest activity and on some Nb monitor foils; integral γ-ray counting only was applied in the case of the Y₂O₃ samples. All necessary corrections were taken into account.

The results are compared to the corresponding results of cross section measurements published in the literature. The uncertainties obtained in this work are considerably smaller in most cases than the uncertainties given by other authors.     

186W(d,p)187W和186W(d,2n)186Re反应激发函数评价及厚靶产额计算

考虑特征γ射线分支比、衰变常量和标准截面等修正,对氘引起的核反应¹⁸⁶W(d,p)¹⁸⁷W和¹⁸⁶W(d,2n)¹⁸⁶Re的激发函数进行了研究。收集并分析了这些反应激发函数的实验测量数据,应用数学方法对分析处理后的实验数据进行了拟合。同时,采用TALYS程序对这些激发函数进行了理论计算。经过综合评价,给出了50 MeV以下¹⁸⁶W(d,p)¹⁸⁷W和¹⁸⁶W(d,2n)¹⁸⁶Re反应激发函数的推荐值,利用得到的¹⁸⁶W(d,2n)¹⁸⁶Re激发函数推荐值计算了医用放射性核素¹⁸⁶Re的厚靶产额。     

~(45)Sc(n,2n)~(44g+m)Sc反应的同质异能素截面比

水文介绍用活化法测量14.6MeV中子引起的~(45)Sc(n,2n)~(44g+m)Sc反应的同质异能素截面比,及用自编的EPRIR程序计算的该核素带有预平衡机制的统计模型同质异能素截面比。通过实验值与理论值的比较,可以验证实验自旋切割因子值,并讨论预平衡机制对该反应的贡献。     

Neutron activation cross-sections at (14.6 ± 0.3) MeV

The activation method has been used to measure 14.6 MeV cross-sections for the following nine reactions which are important for nuclear energy programmes: ⁸⁹Y(n, α)^86mRb, ⁸⁹Y(n, n′)^89mY, ⁸⁹Y(n, 2n)⁸⁸Y, ¹⁰⁷Ag(n, n′)^107mAg, ¹⁰⁷Ag(n, p)^107mPd, ¹⁰⁹Ag(n, n′)^109mAg, ¹⁰⁹Ag(n, p)^109mPd, ¹³⁹La(n, p)¹³⁹Ba, ¹³⁹La(n, α)¹³⁶Cs. Special features included a high-intensity neutron generator ‘KORONA’ with a useable fast neutron flux of 3 × 10¹⁴ n/m² s, a fast rabbit system suitable for cyclic irradiations and measurements for short-lived activities, and a γ-ray spectroscopy system with real time correction of counting losses. The results of this investigation are compared with existing experimental cross-section values. The cross-sections have also been calculated using the EMPIRE code Version 2.19 involving Hauser Feshbach statistical theory with pre-compound emission. Default inputs have been used for nuclear model parameters taken from the RIPL-2 data base. The agreement with the experimental data is generally acceptable within the given experimental uncertainty.     

A theoretical study of excitation functions of isomers and isomeric cross section ratios in alpha induced reactions on Ag

A theoretical study based on statistical and pre-equilibrium calculations of the excitation functions and relevant isomeric cross-section ratios for the ¹⁰⁷Ag (α, n) ¹¹⁰In^m,g, ¹⁰⁷Ag (α, 3n) ¹⁰⁸In^m,g, ¹⁰⁹Ag (α, 3n) ¹¹⁰In^m,g, and ¹⁰⁷Ag (α, αn)¹⁰⁶Ag^m reactions have been carried out in the 10-40 MeV alpha energy range in a consistent way. The calculated excitation functions for the isomeric states, ground states and their ratios have been compared with reported measurements and TENDL-2010 and discussed.