Evaluation of Neutron Activation Cross Sections for ~(93)Nb(n,2n)~(92m)Nb and ~(93)Nb(n,n′)~(93m)Nb Reactions from Threshold to 20 MeV

Niobium is a very important structure material in nuclear fusion engineering. The activation cross sections of neutron interaction with ~(93)Nb must be considered for the evaluation of radiation safety, radiation induced material damage. Meanwhile, knowledge of the neutron(n,2n) and (n,n') reactions have been used for the neutron dosimetry. The dosimetry reaction of ~(93)Nb(n,n')~(93m)Nb is characterized by the low threshold energy less than 0.1     

~(93)Nb~m、~(94)Nb的放化分析

建立了N-苯甲酰-N-苯胲(BPHA)萃取、氨水反萃、结合2次α-安息香肟萃取除Mo、从某元件溶解液中分离93Nbm和94Nb的分离流程。该流程对137Cs和93Mo的去污因子分别为2.4×106和1×103,对144Ce和103Ru的去污因子大于104。采用宽能HPGeγ谱仪对产品进行测量。利用241Am、137Cs、57Co标准源得到仪器在低能部分的效率曲线,内插法得到对93Nbm(16.6 keV)的探测效率为(3.24±0.06)%,并最终确定了某元件溶解液中93Nbm的比活度为(126.87±4.86)Bq/g,94Nb的比活度小于0.05 Bq/g。     

中子与~(93)Nb和~(239)Pu反应数据的理论和评价

正中子与原子核反应数据是核科学研究和核工程设计的重要基础数据,也是核天体物理研究中的关键数据之一。93 Nb是重要的结构材料核,而239Pu是重要的燃料核。在中子与93 Nb反应的总截面、去弹性散射截面、弹性散射截面和弹性散射角分布角分布的实验结果基础上,给出了最佳的光学模型势。应用光学理论模型、预平衡反应的激子模型、多步预平衡反应模型、平衡态反应的理论模型、直接反应理论、核能级密度理论模型、轻粒子发射的理论模型等,计算了中子与93 Nb反应全套数据,结果与实验     

~(238)U,~(235)U和~(93)Nb的次级中子能谱和双微分截面计算

一、引言自1966年Griffin提出激子模型以来,经过人们多年的工作,激子模型在计算次级中子能谱方面取得了一定的成功,用于角分布计算也有所进展。但迄今预平衡计算和平衡(蒸发)计算不能统一,计算结果不能定量地符合实验。其一个主要的原因是激子态     

Determination of the Average Neutron Energy Using Cross Section Ratio of the ~(58)Ni(n,p)~(58g m)Co/~(58)Ni(n,2n)~(57)Ni Reactions

The ~(58)Co/~(57)Ni activation ratio of the nickel foils and the correspondingaverage neutron energy have been measured. The source neutrons were produced by the T(d,n)~4He reaction at 150 kVneutron generator.The nickel foils were irradiated at 0°,40°,60°,96°,110°,130°to the incident deuteron beam.The activities from the residual nuclides ofthe rcactions ~(58)Ni(n,p)~(58g m) Co and ~(58)Ni(n,2n)~(57) Ni were then measured for eachfoil.The self absorption correction of the sample and the coincidence summing     

关于~(95)Zr和~(95)Nb的衰变

裂变产物~(95)Zr和~(95)Nb的衰变,特别是~(95)Zr衰变的分支比,是比较有用的核数据。因而,许多实验室在这方面作过不少工作,但至今结果仍有一定偏离。目前一般采用的衰变纲图如图1所示。我们用Ge(Li)γ谱仪,对~(95)Zr和~(95)Nb所放出的γ射线的能量及相对强度进行了测量。     

~(58)Ni全套中子核数据的评价

评价了~(58)Ni在10~(-5)eV到20MeV能区的全套中子数据。数据包括全截面、弹性、去弹、总非弹,九条分立能级和连续态的非弹及(n,2n),(n,3n),(n,n'α) (n,αn'),(n,n'p) (n,pn'),(n,p),(n,d),(n,t),(n,α)和(n,γ)反应截面,还包括次级中子角分布、双微分截面(DDCS),γ产生数据和共振参数。评价依据直到1995年测量的     

~(58)Ni全套中子核数据的评价(英文)

评价了~(58)Ni在10~(-5)eV到20MeV能区的全套中子数据。数据包括全截面、弹性、去弹、总非弹,九条分立能级和连续态的非弹及(n,2n),(n,3n),(n,n′α) (n,αn′),(n,n′p) (n,pn′),(n,p),(n,d),(n,t),(n,α)和(n,γ)反应截面,还包括次级中子角分布、双微分截面(DDCS),γ产生数据和共振参数。评价依据直到1995年测量的实验数据和用UNF程序的理论计算。评价数据以ENDF/B-6格式入中国评价核数据库第三版(CENDL-3)。     

46MeV/A ~(12)C离子与~(93)Nb相互作用中靶余核的质量和电荷分在研究

利用核化学技术中的离线γ能谱法测定了46MeV/A ~(12)C离子与~(93)Nb相互作用中50个靶余核的生成截面,通过高斯函数拟合得到了电荷分布及质量分布。平衡统计碎裂模型的计算成功地再现了实验结果。     

二氧化锡吸附法分离~(95)Zr和~(95)Nb的研究

随着科学技术及同位素应用的发展,对纯~(95)Zr和~(95)Nb指示剂的需求越来越迫切。从裂变产物~(95)Zr-~(95)Nb平衡体系中分离~(95)Zr和~(95)Nb的方法很多,其中吸附法具有吸附剂来源方便、操作简单、产物纯净等优点而受到人们的重视。特别是硅胶吸附法分离~(95)Zr和~(95)Zb更是不少研究工作者的课题,但是这方面的基础研究工作如关于~(95)Nb的行为和     

Evaluation of the (n,α) Cross Sections for ~(58, 60～62, 64)Ni and ~(Nat)Ni

The cross section of the (n,α) reaction is very important for fusion reactor for monitoring neutron field in the context of radiation induced material damage, radiation safety, neutron dosimetry, etc. The natural nickel consists of five stable isotopes, i. e. ~(58)Ni,~(60～62,64)Ni. Their abundances and threshold energies are given in Table 1.     

High-spin States in ~(91)Nb

A great number of researches have been done near the N~50 region and the results showed that manynuclei in this region are spherical[1]. Some shell model calculations using 82Sr as the core, performed in this region, are in good accordance with the observ…     

AMS Measurement of ~(93)Zr

The zirconium isotope 93Zr is a long-lived pure beta-particle-emitting radionuclide, which is produced by nuclear fission and neutron activation of the stable isotope 92Zr. This element is a constituent of the structural components of nuclear reactor vessels. With AMS it should be possible to detect minute     

~(95)Zr/~(95)Nb衰变率的绝对测量

本文叙述了用4πβ-γ符合方法对~(95)Zr/~(95)Nb衰变率绝对测量原理、步骤和计算公式的推导,以及各种误差的讨论。     

从废旧~(63)Ni放射源中回收~(63)Ni原料技术

为了从废旧63 Ni放射源中回收63 Ni原料,对物理方法、化学方法和电化学方法优缺点进行比较后确定了电化学方法为较优工艺,本研究优化得到电化学法退镀液的组成、浓度以及工艺参数,该方法回收的63 Ni原料比活度较高,可以重新用于63 Ni源的生产。     

用硅胶吸附提取及分离~(95)Zr和~(95)Nb指示剂

本文叙述硅胶-硝酸体系中~(95)Zr、~(95)Nb的吸附,硝酸浓度、温度、硅胶的处理、铀含量等因素对吸附的影响。提出了~(95)Zr、~(95)Nb彼此分离和从混合裂片中直接提取~(95)Zr、~(95)Nb的程序。得到的~(95)Zr中含~(95)Nb<0.4%,~(95)Nb中含~(95)Zr<0.1%。对~(106)Ru、~(187)Cs、~(144)Ce等裂变产物的去污系数大于3×10~4。     

质子滴线核~(17)F+~(58)Ni在近垒能区的弹性散射测量

<正>丰质子区的奇特核在近垒能区的反应机制研究目前已成为核物理领域的热点问题。本工作重点考察质子滴线核~(17)F+~(58)Ni体系的弹性散射,以研究价质子结构对弹性散射过程的影响。~(17)F是最轻的F同位素,其质子分离能仅600keV。在质子破裂阈下存在一束缚的激发态,激发能约为500keV。研究表明该激发态存在质子晕的奇异结构。     

Calculation and Evaluation of Neutron-Induced Reactions on ~(58)Ni Below 150 MeV

Based on the experimental data of total, nonelastic, elastic cross section and elastic scattering angular distributions for n 58Ni reactions, a set of neutron optical model potential parameters is obtained in the     

利用人体毛发~(32)S(n,p)~(32)P反应测定快中子剂量

本文介绍了利用毛发测定事故快中子剂量的方法。对辐照后毛发进行了活化分析,确定了毛发的主要活化产物。用活化分析法确定了成年男性毛发中硫含量,拟定了从毛发中快速分离~(32)P的萃取程序(包括有裂片沾污时的去污程序),同阈探测器进行了剂量对比。本方法采用0.1—0.5克毛发样品,最小可探测的快中子剂量为1拉德。分离、制样4小时可完成。     

Tests of the GIC and Measurements of Angular Distributions and Energy Spectra for ~(58)Ni(n,p)~(58)Co Reaction at 4.1 MeV

On the basis of measurements of double differential cross sections for (n,α) reactions in 5-7 MeV neutron energy region using gridded ionization chamber (GIC), we constructed a new GIC which, compared with the old ones, can bear higher pressure and makes it possible to measure (n,p) reactions up to 6 MeV and (n,xα) reactions up to 20 MeV. To test the new chamber, the saturation property for argon and krypton mixed with a few percent CO_2 was studied using ~(241)Am and compound Pu α source and tritium from ~6Li(n_(th),t)~4He, and the two dimensional spectra for ~(241)Am and Pu α source, ~6Li(n_(th),t)~4He and H(n,p) reactions were measured. The measured energy spectra and angular distributions for α and tritium are reasonable, and the derived data for α, proton and tritium in argon and krypton from the measured spectra data were compared with the calculated ones. They are in good agreement. The angular distributions and energy spectra for ~(58)Ni(n,p)~(58)Co reaction at 4.1 MeV neutron energy were m