Study of Fission Fragment Mass Distribution in ~(28)Si+~(174)Yb at Energy near Coulomb Barrier

正The study of heavy-ion fusion-fission reaction at near-barrier energy region is critical for us to understand the evolution process of the heavyion nuclear reaction and also provides a vital theoretical support for the synthesis of super-heavy nuclei.For the reaction systems with more quasifission,the width of the fission fragment mass     

Fusion of ~(32)S+~(154)Sm at Energy near Coulomb Barrier

正Heavy-ion fusion reactions at energy near the Coulomb barrier have been a hot topic of extensive experimental as well as theoretical studies during the past few decades.The measured fusion cross sections at near-and sub-barrier energies were found to be significantly larger than those expected from the one-dimensional     

Experimental Study for Near-barrier Reaction of ~7Be+~(209) Bi

<正>The radioactive beam physics in one of the current frontiers in nuclear physics.The reaction mechanism in the exotic-beam induced reactions is a hot topic.Considering this,the experimental study for the reaction mechanism of the nearbarrier~7Be+~(209)Bi reaction based on the radioactive-beam line RIBLL1 were performed in the Institute of Modern Physics (IMP) in Lanzhou.     

Removal of ~(131)I~- in Production Process of Fission ~(99)Mo

<正>Currently,~(99) Mo for medical application is mainly extracted from ~(235) U fission products.However,there are more than 100species of nuclides in fission products.~(131)I is one of the fission products with half life of 8.02 dand yield of2.58%.Therefore,the removal of ~(131)I is crucial for the production process of medical ~(99) Mo.     

The Evaluation of Reference Fission Yield Data of ~(132)Te etc.Product Nuclides from ~(235)U Fission

BasedonavailableexperimentaldatauptonowandprocessedbyusingweightedaveragecodeAVERAGandsimultaneousevaluationcodeZOTT,40cumulativefissionyieldsfor132Teetc.and17productnuclidesfrom235Ufissionwereevaluated.Amongthem,37arerecommended,3aretakenasreferenceonlya…     

Determinations of ~(171)Er half-life and some ~(171)Tm transition energies

The neutrons have been captured by Erbium nuclei which were received by using clinical electron linear accelerator. In this experiment, the possibility of the neutron capture process has been observed because of emitted neutrons appearing in the experimental area. In particular,neutron capture of ~(170)Er nucleus has been observed. After the neutron capture of ~(170)Er nucleus, the unstable ~(171)Er has been formed and decayed into the ~(171)Tm. By using this reaction path, some transition energies of ~(171)Tm obtained from the residual activity measurements and the half-life of ~(171)Er have been determined, and they are in agreement with adopted values in the literature.     

The Evaluation of some Reference Fission Yield Data from ~(235)U Fission

Introduction The fission yield data used as standards in the fission yield data measurement and evaluation, or as monitor in the nuclear industry for decay heat estimation, burnup credit study etc., are refered to the reference yield. Among them, the data of ~(235)U fission, especially at thermal energy, are most important ones.     

Study of Relationship Between Neutron Energy and Fission Yields of ~(95)Zr, ~(140)Ba and ~(147)Nd From ~(235)U

This work measures fission yields of 235U induced by neutrons with energy of thermal, 3.0, 5.0, 5.5, 8.0 and 14.8 MeV. The main purpose is to study the relationship between neutron energy and fission fields of 95Zr,140Ba and 147Nd from 235U by measuring the radioactivity of foil with direct gamma spectrometry. The fission yields induced by fast neutrons are get by fast-thermal-ratio method which based on yields from thermal neutrons, yields by thermal neutron are come from absolute measurement. Since fast-thermal-ratio method eliminates uncertainties of gamma intensity, gamma     

铥-170γ 射线照相源研制

本文描述了铥-170γ射线照相源的生产原理,生产工艺,质量控制和产品性能。源的各项技术指标达到了有关标准规定的质量要求。     

常用防护用品对~(32)P,~(90)Sr+~(90)Y,~(147)Pm放射源屏蔽效果的测定

采用FJ358A型低量程β测量仪测量了P等3种β放射源32的定向剂量当量率,给出了3种源源正面空气中的定向剂量当量率与距离的关系曲线;给出了工作服、乳胶手套、防护眼镜等12种物品对3种源定向剂量当量率的屏蔽效果。提出了几点减少个人浅表剂量当量的建议。     

Study on Thermal Annealing Effect of ~(32)S Ion Tracks in PET Film

<正>Latent tracks come into being from the radiation damage caused by the swift heavy ion along its trajectory in the insulating material are called ion tracks or nuclear tracks.Ion tracks will vary gradually over time environment after their formation.In the high temperature environment,     

Yield Energy Dependence and Prompt Fission Neutron Spectra for ~(233)U and ~(232)Th Neutron Induced Fissions

正The fission yield,as well as its yield energy-dependence and prompt fission neutron spectrum(PFNS),play important part in nuclear energy engineering study of Th-U recycle.The concerned experimental data were collected and evaluated,and applied to determine the model parameters.The model was based on Brosa model with     

新型放射性~(32)P-血管支架的制备

近年来 ,血管内近距辐射防治经皮腔内冠状动脉成形术 (ｐｅｒｃｕｔａｎｅｏｕｓｔｒａｎｓｌｕｍｉｎａｌｃｏｒｏ ｎａｒｙａｎｇｉｏｐｌａｓｔｙ ,ＰＴＣＡ)后再狭窄的研究显示了鼓舞人心的结果 ,其中植入放射性血管支架的操作最为简便安全 ,已进行的动物和临床试验也初步显示了乐观的应用前景。在已经研究的多种放射性支架当中 ,32 Ｐ -支架的研究最为深入 ,进入了临床试用阶段[1,2 ] 。目前 ,32 Ｐ -支架的成熟制作方法为同位素离子注入法[3] 。由于32 Ｐ原子直接注入到不锈钢表面下约 3 5ｎｍ处 ,所以结合非常牢固 ,不存在放射性脱落…     

Study on Production Procedure of 1000 Ci Fission ~(99)Mo with Electroplating ~(235)UO_2 Target

正~(99)Mo is the most important medical isotope whose daughter is ~(99)Tc~m which plays a vital role in nuclear medicine.Medical diagnostic imaging techniques using ~(99)Tc~m account for over 70%of all nuclear medicine procedures.The current demand for ~(99)Mo is rough 600 000Ci(6 days)per year.Currently,the global sale of ~(99)Mo is over     

固体径迹法测量水泥反射体中~(252)Cf中子源反射中子

叙述了水泥反射体中~(252)Cf中子源反射中子测量实验原理。测量了无反射体、有反射体、本底三种状态下中子引发~(235)U产生的裂变率。并根据裂变率得到实验模型下水泥反射体对中子的反射系数。比较了不同中子源相同实验模型水泥反射体对中子的反射系数,对反射系数随角度变化趋势进行了分析。同时,对固体径迹探测技术进行了研究,探索了最佳蚀刻条件,得到火花放电计数随信号膜质量厚度及蚀刻厚度变化趋势。标定了固体径迹火花自动计数器效率,发展了固体径迹探测技术。     

Lifetime of 2~+ State in ~(106)Cd

<正>Several nuclei including ~(106)Cd in Aabout 100mass region have been predicted to exhibit E(5)critical point symmetry~([1]).However,the E(5)symmetry in ~(106)Cd is still hard to be identified.One of difficulties is that the B(E2)information,or the mean lifetime,of 2~+ state in ~(106)Cd deter-     

Evaluations for Spontaneous Fission Yield of Gas Products for ~(240)Pu

<正>Based on the fission multi-channel random neck rupture model,the phenomenological models of ~(239)Pu fission system induced by neutrons and ~(240)Pu spontaneous fission(s.f.)system are established.The potential energy was parameterized and determined from experimental data.Without considering the angular momentum,     

Study on Elastic Scattering of ~(21,22,23)Na+~(40) Ca

<正>Reaction with unstable nuclei is a frontier topic in the field of nuclear physics,in which one of the important problems is how the interaction potential of these nuclei is different from that of stable nuclei.By measuring the elastic scattering,the phenomenological optical potential can be extracted to understand the nuclear-nuclear interaction and its reaction mechanism in general.     

Beta-delayed Decay Spectroscopy of Proton-rich Nucleus ~(25)Si

<正>Structure of nucleus far from theβ-stability line is a currently hot topic in the field of nuclear physics.Theβ-decay spectroscopy is an important method to study the nuclear structure,especially for the drip-line nuclei with low yield.     

不同235U快裂变缓发中子群参数比较和验证

分析了ENDF/B7、JEFF3.1、JENDL3.3、CENDL2.2及Keepin数据中的²³⁵U快裂变缓发中子群参数的差异,通过CFBR-Ⅱ堆超瞬发临界实验检验了这几套缓发中子数据的准确性。检验结果表明,用于计算反应堆反应性,Keepin缓发中子群参数仍比数据库数据准确;数据库数据中,JEFF3.1的8群结构数据好于其他数据库6群结构数据。