低能核反应理论的研究与应用

介绍有关低能核反应理论的研究与应用工作．The work for research and application of low energy nuclear reaction theories is introduced.     

高自旋同质异能态束流及其在核谱学中的应用

介绍了在日本理化学研究所利用高自旋同质异能态束流装置上取得的核谱学研究结果。强调了可利用重离子核反应中逆运动学产生高自旋同质界能态束流,并用其进行二次核反应,描述了首次利用高自旋同质异能态束流完成的物理实验． The study of nuclear spectroscopy by using the High spin isomer Beam(HSIB)facility in RIKEN was introduced.The production of HSIB based on the inverse kinematics in heavy ion nuclear reaction,and its application for secondary nuclear reaction were stressed The first experimental result by using HSIB was also briefly discribed.     

金属环境中低能D(d,p)T反应的研究

近年来一系列实验表明, 金属环境中的低能带电粒子引起的核反应截面与气体靶中的相比出现明显增大, 这种现象通常被归结为电子屏蔽效应。 全面介绍了金属环境中D(d, p)T反应电子屏蔽效应的测量方法、 数据分析和实验结果的规律性, 并简要论述了包括德拜等离子体模型在内的各种理论模型对实验结果的解释。 通过研究, 可以获得有关核物理、 核天体物理和凝聚态物理的宝贵知识。 The cross sections σ(E) of low energy nuclear reactions induced by charged particles in metallic environment are much larger than that in gas. Generally, it was taken as the effect of the electron screening. In this work, the experimental method of the D(d, p)T reaction in metallic environment was introduced. The data analysis and the regularity of experimental results were also discussed. All kinds of theoretical models including the Debye model were discussed, which can roughly explain the results of the experiments. The valuable knowledge of nuclear physics, nuclear astrophysics and condensed state physics can be obtained in the study of low energy nuclear reaction in metallic environment.     

低能中子探测的GEANT4模拟研究

研究了GEANT4蒙特卡罗模拟程序在低能中子核反应中应用的可行性, 新版的GEANT(4.9.4版本)升级了老版本在模拟6Li(n, α)3H核反应道的不足, 并且加入了最新截面数据库。 对多个核反应道进行了研究, 模拟结果显示核反应截面、 次级粒子能量和反应的分支比等是正确的; 比较了掺6Li材料热中子探测效率的实验结果与MCNP和GEANT4模拟结果, 它们基本一致。 研究表明, 利用GEANT4研究6Li(n, α)3H是可行的, 这为进一步研究闪烁体中子探测器的位置分辨率模拟提供了有力支持。 The feasible study of Monte Carlo simulation of low energy nuclear reaction was performed based on GEANT4. The reaction channel 6Li(n, α)3H, simulated insufficiently in the old version Geant4, can be given correct results in the new version (version 4.9.4). New cross section library was added into the program. The study of several nuclear reaction channels shows that the cross sections, the secondary particle energies and the branching ratios are consistent with the experimental values. For doped 6Li materials, the comparison of thermal neutrons detection efficiencies of experimental results, MCNP and GEANT4 simulations, shows that the simulations are reasonable. From the studies above, it is feasible to simulate the 6Li(n, α)3H reaction with GEANT4. It will provide helpful information for the further study of the position resolution of scintillation neutron detector.     

谷物种子中蛋白质含量测定的核反应分析法

分析了在高蛋白质谷物育种中对筛选方法的要求, 对谷物中蛋白质测定的方法进行了综述评价, 重点介绍了用于谷物蛋白质测定的核反应分析法的原理及特点. The requirements of the screening method for high protein content in grain breeding are analysed. Methods for the determination of protein content in grain seed are reviewed.The principle and the advantages of the nuclear reaction method for the measurement of protein content in grain seed are discussed in detail.     

中国评价核参数库和IAEA之推荐输入参数库

概述了为核反应模型计算用的“中国评价核参数库”的发展和结构 ,指出了该数据库在国际核反应数据模型计算的“推荐输入参数库”中的作用和地位 .目前正研制更新的CENPL ,一方面将检验、更新和扩充数据 ,特别注重研究适用于更高能区和非稳定核区的模型参数 ;另一方面发展其检索软件和网络软件 ,实现网络在线服务. The Chinese Evaluated Nuclear Parameter Library (CENPL) for the model calculations of nuclear reactions was developed in the past ten years. The International Atomic Energy Agency has constructed a Reference Input Parameter Library (RIPL) for the calculations of nuclear reaction data in the meantime. All data files of CENPL are adopted as the RIPL Starter Files. The model parameters estimated and recommended by our group are specially selected as recommended files. The updated CENPL is being developed...     

14MeV中子引起的核反应截面测量中监督反应的研究

讨论了14MeV中子引起的核反应截面测量中监督反应对测量结果的影响,同时列出了常用的一些监督反应及参数,利用截面的评价值给出了一些监督反应的截面随中子能量变化的关系曲线,并对^27Al（n,p）^27Mg反应做了定性分析,说明了监督反应的选取对反应截面测量的重要性。 It was discussed in this article that the effects of different monitors in the cross section measurements of nuclear reactions induced by 14 MeV neutrons, at the same time some monitors and correlative parameters were listed. The excitation functions of monitors are taken from the evaluatied cross sections, and a qualitative analysis has been performed for ^27Al（n,p） ^27Mg reaction. It indicates that the choice of monitor is very important for cross section measurements     

一个奇异核反应总截面的探测系统及其应用

评述了现有的奇异核反应总截面测量方法,介绍了一套简单可行的测量中能区奇异核反应总截面的探测装置,并对实验的能量刻度、粒子鉴别以及实验结果进行了阐述和讨论． The present status of experimental studies of the total reaction cross sections of exotic nuclei are reviewed. A detector system used for measuring the total reaction cross section of radioactive ions is described. The energy calibration of detectors, particle identification and possible experimental results are discussed.     

实验核物理进展

本文回顾我所实验核物理科研人员在低能核反应机制、中子物理、核衰变性质及核结构研究中所做一系列工作,同时简单介绍了目前工作和设想． The paper reviews the research activities at SINR on experimental nuclear physics. The studies have been focused on mechanism of nuclear reactions, neutron physics,properties of nuclear decay and nuclear structure. Brief introductions are given to the ongoing research projects and future plans in the field of research.     

Theoretical Analysis of Neutron Double-Differential Cross Section of n ＋^19F at 14.2 MeV

A new light nuclear reaction model has been developed and the double-differential measurements of lp shell nuclei have been analyzed successfully. Now, the application of this model is expanded to 19F of the 2s-ld shell nucleus. The double-differential cross section of total outgoing neutron for n ＋^19F reactions at En=14.2 MeV has been calculated and analyzed, which agrees fairly well with the experimental measurements. In this paper, the contributions from different reaction channels to the double-differential cross sections have been analyzed in detail. The calculations indicate that this light nudear reaction model is also able to be used for the 2s-ld shell nucleus so long as the related level scheme couM be provided sufficiently.     

高动量分布对核反应中原子核的阻止本领的影响

利用同位旋相关的量子分子动力学模型研究了中能重离子碰撞过程中,具有不同中质比的中等质量核碰撞系统的高动量分布对原子核的阻止本领的影响,以及这种影响随入射能量的演化。研究结果表明:对于76Kr+76Kr,88Kr+88Kr碰撞系统,当入射能量较小时高动量分布对原子核的阻止本领影响很小;但当反应能量较大的时候,高动量分布对原子核的阻止本领影响较大,且这种影响随着入射能量和碰撞核质量的增大而增大。对于Ca同位素链的反应系统,高动量分布增大了反应系统的原子核的阻止本领。因此,高动量分布对中等质量核碰撞系统的原子核的阻止本领有重要影响,且与入射能量和碰撞核质量密切相关。Based on the isospin-dependent quantum molecular dynamics model, the effect of high momentum distribution on nuclear stopping in medium mass nuclear collision system is studied with different neutron-proton ratio in intermediate energy heavy ion collisions, and the evolution of this effect with the incident energy. The results show that when the incident energy is small, the high momentum distribution has little effect on the nuclear stopping. However, when the reaction energy is large, the high momentum distribution has a great influence on the nuclear stopping and the influence increases with the increase of incident energy and the mass of collision nucleus. For the Ca isotopes reaction system, high momentum distribution increases the nuclear stopping of the reaction system. Therefore, high momentum distribution has an important influence on nuclear stopping in medium mass nuclear collision system, and closely related to the incident energy and the mass of collision nucleus.     

On Nuclear Reaction Rate Theory

A fundamental problem in the theory of cosmological and stellar nucleosynthesis is the determination of reaction rates. The current theories of nuclear kinetics are equilibrium theories with a strict Maxwell-Boltzmannian approach to the evaluation of reaction rates. This paper investigates in some detail the relation between the macroscopic nuclear reaction probability and the microscopic nuclear reaction cross section on the basis of equilibrium-thermodynamic arguments. A general form of the nuclear reaction probability is derived, and the most general collision probability integral is evaluated in closed form for all convenient values of the parameters by using random variables.     

核数据和核模型方法

简要介绍了国际上发展中的核科学和技术及其应用对微观核数据的需求和核数据理论计算中现有标准程序的基本情况,并做了相应的分析和比对 .同时也简要介绍了国际上核数据理论计算中模型方法研究的新进展.Developing nuclear data needs towards to sustainable development on fission reactor design and many nuclear applications out the field of fission reactor technology that are growing economic significance and that have substantial data requirements are introduced. International standard codes used in nuclear data evaluation and calculation are presented and compared with each other. Generally speaking, three rather wide groups of nuclear reaction models used usually are also described...     

加速器质谱技术在核物理与天体物理中的应用

介绍了利用加速器质谱技术在核物理与核天体物理中的应用研究工作．包括放射性核素半衰期的测定、核反应截面的测量、超重元素的寻找、宇宙射线和太阳中微子性质等方面的研究工作.The application work which has been done and can be done in the nuclear physics and nuclear astrophysics using accelerator mass spectrometry is reviewed. The half-life measurement of long-lived radio isotopes, cross section measurement of nuclear reaction, searching for super heavy elements, cosmic study and solar neutrino detection are the main components which have been discussed     

Few-Body Problems in Experimental Nuclear Astrophysics

The 3α-reaction is one of the key reactions in nuclear astrophysics. Since it is a three-body reaction direct measurement is impossible, and therefore the reaction rate must be estimated theoretically. In this contribution I will discuss uncertainties in this reaction rate both at very low temperatures, temperatures typical for Helium burning in red giant stars, and for very high temperatures.     

核反应实验数据库(EXFOR)

核反应实验数据库(EXFOR)及其检索系统提供了丰富的中低能核反应物理信息和数据，已经成为国际上最全面的核反应实验数据汇编。目前，由国际原子能机构核数据科(IAEA/NDS)协调管理，国际核反应数据中心协作网(NRDC)13个成员进行全球性合作，旨在协调国际范围内核反应实验数据的收集、编纂和传播。中国核数据中心(CNDC)作为NRDC成员之一，多年来开展了大量的中子和带电粒子引起的核反应实验测量和建库技术研究。本文介绍了EXFOR数据库的形成、发展和现况，以及数据格式、数据编纂和检索系统，并简要总结了我国核反应实验数据建库及技术研究等方面的工作，如国内期刊检索、EXFOR数据库文档建设、程序开发、国内数据服务及国际合作等。     

Nuclear Moment Studies with Polarized Radioactive Nuclear Beams

Magnetic dipole and electric quadrupole moments of nuclei in the light-mass neutron-rich region have been studied by taking advantage of spin-polarized radioactive nuclear beams that have been obtained from the projectile fragmentation reaction. Analyses of the results reveal a few interesting phenomena characteristic of nuclear structures in this region. In particular, we report in some detail the latest result on the magnetic moment of the ¹⁷C ground state. The distinctly small value of the g-factor obtained, |g(¹⁷C)|=0.5054±0.0025, clearly excludes a I ^π=1/2⁺ candidate for the spin-parity assignment of this marginally bound nucleus, providing a reasonable account of the non-halo nature reported in recent breakup reaction experiments. Finally, future plans at the upcoming radioactive beam facility presently under construction at RIKEN are briefly mentioned. This revised version was published online in September 2006 with corrections to the Cover Date.     

Nuclear fission with inertial confinement

The possibility of inducing an explosive fission reaction in a small amount of fissionable material by a heavy-ion beam from a high-power accelerator driver developed for bringing about fusion in deuterium-tritium cylindrical targets with direct burning is analyzed. The consequences of the use of this method in the nuclear power industry are discussed.     

Nuclear shadowing and Drell-Yan production on heavy nuclei

The suggestion that nuclear shadowing in deep inelastic scattering is primarily a parton phenomenon is extended to the Drell-Yan reaction on heavy nuclei. The nuclear structure functions required to describe the latter process are found to be compatible with those obtained from an analysis of the shadowing data, and lend weight to the hypothesis that this is indeed a parton phenomenon.