【作者】 李霞；

【导师】 周祖英；

【作者基本信息】 中国原子能科学研究院 ， 粒子物理与核物理， 2006， 硕士

【摘要】 没有哪一种粒子能够象中子一样同时在基础物理和应用领域引起了人们的极大兴趣。中子与质子一起构成了原子核；中子常被用作基础核物理研究中的探针，它与核的相互作用揭示了许多核结构的特性。中子散射和衍射技术被广泛应用于凝聚态物理、生物物理、材料测试等方面；当然，中子反应也是核能利用和核弹研制中关键部分。1935年于实验上发现了低能中子反应的共振现象，该现象促进了复合核模型的诞生与完善，对揭示核反应机制起到了关键作用。通常利用共振参数来描述共振反应的特性。由于共振参数存在不受测量条件、温度等因素的影响，方便进行外推等优点，它在基础核物理、核天体物理与核工程方面应用都非常广。从上个世纪发现共振反应以来，积累了一批共振参数，但就核天体物理与核工程的需求而言，仍然非常不足。通常共振能区的全截面和共振参数的测量使用的都是利用电子直线加速器通过轫致辐射产生的白光中子源，由于散裂中子源比轫致辐射中子源有强度大、能区广等特点，越来越受到重视。但无论轫致辐射源还是散裂中子源，我国目前都缺乏。在原子能院的平台建设中有一台强流质子加速器，如果该加速器能够建成，则可用它产生散裂中子源，在共振能区的实验即可进行。本文较详细介绍了共振反应与共振参数意义、一般测量方法与拟合计算的程序SAMMY，介绍了如何利用HI-13串列加速器产生keV共振能区的中子源，并利用此源进行了Al及Be的全截面测量。通过在HI-13上的实验，积累了在共振能区的实验测量方法与经验，从而为进一步的核数据测量任务打下了基础。更多还原

【Abstract】 There is no other particle than the neutron which has attracted so much interest, both in fundamental physics and for applications. It’s one of the basic building blocks of nuclei; it’s often used as the probe in fundamental nuclear physics; its reactions with nuclei review the features of nuclei. Neutron scattering and diffraction are essential tools in condensed matter physics, biology and material testing; and, of course, neutrons are the basis for energy production in nuclear fission and fusion, both in power stations and in the nuclear bomb.The resonance phenonmenon, which is the fluctuation in the cross section spectrum of lower energy neutron reaction, was first discovered in 1935. The resonance feature of nuclear reaction is important to understanding the nuclear structure and reactions. Resonance parameters are often used for the description of the resonance phenonmenon. Because they are not influenced by measurement conditions and temperature, resonance parameters are widely used in fundamental nuclear physics, astrophysics and nuclear engineering. Since the resonance phenonmenon was discovered in the last century, resonance parameters are accumulating. But more nuclei and more accurated resonance parameters are needed for astrophysics and nuclear engineering. The measurements of total cross sections and resonance parameters in the resonance energy region often use white neutron sources generated by bremsstrahlung using a linear accelerator. But spallation neutron sources have higher density and wider energy region. Nowadays, more concentrations focus on spallation sources. But in our country, there are neither linear bremsstrahlung sources nor spallation sources. A high density proton accelerator is planned in China Institute of Atomic Energy. If this accelerator is implementated, we can plan more work about the measurement in the resonance region.This thesis describes the resonance reaction and resonance parameters, the general measurement method, and the SAMMY code for fitting experiment data. It also describes how to generate the keV neutron source using the HI-13 tandem accelerator. The experiment of the total cross section measurement of Al and Be is also explained here. The experiences through such a experiment will benefit the future tasks of nuclear data measurement.更多还原