激光与核——超高强度激光在核科学技术中的应用

随着激光技术的飞速发展和广泛应用,它在核科学技术中的应用越来越受到人们的关注。本文介绍了高功率激光在核科学技术领域的应用情况;给出了激光与原子核相互作用的机理;总结了在目前激光强度能达到的情况下,用高强度的激光开展与原子核物理有关的研究;并分析了激光康普顿背散射γ射线(LCS-γ)在核物理和核嬗变研究中的意义。     

用于不稳定核性质研究的激光共振电离技术

不稳定原子核的基本性质反映了核的内在结构和有效相互作用，可用于研究不稳定核的奇特结构。激光核谱技术通过测量核外电子光谱的超精细结构和同位素移位，可以核模型无关地提取原子核的多个基本性质，是研究不稳定核性质和结构的有力工具之一。多步激光共振电离方法是测量原子或离子超精细结构和同位素移位的方法之一。基于此，国际上发展了多种共振电离谱实验技术，用于放射性核束装置上开展不稳定核基本性质和结构研究。本文首先介绍了激光共振电离方法，以及由此发展的各种共振电离激光谱实验技术。随后详细讨论了近十年来刚发展起来的共线共振电离谱技术。此技术可同时实现超精细结构谱的高分辨和高灵敏度测量，正在核素版图大质量范围内的不稳定核性质和结构研究中发挥重要作用。最后分析了用于国内放射性核束装置的共振电离激光谱技术的发展现状及应用前景。     

γ激光研究中的几个问题

一、为什么γ激光是一大难题?γ激光又称为核激光。它区别于由核辐射泵浦的分子和原子激光(即核泵浦激光)。核激光是原子核能级跃迁放出的γ光子在满足相干条件时形成的相干γ光子。迄今为止,人类所获得的均是分子激光(微波和红     

中子与不稳定原子核反应数据的评价方法研究

<正>中子与不稳定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。建立中子与不稳定原子核反应数据的评价方法是其关键。应用核反应理论模型,在研究不稳定原子核附近的稳定原子核中子反应全套数据基础上,系统研究核反应光学模型势随原子核质量数A、电荷数Z和中子数N的关系;分析不稳定原子核的基态和激发态的自旋和宇称与邻近稳定核的相关物理量的共性和特性及相似性,研究不稳定原子     

基于北京串列加速器的若干核物理实验研究

原子核是主要由短程相互作用制约的量子复杂多体系统，储存着宇宙间绝大部分可见的质量和能量。对原子核的研究，近百年来对人类的生存发展和国家的地位与安全产生了重大影响。过去几十年，短寿命放射性原子核的奇特结构现象不断被揭示，打破了人们对原子核结构的经典认知，开启了不稳定核（放射性核）结构研究的新领域。北京串列加速器核物理国家实验室在过去30多年为我国低能核物理实验提供了基础平台。北京大学实验核物理团队长期以来发展特色实验设备，在北京HI-13串列加速器上完成了系列核物理实验，在原子核奇特结构研究中取得了一批重要成果。本文将介绍团队基于北京HI-13串列加速器开展的几项代表性工作，如基于在束γ谱学的A=70质量区Ge同位素形状演化研究，基于直接核反应实验的轻丰中子核集团结构研究，以及基于北京放射性束装置发展的共线激光谱设备和首次在线激光核谱实验等。     

高功率激光驱动核反应研究进展与展望

近年来，随着高功率激光技术的持续进步，目前在实验室已可获得超过10²² W/cm²的激光聚焦强度，且还在不断提升，这为超高强度激光脉冲触发核过程和核应用开辟了可能性。这样的超强脉冲激光与物质发生相互作用时，会出现很多新的物理现象，并且其产生的高温高压高密度的等离子体极端环境以及诱发的核反应次级粒子束等，也为其他基础和应用研究提供了独特的平台。强激光产生的等离子体环境可用来模拟天体核反应的环境，研究电子屏蔽效应等因素带来的低能核反应截面测量中的不确定性因素，这是目前实验室条件下直接研究天体环境中核反应的唯一技术手段。同时，激光驱动等离子体中核反应的研究也与惯性约束聚变中的燃料设计息息相关。与常规环境温度和压力下的物质相比，等离子体环境中的核反应动力学要复杂得多，对于研究天体核反应和惯性约束聚变也至关重要。因此，除加速器和反应堆外，高功率激光器正成为研究核物理的新平台。激光与核物理的结合不仅有利于具有新颖思想和方法的基础科学研究，也有利于广泛的物理应用领域。激光核物理已成为国际上一门新的交叉学科，也是物理学的重要前沿之一。与传统核物理装置相比，超...     

核物理与核数据中机器学习的应用序言

<正>核物理主要研究原子核体系的结构及其运动规律,对于揭示微观世界的性质、基本相互作用及对称性、宇宙演化以及元素起源等有着重要的科学意义。另一方面,核数据与原子核反应和结构相关,是核科学基础与核应用的交叉学科,在国家总体科学布局中具有重要地位。到目前为止,核物理与核数据的研究中积累了大量的实验测量数据和理论计算结果,但也遇到了不少难题,比如如何从大数据中鉴别稀有事件并提取感兴趣的物理、如何避免维数问题以提高理论计算或分析的效率等、如何可靠预言一些极端条件下核基础研究与核工程应用中的无法测量的关键核素性质、如何提高核数据可靠性的评估等。     

原子核的基础数据库——核科学数据资源共享平台

核数据是指描述和表征原子核这一物质层次的“数据”。它包括:有关原子核性质和由其相互作用支配的基本物理关系的“数据”;描述与原子核有关的基本物理过程,反映核物理基本规律的“数据”;以及对于核物理和核技术的发展及利用是极其关键(和/或重要)的“数据”。在核物理的发展历史中,不断地积累了大量的核数据。基于它们对于核物理及相关学科的基础研究的基本重要性,和在核能及核技术应用中的需要及发展趋势,提出了发展前沿性的核数据,建立《原子核的基础数据库(NBDB)》的计划。这里将介绍NBDB的进展及已提供共享的数据资源。NBDB是一…     

高功率激光与激光核聚变

1964年10月,王淦昌在他开创性的论文中指出:“目前国内外,都在研究和制造可以产生大能量和大功率的光激射器(即莱塞)。我们认为若能使这种光激射器与原子核物理结合起来;发展前途必相当大;其中比较简单易行的就是使光激射与含氘的物质发生作用,使之产生中子。”他在这篇论文里,对利用高功率激光照射含氘物质产生中子的原理、高     

有关重核和超重原子核中量子混沌问题的研究

通过观察和分析重核和超重核中量子谱的统计性质,研究了有限物理体系中量子混沌的一些问题。给出了原子核中量子能谱显示的有序-混沌现象随激发能变化的实验数据;研究了超重核体系中量子谱相邻能级间距分布的规则性随体系的依赖关系,并预言了稳定的超重体系。描述了原子核有序混沌相变现象与原子核形变以及原子核转动的依赖关系;讨论了量子     

Application of Side-On Shadowgraph System in EOS

Experimental measurements of EOS have more and more attention from many physical fields, such as physical geography, astrophysics, ICF, science of material, physics of nuclear weapons. They are important to the practical application and the development of theory of EOS. A series of researches in EOS done by ultraviolet long pulse laser Heaven-I, had prominent characteristics and developed very well. As an important technique to detect the target in EOS, side-on shadowgraph has been wildly applied all the while. In 80s, using framing camera and folded-wavefront interferometer,     

Research Status and Prospect of Muon Physics and Technique

Muon physics and the application of muon technique is an interdisciplinary research which involves particle physics, material science, condensed matter physics, biomolecular science, and archaeology. Many important researches have been done and published in these areas by scientists from North America, Europe, and Japan. Due to the lack of accelerator-based muon source in China, Chinese research groups in these fields mainly rely on overseas muon facilities or on joining international collaborations. Some recent major progress on muon physics and muon technique application, and the prospects of the design, construction, and application of the accelerator-based muon source in China were reported in this paper.     

缪子科学技术前沿及未来发展

缪子物理和缪子应用技术研究是涉及粒子物理、材料科学、凝聚态物理、生物分子、考古学等众多学科的国际前沿交叉研究领域。目前北美、欧洲及日本均在这一领域做出了众多重要成果。由于加速器条件限制,目前国内尚未系统开展加速器缪子方面的实验,相关领域的研究团队主要依托国外装置或参与国际合作开展研究。本文综述性报道了近年国际上开展的几项主要缪子物理科学研究与缪子应用技术进展,并展望了国内在缪子源设计、建设及应用方面的科学前景。     

MeV ion recoil techniques in research and technology

Medium energy accelerators over the last decade have acquired a new role in materials science and technology in addition to their traditional role in nuclear physics. R&D programmes in both areas increasingly employ fast recoil ions generated in heavy ion reactions. Examples of current uses are drawn from nuclear physics, bioengineering and materials analysis. Comments on future trends are made.     

核物理与核技术专业的核物理实验课程的现状及改进

综述了高校核物理与核技术专业本科生的核物理实验课程现状,并对未来改进提出几点看法。     

Efficient combination and enhancement of high-power mid-infrared pulses in plasmas

High-power intense optical sources in the mid-to-long wavelength infrared region are very attractive for a wide range of fields from fundamental research to materials science and biology applications. However, there are still significant challenges in extending long-wavelength infrared pulses into the relativistic regime using conventional optical techniques. Here, based upon a new type of plasma-based optical method, we present an efficient scheme capable of combining several high-power long-wa...     

School of fundamental studies for nuclear power

The development of a new industry, associated with the practical application of the achievements of nuclear physics, mastery of the fission chain reaction, solution of urgent problems of the defense industry, development and creation of nuclear-power installations for different purposes, has made it necessary to train new types of specialists capable of solving diverse problems, from theoretical and experimental investigations to practical engineering developments. The problem of training specialists and scientific investigations for nuclear power and closely related fields of science and technology was assigned to the Moscow Engineering Physics Institute and is closely related with industrial and academic science centers and enterprises, developing the scientific principles of new forms of nuclear technology. Over the half-century of its history, thanks to the close creative collaboration with the Academy of Science and Industry over many years, the MEPI has substantially expanded the direction of scientific investigations and the training of specialists, but nuclear power has always been and remains the priority field for application of its intellectual potential. Translated from Atomnaya énergiya, Vol. 87, No. 1, pp. 3–10, July 1999.     

核数据评价与中国评价核数据库CENDL

核数据是核基础研究、核能开发与利用以及核技术发展的基础数据,是连接核物理基础研究与核工程和核技术应用的重要桥梁,在国防与国民经济建设以及核科学发展领域起重要作用。核数据评价建库与检验是核数据研究过程中的两个重要部分,是核数据应用于核工程必不可少的环节。本文介绍了核数据内涵、核数据研究意义以及国内外核数据评价研究的简要发展历史,并结合中国评价核数据库CENDL的研究过程介绍了实验数据调研与分析评价、核数据理论模型计算、核数据统调建库与核数据宏观检验的主要评价核数据研究过程,以及我国自主建立的核数据评价方法和技术、模型及计算程序、评价数据建库和评价数据库的检验方法;介绍了基于我国自主建立的核数据评价建库与检验系统而研制的中国评价核数据库最新版CENDL 32以及对其进行的相关基准检验及应用结果;最后简要介绍了CENDL 32在反应堆屏蔽设计以及压水堆、高温堆等方面的实际应用以及与其他主流评价核数据库的比对结果。     

JENDL: Nuclear databases for science and technology

It is exactly 50 years since the Japanese Nuclear Data Committee was founded both in the Atomic Energy Society of Japan and in the former Japan Atomic Energy Research Institute. The committee promoted the development of Japan’s own evaluated nuclear data libraries. As a result, we managed to produce a series of Japanese Evaluated Nuclear Data Libraries (JENDLs) to be used in various fields for science and technology. The libraries are categorized into general-purpose and special-purpose ones. The general-purpose libraries have been updated periodically by considering the latest knowledge on experimental and theoretical nuclear physics that was available at the time of the updates. On the other hand, the special-purpose libraries have been issued in order to meet the needs for particular application fields. This paper reviews the research and development for those libraries.     

Research activities on nuclear reactor physics and thermal-hydraulics in Japan after Fukushima-Daiichi accident

Research and development in nuclear reactor physics and thermal-hydraulics continue to be vital parts of nuclear science and technology in Japan. The Fukushima accident not only brought tremendous change in public attitudes towards nuclear engineering and technology, but also had huge influence towards the research and development culture of scientific communities in Japan. After the Fukushima accident, thorough accident reviews were completed by independent committees, namely, Tokyo Electric Power Company (TEPCO), the Japanese government, the Diet of Japan, the Rebuild Japan Initiative Foundation, and the Nuclear and Industrial Safety Agency. Reactor physics and thermal-hydraulics divisions of Atomic Energy Society of Japan (AESJ) also issued the roadmaps after the accident. As a result, lessons learned from the accident were made clear, and a number of new research activities were initiated. The present paper reviews ongoing nuclear engineering research activities in Japanese institutes, universities, and corporations, focusing on the areas in reactor physics and thermal-hydraulics since the Fukushima accident to the present date.