高功率激光驱动核反应研究进展与展望

Nuclear Reactions Driven by High-power Laser:Current Status and Prospects

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1022W/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,超强激光器具有脉冲宽度短、时间分辨率高、通量大等特性,这给核反应研究带来独特机遇的同时,也给核反应产物测量带来了挑战。本文从激光与物质的相互作用开始,介绍了世界上的激光装置,评述了激光驱动核反应的研究意义、研究特点与挑战,总结了激光驱动核反应的实验研究方法以及产物探测与标定技术,同时介绍了最新的研究进展和对未来研究的展望。

In recent years,with the rapid development of high-intensity laser technologies,a focused laser peak intensity of over 1022 W/cm 2 can be achieved in nowadays laboratory and the record is still being renewed.The sustained technological progress in high-intensity lasers is opening up the possibility of super-intense laser pulses to trigger nuclear processes and nuclear applications.The high-intensity lasers bring various new physical phenomena including accelerated particle beams and nuclear reactions when they interact with matter.Moreover,the extreme environment of high temperature,high pressure and high density plasma produced in the interaction,as well as the induced secondary particle beam of nuclear reaction,also provide a unique platform for other basic and application research.With high-intensity lasers,extreme physical conditions similar to those inside stars and supernovae can be created,which makes it possible to investigate various astrophysical processes in earth-based laboratories.Especially it can remove the uncertainty due to the electron screening effect in the measurement of cross-sections at low-energies.It is practically the only known method for scientists to study nuclear reactions in astronomical environments.Meanwhile,the research of nuclear reaction in laser-driven plasma is also closely related to the fuel target design in inertial confinement fusion(ICF).Laser driven nuclear reaction dynamics in plasma environment is critically important for research of astrophysical reactions and design of inertial confinement fusion.The dynamics is much more complicated compared with the matters in ambient temperature and pressure.Laser nuclear physics has received considerable attention as a new research area for the unique nuclear processes and nuclear applications.Therefore,lasers are becoming a new platform for investigating nuclear physics in addition to accelerators and reactors.The combination of laser plasma physics with nuclear physics benefits not only the fundamental scientific research with novel ideas and methods,but also wide physical application fields.Laser nuclear physics has become a new critical interdisciplinary subject,and one of the important frontiers of physics.Compared with traditional nuclear physics devices,high-intensity lasers have distinctive characteristics such as short pulse width,excellent time resolution,and high flux.These characteristics bring unique research opportunities,on the other hand,it also bring challenges to the detection of nuclear reaction products.Starting from the interaction between laser and matter,the laser devices in the world,reviews the motivation,characteristics and challenges of research of laser-driven nuclear reactions were introduced in this paper,and the research methods,production detection and calibration technology for the laser-driven nuclear reactions were summarized,and the latest research progress and prospects for future research of laser-driven nuclear reactions were introduced.