超过30 GeV的强激光锁相直接电子加速  

Over-30-GeV intense laser phase-locked direct electron acceleration

作　　者：朱翰辰 周楚亮 李晓锋 田野 李儒新[1,2,3] Zhu Han-Chen;Zhou Chu-Liang;Li Xiao-Feng;Tian Ye;Li Ru-Xin(School of Physical Sciences,University of Science and Technology of China,Hefei 230026,China;State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Shanghai Tech University,Shanghai 201210,China)

机构地区：[1]中国科学技术大学物理学院,合肥230026 [2]中国科学院上海光学精密机械研究所,强场激光物理国家重点实验室,上海201800 [3]上海科技大学,上海201210

出　　处：《物理学报》2024年第19期31-39,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12388102,12325409,U226720057);基础研究特区计划(批准号:JCYJ-SHFY-2021-002);中国科学院基础研究领域青年团队计划(批准号:YSBR-060)资助的课题。

摘　　要：当超强激光斜入射辐照固体时,预脉冲会先将固体表面等离子体化,随后主脉冲将与等离子体相互作用并最终被等离子体反射.同时,等离子体中的部分电子将锁定在激光场的加速位相,随后在激光场中获得有效加速,该过程被称为锁相电子加速.由于目前超强激光的电场强度已接近TV/m量级,因此如果电子在激光场加速位相中停留足够长的时间,便有可能获得百GeV甚至TeV量级的能量.本文针对现有的超强激光参数,通过单电子动力学模型,对锁相机制中电子在激光场的加速过程展开系统研究.研究结果表明,峰值功率为10 PW量级的强激光可将电子直接加速至30 GeV左右.本研究还给出了锁相加速机制中锁相电子的远场能量角分布,以及最终能量等与激光场强度的定标关系.考虑到激光强度的不断提高并且激光锁相电子加速机制也适用于正电子加速,因此本研究结果将有望应用于小型化正负电子对撞机及高能伽马射线源等领域.When an intense laser obliquely irradiates a solid,a pre-pulse will first ionize the solid surface,followed by the main pulse interacting with the plasma and ultimately being reflected by the plasma.Simultaneously,certain electrons within the plasma will be trapped in the accelerating phase of the laser field,subsequently gaining effective acceleration within the field,this phenomenon is known as phase-locked electron acceleration.Given the current intense lasers' electric field intensity nearing the TV/m range,electrons could potentially acquire energy levels on the order of hundreds of GeV or even TeV,provided they stay in the accelerating phase of the laser field long enough.Here,we initially use PIC(Particle-in-Cell) simulations to simulate the interaction process between laser pulses and plasma,thereby obtaining the properties of phase-locked electrons.In order to reduce computational demands,we turn to use a three-dimensional(3D) test particle model to calculate the subsequent interactions of these electrons with the reflected laser field.By this model,we obtain the data of the locked-phase electrons after having interacted with the reflected laser(Fig.(a)).Furthermore,we use this model to calculate the dynamical behavior of electrons under different initial conditions(Fig.(b)).Under the laser intensity of a_0=350(a_(0) is the normalized laser vector potential),the energy of the electrons directly accelerated by the laser is enhanced to 32 GeV.In contrast,under the same laser intensity,the energy of the electrons accelerated by ponderomotive force is only 0.35 GeV.The research findings indicate that the strong laser with peak power around 10 PW can directly accelerate electrons to approximately 30 GeV.Additionally,this study outlines the optimal initial conditions for injecting electrons into the laser field and the final electron energy within the phase-locked acceleration mechanism,thereby establishing a calibration relationship with the laser field intensity.Given the continual enhancement of laser inten

关 键 词：超高能电子加速器 激光直接电子加速 锁相电子加速 正负电子对撞机 

分 类 号：TL50[核科学技术—核技术及应用] TN24[电子电信—物理电子学]