用于强激光等离子体超热电子温度诊断的电子堆栈谱仪的设计及刻度  

Design and Calibration of Electron Stack Spectrometer for Diagnosing Hot Electron Temperature in Intense Laser-plasma Interactions

作　　者：薄楠 田宝贤 王浩然 王乃彦 BO Nan;TIAN Baoxian;WANG Haoran;WANG Naiyan(Key Laboratory of Beam Technology of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing 100875,China;Department of Nuclear Physics,China Institute of Atomic Energy,Beijing 102413,China;Nuctech Company Limited,Beijing 100085,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]北京师范大学物理与天文学院射线束技术教育部重点实验室,北京100875 [2]中国原子能科学研究院核物理研究所,北京102413 [3]同方威视技术股份有限公司,北京100085 [4]清华大学工程物理系,北京100084

出　　处：《原子能科学技术》2025年第4期934-945,共12页Atomic Energy Science and Technology

基　　金：中核集团院士基金;中核集团“青年英才”启明星项目(18FY010270724294);国家自然科学基金(1220051312)。

摘　　要：为准确测量强激光与固体靶相互作用产生的等离子体电子温度,本文提出一种基于电子堆栈谱仪的诊断方法。由于强激光与物质相互作用过程伴随着强电磁脉冲和高通量辐射,传统电子学测量手段易受干扰而无法正常工作,为此设计并搭建了一套基于富士公司成像板(image plate,简称IP板)的电子堆栈谱仪。利用电子加速器出射的单能电子源对谱仪进行了实验刻度,并结合Geant4蒙特卡罗模拟方法完成了0.2~4.0 MeV范围内谱仪响应矩阵的计算与验证。实验结果与模拟计算表现出良好的一致性,验证了响应矩阵的准确性和可靠性。此外,还实验确定了BAS-SR型IP板电子每沉积单位MeV能量时放出(0.379±0.035) PSL(photostimulated luminescence,光激流明),即对电子沉积能量的响应系数为(0.379±0.035) PSL/MeV。响应矩阵的实验刻度为电子堆栈谱仪对强激光等离子体超热电子温度诊断奠定必要的基础准备。The interaction of relativistic intense lasers with matter generates complex plasma environments characterized by extreme conditions,such as high temperatures and densities,which are critical to fields like laser-driven inertial confinement fusion(ICF),high-energy-density physics,and strong-field physics.Accurate diagnosis of the hot electron temperature within these plasmas is essential for understanding energy coupling mechanisms and the spatiotemporal evolution of the plasma.However,the intense electromagnetic pulses(EMPs) and high-flux radiation produced during these interactions pose significant challenges to conventional electronic measurement techniques,often leading to signal saturation or interference.To address these issues,this study introduces the design,construction,and calibration of a passive electron stack spectrometer based on image plate(IP),specifically tailored for diagnosing hot electron temperatures in laser-plasma interactions.The electron stack spectrometer leverages the advantages of IP,including high radiation sensitivity,a wide dynamic range,and reusability,making it suitable for environments with strong EMPs.The spectrometer consists of multiple layers of low-Z absorption materials(e.g.,aluminum,titanium,and graphite) interleaved with BAS-SR-type IPs,chosen for their enhanced sensitivity to electrons over gamma rays.The design covers an energy range of 0.2 to 4.0 MeV,aligning with the expected electron energies produced by laser intensities of 10^(18) to 10^(20) W/cm2.A collimator and shielding ensure precise measurements by minimizing scattered radiation,and the modular structure allows for accurate alignment with the laser target.Calibration was performed using a monoenergetic electron beam from a 2 MeV radiofrequency superconducting accelerator at Peking University.The experimental setup included a beryllium window for vacuum isolation,an electromagnet that measures the energy of electron beam and a Faraday cup to measure beam charge,with a plastic scintillator detector cross-refere

关 键 词：相对论性强激光 堆栈谱仪 超热电子 成像板 

分 类 号：TL65[核科学技术—核技术及应用] O4-33[理学—物理] O536