势能助力靶原子离化激发辐射近红外光谱  

Potential-Assisted Target Atomic Ionization Excitation Radiation Near-Infrared Spectra

作　　者：张颖[1,2] 徐忠峰[2] 王兴[2] 任洁茹[2] 张艳宁 梅策香 周贤明[1] 梁昌慧 王伟[3] 张小安[1,3] Zhang Ying;Xu Zhongfeng;Wang Xing;Ren Jieru;Zhang Yanning;Mei Cexiang;Zhou Xianming;Liang Changhui;Wang Wei;Zhang Xiaoan(Ion Beam and Optical Physical Laboratory,Xianyang Normal University,Xianyang 712000,Shaanxi,China;School of Physics,Xi an Jiaotong University,Xi an 710049,Shaanxi,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China)

机构地区：[1]咸阳师范学院离子束与光物理实验室,陕西咸阳712000 [2]西安交通大学物理学院,陕西西安710049 [3]中国科学院近代物理研究所,甘肃兰州730000

出　　处：《光学学报》2024年第7期27-34,共8页Acta Optica Sinica

基　　金：国家自然科学基金(12120101005,12205247);陕西省教育厅科学研究计划(22JK0604);咸阳市离子束与光物理重点实验室(L2022-CXNL-ZDSYS-001)。

摘　　要：用动能为1360 keV的129Xeq+(q=17,20,23,25,27)高电荷态离子分别入射到金属Al和Ti固体靶表面,测量高电荷离子与表面相互作用过程中离子俘获表面电子完成中性化所形成的激发态Xe原子和低电离态Xe离子退激辐射的近红外光谱线(800~1700 nm),以及靶原子被离化激发、退激辐射的光谱线。实验结果表明:高电荷态离子入射金属表面的过程中,携带的势能在飞秒量级的时间内沉积到靶表面,使靶原子离化激发,较强的库仑势能可使靶原子形成高离化态和复杂的电子组态、退激辐射光谱线。随着入射离子的电荷态增加,测量谱线的强度增大,该变化趋势与入射离子的势能随电荷增加的变化趋势大体一致,说明经典过垒模型在近玻尔速度能区是成立的。Objective 129Xeq+(q=17,20,23,25,27)highly charged ions with a kinetic energy of 1360 keV are incident on the surface of metal Al and Ti solid targets respectively.The near-infrared spectral lines(800‒1700 nm)of excited Xe atoms and low ionized Xe ions,and the spectral lines of excited target atoms and excited by ionization are measured during the interaction between the highly charged ions and the surface to achieve surface electron neutralization.The experimental results show that during the process of high charged ion incident on the metal surface,the potential energy carried by the ion instantly(in the femtosecond range)deposits on the target surface,ionizing and exciting the target atoms.Due to the strong Coulomb potential energy,the target atoms can form a highly ionized state and complex electronic configuration to de-excite the emission spectrum.As the charge state of the incident ion increases,the measured spectral line intensity rises,and the increasing trend is generally consistent with the growing trend of the potential energy of the incident ion,which indicates that the classical over-the-barrier model is valid in the near Bohr velocity energy region.We also hope that our experimental data can provide basic support for related research and provide new methods for spectral measurement.Methods The experiment is performed at the Heavy Ion Research Facility in Lanzhou(HIRFL)and the experimental platform is shown in Fig.1.Gaseous 129Xe atoms repeatedly collide with electrons in an 18 GHz microwave field in the ECR,gradually peeling off to form highly charged 129Xeq+ions.They are introduced at the required voltage for the experiment,and the required projectile ions are selected by analytical magnets based on the charge-to-mass ratio.The beam spot is controlled to be less than 5 mm using a beam splitter,quadrupole lens,and aperture,and the beam intensity is recorded via a Faraday tube.The beam enters a metal ultra-high vacuum chamber with magnetic shielding(vacuum degree maintained at 10-8 Pa).The chemical

关 键 词：原子与分子物理学 高电荷态离子 经典过垒模型 禁戒跃迁 近红外光谱 

分 类 号：O571.33[理学—粒子物理与原子核物理]