Mapping non-laminar proton acceleration in laser-driven target normal sheath field  

作　　者：C.Y.Qin H.Zhang S.Li S.H.Zhai A.X.Li J.Y.Qian J.Y.Gui F.X.Wu Z.X.Zhang Y.Xu X.Y.Liang Y.X.Leng B.F.Shen L.L.Ji R.X.Li 

机构地区：[1]State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [3]CAS Center for Excellence in Ultra-intense Laser Science,Shanghai 201800,China [4]Department of Physics,Shanghai Normal University,Shanghai 200234,China [5]ShanghaiTech University,Shanghai 201210,China

出　　处：《High Power Laser Science and Engineering》2022年第1期10-16,共7页高功率激光科学与工程（英文版）

基　　金：supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB16);National Natural Science Foundation of China(Nos.11875307,11935008,11804348,11705260,11905278,and 11975302);Youth Innovation Promotion Association of the Chinese Academy of Sciences.

摘　　要：We report on experimental observation of non-laminar proton acceleration modulated by a strong magnetic field in laser irradiating micrometer aluminum targets.The results illustrate the coexistence of ring-like and filamentation structures.We implement the knife edge method into the radiochromic film detector to map the accelerated beams,measuring a source size of 30-110μm for protons of more than 5 MeV.The diagnosis reveals that the ring-like profile originates from low-energy protons far off the axis whereas the filamentation is from the near-axis high-energy protons,exhibiting non-laminar features.Particle-in-cell simulations reproduced the experimental results,showing that the short-term magnetic turbulence via Weibel instability and the long-term quasi-static annular magnetic field by the streaming electric current account for the measured beam profile.Our work provides direct mapping of laser-driven proton sources in the space-energy domain and reveals the non-laminar beam evolution at featured time scales.

关 键 词：knife-edge technique laser-plasma interaction non-laminar proton source target normal sheath acceleration Weibel instability 

分 类 号：TN249[电子电信—物理电子学]