Acceleration of Protons from a Double-Layer or Multi-Ion-Mixed Foil Irradiated by Ultraintense Lasers  

作　　者：王伟民 盛政明 於陆勒 李玉同 KAWATA Shigeo 张杰 

机构地区：[1]Beijing National Laboratory of Condensed Matter Physics,Institute of Physics,CAS [2]Graduate School of Engineering,Utsunomiya University [3]Department of Physics,Shanghai Jiao Tong University

出　　处：《Plasma Science and Technology》2010年第3期277-283,共7页等离子体科学和技术（英文版）

基　　金：supported in part by National Natural Science Foundation of China (Nos. 10734130, 10925421, 10935002, 10974250);the National High-Tech ICF Committee in China and the National Basic Research Program of China (Nos. 2007CB815100, 2009GB105002);the JSPS-CAS Core-University Program on Plasma and Nuclear Fusion, and CORE (Center for Optical Research and Education) at Utsunomiya University Japan

摘　　要：Acceleration of protons by the radiation pressure of a circularly polarized laser pulse with the intensity up to 1021 W/cm^2 from a double-layer or multi-ion-mixed thin foil is investigated by two-dimensional particle-in-cell simulations. The double-layer foil is composed of a heavy ion layer and a proton layer. It is found that the radiation pressure acceleration can be classified into three regimes according to the laser intensity due to the different critical intensities for laser transparency with different ion species. When the laser intensity is moderately high, the laser pushes the electrons neither so slowly nor so quickly that the protons can catch up with the electrons, while the heavy ions cannot. Therefore, the protons can be accelerated efficiently. The proton beam generated from the double-layer foil is of better quality and higher energy than that from a pure proton foil with the same areal electron density. When the laser intensity is relatively low, both the protons and heavy ions are accelerated together, which is not favorable to the proton acceleration. When the laser intensity is relatively high, neither the heavy ions nor the protons can be accelerated efficiently due to the laser transparency through the target.Acceleration of protons by the radiation pressure of a circularly polarized laser pulse with the intensity up to 1021 W/cm^2 from a double-layer or multi-ion-mixed thin foil is investigated by two-dimensional particle-in-cell simulations. The double-layer foil is composed of a heavy ion layer and a proton layer. It is found that the radiation pressure acceleration can be classified into three regimes according to the laser intensity due to the different critical intensities for laser transparency with different ion species. When the laser intensity is moderately high, the laser pushes the electrons neither so slowly nor so quickly that the protons can catch up with the electrons, while the heavy ions cannot. Therefore, the protons can be accelerated efficiently. The proton beam generated from the double-layer foil is of better quality and higher energy than that from a pure proton foil with the same areal electron density. When the laser intensity is relatively low, both the protons and heavy ions are accelerated together, which is not favorable to the proton acceleration. When the laser intensity is relatively high, neither the heavy ions nor the protons can be accelerated efficiently due to the laser transparency through the target.

关 键 词：ion acceleration radiation pressure acceleration intense laser foil interaction particle-in-cell simulation 

分 类 号：TN24[电子电信—物理电子学]