Energetic Laser-Ion Acceleration by Strong Charge-Separation Field

• 作 者: 黄永盛 王乃彦 施义晋 汤秀章 毕远杰 高喆
• 机 构: China Institute of Atomic Energy,Department of Engineering Physics,Tsinghua University,
• 出 处: Plasma Science and Technology
• 发表日期: 2010年03期
• 关键词: acceleration relativistic length nowadays isothermal adequate intense deduced St

The laser-ion acceleration from the ultra-short and ultra-intense laser-matter interactionsattracts more and more interest nowadays. When a laser pulse interacts with a target,relativistic electrons are generated in a period of few femtoseconds and driven away by the ponderomotiveforce, then a huge charge-separation field forms. In general cases, the ion accelerationis determined by this charge-separation field and the scale length of the plasma density. A generaltime-dependent solution is obtained to describe laser-plasma isothermal expansions into a vacuum,which is the fundamental theory of the laser-ion acceleration. It is adequate for non-quasi-neutralplasmas and different types of the scale length of the density gradient. The previous solutionsare some special cases of our general solution. It is found that there exist both a compressionlayer of the ion velocity distribution and a potential well for some initial conditions. However,many unaccounted idiographic solutions, which may be used to reveal new mechanisms of ionacceleration, may be deduced from our general solutions.

The laser-ion acceleration from the ultra-short and ultra-intense laser-matter interactions, more and more interest nowadays. When a laser pulse interacts with a target, relativistic electrons are generated in a period of few femtoseconds and driven away by the ponderomotive force, then a huge charge-separation field forms. In general cases, the ion acceleration is determined by this charge-separation field and the scale length of the plasma density. A generaltime-dependent solution is obtained to describe laser-plasma isothermal expansions into a vacuum, which is the fundamental theory of the laser-ion acceleration. It is adequate for non-quasi-neutralplasmas and different types of the scale length of the density gradient. The previous solutions are some special cases of our general solution. It is found that there exist both a compression layer of the ion velocity distribution and a potential well for some initial conditions. However, many unaccounted idiographic solutions, which may be used to reveal new mechanisms of ionacceleration, may be deduced from our general solutions.