Miyazaki S, Kawata S, Sonobe R, Kikuchi T
Department of Material Science and Engineering, Utsunomiya University, Yohtoh 7-1-2, Utsunomiya 321-8585, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 May;71(5 Pt 2):056403. doi: 10.1103/PhysRevE.71.056403. Epub 2005 May 9.
A suppression of a transverse divergence of high-energy protons generated by an interaction of a laser with a thin slab foil is investigated in this paper by 2.5-dimensional particle-in-cell simulations. When an intense (approximately 10(24) W/m(2)) short-pulse (a few ten femtoseconds) laser illuminates a thin foil target of a hydrogen, foil electrons are accelerated and compressed longitudinally by a laser light pressure and fast electron bunches are produced in the thin foil target. The fast electron bunches pass through the foil target, and a strong magnetic field is produced near the opposite side of the foil target. Because the strong magnetic field confines the electrons, a localization of the electrons is observed at the opposite side of a laser illumination surface. The local electron bunch produces not only a longitudinal electric field, but also a transverse electric field, which is directed toward the laser axis. Protons are accelerated and extracted from the foil, and the proton bunch divergence is successfully suppressed by the transverse electric field.
本文通过二维半粒子模拟研究了激光与薄平板箔相互作用产生的高能质子横向发散的抑制情况。当强（约10(24)W/m(2)）短脉冲（几十飞秒）激光照射氢薄箔靶时，箔电子被激光光压纵向加速和压缩，在薄箔靶中产生快速电子束团。快速电子束团穿过箔靶，在箔靶相对侧附近产生强磁场。由于强磁场限制电子，在激光照射面的相对侧观察到电子的局域化。局部电子束团不仅产生纵向电场，还产生指向激光轴的横向电场。质子从箔中被加速和引出，并且质子束团的发散被横向电场成功抑制。
