【摘要】 现有激光等离子体加速机制中纵向电场对离子的有效加速长度很短(微米量级),且束流能散大,得到的离子能量较低.当采用圆偏振激光和固体靶相互作用时,如果激光的归一化光强矢量a与靶的电子面密度nn0cλDL相当时,则存在一种稳相加速机制.此时激光和等离子相互作用产生的静电场不仅可以用于加速离子,而且还可以在纵向对离子进行聚束,从而可以有效地降低束流能散.数值模拟结果表明,利用激光加速可以得到能散小于5%的单能离子束,这对激光加速器走向实际应用有着重要意义.更多还原

【Abstract】 A new ion acceleration method called phase-stable acceleration is proposed by use of circularly-polarized laser pulses.When the initial target density n0 and thickness D satisfy aL～(n0/nc)D/λL and D>1(where aL,λL,ls,and nc are the normalized laser amplitude,the laser wavelength in vacuum,the plasma skin depth,and the critical density of the incident laser pulse,respectively),a quasi-equilibrium for electrons is established due to the light pressure and the electrostatic field built up at the interacting front of the laser pulse.The ions located within the skin-depth of the laser pulse are synchronously accelerated and bunched by the electrostatic field,and thereby a monoenergetic and high intensity proton beam can be generated.更多还原