论文标题
斜发生率和碰撞脉冲对相对透明的超薄靶标激光驱动的质子加速度的影响
Effects of oblique incidence and colliding pulses on laser-driven proton acceleration from relativistically transparent ultrathin targets
论文作者
论文摘要
超薄固体箔的使用提供了从激光 - 物质相互作用加速质子的最佳条件。当目标足够薄，以至于相对论自我诱导的透明度（RSIT）设置在介入时，所有目标电子都会被激光加热至高能，从而最大程度地提高了加速电场，因此最终离子能量。在这项工作中，我们首先研究了透明的ch $ _2 $ solid铝箔在从正常变成斜变变（$ 45^\ circ $）的发病率时，如何通过超明秒的激光脉冲进行离子加速度。由于电子加热，我们发现可以在倾斜的发生率但最薄的最佳目标下获得更高的质子能。然后，我们表明，可以通过将激光脉冲分成两个聚焦在相反的入射角的半脉冲中，从而进一步改善质子加速度。与单个正常入射脉冲的参考案例相比，据报道，在最大质子能量中增加了$ \ sim 30 \，\％$，在高能量质子电荷中增加了$ \ sim 4 $。
The use of ultrathin solid foils offers optimal conditions for accelerating protons from laser-matter interactions. When the target is thin enough that relativistic self-induced transparency (RSIT) sets in, all of the target electrons get heated to high energies by the laser, which maximizes the accelerating electric field and therefore the final ion energy. In this work, we first investigate how ion acceleration by ultraintense femtosecond laser pulses in transparent CH$_2$ solid foils is modified when turning from normal to oblique ($45^\circ$) incidence. Due to stronger electron heating, we find that higher proton energies can be obtained at oblique incidence but in thinner optimum targets. We then show that proton acceleration can be further improved by splitting the laser pulse into two half-pulses focused at opposite incidence angles. An increase by $\sim 30\,\%$ in the maximum proton energy and by a factor of $\sim 4$ in the high-energy proton charge is reported compared to the reference case of a single normally incident pulse.
