The energy of protons accelerated by ultra-intense lasers in the target normal sheath acceleration (TNSA) mechanism can be greatly enhanced by the laser parameter optimization. We propose to investigate the optimization of laser parameters for proton acceleration using double laser pulses in TNSA mechanism. The sheath field generation at the rear side of the target is significantly affected by the introduction of second laser pulse in TNSA mechanism, and consequently, the energy of the accelerated protons is also modified. The second laser pulse was introduced with different delays to study its impact on proton acceleration. Our study shows that the interplay of laser intensity and pulse duration of both laser pulses affects the proton acceleration. It was found that the proton maximum energy is the function of both laser intensity and pulse duration. A number of simulations have been performed to obtain maximum proton energy data under different combinations of laser intensity and pulse duration for the two laser pulses. The simulation results account for the underline physics for the proton bunch energy and the sheath field as a function of pulse intensity and pulse delay.

通过激光参数优化，可以大大增强目标法向鞘层加速（TNSA）机制中超强激光所加速的质子能量。我们建议研究使用TNSA机制中的双激光脉冲优化质子加速的激光参数。在TNSA机构中引入第二激光脉冲会显着影响靶后侧的鞘场生成，因此，加速质子的能量也会发生变化。以不同的延迟引入第二个激光脉冲，以研究其对质子加速的影响。我们的研究表明，两个激光脉冲的激光强度和脉冲持续时间之间的相互作用会影响质子加速度。发现质子最大能量是激光强度和脉冲持续时间的函数。在两个激光脉冲的激光强度和脉冲持续时间的不同组合下，已经进行了许多模拟以获得最大的质子能量数据。仿真结果说明了质子束能量和鞘层场作为脉冲强度和脉冲延迟的函数的下划线物理性质。