论文标题
离子加速度具有较少的循环相对论激光脉冲来自箔目标的激光脉冲
Ion acceleration with few cycle relativistic laser pulses from foil targets
论文作者
论文摘要
由11 fs激光脉冲与超高对比度（<10^-10）和10^19 W/cm^2峰值强度与在正常情况下（0度）和45度激光发病率的各种材料和厚度制成的箔目标的相互作用和45度激光靶标产生的离子加速度。质子的最大能量从目标的后部和前侧加速均高于1 MeV。使用51 nm厚的Al靶标，在45度激光发射率下，从激光脉冲能量到质子束的转化效率高达1.4％。出色的激光对比表明，由于高斯颞激光脉冲的形状，真空加热通过brunels效应作为一种涉及自然起源的较小的预皮质的吸收机制。实验结果与理论估计值是合理的一致性，即质子从目标后部向前方向的质子加速度很好地解释了TNSA样机制，而质子的加速度可以通过在微小的plasma中的微小pre-plasma中形成一个带电的腔。来自带电腔的爆炸库仑田也是厚目标处的前向离子的来源。
Ion acceleration resulting from the interaction of 11 fs laser pulses of ~35 mJ energy with ultrahigh contrast (<10^-10), and 10^19 W/cm^2 peak intensity with foil targets made of various materials and thicknesses at normal (0-degree) and 45-degree laser incidence is investigated. The maximum energy of the protons accelerated from both the rear and front sides of the target was above 1 MeV. A conversion efficiency from laser pulse energy to proton beam is estimated to be as high as ~1.4 % at 45-degree laser incidence using a 51 nm-thick Al target. The excellent laser contrast indicates the predominance of vacuum heating via the Brunels effect as an absorption mechanism involving a tiny pre-plasma of natural origin due to the Gaussian temporal laser pulse shape. Experimental results are in reasonable agreement with theoretical estimates where proton acceleration from the target rear into the forward direction is well explained by a TNSA-like mechanism, while proton acceleration from the target front into the backward direction can be explained by the formation of a charged cavity in a tiny pre-plasma. The exploding Coulomb field from the charged cavity also serves as a source for forward-accelerated ions at thick targets.
