Probing ultrafast dynamics of solid-density plasma generated by high-contrast intense laser pulses
Probing ultrafast dynamics of solid-density plasma generated by high-contrast intense laser pulses
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DOI：
10.1063/1.5005176
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发表时间：
2018
影响因子：
2.2
通讯作者：
K. Jana;D. Blackman;M. Shaikh;A. D. Lad;D. Sarkar;I. Dey;A. Robinson;J. Pasley;G. Kumar
中科院分区：
文献类型：
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作者：
K. Jana;D. Blackman;M. Shaikh;A. D. Lad;D. Sarkar;I. Dey;A. Robinson;J. Pasley;G. Kumar
我们使用时间分辨泵浦-探测多普勒光谱法，研究了高对比度（皮秒对比度为10−9）、高强度（104 × 1018 W/cm 2）激光脉冲产生的固体密度等离子体的超快动力学。实验表明，在早期的时间延迟（2-4.3 ps），蓝移的快速上升，然后快速下降（4.3-8.3 ps），然后在较晚的时间延迟（>8.3 ps），蓝移缓慢上升。模拟结果表明，早期的观察，特别是没有任何红移的反射探头，只能再现，如果前表面是不受扰动的激光预脉冲的时刻，高强度脉冲到达。能够诊断低水平前等离子体形成的存在的灵活诊断将可用于激光产生的质子和离子产生中的潜在应用，例如癌症治疗和安全成像。
We present ultrafast dynamics of solid-density plasma created by high-contrast (picosecond contrast ∼10−9), high-intensity (∼4 × 1018 W/cm2) laser pulses using time-resolved pump-probe Doppler spectrometry. Experiments show a rapid rise in blue-shift at early time delay (2–4.3 ps) followed by a rapid fall (4.3–8.3 ps) and then a slow rise in blue-shift at later time delays (>8.3 ps). Simulations show that the early-time observations, specifically the absence of any red-shifting of the reflected probe, can only be reproduced if the front surface is unperturbed by the laser pre-pulse at the moment that the high intensity pulse arrives. A flexible diagnostic which is capable of diagnosing the presence of low-levels of pre-plasma formation would be useful for potential applications in laser-produced proton and ion production, such as cancer therapy and security imaging.