School of Physics, Georgia Institute of Technology, 837 State St. NW, Atlanta, Georgia 30332, USA.
Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA.
Rev Sci Instrum. 2022 Dec 1;93(12):123508. doi: 10.1063/5.0101803.
We report recent single-shot spatiotemporal measurements of laser pulses, including pulse-front tilt (PFT) and spatial chirp, taken at the Compact Multipulse Terawatt laser at the Jupiter Laser Facility in Livermore, CA. STRIPED FISH, a device that measures the complete 3D electric field of fs to ps laser pulses on a single shot, was adapted to near infrared for these measurements. We present the design of the instrument used for these experiments, the on-shot measurements of systematic high-order PFT, and shot-to-shot variations in the measurements of spatiotemporal couplings. Finally, we simulate the effect of PFT in target normal sheath acceleration experiments. These simulations showed that pulse front tilt can steer hot electrons, shape the distribution of the accelerating sheath field, and increase the variability of cutoff energy in the resulting proton spectra. While these effects may be detrimental to experimental accuracy if the pulse front tilt is left unmeasured, hot electron steering shows promise for precision manipulation of the particle source for a range of applications, including irradiation of secondary targets for opacity measurements, radiography, or neutron generation.
我们报告了最近在加利福尼亚州利弗莫尔的朱庇特激光设施的紧凑型多脉冲太瓦激光器上进行的单次激光脉冲的时空测量,包括脉冲前沿倾斜(PFT)和空间啁啾。STRIPED FISH 是一种在单次测量中测量 fs 到 ps 激光脉冲完整 3D 电场的设备,已适应近红外光进行这些测量。我们介绍了用于这些实验的仪器设计、系统高阶 PFT 的单次测量以及时空耦合测量中的单次变化。最后,我们模拟了 PFT 在靶法线鞘加速实验中的影响。这些模拟表明,脉冲前沿倾斜可以引导热电子、形成加速鞘场的分布,并增加所得质子能谱中截止能量的可变性。虽然如果不测量脉冲前沿倾斜,这些影响可能会对实验精度产生不利影响,但热电子引导有望为各种应用中的粒子源的精确控制提供前景,包括二次靶的辐照以进行不透明度测量、射线照相或中子产生。