We present a novel photonic Doppler velocimetry (PDV) design for laser-driven shock-wave experiments. This PDV design is intended to provide the capability of measuring the free-surface velocity of shocked opaque materials in the terapascal range. We present measurements of the free-surface velocity of gold for as long as ∼2 ns from the shock breakout, at pressures of up to ∼7 Mbar and a free-surface velocity of 7.3 km/s with an error of ∼1.5%. Such laboratory pressure conditions are achieved predominantly at high-intensity laser facilities where the only velocity diagnostic is usually line-imaging velocity interferometry for any reflector. However, that diagnostic is limited by the lower dynamic range of the streak camera (at a temporal resolution relevant to laser shock experiments) to measure the free-surface velocity of opaque materials up to pressures of only ∼1 Mbar. We expect the proposed PDV design to allow the free-surface velocity of opaque materials to be measured at much higher pressures.

中文翻译：

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使用光子多普勒测速仪在激光驱动冲击波实验中测量不透明材料的自由表面速度

我们提出了一种用于激光驱动冲击波实验的新型光子多普勒测速 (PDV) 设计。这种 PDV 设计旨在提供在万亿级范围内测量受冲击不透明材料的自由表面速度的能力。我们提供了自冲击爆发后长达 2 ns 的金自由表面速度的测量结果，压力高达 7 Mbar，自由表面速度为 7.3 km/s，误差为 1.5%。这种实验室压力条件主要在高强度激光设施中实现，其中唯一的速度诊断通常是任何反射器的线成像速度干涉测量法。然而，该诊断受到条纹相机较低动态范围的限制（以与激光冲击实验相关的时间分辨率）来测量不透明材料的自由表面速度，压力仅为~1 Mbar。我们期望提议的 PDV 设计允许在更高的压力下测量不透明材料的自由表面速度。