Ao T, Dolan D H
Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
Rev Sci Instrum. 2011 Feb;82(2):023907. doi: 10.1063/1.3551954.
Photonic Doppler velocimetry (PDV) has rapidly become a standard diagnostic for measuring velocities in dynamic compression research. While free surface velocity measurements are fairly straightforward, complications occur when PDV is used to measure a dynamically loaded sample through a window. Fresnel reflections can severely affect the velocity and time resolution of PDV measurements, especially for low-velocity transients. Shock experiments of quartz compressed between two sapphire plates demonstrate how optical window reflections cause ringing in the extracted PDV velocity profile. Velocity ringing is significantly reduced by using either a wedge window or an antireflective coating.
光子多普勒测速仪（PDV）已迅速成为动态压缩研究中测量速度的标准诊断工具。虽然自由表面速度测量相当简单，但当使用PDV通过窗口测量动态加载的样品时会出现复杂情况。菲涅耳反射会严重影响PDV测量的速度和时间分辨率，尤其是对于低速瞬态情况。在两块蓝宝石板之间压缩石英的冲击实验表明了光学窗口反射如何在提取的PDV速度剖面中引起振铃。通过使用楔形窗口或抗反射涂层，速度振铃会显著降低。
