Investigation of shock waves and fluid flows which are generated by short and ultrashort intense laser pulses within a small volume (lateral dimension less than 10 micron, mostly micro channels)

本课题研究的是在小体积内的气体或液体（或一般的流体）中产生冲击波的强纳米、皮科和飞秒激光脉冲。冲击波将在微通道内的流体中产生（在下文中，微通道应称为非常小的通道和/或毛细管）。将在事件和反射冲击之前和之后调查流体参数及其状态的变化。与在较大尺度管道中由膜破裂引发的微型冲击波相比，本项目的微型冲击波将由高功率激光产生的等离子体产生，例如在微通道内或直接在其前面。研究将集中在：a）等离子体形成和膨胀，B）在生成区域内的密度和速度，以及c）在微通道的感应距离内，以及最后d）在稳定的平面冲击波区域。对于调查，将应用具有时间分辨率的各种诊断（激光差分干涉测量法、莫尔诊断法、LDA、PIV等）。特别是对国际社会而言，强激光脉冲产生的微冲击波构成了一个新的物理学领域。所获得的结果将为微流控、纳米技术、医学物理等领域的应用奠定重要的物理基础。

Topic is the investigation of intense nano, pico and femtosecond laser pulse generated shock waves in gases or liquids (or in general in a fluid) within a small volume. The shock waves will be generated in fluids within micro channels (in the following micro channel should term very small channels and/or capillaries). Parameters of the fluid and changes of its state will be investigated in front of and behind the incident and reflected shock. In contrast to mini shock waves that are initiated by membrane bursts in larger scale pipes, the micro shock waves of the present project will be generated from a high power laser generated plasma, e.g. within a micro channel or directly in front of it. The investigations will be concentrated on: a) plasma formation and expansion, b) density and velocity within the region of generation and c) within the induction distance of the micro channel and finally d) in the region of stabilized plane shock waves. For the investigations various diagnostics with temporal resolution will be applied (laser differential interferometry, Moire diagnostics, LDA, PIV, etc.). In particular, with respect to the international community, micro shock waves generated by intense laser pulses comprise a new area of physics. The acquired results will built an important physical fundament for applications such as micro fluidics, nano technology, medical physics and many other interesting topics.