Brown Michael S, Erickson Thomas, Frische Kyle, Roquemore William M
Air Force Research Laboratory, Propulsion Directorate, 1950 Fifth St., Wright-Patterson AFB, Ohio 45433, USA.
Opt Express. 2011 Jun 20;19(13):12241-7. doi: 10.1364/OE.19.012241.
Pump/probe optical-transmission measurements are used to monitor in space and time the ionization of a liquid column of water following impact of an 800-nm, 45-fs pump pulse. The pump pulse strikes the 53-μm-diameter column normal to its axis with intensities up to 2 × 10(15) W/cm2. After the initial photoinization and for probe delay times < 500 fs, the neutral water surrounding the beam is rapidly ionized in the transverse direction, presumably by hot electrons with initial velocities of 0.55 times the speed of light (relativistic kinetic energy of ~100 keV). Such velocities are unusual for condensed-matter excitation at the stated laser intensities.
泵浦/探测光传输测量用于在空间和时间上监测800纳米、45飞秒泵浦脉冲撞击后水柱的电离情况。泵浦脉冲垂直于其轴撞击直径为53微米的水柱，强度高达2×10¹⁵瓦/平方厘米。在初始光电离之后，对于探测延迟时间小于500飞秒的情况，光束周围的中性水在横向迅速电离，推测是由初始速度为光速0.55倍（相对论动能约为100千电子伏）的热电子引起的。在所述激光强度下，这种速度对于凝聚态物质激发来说是不寻常的。
