TY - JOUR KW - Plasma diagnostics KW - Copper KW - Laser ablation KW - Electron beam applications KW - High-speed optical techniques KW - Plasma production by laser AU - Junjie Li AU - Xuan Wang AU - Zhaoyang Chen AU - Richard Clinite AU - Samuel S Mao AU - Pengfei Zhu AU - Zhengming Sheng AU - Jie Zhang AU - Jianming Cao AB -

Plasma dynamics in the early stage of laser ablation of a copper target are investigated in real time by making ultrafast electron shadow images and electron deflectometry measurements. These complementary techniques provide both a global view and a local perspective of the associated transient electric field and charge expansion dynamics. The results reveal that the charge cloud above the target surface is composed predominantly of thermally ejected electrons and that it is self-expanding, with a fast front-layer speed exceeding 107 m/s. The average electric field strength of the charge cloud induced by a pump fluence of 2.2 J/cm2 is estimated to be ∼ 2.4×105 V/m.

BT - Journal of Applied Physics DA - 03/2010 DO - 10.1063/1.3380846 IS - 8 LA - eng N2 -

Plasma dynamics in the early stage of laser ablation of a copper target are investigated in real time by making ultrafast electron shadow images and electron deflectometry measurements. These complementary techniques provide both a global view and a local perspective of the associated transient electric field and charge expansion dynamics. The results reveal that the charge cloud above the target surface is composed predominantly of thermally ejected electrons and that it is self-expanding, with a fast front-layer speed exceeding 107 m/s. The average electric field strength of the charge cloud induced by a pump fluence of 2.2 J/cm2 is estimated to be ∼ 2.4×105 V/m.

PY - 2010 T2 - Journal of Applied Physics TI - Ultrafast electron beam imaging of femtosecond laser-induced plasma dynamics VL - 107 ER -