Speaker
Description
Laser-induced streaking (LIS) of electron beam, first observed by Zewail group back in 1994, is a unique phenomenon in UED that is often used to conveniently identify time-zero in UED experiments. In the gas phase, LIS originates from plasma field created by strong field ionization of sample molecules, hence named as “photoionization-induced lensing” by Zewail. Separately, LIS can also be achieved with THz pulses, known as the THz streaking. THz streaking do not involve photoionization, but originates from the amplification of the electric field of THz pulses by a metal cavity. In this presentation, I will show our preliminary results on LIS in liquid-phase UED. We found that in liquid-phase, LIS can originate from a third mechanism that is different from the two mechanisms above. In addition to the main beam, liquid-phase LIS also streaks the diffraction pattern. This phenomenon creates both complexity and new opportunity for future liquid-phase UED experiments.
