Ultrafast electron diffraction

Ultrafast Electron Diffraction (UED) is a pump-probe experiment method based on electron diffraction from ultrafast electron pulses. The pump laser will inject to the sample to induce the transitions, after finite time, another UV laser will hit the photocathode to produce electron pulses. After pass through the sample, the electron pulse will be scatterd and formed diffraction patterns on CCD camera carrying the structure information of sample. By adjusting the time difference between the pump laser and UV laser, people can obtain a series of diffraction patterns with different time, which can be used to examine the dynamics of charge carriers, atoms and molecules.