Abstract
Ultrafast electron microscopy harbors femtosecond time resolution and atomic level spatial resolution. In NTHU/NSRRC time-resolved electron microscopy proposal, a transmission electron microscope (TEM) integrated with a femtosecond laser system was used to generate ultrafast electron probe for the study of transient state of various materials and bio samples. Space charge effect influenced such a short bunch seriously and consequently caused bunch broadening and energy spread. In the thesis, we derived coupled envelope equations incorporated with space charge effect as well as external fields and compared with PARMELA simulation code. PARMELA is also used to analyze space charge effect in Gaussian distributed bunch due to laser intensity distribution. The simulation results indicated the tendency of broadening caused by space charge effect is linear in drift space. And halo effect was found in the polepiece lens. In addition, we discussed energy spread of the bunch which related to matter wave dispersion in TEM components. At the end, we designed a RF buncher attached with a solenoid lens to compensate longitudinal and transverse broadening.