A Novel Technique to Model Ultrafast Electron Microscope

A special feature of ultrafast electron microscopes is that only a single shot of electron bunch at extremely high spatial and temporal resolution is needed. A numerical technique using a virtual moving mesh to encapsulate the bunch was developed and implemented in Beam Optics Analyzer. The Poisson electric field due to space charge is solved only for the moving mesh; thus, can be at very high fidelity but requires much less computational resources. The method is found to be very efficient and accurate. The transverse emittance with thermal effects grows to less than
$0.09 \pi\mu$
.