  The coherent synchrotron radiation (CSR) of a high brightness electron beam
traversing a series of dipoles, such as transport or recirculation arcs, may
result in the microbunching instability ({\mu}BI). To accurately quantify the
direct consequence of this effect, we further extend our previously developed
semi-analytical Vlasov solver [C. -Y. Tsai et al., FEL Conference 2014
(THP022)] to include more relevant coherent radiation models than the
steady-state free-space CSR impedance, such as the entrance and exit transient
effects derived from upstream beam entering to and exiting from individual
dipoles. The resultant microbunching gain functions and spectra for our example
lattices are presented and compared with particle tracking simulation. Some
underlying physics with inclusion of these effects are also discussed.
