Abstract: We study photocathode of linear induction accelerator.A photoemission model was implemented which takes into account details such as photocathode material and laser source.A relationship between photocathode and macro particle initial condition is established.We achieved this model in LIAPIC code.A photocathode injector model was set up to simulate photoemission.At last,the model is verified.Simulation results are concordant with experiment.

Key words: linear induction accelerator, photocathode, quantum efficiency, injector, particle in cell