FEL simulation in the boosted frame

[rl3418]

I'm trying to do a 1D simulation of an gamma=200 beam travelling through an undulator. I transformed everything to a frame with gamma_f=50 and performed a simulation in that frame. The results I obtained from WarpX is very different compared to OSIRIS. I have attached to input file I used and a comparison of the density evolution in the boosted frame.

200_50.txt
osiris_200_50.txt