How to set the boundary condition of EM field when simulating shock?

[Changxiang-Mao]

Dear all,

I am simulating a 1D magnetized collisionless shock. The setup is: initially, cold plasma(proton and electron) is uniformly distributed in the simulation domain with a constant velocity -v0. Plasma is continuously injected from the right boundary. Initially, Bz = B0 = 1., Ey = -v0 * B0. Boundary conditions for particles are [["reflective","remove"]]. Boundary conditions for EM fields is [["silver-muller"]]. The complete parameters are in "a0.py".
a0.py
The result is as follow:

According to first panel, there does forms a shock. However, for Ey and Bz panel, it is obviously that around x~82000 both Ey and Bz have a jump. This behaviour is not what I want. This strange behaviour comes most likely from [["silver-muller"]] boundary condition as I described in issue #855 .

I would like to ask how to handle this issue?