“…The boundaries of the numerical simulation model are shown in figure 3. The nonmagnetic cover (the numbers are 1, 9), dielectric (2, 3, 7, 8), anode (4, 5, 6), cathode (11,12), free-space boundary (10, 13) and symmetry boundary (14) are shown respectively. The secondary electron emission model on all ceramic walls is considered, and the cathode potential was set to 0 V, the PIC calculation was performed for a discharge voltage of 300 V and a propellant mass flow of 3.9 mg s −1 .…”