The correlation of edge plasma current, electric field and divertor condition in tokamak

•The poloidal current jx is mainly dominated by parallel current, while the radial current mainly consists of ion-friction and diamagnetic current.•The divertor regime plays an important role in electric field and drift.•The effects of Bt direction on the divertor plasma can also be affected by the divertor plasma regime. The particle transport in divertor region of current size tokamak can be affected by electric field (E) significantly through the E × B drift. The plasma current, which is associated with drifts closely, affects E. In this work, the SOLPS-ITER code package is used to evaluate the influence of divertor regime, plasma current, toroidal magnetic field Bt direction on the electric field as well as divertor plasma. It is found that the poloidal current (jx) is dominated by parallel current, while the radial current (jy) mainly consists of diamagnetic and ion-neutral friction current near the target. The divertor regime plays an important role in electric field. (i) The poloidal electric field (Ex) is mainly affected by the electron density (ne) and temperature (Te) in high recycling regime, and the parallel plasma current (j||) plays an important role in Ex in detached regime. (ii) The radial electric field (Ey) is reduced significantly as divertor varies from high recycling regime to detached regime. It is also found that the Bt direction affects Ex and Ey in the divertor region significantly with low upstream density, while the role is weakened with high upstream density. The divertor asymmetry is also evaluated in different Bt with low/high upstream density. The dependence of E on divertor regime and Bt direction, and the corresponding impact on particle transport and divertor plasma are systemically studied and are important for steady-state discharge in current size tokamak.