Influence of the X-point location on edge plasma transport in the J-TEXT tokamak with a high-field-side single-null divertor

High-density experiments in the high-field-side mid-plane single-null divertor configuration have been performed for the first time on J-TEXT. The experiments show an increase in the highest central channel line-averaged density from 2.73x10(19)m-3 6.49x10(19)m(-3) 50%) with an increase in the plasma density. To better understand the underlying physics mechanisms, the 3D edge Monte Carlo code coupled with EIRENE (EMC3-EIRENE) has been implemented for the first time on J-TEXT. The simulation results show good agreement with the experimental findings. As the X-point moves away from the target, the divertor power decay length drops and the scrape-off layer impurity screening effect is enhanced.