Toroidal modeling of the effect of resonant q95 on n = 1 error field penetration in EAST

The plasma response to the n = 1 resonant magnetic perturbation in EAST has been systematically investigated using the MARS-F/Q codes, focusing on the roles of q95 and in error field penetration. Here, q95 refers to the safety factor at 95% poloidal magnetic flux, which is varied within the low-q95 operational regime () by adjusting the plasma current. The normalized beta, , is increased by modifying the pressure profile, while remaining below the no-wall beta limit. The resonant q95 effect observed in the linear response not only influences the penetration of edge resonant components but also affects the q95-dependence of penetration threshold, with neoclassical toroidal viscosity torque identified as the dominant mechanism. Furthermore, increasing shifts the resonant q95 window. Both linear and quasi-linear simulations reveal that a higher enhances the influence of resonant q95 effect on the component. The impact of q95 on the , which represents the scaling index between penetration threshold and , shows that becomes increasingly negative with rising q95. This indicates that the destabilizing effect of βN on magnetic field penetration becomes more significant at higher q95 due to enhanced mode coupling. These findings suggest that modestly adjusting q95 towards weaker resonant regions can improve error field tolerance, which is beneficial for operational scenarios aimed at mitigating the risk of locked modes. Additionally, the capability to prevent locked mode induced by increasing βN diminishes as q95 increases.