Core-localized ECRH-induced degradation of ion heat confinement in the HL-3 tokamak

Core-localized electron cyclotron resonance heating (ECRH) often raises the electron temperature, whereas the ion temperature may remain unchanged or even decrease. We investigate this ion-channel response in deuterium L-mode plasmas on the HL-3 tokamak using kinetic profiles, interpretive power-balance analysis, and local turbulence modeling. Three states are compared: #11843 at 425 ms under neutral beam injection only (NBI-only, pre-ECRH), #11843 at 600 ms (NBI+ECRH), and #11844 at 600 ms (NBI-only reference). After ECRH is applied, the core electron temperature increases whereas the core ion temperature decreases. Source analysis identifies no significant reduction in net ion heating between the two #11843 states. The inferred increase in ion heat transport is dominated by the turbulent component after neoclassical subtraction. Local trapped gyro-Landau-fluid (TGLF) sensitivity scans indicate that this behavior is consistent with enhanced ion-scale turbulent transport driven by changes in local dimensionless parameters, rather than by a reduction in net ion heating.