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 (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 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.