Pedestal parameter dependences of $n$ = 1, RMP-driven, ELM-crash control on KSTAR

RMP ELM-crash control is expected to be unified soon in terms of the accessibility conditions among multiple devices, helping us to predict the performance in ITER and beyond. Utilizing the improved Thomson scattering profiles in KSTAR, we have launched a rigorous edge parameter scan, focusing on a few key edge parameters, such as edge plasma rotation and collisionality ($\nu^*_e$). Based on a typical $n$=1 RMP-driven, ELM-crash-suppression condition at $q_{95}\sim$5, both parameters have been explored using a controlled divertor gas puff under $P_{NBI}$=2.85 MW, where $\nu^*_e$ varied from $\sim$0.2 to $\sim$1.0 (at $Z_{eff}$=2). The ELM-crash-suppression was observed at $0.4<\nu^{*}_e<0.7$ with $I_{RMP}$=1.7 kA/turn. Interestingly the ELM-suppression window was slightly expanded to $0.3<\nu^*_e<0.8$ by applying more $I_{RMP}$ of 2.1 kA/turn. To quantify the uncertainties of the prior estimates, a set of qualified data in previous run-campaigns are reprocessed. So far, both parameters remain in a similar range, despite more diversified conditions; $P_{NBI}=2.8-3.4$, and $q_{95}\sim5.1-5.5$. But, to ascertain whether the limits of $\nu^*_e$ exist, along with an edge rotation threshold for ITER-like low-torque plasma, additional scans are planned in KSTAR as ITPA-PEP activity.