Close coupling of the peeling ballooning and external kink modes in high poloidal-beta discharges with strong shape and large pedestal width

In plasmas with strong shape and large pedestal width, like DIII-D high poloidal-beta discharges, the eigenvalue spectrum of peeling ballooning mode (PBM) is shown to shift very low-n regime near one, where n toroidal number. This peeling-type has a further = 1, thus being smoothly connected 1 external kink (EKM), as normalized beta (βN) increases. Once this connection occurs, takes mixture form PBM EKM its structure varying from PBM-like EKM-like one βN The stability also becomes sensitive both local gradient global βN, allowing an anti-correlation between two driving forces. These results appear provide qualitative explanation unexpected features observed in that is, dominance edge-localized-modes negative correlation height internal transport barrier strength.