Effect of resistivity on the pedestal MHD stability in JET

Abstract The ELM triggering mechanism in tokamaks is not yet fully understood. For example, the JET tokamak with ITER-like wall (commonly called JET-ILW), ELMs are sometimes triggered before ideal peeling-ballooning (PB) boundary reached. This typically occurs for shots high input power and gas rate. discrepancy between model experiment has previous works been clearly correlated relative shift electron temperature density pedestals. also resistivity middle-bottom of pedestal. present work shows that resistive MHD can have a significant impact on PB stability inclusion removes correlation from (the difference position pedestals) significantly improves agreement experimental results. key parameter at pedestal bottom, near separatrix, while middle/top negligible effect plasmas.