Radial Electric Fields duringL-to-HTransition and Edge-Localized Modes from Charge-Exchange Diagnostics of Ripple-Trapped Particles

Neutral fluxes from charge-exchange processes with ripple-trapped particles depend on radial electric fields. Their time behavior during $L$-to-$H$ transition and edge-localized modes (ELMs) was studied with a time resolution of up to 50 μs. No jumps at the L-to-H transition are observed that are faster than the increase of the field after ELMs. The signature of the neutral particle spectra is different for $L$ and $H$ modes and allows discrimination of the modes. ELMs and electric fields are present during the CDH (completely detached H) mode.