Electron temperature fluctuation measurements of pedestal fluctuations in improved confinement regimes at ASDEX Upgrade

Improved confinement regimes, including stationary ELM-free H-mode (similar to the EDA H-mode), QH-mode, and I-mode, have the benefit of high energy confinement without the presence of ELMs. These three regimes all have edge modes thought to be associated with their favorable confinement properties. Temperature fluctuation measurements provide important information on scaling and transitions between L-mode, H-mode, and improved confinement regimes. These measurements can be obtained using Correlation Electron Cyclotron Emission (CECE) with high temporal (4 MHz) and good spatial (4 mm) resolution. This work presents temperature fluctuation measurements in improved confinement regimes at ASDEX Upgrade from a multi-channel CECE radial comb. In this work, edge modes are localized, and the structure of broadband turbulence is compared between L-mode and several types of improved regimes.