Parameter space of low frequency inter-ELM modes

Introduction: The ELM cycle of type-I ELMs consists of different phases characterized by the evolution of kinetic profiles on different time scales [1] and distinct MHD and turbulence activity. In the latest phase of the ELM cycle, the pressure gradients are clamped. During this phase low [2], medium [3] and high frequency [4] MHD modes develop simultaneously in the steep gradient region. The high-frequency modes are located close to the minimum of the Er well, and are measured as fluctuations in the radial magnetic field on both, low and high field side [4]. The focus of the work presented here is the low-frequency modes. The low frequency modes are measured only at the low field side and are located further inwards, towards the pedestal top [5]. They appear as fluctuations in the electron density, the electron temperature and as magnetic fluctuations. These modes rotate poloidally in the electron diamagnetic direction with the velocity of the background flow at that position [5]. The nature of this mode is not yet clear. In this work, we show the dependences of the low-frequency mode characteristics on some of the plasma and ELM parameters