Towards a quantitative comparison between electron scale turbulence experiment and simulation

Juan Ruiz Ruiz


Tuesday, December 5, 2017


PSFC Student Seminars

Achieving high plasma confinement is a critical requirement towards achieving successful fusion operation in future fusion devices. Current tokamak experiments exhibit heat losses caused by turbulent fluctuations that take place at ion and electron gyro-radius scales, which degrade the confinement of the plasma and impede fusion reactions to take place. Spherical tokamaks exhibit heat losses due to ions to be negligible (under some parametric regimes), but heat losses due to electrons remain unexplained and are the dominant heat loss mechanism. One of the main candidates to explain the transport of electron heat in spherical tokamaks are turbulent fluctuations taking place at electron gyro-radius scales. However, current models of electron scale turbulence have still to be properly validated against experimental measurements in spherical tokamaks.

In this talk I will explain how electron scale turbulence can be studied experimentally and numerically in spherical tokamaks. I will emphasize on the importance of designing synthetic numerical experiments that mimic tokamak experimental measurements, called synthetic diagnostics, in order to validate plasma turbulence models against experiments. I will present my current efforts to design a synthetic diagnostic to study electron scale turbulence and the transport of electron heat in the National Spherical Tokamak eXperiment (NSTX).