The confinement of helium tokamak plasmas, impact of electron heating, turbulent transport and zonal flows

摘要

Helium plasmas in tokamaks are regularly observed to have a reduced confinement with respect to deuterium plasmas [1,2], which is inconsistent with the gyro-Bohm scaling of turbulent transport. A theoretical explanation of this confinement reduction is required to reliably predict the plasma confinement in the initial non-nuclear phases of ITER operation and also extend the understanding of the isotope effect, hydrogen and helium having the same Larmor radius.