Isotope effects on turbulent transport and entropy transfer processes in toroidal plasmas

In this article, additional discussions on the nonlinear entropy transfer between turbulence and zonal flows are given for the isotope ion mass effects on the trapped-electron-mode (TEM) driven turbulent transport shown in Ref. 1. Spectral analyses with the triad entropy transfer function reveal that the case with heavier isotope ions indicates a relatively smaller negative transfer (from zonal flows to turbulence), which implies to the weaker nonlinear decay of zonal flows.