Global full-f Gyrokinetic simulations of isotope scaling in ion temperature gradient driven turbulence

Idomura, Yasuhiro   

Numerical experiments of hydrogen (H) and deuterium (D) plasmas with ion and electron heating conditions were conducted using the Gyrokinetic Toroidal 5D full-f Eulerian code GT5D. The energy confinement time in the ion heated numerical experiments was almost independent of isotope mass, and the plasma size scaling gives Bohm scaling. On the other hand, the electron heated numerical experiments showed a clear isotope effect. In this case, in addition to the plasma size scaling, the isotope dependency of the collisional energy transfer from electrons to ions contributed to the total isotope scaling by enhancing the ion heat transport channel. Systematic electron heating power scans for the H and D plasmas showed similar ion and electron temperature profiles at an H to D heating power ratio of 1.4. These results qualitatively agree with the isotope scaling in L-mode experiments with ion and electron heating conditions.