Analysis of T_e/T_i Effect on Confinement Properties

Abstract

In order to improve the prediction capability of confinement properties in burning plasmas with intensive electron heating, we have re-visited the DB3v10 International H-mode Confinement Database with emphasis on the temperature ratio T_e/T_i and considerations on kinetic profiles. It was thereby found that the impact of T_e/T_i is more apparent for discharges with peaked density profiles. Namely, H_H factor improves with an increase of peakedness in the density profile for T_e/T_i < 1, whereas it tends to deteriorate with the density peaking for T_e/T_i > 1. The confinement scaling with a contribution of T_e/T_i was also elaborated. In addition, the influence of T_e/T_i described above was examined qualitatively with GS2 and GLF23 codes, which provided results corroborating the performed regression analysis, indicating the interplay of ITG and TEM in the turbulence transport.