2015/03/01 by T. Happel, A. Bañón Navarro, G. D. Conway +11 · 1 citation
Materials Science · Physics and Astronomy · #Fusion materials and technologies #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research
paper · doi:10.1063/1.4914153
openalex publication_date 2015/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Additional electron cyclotron resonance heating (ECRH) is used in an ion-temperature-gradient instability dominated regime to increase R/LTe in order to approach the trapped-electron-mode instability regime. The radial ECRH deposition location determines to a large degree the effect on R/LTe. Accompanying scale-selective turbulence measurements at perpendicular wavenumbers between k⊥ = 4–18 cm−1 (k⊥ρs = 0.7–4.2) show a pronounced increase of large-scale density fluctuations close to the ECRH radial deposition location at mid-radius, along with a reduction in phase velocity of large-scale density fluctuations. Measurements are compared with results from linear and non-linear flux-matched gyrokinetic (GK) simulations with the gyrokinetic code GENE. Linear GK simulations show a reduction of phase velocity, indicating a pronounced change in the character of the dominant instability. Comparing measurement and non-linear GK simulation, as a central result, agreement is obtained in the shape of radial turbulence level profiles. However, the turbulence intensity is increasing with additional heating in the experiment, while gyrokinetic simulations show a decrease.