Electromagnetic properties of edge turbulence in fusion plasma devices
- Liu, Bing
- Juan Carlos Hidalgo Vera Director/a
- Monica Spolaore Director/a
Universidad de defensa: Universidad Carlos III de Madrid
Fecha de defensa: 04 de noviembre de 2016
- Leonardo Giudicotti Presidente/a
- Luis García Gonzalo Secretario
- Francisco Miguel Castejon Magaña Vocal
Tipo: Tesis
Resumen
This thesis work consists of three pillars. First, the isotope dependence of long-range correlation (due to, e.g. zonal flow and GAMs) has been studied in the TJ-II stellarator and ISTTOK tokamak with dual Langmuir probes. In TJ-II, It has been found that LRC slightly decreases with isotope mass, in contrast to tokamak results. In ISTTOK, GAM amplitude has been found to be higher in D than H dominated plasmas, in agreement with other tokamak results. Using biorthogonal decomposition (BOD), GAM and low frequency coherent modes were separated; their spectral and spatial structure properties were studied. In addition, measurements of Reynolds stress and Maxwell stress have been made using an electromagnetic probe during L-H transition in TJ-II. Second, macroscale flows and non-diffusive behavior of particle dynamics have been found around magnetic islands in TJ-II and RFX-mod with the analysis of long-range spatial and temporal correlation (Hurst exponent). In TJ-II, during dynamic configuration scan experiments, rational surfaces have been found to affect the development of long-range spatial and temporal correlation. In RFX-mod, LRC has been detected at both sides of the m=0 island. The possible relation between long-range temporal correlation (Hurst exponent) and the phase angle of magnetic perturbation was also studied. Third, a new strategy for studying plasma potential asymmetries in magnetic flux surface has been developed based on edge electrode biasing and probe measurements.