Dynamics of cold pulses induced by super-sonic molecular beam injection in the EAST tokamak
Abstract
Evolution of electron temperature, electron density and its fluctuation with high spatial and temporal resolutions are presented for the cold pulse propagation induced by super-sonic molecular beam injection (SMBI) in ohmic plasmas in the EAST tokamak. The non-local heat transport occurs for discharges with plasma current [ image ] kA ([ image ]), and electron density ne0 below a critical value of [ image ] m-3. In contrary to the response of core electron temperature and electron density (roughly 10 ms after SMBI), the electron density fluctuation in the plasma core increases promptly after SMBI and reaches its maximum around 15 ms after SMBI. The electron density fluctuation in the plasma core begins to decrease before the core electron temperature reaches its maximum (roughly 30 ms). It was also observed that the turbulence perpendicular velocity close to the inversion point of the temperature perturbation changes sign after SMBI.
- Publication:
-
Nuclear Fusion
- Pub Date:
- April 2019
- DOI:
- 10.1088/1741-4326/ab0665
- arXiv:
- arXiv:1810.05352
- Bibcode:
- 2019NucFu..59d4005L
- Keywords:
-
- non-local transport;
- turbulence measurement;
- high spatial and temporal resolutions;
- turbulence spreading;
- Physics - Plasma Physics
- E-Print:
- doi:10.1088/1741-4326/ab0665