Local dependence of ion temperature gradient on magnetic configuration, rotational shear and turbulent heat flux in MAST

Autor:	Ghim, Y. -c., Field, A. R., Schekochihin, A. A., Highcock, E. G., Michael, C., Team, the MAST
Rok vydání:	2012
Předmět:	Physics - Plasma Physics
Druh dokumentu:	Working Paper
Popis:	Experimental data from the Mega Amp Spherical Tokamak (MAST) is used to show that the inverse gradient scale length of the ion temperature R/LTi (normalized to the major radius R) has its strongest local correlation with the rotational shear and the pitch angle of the magnetic field (or, equivalently, an inverse correlation with q/{\epsilon}, the safety factor/the inverse aspect ratio). Furthermore, R/LTi is found to be inversely correlated with the gyro-Bohm-normalized local turbulent heat flux estimated from the density fluctuation level measured using a 2D Beam Emission Spectroscopy (BES) diagnostic. These results can be explained in terms of the conjecture that the turbulent system adjusts to keep R/LTi close to a certain critical value (marginal for the excitation of turbulence) determined by local equilibrium parameters (although not necessarily by linear stability). Comment: 6 pages, 3 figures, submitted to PRL
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1211.2883 Zobrazit plný text záznamu View this record from Arxiv