Radial variation of heat transport in L-mode JET discharges. (22nd March 2019)

• Record Type: Journal Article
• Authors: van Milligen, B.Ph.; Carreras, B.A.; de la Luna, E.; Solano, E.R.
• Other Names: collab.
• Is Part Of: Nuclear fusion. Volume 59:Number 5(2019:May)
• Publication Date: 2019-03-22
• Subjects: fusion -- magnetic confinement -- heat transport -- transport barriers; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/ab03e1
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: In this paper, we analyze heat transport in the JET tokamak using data from its high resolution ECE diagnostic and analyses based on the transfer entropy (TE). The analysis reveals that heat transport is not smooth and continuous, but is characterized by 'trapping regions' separated by 'minor transport barriers'. Heat may 'jump over' these barriers and when the heating power is raised, this 'jumping' behavior becomes more prominent. To check that our results are relevant for global heat transport, we deduced an effective diffusion coefficient from the TE results. Both its value and overall radial variation are consistent with heat diffusivities reported in literature. The detailed radial structure of the effective diffusion coefficient was shown to be linked to the mentioned minor transport barriers.