Effects of nitrogen seeding on core ion thermal transport in JET ILW L-mode plasmas. (5th January 2018)

• Record Type: Journal Article
• Authors: Bonanomi, N.; Mantica, P.; Citrin, J.; Giroud, C.; Lerche, E.; Sozzi, C.; Taylor, D.; Tsalas, M.; Van Eester, D.
• Other Names: collab.
• Is Part Of: Nuclear fusion. Volume 58:Number 2(2018:Feb.)
• Publication Date: 2018-01-05
• Subjects: turbulent transport -- gyrokinetic simulations -- quasilinear simulations -- nuclear fusion -- light impurities in JET; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/aa9e7c
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: A set of experiments was carried out in JET ILW (Joint European Torus with ITER-Like Wall) L-mode plasmas in order to study the effects of light impurities on core ion thermal transport. N was puffed into some discharges and its profile was measured by active Charge Exchange diagnostics, while ICRH power was deposited on- and off-axis in ( 3 H e ) − D minority scheme in order to have a scan of local heat flux at constant total power with and without N injection. Experimentally, the ion temperature profiles are more peaked for similar heat fluxes when N is injected in the plasma. Gyro-kinetic simulations using the GENE code indicate that a stabilization of Ion Temperature Gradient driven turbulent transport due to main ion dilution and to changes in T e / T i and s / q is responsible of the enhanced peaking. The quasi-linear models TGLF and QuaLiKiz are tested against the experimental and the gyro-kinetic results.