Alpha heating and isotopic mass effects in JET plasmas with sawteeth. (9th February 2016)

• Record Type: Journal Article
• Authors: Budny, R.V.
• Other Names: collab.
• Is Part Of: Nuclear fusion. Volume 56:Number 3(2016:Mar.)
• Publication Date: 2016-02-09
• Subjects: JET -- alpha heating -- transport modeling -- energy balance -- ITER -- integrated modeling; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/56/3/036013
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: The alpha heating experiment in the Joint European Torus (JET) 1997 DTE1 campaign is re-examined. Several effects correlated with tritium content and thermal hydrogenic isotopic mass < A > weaken the conclusion that alpha heating was clearly observed. These effects delayed the occurrence of significant sawtooth crashes allowing the electron and ion temperatures T e and T i to achieve higher values. Under otherwise equal circumstances T e and T i were typically higher for discharges with higher < A >, and significant scaling of T i, T e, and total stored energy with < A > were observed. The higher T i led to increased ion–electron heating rates with magnitudes comparable to those computed for alpha electron heating. Rates of other heating/loss processes also had comparable magnitudes. Simulations of T e assuming the observed scaling of T i are qualitatively consistent with the measured profiles, without invoking alpha heating