EDGE2D-EIRENE and ERO2.0 predictions of nitrogen molecular break-up and transport in the divertor of JET low-confinement mode plasmas. (October 2022)

• Record Type: Journal Article
• Authors: Mäenpää, R.; Kumpulainen, H.; Groth, M.; Romazanov, J.; Lomanowski, B.; Brezinsek, S.; Di Genova, S.; Karhunen, J.; Lawson, K.; Meigs, A.G.; Menmuir, S.; Shaw, A.
• Is Part Of: Nuclear materials and energy. Volume 33(2022)
• Publication Date: 2022-10
• Subjects: Nitrogen emission -- JET -- EDGE2D-EIRENE -- ERO2.0; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2022.101273
• Languages: English
• ISSNs: 2352-1791

Abstract

Highlights: Nitrogen-seeded partially detached JET l -mode plasmas studied using EDGE2D-EIRENE and ERO2.0. Nitrogen line intensities (N I to N V) in the outer divertor are reproduced to within 50% with EDGE2D-EIRENE. Nitrogen line intensity peak locations shown to be highly sensitive to the upstream electron density. ERO2.0 simulations with nitrogen molecular dissociation reactions included suggest a high-degree of molecular recycling. Abstract: EDGE2D-EIRENE simulations of nitrogen-seeded partially detached JET l -mode plasmas show that the divertor N I to N V radiation distributions are highly sensitive to the upstream electron density, and less sensitive to changes in the assumed cross-field particle diffusivity for nitrogen ions. The EDGE2D-EIRENE simulations reproduce the peak intensities of N I to N V as measured by vertically viewing divertor filterscopes to within 50 % for a narrow range of the upstream electron density within the experimental uncertainties, while the predicted profiles are narrower than the measured ones. Including nitrogen atoms only in the ERO2.0 simulations implies lower N III and N IV peak intensities by one and two thirds, respectively, compared to EDGE2D-EIRENE. If nitrogen is assumed to recycle exclusively as molecules instead of atoms, ERO2.0 predicts that the N III and N IV intensities in the divertor increase by up to a factor of two and that the time-averaged, volume-integrated number of N 5+ to N 7+ ions in the plasma also increases by approximately a factor of 2.