2013/01/31 by S. Saarelma, M. N. A. Beurskens, M.N.A. Beurskens +8 · 56 citations
Physics and Astronomy · #Atmospheric-pressure plasma #Ballooning #Collisionality #Dust and Plasma Wave Phenomena #Jet (fluid) #Laser-Plasma Interactions and Diagnostics #Magnetic confinement fusion research #Magnetohydrodynamics #Pedestal #Plasma #Pressure gradient #Tokamak #physics.plasm-ph
paper · pdf · doi:10.1088/0029-5515/53/12/123012
published in Nuclear Fusion 53(12), 123012 (IOP Publishing) · submitted to Nuclear Fusion, 23 pages, for EFDA-JET contributors see the Appendix of F. Romanelli et al., Proceedings of the 24th IAEA Fusion Energy Conference 2012, San Diego, USA
openalex publication_date 2013/11/12 · arxiv created 2013/12/04 · arxiv updated 2013/12/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The pedestal profile measurements in high triangularity JET plasmas show that with low fuelling the pedestal width decreases during the ELM cycle and with high fuelling it stays constant. In the low fuelling case the pedestal pressure gradient keeps increasing until the ELM crash and in the high fuelling case it initially increases then saturates during the ELM cycle. Stability analysis reveals that both JET plasmas become unstable to finite- n ideal MHD peeling–ballooning modes at the end of the ELM cycle. During the ELM cycle, n = ∞ ideal MHD ballooning modes and kinetic ballooning modes are found to be locally stable in most of the steep pressure gradient region of the pedestal owing to the large bootstrap current, but to be locally unstable in a narrow region of plasma at the extreme edge. Unstable micro-tearing modes are found at the JET pedestal top, but they are sub-dominant to ion temperature gradient modes. They are insensitive to collisionality and stabilized by increasing density gradient.