Year: 2026
Type: article
Abstract: Recent experiments reported a correlation between power law core temperature spectra and D α emission, suggesting that heat avalanches penetrate the SOL. This paper derives a threshold criterion for avalanche penetration using a reduced model. Avalanches with ( ∇ T ~ ) rms > ∇ T ~ crit at the separatrix are predicted to penetrate, and so broaden the SOL and heat load distribution. ∇ T ~ crit is ∼ 1 / τ ∥ , where τ ∥ is the parallel heat flow time through the SOL. Penetration occurs when avalanches are strong enough to steepen sufficiently to shock at the separatrix. A positive correlation is found between the nonlinear drive for steepening and the penetration depth. In particular, penetration depth exceeds that of the heuristic drift limit when shocks form. Implications for numerical and physical experiments are also discussed.
Source: Nuclear Fusion
Authors: Y. Kosuga, R. Matsui, P.H. Diamond
Institutions: Kyushu University, University of California San Diego
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,595
Awards: INVESTIGATIONS IN ANOMALOUS TRANSPORT AND IGNITION PHYSICS, G2203179303, G222768804, INVESTIGATIONS IN ANOMALOUS TRANSPORT AND IGNITION PHYSICS, Reduction of heat load on divertor by turbulence and transport, G3223208087, G3341554066, INVESTIGATIONS IN ANOMALOUS TRANSPORT AND IGNITION PHYSICS, G4788971108, Isaac Newton Institute for Mathematical Sciences, G6207939895, Plasma Turbulence Obseravation System (PLATOS) for puzzling out the principles of structural formation and functional expression in turbulent plasmas
OpenAlex ID: W7128469836