Stochastic effects on phase-space holes and clumps in kinetic systems near marginal stability

Autor(es)

Woods, B. J. Q. ^[1] ; Duarte, V. N. ^{[2, 3]} ; De-Gal, A. J. ^[1] ; Gorelenkov, N. N. ^[3] ; Vann, R. G. L. ^[1]

Afiliação do(s) autor(es)

^[1] Univ York, York Plasma Inst, Dept Phys, York YO10 5DD, N Yorkshire - England

^[2] Univ Sao Paulo, Inst Phys, BR-05508090 Sao Paulo, SP - Brazil

^[3] Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 - USA

• Tipo de documento: Artigo Científico
• Fonte: NUCLEAR FUSION; v. 58, n. 8 AUG 2018.
• Citações Web of Science: 3

Resumo

The creation and subsequent evolution of marginally-unstable modes have been observed in a wide range of fusion devices. This behaviour has been successfully explained, for a single frequency shifting mode, in terms of phase-space structures known as a `hole' and `clump'. Here, we introduce stochasticity into a 1D kinetic model, affecting the formation and evolution of resonant modes in the system. We find that noise in the fast particle distribution or electric field leads to a shift in the asymptotic behaviour of a chirping resonant mode; this noise heuristically maps onto radial microturbulence via canonical toroidal momentum scattering, affecting hole and clump formation. While the mechanism allowing for the formation of the hole and clump is coherent, the lifetime of a hole and clump is shown to be highly sensitive to initial conditions, affecting the temporal profile of a single bursting event in mode amplitude. (AU)

• Processo FAPESP: 14/03289-4 - Teoria quase-linear da interação de partículas energéticas com automodos de Alfvén induzidos por toroidicidade
• Beneficiário: Vinícius Njaim Duarte
• Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 12/22830-2 - Modos acústicos geodésicos e contínuo de Alfvén em colunas de plasma com rotação
• Beneficiário: Vinícius Njaim Duarte
• Linha de fomento: Bolsas no Brasil - Doutorado