Turbulent regimes in the tokamak scrape-off layer

Mosetto, Annamaria; Halpern, Federico D.; Jolliet, S├ębastien; Loizu, Joaquim; Ricci, Paolo
September 2013
Physics of Plasmas;Sep2013, Vol. 20 Issue 9, p092308
Academic Journal
The non-linear turbulent regimes in the tokamak scrape-off layer (SOL) are identified according to the linear instability responsible for the perpendicular transport. Four regions of the SOL operational parameters are determined where turbulence is driven by the inertial or resistive branches of the ballooning mode or of drift waves. The analysis, based on the linear electrostatic drift-reduced Braginskii equations, evaluates the pressure scale length self-consistently from the balance between plasma losses at the vessel and perpendicular turbulent transport. The latter is estimated by assuming that turbulence saturation occurs due to a local flattening of the plasma gradients and associated removal of the linear instability drive; it is also shown that transport is led by the mode that maximizes the ratio of the linear growth to the poloidal wavenumber. The methodology used to identify the turbulent regimes is confirmed by the results of non-linear simulations of SOL turbulence. The identification of the turbulent regimes, the predicted pressure scale length, and the poloidal wavenumber of the leading mode are in reasonable agreement with non-linear simulation results.


Related Articles

  • Magnetic stochasticity and transport due to nonlinearly excited subdominant microtearing modes. Hatch, D. R.; Pueschel, M. J.; Jenko, F.; Nevins, W. M.; Terry, P. W.; Doerk, H. // Physics of Plasmas;Jan2013, Vol. 20 Issue 1, p012307 

    Subdominant, linearly stable microtearing modes are identified as the main mechanism for the development of magnetic stochasticity and transport in gyrokinetic simulations of electromagnetic ion temperature gradient driven plasma microturbulence. The linear eigenmode spectrum is examined in...

  • Multi-field characteristics and eigenmode spatial structure of geodesic acoustic modes in DIII-D L-mode plasmas. Wang, G.; Peebles, W. A.; Rhodes, T. L.; Austin, M. E.; Yan, Z.; McKee, G. R.; La Haye, R. J.; Burrell, K. H.; Doyle, E. J.; Hillesheim, J. C.; Lanctot, M. J.; Nazikian, R.; Petty, C. C.; Schmitz, L.; Smith, S.; Strait, E. J.; Van Zeeland, M.; Zeng, L. // Physics of Plasmas;Sep2013, Vol. 20 Issue 9, p092501 

    The geodesic acoustic mode (GAM), a coherent form of the zonal flow, plays a critical role in turbulence regulation and cross-magnetic-field transport. In the DIII-D tokamak, unique information on multi-field characteristics and radial structure of eigenmode GAMs has been measured. Two...

  • Plasma turbulence in the scrape-off layer of tokamak devices. Ricci, Paolo; Rogers, B. N. // Physics of Plasmas;Jan2013, Vol. 20 Issue 1, p010702 

    Plasma turbulence is explored in the scrape-off layer of tokamak devices using three-dimensional global two-fluid simulations. Two transport regimes are discussed: one in which the turbulent fluctuations saturate nonlinearly due to the Kelvin-Helmholtz instability, and another in which the...

  • Neoclassical transport coefficients for finite-aspect-ratio and bean-shaped tokamak plasmas. Crume, E. C.; Beasley, C. O.; Hirshman, S. P.; van Rij, W. I. // Physics of Fluids (00319171);Apr87, Vol. 30 Issue 4, p1152 

    Numerically calculated tokamak equilibria are used to compute banana-plateau transport coefficients for finite-aspect-ratio, finite-beta plasmas. Calculations are presented for the Spherical Torus Experiment (STX) (NTIS Document No. DE 86004663) and the Princeton Beta Experiment (PBX) (NTIS...

  • Neoclassical transport coefficients for tokamaks with bean-shaped flux surfaces. Chang, C. S.; Kaye, S. M. // Physics of Fluids B: Plasma Physics;Feb91, Vol. 3 Issue 2, p395 

    Simple analytic representations of the neoclassical transport coefficients for indented flux surfaces are presented. It is shown that a transport coefficient for an indented flux surface can be expressed in terms of a linear combination of the previously known transport coefficients for two...

  • Transport properties of the interacting magnetic-island model of tokamak plasmas. Gianakon, T.A.; Callen, J.D.; Hegna, C.C. // Physics of Plasmas;Jul94, Vol. 1 Issue 7, p2245 

    Explores the equilibrium and transient transport properties of a mixed magnetic topology model for tokamak equilibria. Composition of magnetic topology; Nonlinear dependence of the heat flux on the pressure gradient; Exhibition of a heat pulse diffusion coefficient larger than the power balance...

  • The impact of a biasing radial electric field on the scrape-off layer in a divertor tokamak. Rozhansky, V.; Tendler, M. // Physics of Plasmas;Aug94, Vol. 1 Issue 8, p2711 

    Addresses the issue of transport on open field lines using a fluid approach invoking anomalous inertia and viscosity. Emphasis of the model on transport of the toroidal momentum; Benefits of tokamaks with divertors from an amplification of the electric field; Phenomena resulting from the...

  • On the statistical mechanics of self-organized profiles. Medvedev, M.V.; Diamond, P.H. // Physics of Plasmas;Oct96, Vol. 3 Issue 10, p3745 

    Analyzes the radial structure of tokamak profiles determined by anomalous transport elucidated by studying the statistical mechanics of a sand pile automation for which the toppling conditions depend on local gradient. Markovian nature of the sand pile dynamics; Spatial profiles obtained from...

  • Formation of core transport barriers by parallel flow. Sen, S. // Physics of Plasmas;Apr98, Vol. 5 Issue 4, p1000 

    Demonstrates the formation of the tokamak core transport barriers by parallel flow. Stabilization of the drift-ballooning modes through a radially varying parallel flow profile; Description of the scale length of the flow profile; Use of the purely parallel flow to create transport barriers;...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics