Neoclassical momentum transport in a collisional stellarator and a rippled tokamak

Simakov, Andrei N.; Helander, Per
April 2009
Physics of Plasmas;Apr2009, Vol. 16 Issue 4, p042503
Academic Journal
Short mean-free path two-fluid equations are employed to evaluate the lowest order nonambipolar radial current in plasma confined by a three-dimensional toroidal magnetic field. The result is used to obtain a necessary condition for intrinsic ambipolarity of plasma transport in such a field and to derive a criterion for the importance of the toroidal field ripple for collisional tokamak plasma rotation. The ripple effects on toroidal plasma rotation are found to be negligible if the characteristic perpendicular length scale is determined by the pedestal width of order the poloidal ion gyroradius (as may be the case in the H-mode regime), but may conceivably become important for more shallow plasma gradients.


Related Articles

  • Magnetic Fields in Star-Forming Regions: Theoretical Aspects. Galli, Daniele // Astrophysics & Space Science;Jan2005, Vol. 295 Issue 1/2, p43 

    We review the basic theoretical elements leading to our current understanding of the role of magnetic fields in the process of star formation. In particular, we concentrate on: (i) the relevance of the mass-to-flux ratio for the stability of molecular clouds; (ii) the consequences of magnetic...

  • Energy balance of a plasma opening switch in the conduction stage. Loginov, S. V. // Technical Physics Letters;Aug2007, Vol. 33 Issue 8, p667 

    The energy balance of a plasma opening switch (POS) in the stage of conduction is calculated for a system, in which the dominating process is the magnetic field penetration into the plasma bridge volume due to the snowplow effect. This mechanism is typical of a microsecond POS for the megaampere...

  • Deterministic Domain Wall Motion Orthogonal To Current Flow Due To Spin Orbit Torque. Bhowmik, Debanjan; Nowakowski, Mark E.; You, Long; Lee, OukJae; Keating, David; Wong, Mark; Bokor, Jeffrey; Salahuddin, Sayeef // Scientific Reports;7/3/2015, p11823 

    Spin-polarized electrons can move a ferromagnetic domain wall through the transfer of spin angular momentum when current flows in a magnetic nanowire. Such current induced control of a domain wall is of significant interest due to its potential application for low power ultra high-density data...

  • Improved angular momentum evolution model for solar-like stars. Gallet, F.; Bouvier, J. // Astronomy & Astrophysics / Astronomie et Astrophysique;May2015, Vol. 577, p1 

    Context. Understanding the physical processes that dictate the angular momentum evolution of solar-type stars from birth to maturity remains a challenge for stellar physics. Aims. We aim to account for the observed rotational evolution of low-mass stars over the age range from 1 Myr to 10 Gyr....

  • Probability of orbit transition in asymmetric toroidal plasma. Cary, John R.; Shasharina, S. G. // Physics of Fluids B: Plasma Physics;Jul93, Vol. 5 Issue 7, p2098 

    Trapped particles in stellarators and tokamaks can be either locally trapped in the ripple wells or toroidally trapped by the 1/R variation of the magnetic field strength. Transitioning particles make transitions back and forth between these two states. The transition probability gives the...

  • Analysis of toroidal phasing of resonant magnetic perturbation effects on edge transport in the DIII-D tokamak. Wilks, T. M.; Stacey, W. M.; Evans, T. E. // Physics of Plasmas;May2013, Vol. 20 Issue 5, p052505 

    Resonant Magnetic Perturbation (RMP) fields produced by external control coils are considered a viable option for the suppression of Edge Localized Modes in present and future tokamaks. In DIII-D, the RMPs are generated by six pairs of I-coils, each spanning 60° in toroidal angle, with the...

  • Evaluation of the toroidal torque driven by external non-resonant non-axisymmetric magnetic field perturbations in a tokamak. Kasilov, Sergei V.; Kernbichler, Winfried; Martitsch, Andreas F.; Maassberg, Henning; Heyn, Martin F. // Physics of Plasmas;2014, Vol. 21 Issue 9, p1 

    The toroidal torque driven by external non-resonant magnetic perturbations (neoclassical toroidal viscosity) is an important momentum source affecting the toroidal plasma rotation in tokamaks. The well-known force-flux relation directly links this torque to the non-ambipolar neoclassical...

  • δf Monte Carlo calculation of neoclassical transport in perturbed tokamaks. Kim, Kimin; Park, Jong-Kyu; Kramer, Gerrit J.; Boozer, Allen H. // Physics of Plasmas;Aug2012, Vol. 19 Issue 8, p082503 

    Non-axisymmetric magnetic perturbations can fundamentally change neoclassical transport in tokamaks by distorting particle orbits on deformed or broken flux surfaces. This so-called non-ambipolar transport is highly complex, and eventually a numerical simulation is required to achieve its...

  • Interpretation of edge pedestal rotation measurements in DIII-D. Stacey, W. M.; Groebner, R. J. // Physics of Plasmas;Jan2008, Vol. 15 Issue 1, p012503 

    A novel methodology for inferring experimental toroidal angular momentum transfer rates from measured toroidal rotation velocities and other measured quantities has been developed and applied to analyze rotation measurements in the DIII-D [J. Luxon, Nucl. Fusion 42, 6149 (2002)] edge pedestal....


Read the Article


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

Try another library?
Sign out of this library

Other Topics