Entropy production rate in tokamaks with nonaxisymmetric magnetic fields

Garbet, X.; Abiteboul, J.; Trier, E.; Gürcan, Ö.; Sarazin, Y.; Smolyakov, A.; Allfrey, S.; Bourdelle, C.; Fenzi, C.; Grandgirard, V.; Ghendrih, P.; Hennequin, P.
July 2010
Physics of Plasmas;Jul2010, Vol. 17 Issue 7, p072505
Academic Journal
A variational principle based on an extremum of entropy production rate is derived for an integrable Hamiltonian system in the presence of two perturbations, which are resonant on neighboring or identical resonant surfaces. This method can be used to calculate the neoclassical transport in a magnetic fusion device with a nonaxisymmetric magnetic field. When applied to a tokamak with ripple, it provides an efficient means to discriminate between various regimes, depending on collisionality and ripple amplitude. This technique provides a means to test simplified collision operators suitable for gyrokinetic codes. It is found that these operators need only satisfy modest requirements in order to recover the correct neoclassical equilibrium, at least in the large aspect ratio limit. Finally, it appears that the toroidal viscous damping rate due to ripple is usually not negligible, thus removing the degeneracy between the radial electric field and the toroidal velocity.


Related Articles

  • Full-Wave Studies of Lower Hybrid Wave Propagation in Tokamaks. Bonoli, P. T.; Wright, J. C.; Richardson, A. S.; Schmidt, A. E.; Phillips, C. K.; Valeo, E. // AIP Conference Proceedings;11/26/2009, Vol. 1187 Issue 1, p359 

    A full-wave electromagnetic field solver valid the lower hybrid range of frequencies (LHRF) has been developed that utilizes a semi-spectral representation for the RF electric field. Spurious numerical behavior of the field solver that was found to be related to the inclusion of finite electron...

  • Single-particle motion in nonaxisymmetric static electric and magnetic fields. Weitzner, Harold // Physics of Plasmas;Oct95, Vol. 2 Issue 10, p3595 

    Studies the motion of a single particle of small Larmor radius in static, nonaxisymmetric electric and magnetic fields. Application of the technique of iteration of canonical transformations for a Hamiltonian system; Discussion of the appropriate transformations to guiding center coordinates...

  • The relativistic drift Hamiltonian. Boozer, Allen H. // Physics of Plasmas;Sep96, Vol. 3 Issue 9, p3297 

    Focuses on the relativistic Hamiltonian for the guiding center motion of particles in electric and magnetic fields in canonical form. Comparison of the particle gyroradius with the spatial scale of the magnetic and electric fields; Comparison of the cyclotron frequency with the temporal scale...

  • An accurate symplectic calculation of the inboard magnetic footprint from statistical topological noise and field errors in the DIII-D. Punjabi, Alkesh; Ali, Halima // Physics of Plasmas;Feb2011, Vol. 18 Issue 2, p022509 

    Any canonical transformation of Hamiltonian equations is symplectic, and any area-preserving transformation in 2D is a symplectomorphism. Based on these, a discrete symplectic map and its continuous symplectic analog are derived for forward magnetic field line trajectories in natural canonical...

  • Lifshits tails for random smooth magnetic vortices. Borg, J. L.; Pulé, J. V. // Journal of Mathematical Physics;Dec2004, Vol. 45 Issue 12, p4493 

    We study the density of states of the Pauli Hamiltonian with a Poisson random distribution of smooth finite-width vortices and we obtain classical bounds for the Lifshits tails for them. These Hamiltonians are smooth approximations to the self-adjoint extensions of the Aharonov–Bohm...

  • Quantum adiabatic switching. Kohen, Daniela; Tannor, David J. // Journal of Chemical Physics;2/15/1993, Vol. 98 Issue 4, p3168 

    The quantum adiabatic theorem is explored as a potentially useful tool for obtaining highly excited eigenstates without requiring the calculation of all lower states. Starting in an eigenstate of some H0, the Hamiltonian is deformed adiabatically to the final H; the state of the system at the...

  • Lifting particle coordinate changes of magnetic moment type to Vlasov-Maxwell Hamiltonian dynamics. Morrison, P. J.; Vittot, M.; de Guillebon, L. // Physics of Plasmas;Mar2013, Vol. 20 Issue 3, p032109 

    Techniques for coordinate changes that depend on both dependent and independent variables are developed and applied to the Maxwell-Vlasov Hamiltonian theory. Particle coordinate changes with a new velocity variable dependent on the magnetic field, with spatial coordinates unchanged, are lifted...

  • The giant anisotropic magnetocaloric effect in DyAl2. von Ranke, P. J.; de Oliveira, N. A.; Plaza, E. J. R.; de Sousa, V. S. R.; Alho, B. P.; Carvalho, A. Magnus G.; Gama, S.; Reis, M. S. // Journal of Applied Physics;Nov2008, Vol. 104 Issue 9, p093906 

    We report on calculations of the anisotropic magnetocaloric effect in DyAl2 using a model Hamiltonian including crystalline electrical field effects. The anisotropic effect is produced by the rotation of a constant magnetic field from the easy to a hard magnetic direction in the crystal and is...

  • Radial electric field and rotation of the ensemble of plasma particles in tokamak. Sorokina, E.; Ilgisonis, V. // Plasma Physics Reports;Apr2012, Vol. 38 Issue 4, p279 

    The velocity of macroscopic rotation of an ensemble of charged particles in a tokamak in the presence of an electric field has been calculated in a collisionless approximation. It is shown that the velocity of toroidal rotation does not reduce to a local velocity of electric drift and has...


Read the Article


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

Try another library?
Sign out of this library

Other Topics