The space of toroidal automorphic forms was introduced by Zagier in the 1970s: a GL2-automorphic form is toroidal if it has vanishing constant Fourier coefficients along all embedded non-split tori. The interest in this space stems (amongst others) from the fact that an Eisenstein series of weight s is toroidal for a given torus precisely if s is a non-trivial zero of the zeta function of the q...

It is experimentally observed that tokamak plasmas exhibits macroscopic flow in the toroidal and poloidal directions. Both the flow can considerably change the equilibrium parameters of tokamak. Equilibrium of HT-6M is revisited as a case study and its equilibrium parameters are simulated in the presence of toroidal and poloidal flows with the FLOW Code developed by L. Guazzotto at that Univers...

Tokamak plasma transport equations are usually obtained by flux surface averaging the collisional Braginskii equations. However, tokamak plasmas are not in collisional regimes. Also, ad hoc terms are added for: neoclassical effects on the parallel Ohm’s law; fluctuation-induced transport; heating, current-drive and flow sources and sinks; small magnetic field non-axisymmetries; magnetic field t...

The work deals with one of the topics of collective motion. In the frame of Nuclear Fluid Dynamics, a model which portrays the nuclear matter as a quantum elastic body, the torus-like motions and their associated energies are computed using the thirteen moment approximation. Such excitations correspond to the Hill vortex known from classical Hydrodynamics. There are also calculated the nonvanis...

Heat transfer characteristics of air flows in concentric toroidal annular tubes filled with porous media were numerically investigated. The toroidal annulus is constant walls temperature where the outer wall temperature is lower than the inlet temperature. The numerical methodology was based on the finite difference approximation method. The computations were performed for vertical and horizont...

Tokamak plasma transport equations are usually obtained by flux surface averaging the collisional Braginskii equations. However, tokamak plasmas are not in collisional regimes. Also, ad hoc terms are added for neoclassical effects on the parallel Ohm’s law, fluctuation-induced transport, heating, current-drive and flow sources and sinks, small magnetic field nonaxisymmetries, magnetic field tra...

We study the microwave absorption during electron cyclotron resonance heating (ECRH) by extraordinary wave at second harmonic (X2 mode) in T-10 tokamak and TJ-II stellarator a wide range of plasma densities, compare experiments with classical formulas for injected ECR power. Empirical relations efficiency critical density n cr , which separates regions full partial power, are obtained using num...

This paper reports on the results of recent experiments performed on the JET tokamak on Alfvén Eigenmodes (AEs) with toroidal mode number (n) in the range |n|=3-15. The stability properties of these medium-n AEs are investigated experimentally using a set of compact in-vessel antennas, providing a direct and real-time measurement of the frequency, damping rate and amplitude for each individual ...

Magnetic islands have been implemented in the gyrokinetic toroidal code to study the effects of the islands on microturbulence. The pressure profile flattening is verified in the simulation with the islands. Simulations of ion temperature gradient instability find that different toroidal modes are linearly coupled together and that toroidal spectra become broader when the island width increases...

In this Letter, the influence of the "Coriolis drift" on small scale instabilities in toroidal plasmas is shown to generate a toroidal momentum pinch velocity. Such a pinch results because the Coriolis drift generates a coupling between the density and temperature perturbations on the one hand and the perturbed parallel flow velocity on the other. A simple fluid model is used to highlight the p...