Fully toroidal ion temperature gradient driven drift modes

Abstract

A simple quadratic dispersion relation is derived for electrostatic ion temperature gradient driven modes without expansion in the inverse aspect ratio. It is also shown that these modes experience the local curvature only on the outside of the magnetic surface.

Analytical eigenvalue solution for ηi modes of general modewidth

“…Advanced fluid models [1][2][3][4][5] have recently lead to a rapid development of physics based simulations of transport in fusion plasmas. [6][7][8] The problem of finding good solutions of linear eigenvalue problems in transport codes using advanced fluid models is a rather difficult one.…”

Kinetic Effects on Collisionless High-n Ballooning Modes and Ion Temperature Gradient Modes in a Model Helical Geometry

“…Φ and the frequency are complex in the covering space, and the poloidal angle θ is transformed into extended poloidal angle χ ∈ (−∞, ∞). We show in our figures the dependence of the absolute value of Φ on the extended angle χ as in [1,18,20,21] in contrast to [15,16,19], where both real and imaginary parts of Φ are shown versus χ. Having in mind ballooning transform [4] and eikonal approximation used, the imaginary part of the frequency gives the unstable modes growth rate.…”

“…The ion fluid model is similar to those in [20,21]. From the ion continuity equation, including the polarization and the stress tensor drifts, it follows that…”

Effects of parallel ion motion on electromagnetic toroidal ion temperature gradient modes in a fluid model

“…[1][2][3][4][5][6][7][8][9] Although a kinetic description of the plasma is more detailed than a fluid description, the latter may give simpler and more explicit results. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Also the access of computing power is in general not crucial with fluid codes.…”

“…It includes all the curvature effects in the continuity and energy equations, and an important role is played by the ion diamagnetic heat flow which is used in the energy equation to close the fluid hierarchy. 1,2,4,5 The model is basically reactive (i.e., collisionless) and has been successfully used to study effects such as electron trapping and impurities on mode structure and particle and energy transport and confinement. [11][12][13][18][19][20][21][22][23][24][25] In the original version of the model, the phase velocity of the drift modes along the background magnetic field is assumed to be much larger than the ion thermal velocity.…”