Weakly Relativistic and Nonrelativistic Estimates of EBW Heating in the TJ-II Stellarator

Section: Applications Of This Methods To Iter Plasmasmentioning

confidence: 99%

The exact plasma dispersion functions in the complex region

Castejón¹,

Павлов²

2008

“…Here, the functions F + (z), F − (z) are the boundary values of integral (8) when the argument z tends to the contour from the right or from the left-hand side with respect to the integration direction, respectively. The letter P before integral denotes its principal value in the Cauchy sense.…”

Section: Functions Generating Elements Of the Fully Relativistic Diel...mentioning

confidence: 99%

“…Due to the fact that relativistic effects are less important for large values of N || , which are customary when dealing with electron Bernstein waves, relativistic effects are usually neglected in the calculations. Nevertheless, weakly-relativistic calculations have shown that those effects are not negligible for electron temperatures of the order of 1 keV [8] and those effects will be even more important for the temperatures that can be achieved in fusion reactors like ITER. The same happens in extremely hot astrophysical plasmas.…”

Section: Introductionmentioning

confidence: 99%

The fully relativistic dielectric tensor for arbitrary wave vectors

Павлов

Castejón

2018

We present a new exact integral form of the fully relativistic dielectric tensor in the electron cyclotron frequency range for plasmas in the presence of a magnetic field. This form is suitable for numerical applications for arbitrary wave numbers since all the integrals that appear in the expressions are 1D ones and, hence, can be evaluated with arbitrary precision. Thus, this new form of the dielectric tensor has interest from the point of view of studying arbitrary fast and slow electron cyclotron waves in fusion laboratory plasmas for the purpose of plasma heating and current drive in magnetic traps, as well as in extremely hot astrophysical plasmas with the goal of further development and understanding the physics of plasma waves. It is easy to see that such fully relativistic approach to studying plasma waves can also be extended into the ion cyclotron frequency range.

“…The weakly relativistic dispersion relation developed in appendix A has been introduced in the ray tracing code TRUBA, thus allowing us to take into account the relativistic effects both on ray trajectories and on power absorption [18]. The effect on the final power deposition profile will be more important for large single pass absorption along the plasma column, since in this case the resonant zones will be more clearly determined along the ray path.…”

Section: The Relativistic Effects In Tj-iimentioning

confidence: 99%

Computation of EBW heating in the TJ-II stellarator

Castejón¹,

Cappa²,

Tereshchenko

et al. 2008

Self Cite

The theoretical properties of electron Bernstein wave (EBW) plasma heating in the TJ-II stellarator are presented in this work. Previous studies carried out in this device have demonstrated that the O–X–B mode conversion at the fundamental electron cyclotron harmonic is the best scenario for plasma heating. This scheme presents high absorbed power for central densities above 1.2 × 1019 m−3 and has no upper density limit. In this paper, the ray tracing code TRUBA has been used in its non-relativistic modality to optimize the power injection position and to design a launching system that provides the optimum theoretical results. The main characteristics of the system, whose final design is based on the former calculations, are described. To explore the importance of relativistic effects and to compare them with the non-relativistic calculations, the weakly relativistic dispersion relation, valid for and thus suitable for EBW at low cyclotron harmonics, has been obtained and included in TRUBA. Although they are of little importance for the optimization calculations, the relativistic effects are shown to be not negligible both in the ray trajectories and in the power absorption estimations for temperatures above 1 keV.