382 research outputs found
On stability of collisional coupling between relativistic electrons and ions in hot plasmas
The collisional coupling of relativistic electrons and non-relativistic ions
in hot plasmas has been analysed. It is found that relativistic effects produce
a new feature: while the condition T_e<3T_i guarantees a stable collisional
coupling between electrons and ions in low-temperature plasmas, relativistic
effects shift the upper T_e/T_i boundary of stability to higher values.
Moreover, for sufficiently high temperatures, T_{e,i} > 75 keV, collisional
decoupling between relativistic electrons and ions becomes impossible
Relativistic neoclassical radial fluxes in the 1/nu regime
The radial neoclassical fluxes of electrons in the 1/nu regime are calculated
with relativistic effects taken into account and compared with those in the
non-relativistic approach. The treatment is based on the relativistic
drift-kinetic equation with the thermodynamic equilibrium given by the
relativistic Maxwell-J\"uttner distribution function. It is found that for the
range of fusion temperatures, T_e<100 keV, the relativistic effects produce a
reduction of the radial fluxes which does not exceed 10%. This rather small
effect is a consequence of the non-monotonic temperature dependence of the
relativistic correction caused by two counteracting factors: a reduction of the
contribution from the bulk and a significant broadening with the temperature
growth of the energy range of electrons contributing to transport.
The relativistic formulation for the radial fluxes given in this paper is
expressed in terms of a set of relativistic thermodynamic forces which is not
identical to the canonical set since it contains an additional relativistic
correction term dependent on the temperature. At the same time, this
formulation allows application of the non-relativistic solvers currently used
for calculation of mono-energetic transport coefficients.Comment: 10 pages, 2 figure
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