Speaker
Description
The radio zebras are observed in radiograms of Sun, Jupiter and also pulsar in Crab nebula. They are interpreted as a resonance between the plasma frequency, the cyclotron frequency, and the generated electrostatic wave by the double plasma resonance theory. It assumes that the plasma composes of the cold, thermal, and dense background component together with hot and rare hot electrons with a loss-cone type of the velocity distribution function. Until now, only the branches, that are above the plasma frequency, have been studied (Zheleznyakov and Zlotnik 1975a, Winglee and Dulk 1986, Yasnov and Karlický 2004, Benáček et al. 2017). However, in the plasma, many electrostatic unstable branches exist in $\omega - k_\perp$ domain. We computed the growth rate $\gamma$ for all the branches. We took into account the "specific width" of the dispersion branches, and we introduced a new parameter, the integrated growth rate $\Gamma$, to compare the theoretical expectations with particle-in-cell model. We showed the branch positions and their growth rates for minimal and maximum value $\Gamma$. We computed the influence of the hot component and background plasma temperatures. We found that the integrated growth rate $\Gamma$ is in a good agreement with the particle-in-cell model. The integrated growth rate has maximum when the sufficiently long and wide branches cross the positive growth rate region.
