Snapshots of poloidal planes with established electromagnetic turbulent profiles on a toroidal geometry with an outer limiter. Results are shown after 0.8 ms simulated time: (a) electron density, (b) electron temperature, (c) radial ExB drift, (d) electric potential, (e) parallel current density, and (f) parallel electromagnetic potential. Fig. 4 of the paper by R. Düll et al. https://onlinelibrary.wiley.com/doi/10.1002/ctpp.202300147
In this paper, the laser pulse evolution arising from the field ionization during the interaction of a long laser pulse with gaseous hydrogen atoms is investigated using the kinetic 1D-3 V Particle-In-Cell (PIC) Smilei simulation code. After performing various simulations, it is shown that the field ionization of hydrogen atoms has a non-negligible effect on the evolution of the laser pulse compared to the pre-ionized plasma case. The results of our simulations show that the amount of these evolutions is strongly dependent on the parameters of the laser and initial ionization assumed. In this regard, two main mechanisms are responsible for the changes in the generated radiations and then the evolution of the laser pulse. When the average degree of ionization is weak, the backscattered Raman radiations can provide the necessary conditions for the chaotic behavior to occur and the laser pulse to evolve. When the laser and plasma pulse parameters (such as the laser pulse amplitude, hydrogen atoms density, and the rise time of pulse) are selected so that a strong space charge field is formed, the wave breaking (which happened faster due to density changes during the field ionization) is the main factor for evolutions in the laser pulse.
Ion acoustic waves (IAWs) are theoretically researched in a negative ion plasma (NIP) with warm light ions, cold heavy ions, and distributed electrons. The reductive perturbation method (RPM) is used to simplify two-fluid plasma equations and the relevant ZK equation and solitary solution of IAWs are derived. Small-k expansion method is applied to obtained the instability growth rate of IAWs. The flatness and tail parameters modify the amplitude, width, soliton energy, and instability growth rate. It is noted that the increscent flatness and tail parameters result in the increasing amplitude, width, and soliton energy. Increasing flatness and tail parameters lead to the decreasing growth rate. These results will be helpful in understanding the plasma dynamics for NIP system containing distributed electrons in Earth's ionosphere.
This investigation explores the characteristics of electrostatic surface plasma waves within the framework of a spin-polarized quantum plasma. Utilizing the spin-polarized quantum hydrodynamic model and incorporating essential elements like Fermi pressure and Bohm potential, we derive the dispersion relation governing surface plasma waves at a plasma–vacuum interface. Through Fourier decomposition of the hydrodynamic model, we establish the dispersion relation that outlines the behavior of surface plasmons under conditions of small amplitude. Quantum effects, encompassing degenerate pressure, and Bohm potential are considered with specific attention given to the spin polarization effect, treating spin up, and spin down electrons as distinct species. The resulting dispersion relation demonstrates that, regardless of the degree of spin matching, Bohm potential significantly alters the phase speed in the limit of a large wave vector. Increasing spin mismatch in the quantum plasma leads to a decrease in the phase speed of the surface mode for a fixed value of the plasmonic coupling parameter . Our findings bear relevance to graphene-based plasmonic systems, aligning with some of the observations reported in Gao et al. (2013) and Guo et al. (2019).
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