Numerical Heating in Hybrid Plasma Simulations
1997; Elsevier BV; Volume: 133; Issue: 1 Linguagem: Inglês
10.1006/jcph.1997.5678
ISSN1090-2716
Autores Tópico(s)Laser-induced spectroscopy and plasma
ResumoThe numerical heating in hybrid particle–fluid simulations has been investigated with emphasis on the regimeZTe/Ti⪢ 1, whereZis the charge state of the ions andTeandTiare the electron and ion temperatures, respectively. For the simple case of particle ions advanced in the ambipolar field due to quasineutral isothermal fluid electrons, the heating rate is observed to be weakly dependent on time step, inversely proportional to the number of simulation particles per grid cell and strongly increasing with increasingZTe/Ti. Additional smoothing, due to finite Debye length, or introduced through numerical means such as higher order particle interpolation or smoothing of grid quantities, is observed to significantly reduce this heating. Both one- and two-dimensional results are presented. These results are important to hybrid particle simulations of laser generated plasmas, a regime whereZTe/Ti⪢ 1 is often encountered. As a relevant example, simulations of stimulated Brillouin scattering are presented illustrating the deleterious effect of numerical heating and attendant distortions to the particle distribution function.
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