Počet záznamů: 1
Protons and alpha particles in the expanding solar wind: Hybrid simulations
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SYSNO ASEP 0425964 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Protons and alpha particles in the expanding solar wind: Hybrid simulations Tvůrce(i) Hellinger, Petr (UFA-U) RID, ORCID
Trávníček, Pavel M. (UFA-U) RID, ORCIDCelkový počet autorů 2 Zdroj.dok. Journal of Geophysical Research-Space Physics. - : Wiley - ISSN 2169-9380
Roč. 118, č. 9 (2013), s. 5421-5430Poč.str. 10 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova solar wind ; ion energetics Vědní obor RIV BL - Fyzika plazmatu a výboje v plynech Institucionální podpora UFA-U - RVO:68378289 UT WOS 000325483800003 DOI 10.1002/jgra.50540 Anotace We present results of a twodimensional hybrid expanding box simulation of a plasma system with three ion populations, beam and core protons, and alpha particles (and fluid electrons), drifting with respect to each other. The expansion with a strictly radial magnetic field leads to a decrease of the ion perpendicular to parallel temperature ratios as well as to an increase of the ratio between the ion relative velocities and the local Alfven velocity creating a free energy for many different instabilities. The system is most of the time marginally stable with respect to kinetic instabilities mainly due to the ion relative velocities; these instabilities determine the system evolution counteracting some effects of the expansion. Nonlinear evolution of these instabilities leads to large modifications of the ion velocity distribution functions. The beam protons and alpha particles are decelerated with respect to the core protons and all the populations are cooled in the parallel direction and heated in the perpendicular one. On the macroscopic level, the kinetic instabilities cause large departures of the system evolution from the double adiabatic prediction and lead to perpendicular heating and parallel cooling rates which are comparable to the heating rates estimated from the Helios observations. Pracoviště Ústav fyziky atmosféry Kontakt Kateřina Adamovičová, adamovicova@ufa.cas.cz, Tel.: 272 016 012 ; Kateřina Potužníková, kaca@ufa.cas.cz, Tel.: 272 016 019 Rok sběru 2014
Počet záznamů: 1