The Parametric Instability of Alfven Waves: Effects of Temperature Anisotropy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F17%3A00484356" target="_blank" >RIV/67985815:_____/17:00484356 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.3847/1538-4357/aa9bef" target="_blank" >http://dx.doi.org/10.3847/1538-4357/aa9bef</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/aa9bef" target="_blank" >10.3847/1538-4357/aa9bef</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The Parametric Instability of Alfven Waves: Effects of Temperature Anisotropy

Popis výsledku v původním jazyce

We study the stability of large-amplitude, circularly polarized Alfven waves in an anisotropic plasma described by the double-adiabatic/CGL closure, and in particular the effect of a background thermal pressure anisotropy on the well-known properties of Alfven wave parametric decay in magnetohydrodynamics ( MHD). Anisotropy allows instability over a much wider range of values of parallel plasma beta (beta(parallel to)) when xi= p(0 perpendicular to)/p(0 parallel to) > 1. When the pressure anisotropy exceeds a critical value, xi >= xi* with xi*similar or equal to 2.7, there is a new regime in which the parametric instability is no longer quenched at high beta(parallel to), and in the limit beta(parallel to) >> 1, the growth rate becomes independent of beta(parallel to). In the opposite case of xi < xi*, the instability is strongly suppressed with increasing parallel plasma beta, similarly to the MHD case. We analyze marginal stability conditions for parametric decay in the (xi, beta(parallel to)) parameter space and discuss possible implications for Alfvenic turbulence in the solar wind.

Název v anglickém jazyce

The Parametric Instability of Alfven Waves: Effects of Temperature Anisotropy

Popis výsledku anglicky

We study the stability of large-amplitude, circularly polarized Alfven waves in an anisotropic plasma described by the double-adiabatic/CGL closure, and in particular the effect of a background thermal pressure anisotropy on the well-known properties of Alfven wave parametric decay in magnetohydrodynamics ( MHD). Anisotropy allows instability over a much wider range of values of parallel plasma beta (beta(parallel to)) when xi= p(0 perpendicular to)/p(0 parallel to) > 1. When the pressure anisotropy exceeds a critical value, xi >= xi* with xi*similar or equal to 2.7, there is a new regime in which the parametric instability is no longer quenched at high beta(parallel to), and in the limit beta(parallel to) >> 1, the growth rate becomes independent of beta(parallel to). In the opposite case of xi < xi*, the instability is strongly suppressed with increasing parallel plasma beta, similarly to the MHD case. We analyze marginal stability conditions for parametric decay in the (xi, beta(parallel to)) parameter space and discuss possible implications for Alfvenic turbulence in the solar wind.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA15-10057S" target="_blank" >GA15-10057S: Ionty ve slunečním větru: korelace, omezení a kausalita</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astrophysical Journal

ISSN

0004-637X

e-ISSN

—

Svazek periodika

851

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

"99/1"-"99/9"

Kód UT WoS článku

000418350300002

EID výsledku v databázi Scopus

2-s2.0-85039749425