Microstructure in two- and three-dimensional hybrid simulations of perpendicular collisionless shocks

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F16%3A00464290" target="_blank" >RIV/68378289:_____/16:00464290 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985815:_____/16:00463957

Výsledek na webu

<a href="http://dx.doi.org/10.1017/S0022377816000660" target="_blank" >http://dx.doi.org/10.1017/S0022377816000660</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1017/S0022377816000660" target="_blank" >10.1017/S0022377816000660</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Microstructure in two- and three-dimensional hybrid simulations of perpendicular collisionless shocks

Popis výsledku v původním jazyce

Supercritical collisionless perpendicular shocks have an average macrostructure determined primarily by the dynamics of ions specularly reflected at the magnetic ramp. Within the overall macrostructure, instabilities, both linear and nonlinear, generate fluctuations and microstructure. To identify the sources of such microstructure, high-resolution two-and three-dimensional simulations have been carried out using the hybrid method, wherein the ions are treated as particles and the electron response is modelled as a massless fluid. We confirm the results of earlier two-dimensional (2-D) simulations showing both field-parallel aligned propagating fluctuations and fluctuations carried by the reflected-gyrating ions. In addition, it is shown that, for 2-D simulations of the shock coplanarity plane, the presence of short-wavelength fluctuations in all magnetic components is associated with the ion Weibel instability driven at the upstream edge of the foot by the reflected-gyrating ions. In 3-D simulations we show for the first time that the dominant microstructure is due to a coupling between field-parallel propagating fluctuations in the ramp and the motion of the reflected ions. This results in a pattern of fluctuations counter-propagating across the surface of the shock at an angle inclined to the magnetic field direction, due to a combination of field-parallel motion at the Alfven speed of the ramp and motion in the sense of gyration of the reflected ions.

Název v anglickém jazyce

Microstructure in two- and three-dimensional hybrid simulations of perpendicular collisionless shocks

Popis výsledku anglicky

Supercritical collisionless perpendicular shocks have an average macrostructure determined primarily by the dynamics of ions specularly reflected at the magnetic ramp. Within the overall macrostructure, instabilities, both linear and nonlinear, generate fluctuations and microstructure. To identify the sources of such microstructure, high-resolution two-and three-dimensional simulations have been carried out using the hybrid method, wherein the ions are treated as particles and the electron response is modelled as a massless fluid. We confirm the results of earlier two-dimensional (2-D) simulations showing both field-parallel aligned propagating fluctuations and fluctuations carried by the reflected-gyrating ions. In addition, it is shown that, for 2-D simulations of the shock coplanarity plane, the presence of short-wavelength fluctuations in all magnetic components is associated with the ion Weibel instability driven at the upstream edge of the foot by the reflected-gyrating ions. In 3-D simulations we show for the first time that the dominant microstructure is due to a coupling between field-parallel propagating fluctuations in the ramp and the motion of the reflected ions. This results in a pattern of fluctuations counter-propagating across the surface of the shock at an angle inclined to the magnetic field direction, due to a combination of field-parallel motion at the Alfven speed of the ramp and motion in the sense of gyration of the reflected ions.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BL - Fyzika plasmatu a výboje v plynech

OECD FORD obor

—

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Journal of Plasma Physics

ISSN

0022-3778

e-ISSN

—

Svazek periodika

82

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

23

Strana od-do

"905820401/1"-"905820401/23"

Kód UT WoS článku

000381516900006

EID výsledku v databázi Scopus

2-s2.0-85014495068