Preferential Acceleration of Heavy Ions in a Spontaneously Fragmenting Flare Current Sheet

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F22%3A00556101" target="_blank" >RIV/67985815:_____/22:00556101 - isvavai.cz</a>

Alternative codes found

RIV/44555601:13440/22:43896926

Result on the web

<a href="http://hdl.handle.net/11104/0330922" target="_blank" >http://hdl.handle.net/11104/0330922</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ac4fc9" target="_blank" >10.3847/1538-4357/ac4fc9</a>

Result language

angličtina

Original language name

Preferential Acceleration of Heavy Ions in a Spontaneously Fragmenting Flare Current Sheet

Original language description

We study the ion acceleration in a mesoscale, spontaneously fragmenting flare current sheet (SFCS) characterized by the presence of a plasmoid cascade. The main subject of our investigation is to determine whether and how plasmoid cascades at intermediate scales in a fragmented current sheet of a solar flare can impact the (preferential) acceleration of specific ions. The time evolution of the SFCS is obtained from high-resolution 2.5D MHD simulations. The ion trajectories (in the background fields resulting from the MHD model), energies, and pitch angles are calculated using a relativistic test-particle code based on the half-acceleration-rotation-half-acceleration method. For light ions, the main acceleration effects of electromagnetic fields within the SFCS are analyzed using the guiding center approximation. We identify regions with the most-efficient ion acceleration within the SFCS, the accelerator efficiency, and spectra of the accelerated ions. The influence of the charge-to-mass ratio on ion behavior is also studied and resulting ion abundances are compared with observational data. The main ion acceleration takes place in the regions with a strong polarization term, which is part of the first-order Fermi acceleration. Because the term is mass dependent, heavier ions undergo preferential acceleration. The ion energy spectra, abundance-enhancement factors, and differential fluxes, obtained from the model, exhibit power-law profiles, in agreement with observed solar energetic particle events. Nonetheless, the obtained slopes for the abundance-enhancement factor do not exactly match the observed data. The computed slopes and profiles are not sensitive to changes in the initial plasma temperature.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

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

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Volume of the periodical

927

Issue of the periodical within the volume

2

Country of publishing house

GB - UNITED KINGDOM

Number of pages

18

Pages from-to

177

UT code for WoS article

000768517800001

EID of the result in the Scopus database

2-s2.0-85127476110