Proton Beam Abundance Variations and Their Relation to Alpha Particle Properties

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F21%3A10439894" target="_blank" >RIV/00216208:11320/21:10439894 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=W_buZaxmt7" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=W_buZaxmt7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ac2c03" target="_blank" >10.3847/1538-4357/ac2c03</a>

Result language

angličtina

Original language name

Proton Beam Abundance Variations and Their Relation to Alpha Particle Properties

Original language description

Less abundant but still dynamically important solar wind components are the proton beam and alpha particles, which usually contribute similarly to the total ion momentum. The main characteristics of alpha particles are determined by the solar wind source region, but the origin of the proton beam and its properties are still not fully explained. We use the plasma data measured in situ on the path from 0.3 to 1 au (Helios 1 and 2) and focus on the proton beam development with an increasing radial distance as well as on the connection between the proton beam and alpha particle properties. We found that the proton beam relative abundance increases with increasing distance from the Sun in the collisionally young streams. Among the mechanisms suggested for beam creation, we have identified the wave-particle interactions with obliquely propagating Alfven modes being consistent with observations. As the solar wind streams get collisionally older, the proton beam decay gradually dominates and the beam abundance is reduced. In search for responsible mechanisms, we found that the content of alpha particles is correlated with the proton beam abundance, and this effect is more pronounced in the fast solar wind streams during the solar maximum. We suggest that Coulomb collisions are the main agent leading to merging of the proton beam and core. We are also showing that the variations of the proton beam abundance are correlated with a decrease of the alpha particle velocity in order to maintain the total momentum balance in the solar wind frame.

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

10305 - Fluids and plasma physics (including surface physics)

Project

<a href="/en/project/GA19-18993S" target="_blank" >GA19-18993S: Transport of energy of solar wind variations from larger to smaller scales</a><br>

Continuities

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

Publication year

2021

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

—

Volume of the periodical

923

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

8

Pages from-to

170

UT code for WoS article

000732557200001

EID of the result in the Scopus database

2-s2.0-85122963782