Proton Beam Abundance Variations and Their Relation to Alpha Particle Properties
The result's identifiers
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>
Alternative languages
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
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10305 - Fluids and plasma physics (including surface physics)
Result continuities
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)
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astrophysical Journal
ISSN
0004-637X
e-ISSN
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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