ANGEOD Annales Geophysicae Discussions ANGEOD Ann. Geophys. Discuss. 2568-6402 Göttingen, Germany 10.5194/angeo-2020-72 Dynamics of He++ ions at interplanetary shocks Sapunova Olga V. 1 Borodkova Natalia L. 1 Zastenker Georgii N. 1 Yermolaev Yuri I. https://orcid.org/0000-0003-1149-482X 1 Space Research Institute of the Russian Academy of Sciences, Moscow, Russia Russian Science Foundation 16-12-10062 16 12 2020 2020 1 9 Copyright: © 2020 Olga V. Sapunova et al. 2020 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://angeo.copernicus.org/preprints/angeo-2020-72/ The full text article is available as a PDF file from https://angeo.copernicus.org/preprints/angeo-2020-72/angeo-2020-72.pdf

<p>Variations of parameters of twice-ionized helium ions &ndash; He<sup>++</sup> ions or α-particles &ndash; in the solar wind plasma during the interplanetary shock front passage are investigated. We used the data measured by the BMSW (Bright Monitor of Solar Wind) instrument installed on the SPEKTR-R satellite, which operated since August 2011 to 2019 and registered 57 interplanetary shocks. According to received data, the parameters of He<sup>++</sup> ions were calculated: velocity Vα, temperature Tα, absolute density Nα and relative density (helium abundance) Nα/Np. The correlation of changes in helium abundance Nα/Np with the parameters β<sub>i</sub>, θ<sub>Bn</sub> and M<sub>MS</sub> were investigated.</p>