M. Martucci , A. Oliva , R. Battiston , S. Beolé , P. Cipollone , A. Contin , M. Cristoforetti , C. De Donato , C. De Santis , A. Di Luca , F.M. Follega , G. Gebbia , R. Iuppa , A. Lega , M. Lolli , G. Masciantonio , M. Mese , C. Neubuser , R. Nicolaidis , F. Nozzoli , P. Zuccon
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引用次数: 0
Abstract
Cosmic rays’ interactions with the residual atmosphere surrounding the Earth produce a variety of particles, like electrons, positrons, protons, anti-protons, and Helium nuclei that can be observed below the local geomagnetic cutoff. In this work, we present new measurements of downward-going, albedo proton fluxes with kinetic energy in the range 40–250 MeV, performed by the High-Energy Particle Detector (HEPD-01) on board of the China Seismo-Electromagnetic Satellite - CSES-01 - at an altitude of 500 km. Employing a dedicated trajectory-tracing simulation routine, the protons collected by HEPD-01 are classified into quasi-trapped (QT), long lifetime (10 s) particles concentrating in the equatorial region of the Earth, and un-trapped (UT), distributed at all latitudes; the latter includes both precipitating short lifetime particles (UT) and pseudo-trapped long lifetime (UT) populations, abundant in the so-called penumbra regions. The temporal trend of re-entrant protons between 2018 and 2022 is also reported, assessing the stability of such population during the data-taking period of HEPD-01; this highlights their independence from the long-term modulating effect of the solar activity.
期刊介绍:
Astroparticle Physics publishes experimental and theoretical research papers in the interacting fields of Cosmic Ray Physics, Astronomy and Astrophysics, Cosmology and Particle Physics focusing on new developments in the following areas: High-energy cosmic-ray physics and astrophysics; Particle cosmology; Particle astrophysics; Related astrophysics: supernova, AGN, cosmic abundances, dark matter etc.; Gravitational waves; High-energy, VHE and UHE gamma-ray astronomy; High- and low-energy neutrino astronomy; Instrumentation and detector developments related to the above-mentioned fields.