Heliospheric Energetic Particle Flux Variations

1999 ◽  
pp. 75-85
Author(s):  
P. Király
Keyword(s):  
Energetic Particle ◽  
Particle Flux ◽  
Energetic Particle Flux

scholarly journals Energetic-particle-flux decreases related to magnetic cloud passages as observed by the Helios 1 and 2 spacecraft

2013 ◽  
Vol 556 ◽  
pp. A146 ◽  
Author(s):  
J. J. Blanco ◽  
M. A. Hidalgo ◽  
R. Gómez-Herrero ◽  
J. Rodríguez-Pacheco ◽  
B. Heber ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Particle Flux ◽  
Magnetic Cloud ◽  
Energetic Particle Flux

Current sheets, magnetic islands and associated particle acceleration in the solar wind as observed by Ulysses near the ecliptic plane

2020 ◽  
Author(s):  
Olga Malandraki ◽  
Olga Khabarova ◽  
Roberto Bruno ◽  
Gary Zank ◽  
Gang Li and the ISSI-405 team
Keyword(s):  
Solar Wind ◽  
Particle Acceleration ◽  
Magnetic Reconnection ◽  
Energetic Particle ◽  
Particle Flux ◽  
Energetic Particles ◽  
Magnetic Islands ◽  
Intermittent Turbulence ◽  
Current Sheets ◽  
Energetic Particle Flux

<p>Recent studies of particle acceleration in the heliosphere have revealed a new mechanism that can locally energize particles up to several MeV/nuc. Stream-stream interactions as well as the heliospheric current sheet – stream interactions lead to formation of large magnetic cavities, bordered by strong current sheets (CSs), which in turn produce secondary CSs and dynamical small-scale magnetic islands (SMIs) of ~0.01AU or less owing to magnetic reconnection. It has been shown that particle acceleration or re-acceleration occurs via stochastic magnetic reconnection in dynamical SMIs confined inside magnetic cavities observed at 1 AU. The study links the occurrence of CSs and SMIs with characteristics of intermittent turbulence and observations of energetic particles of keV-MeV/nuc energies at ~5.3 AU. We analyze selected samples of different plasmas observed by Ulysses during a widely discussed event, which was characterized by a series of high-speed streams of various origins that interacted beyond the Earth’s orbit in January 2005. The interactions formed complex conglomerates of merged interplanetary coronal mass ejections, stream/corotating interaction regions and magnetic cavities. We study properties of turbulence and associated structures of various scales. We confirm the importance of intermittent turbulence and magnetic reconnection in modulating solar energetic particle flux and even local particle acceleration. Coherent structures, including CSs and SMIs, play a significant role in the development of secondary stochastic particle acceleration, which changes the observed energetic particle flux time-intensity profiles and increases the final energy level to which energetic particles can be accelerated in the solar wind.</p>

scholarly journals Cosmic ray and solar energetic particle flux in paleomagnetospheres

2010 ◽  
Vol 62 (3) ◽  
pp. 333-345 ◽  
Author(s):  
Anja Stadelmann ◽  
Joachim Vogt ◽  
Karl-Heinz Glassmeier ◽  
May-Britt Kallenrode ◽  
Gerd-Hannes Voigt
Keyword(s):  
Energetic Particle ◽  
Particle Flux ◽  
Solar Energetic Particle ◽  
Cosmic Ray ◽  
Energetic Particle Flux

scholarly journals Recurrent Solar Energetic Particle Flux Enhancements Observed near Earth and Mars

2020 ◽  
Vol 902 (1) ◽  
pp. 13
Author(s):  
C. Krishnaprasad ◽  
Smitha V. Thampi ◽  
Anil Bhardwaj ◽  
Christina O. Lee ◽  
K. Kishore Kumar ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Particle Flux ◽  
Solar Energetic Particle ◽  
Energetic Particle Flux

scholarly journals Properties of a cusp diamagnetic cavity boundary

2008 ◽  
Vol 26 (11) ◽  
pp. 3501-3509 ◽  
Author(s):  
B. M. Walsh ◽  
T. A. Fritz ◽  
J. Chen
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Energetic Particle ◽  
Lower Energy ◽  
Particle Flux ◽  
Boundary Orientation ◽  
Cavity Boundary ◽  
Energetic Particle Flux ◽  
Energy Dependent ◽  
Energy Channels

Abstract. While crossing through the high-altitude dayside cusp on 29 September 1978 and again on 30 October 1978, the ISEE-1 spacecraft observed enhanced energetic particle flux and a depressed and turbulent magnetic field, the signature characteristics of a cusp diamagnetic cavity. As ISEE-1 approached the cavity during each event, a boundary sounding technique was used to measure properties of an emitting boundary. Sounding over multiple energy channels reveals an energy dependent boundary with lower energy particles filling a larger cavity than higher energy particles. Relative motion of the boundary as well as boundary orientation are also measured. The two cusp events were measured at different locations and during different geomagnetic and solar wind conditions; however, they show similar results.

scholarly journals Interpretation of increased energetic particle flux measurements by SEPT aboard the STEREO spacecraft and contamination

2018 ◽  
Vol 611 ◽  
pp. A100 ◽  
Author(s):  
S. Wraase ◽  
B. Heber ◽  
S. Böttcher ◽  
R. Bucik ◽  
N. Dresing ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Particle Flux ◽  
Interplanetary Medium ◽  
Relativistic Electrons ◽  
Response Functions ◽  
Flux Measurements ◽  
Energetic Particle Flux ◽  
Flux Increase ◽  
Good Agreement

Context. Interplanetary (IP) shocks are known to be accelerators of energetic charged particles observed in-situ in the heliosphere. However, the acceleration of near-relativistic electrons by shocks in the interplanetary medium is often questioned. On 9 August 2011 a corotating interaction region (CIR) passed STEREO B (STB), which resulted in a flux increase in the electron and ion channels of the Solar Electron and Proton Telescope (SEPT). Because electron measurements in the few keV to several 100 keV range rely on the so-called magnet foil technique, which is utilized by SEPT, ions can contribute to the electron channels. Aim. We aim to investigate whether the flux increase in the electron channels of SEPT during the CIR event on 9 August 2011 is caused by ion contamination only. Methods. We compute the SEPT response functions for protons and helium utilizing an updated GEANT4 model of SEPT. The CIR energetic particle ion spectra for protons and helium are assumed to follow a Band function in energy per nucleon with a constant helium to proton ratio. Results. Our analysis leads to a helium to proton ratio of 16.9% and a proton flux following a Band function with the parameters I0 = 1.24 × 104 (cm2 s sr MeV nuc−1)−1, Ec = 79 keV nuc−1, and spectral indices of γ1 = −0.94 and γ2 = −3.80, which are in good agreement with measurements by the Suprathermal Ion Telescope (SIT) aboard STB. Conclusions. Since our results explain the SEPT measurements, we conclude that no significant amount of electrons were accelerated between 55 and 425 keV by the CIR.

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