Drift motion and perpendicular diffusion of energetic particles in interplanetary space based on spacecraft data

1982 ◽  
Vol 86 (1) ◽  
pp. 197-207 ◽  
Author(s):  
X. Moussas ◽  
J. J. Quenby ◽  
J. F. Valdes-Galicia
Keyword(s):  
Interplanetary Space ◽  
Energetic Particles ◽  
Drift Motion ◽  
Perpendicular Diffusion ◽  
Spacecraft Data

scholarly journals On the Turbulent Reduction of Drifts for Solar Energetic Particles

2021 ◽  
Vol 922 (2) ◽  
pp. 200
Author(s):  
J. P. van den Berg ◽  
N. E. Engelbrecht ◽  
N. Wijsen ◽  
R. D. Strauss
Keyword(s):  
Pitch Angle ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Particle Distributions ◽  
Magnetic Turbulence ◽  
Field Diffusion ◽  
Background Magnetic Field ◽  
Perpendicular Diffusion ◽  
Inner Heliosphere

Abstract Particle drifts perpendicular to the background magnetic field have been proposed by some authors as an explanation for the very efficient perpendicular transport of solar energetic particles (SEPs). This process, however, competes with perpendicular diffusion caused by magnetic turbulence, which can also disrupt the drift patterns and reduce the magnitude of drift effects. The latter phenomenon is well known in cosmic-ray studies, but not yet considered in SEP models. Additionally, SEP models that do not include drifts, especially for electrons, use turbulent drift reduction as a justification of this omission, without critically evaluating or testing this assumption. This article presents the first theoretical step for a theory of drift suppression in SEP transport. This is done by deriving the turbulence-dependent drift reduction function with a pitch-angle dependence, as is applicable for anisotropic particle distributions, and by investigating to what extent drifts will be reduced in the inner heliosphere for realistic turbulence conditions and different pitch-angle dependencies of the perpendicular diffusion coefficient. The influence of the derived turbulent drift reduction factors on the transport of SEPs are tested, using a state-of-the-art SEP transport code, for several expressions of theoretically derived perpendicular diffusion coefficients. It is found, for realistic turbulence conditions in the inner heliosphere, that cross-field diffusion will have the largest influence on the perpendicular transport of SEPs, as opposed to particle drifts.

SOLAR ENERGETIC PARTICLES

2005 ◽  
Vol 20 (29) ◽  
pp. 6634-6641
Author(s):  
PÉTER KIRÁLY
Keyword(s):  
Solar Cycle ◽  
Interplanetary Space ◽  
Energetic Particles ◽  
Vital Role ◽  
Solar Energetic Particles ◽  
Interstellar Space ◽  
Interplanetary Shocks ◽  
Quiet Time ◽  
Solar Origin ◽  
Suprathermal Particles

Energetic particles recorded in the Earth environment and in interplanetary space have a multitude of origins, i.e. acceleration and propagation histories. At early days practically all sufficiently energetic particles were considered to have come either from solar flares or from interstellar space. Later on, co-rotating interplanetary shocks, the termination shock of the supersonic solar wind, planetary bow shocks and magnetospheres, and also coronal mass ejections (CME) were recognized as energetic particle sources. It was also recognized that less energetic (suprathermal) particles of solar origin and pick-up ions have also a vital role in giving rise to energetic particles in interplanetary disturbances. The meaning of the term "solar energetic particles" (SEP) is now somewhat vague, but essentially it refers to particles produced in disturbances fairly directly related to solar processes. Variation of intensity fluctuations with energy and with the phase of the solar cycle will be discussed. Particular attention will be given to extremes of time variation, i.e. to very quiet periods and to large events. While quiet-time fluxes are expected to shed light on some basic coronal processes, large events dominate the fluctuation characteristics of cumulated fluence, and the change of that fluctuation with energy and with the phase of the solar cycle may also provide important clues. Mainly ISEE-3 and long-term IMP-8 data will be invoked. Energetic and suprathermal particles that may never escape into interplanetary space may play an important part in heating the corona of the sun.

Radio Tracking of Solar Energetic Particles through Interplanetary Space

Science ◽  
1972 ◽  
Vol 178 (4062) ◽  
pp. 743-745 ◽  
Author(s):  
J. Fainberg ◽  
L. G. Evans ◽  
R. G. Stone
Keyword(s):  
Interplanetary Space ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Radio Tracking
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