scholarly journals Constraining Suprathermal Electron Evolution in a Parker Spiral Field with Cassini Observations

2021 ◽  
Author(s):  
G. A. Graham ◽  
M. R. Bakrania ◽  
I. J. Rae ◽  
C. J. Owen ◽  
A. P. Walsh ◽  
...  
Keyword(s):  
Suprathermal Electron ◽  
Parker Spiral

scholarly journals Suprathermal electron evolution in a Parker spiral magnetic field

2008 ◽  
Vol 113 (A11) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. J. Owens ◽  
N. U. Crooker ◽  
N. A. Schwadron
Keyword(s):  
Magnetic Field ◽  
Suprathermal Electron ◽  
Parker Spiral

scholarly journals Some Anomalies in the Raman spectrum from laser-produced plasmas

1988 ◽  
Vol 6 (2) ◽  
pp. 287-294
Author(s):  
T. J. M. Boyd ◽  
G. A. Gardner ◽  
G. A. Coutts
Keyword(s):  
Raman Spectrum ◽  
Light Wave ◽  
Scattered Light ◽  
Thomson Scattering ◽  
Hot Electron ◽  
Conventional Theory ◽  
Suprathermal Electron ◽  
Suprathermal Electrons ◽  
Scattered Spectrum

Many experiments show features of the Raman spectrum at variance with the predictions of conventional theory. One persistent discrepancy, the cut-off in the spectrum of scattered light at about 1·5λ0, led Simon and Short to postulate that the scattered spectrum is not Raman light as such, but derives from enhanced Thomson scattering from plasmas in which a population of suprathermal electrons is present. We describe a set of simulations which model the propagation of a light wave through a plasma characterized by two electron temperatures with the hot electron fraction varying between 0 and 0·05. The results show that enhanced Thomson scattering will contribute to the spectra observed in some experiments at least and confirm the contention that the spectrum of the scattered light is not especially sensitive to the width of the suprathermal electron feature. We have also examined the effect of a finite quiver velocity on the enhanced Thomson spectrum as a function of the population of suprathermal electrons, in particular its effect on the wavelength bands.

Global coronal and heliospheric magnetic field modelling for Solar Orbiter

2021 ◽  
Author(s):  
Thomas Wiegelmann ◽  
Thomas Neukirch ◽  
Iulia Chifu ◽  
Bernd Inhester
Keyword(s):  
Magnetic Field ◽  
Solar Rotation ◽  
Coronal Magnetic Field ◽  
Important Research ◽  
Parker Spiral ◽  
Important Research Topic ◽  
Mhd Equilibria ◽  
Solar Wind Flow ◽  
Nonlinear Force

<p>Computing the solar coronal magnetic field and plasma<br>environment is an important research topic on it's own right<br>and also important for space missions like Solar Orbiter to<br>guide the analysis of remote sensing and in-situ instruments.<br>In the inner solar corona plasma forces can be neglected and<br>the field is modelled under the assumption of a vanishing<br>Lorentz-force. Further outwards (above about two solar radii)<br>plasma forces and the solar wind flow has to be considered.<br>Finally in the heliosphere one has to consider that the Sun<br>is rotating and the well known Parker-spiral forms.<br>We have developed codes based on optimization principles<br>to solve nonlinear force-free, magneto-hydro-static and<br>stationary MHD-equilibria. In the present work we want to<br>extend these methods by taking the solar rotation into account.</p>

High Energy Particle Spectrometer for ESA Lagrange mission

2021 ◽  
Author(s):  
Wojtek Hajdas ◽  
Radoslaw Marcinkowski ◽  
Hualin Xiao ◽  
Ronny Kramert
Keyword(s):  
Solar Energetic Particle ◽  
Heavy Ion ◽  
High Energy ◽  
High Energy Particle ◽  
Energy Particle ◽  
Detection Systems ◽  
Parker Spiral ◽  
Final Design ◽  
Radiation Tolerant

<p>The LGR High Energy Particle Spectrometer HEPS for the ESA Lagrange mission belongs to the satellite in-situ instrument suite. The satellite will be placed at the Lagrange point L5 for space weather measurements and real-time observations and alerts. The HEPS instrument with its six detector subsystems will enable the detecting of electrons, protons, and heavy ions at high flux conditions during Solar Energetic Particle Events. The electron and proton detection systems rely on standard telescope techniques covering energy ranges from 100 keV to 15 MeV and 3 MeV to 1 GeV respectively. Two sets of telescopes will be installed facing opposite directions along the Parker spiral. Additional detector with a wide angular range will enable measurements of angular distributions of particles traveling towards the satellite from the Sun. The HEPS heavy-ion telescope HIT represents a new design utilizing a set of scintillators and SiPM light converters. HIT electronics is equipped with a dedicated radiation-tolerant ASIC optimized for low power use and fast signal detections. The first model of HIT was developed and verified for spectroscopic measurements and ion identification. We report on test measurements as well as Monte Carlo simulations of the whole instrument. Results will be discussed and implications on the final design of the instrument provided.</p>

scholarly journals Tests for coronal electron temperature signatures in suprathermal electron populations at 1 AU

2017 ◽  
Vol 35 (6) ◽  
pp. 1275-1291 ◽  
Author(s):  
Allan R. Macneil ◽  
Christopher J. Owen ◽  
Robert T. Wicks
Keyword(s):  
Solar Wind ◽  
Electron Temperature ◽  
Energy Content ◽  
The Sun ◽  
Particle Interactions ◽  
Core Electron ◽  
Suprathermal Electron ◽  
Electron Distributions ◽  
The Relationship ◽  
Coronal Electron

Abstract. The development of knowledge of how the coronal origin of the solar wind affects its in situ properties is one of the keys to understanding the relationship between the Sun and the heliosphere. In this paper, we analyse ACE/SWICS and WIND/3DP data spanning  > 12 years, and test properties of solar wind suprathermal electron distributions for the presence of signatures of the coronal temperature at their origin which may remain at 1 AU. In particular we re-examine a previous suggestion that these properties correlate with the oxygen charge state ratio O7+ ∕ O6+, an established proxy for coronal electron temperature. We find only a very weak but variable correlation between measures of suprathermal electron energy content and O7+ ∕ O6+. The weak nature of the correlation leads us to conclude, in contrast to earlier results, that an initial relationship with core electron temperature has the possibility to exist in the corona, but that in most cases no strong signatures remain in the suprathermal electron distributions at 1 AU. It cannot yet be confirmed whether this is due to the effects of coronal conditions on the establishment of this relationship or due to the altering of the electron distributions by processing during transport in the solar wind en route to 1 AU. Contrasting results for the halo and strahl population favours the latter interpretation. Confirmation of this will be possible using Solar Orbiter data (cruise and nominal mission phase) to test whether the weakness of the relationship persists over a range of heliocentric distances. If the correlation is found to strengthen when closer to the Sun, then this would indicate an initial relationship which is being degraded, perhaps by wave–particle interactions, en route to the observer.

Three-dimensional Multispecies Simulation of the Solar Wind Interaction with Mars Under Different Interplanetary Magnetic Field Orientations

2021 ◽  
Vol 921 (2) ◽  
pp. 139
Author(s):  
Yun Li ◽  
Haoyu Lu ◽  
Jinbin Cao ◽  
Shibang Li ◽  
Christian Mazelle ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Three Dimensional ◽  
Polarity Reversal ◽  
Solar Wind Interaction ◽  
Magnetic Structures ◽  
Parker Spiral ◽  
Global Configuration ◽  
Spiral Angle

Abstract Without the intrinsic magnetic field, the solar wind interaction with Mars can be significantly different from the interaction with Earth and other magnetized planets. In this paper, we investigate how a global configuration of the magnetic structures, consisting of the bow shock, the induced magnetosphere, and the magnetotail, is modulated by the interplanetary magnetic field (IMF) orientation. A 3D multispecies numerical model is established to simulate the interaction of solar wind with Mars under different IMF directions. The results show that the shock size including the subsolar distance and the terminator radius increases with Parker spiral angle, as is the same case with the magnetotail radius. The location and shape of the polarity reversal layer and inverse polarity reversal layer in the induced magnetotail are displaced to the y < 0 sector for a nonzero flow-aligned IMF component, consistent with previous analytical solutions and observations. The responses of the Martian global magnetic configuration to the different IMF directions suggest that the external magnetic field plays an important role in the solar wind interaction with unmagnetized planets.

scholarly journals Dawn/Dusk Asymmetry of the Martian UltraViolet Terminator Observed Through Suprathermal Electron Depletions

2019 ◽  
Vol 124 (8) ◽  
pp. 7283-7300 ◽  
Author(s):  
M. Steckiewicz ◽  
P. Garnier ◽  
R. Lillis ◽  
D. Toublanc ◽  
F. Leblanc ◽  
...  
Keyword(s):  
Suprathermal Electron
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