Monte Carlo test-particle model of Mercury's ionized exosphere: Global structure and dynamics

2020 ◽  
Author(s):  
Anita Linnéa Elisabeth Werner ◽  
François Leblanc ◽  
Jean-Yves Chaufray ◽  
Ronan Modolo
Keyword(s):  
Monte Carlo ◽  
Density Distribution ◽  
Test Particle ◽  
Plasma Sheet ◽  
Global Structure ◽  
Charge Ratio ◽  
Particle Model ◽  
Monte Carlo Test ◽  
Ion Density ◽  
Photo Ionization

<div>The Mercury plasma environment is enriched in heavy ions (mass-per-charge ratio m/q > 4) from photo-ionization of the tenuous exosphere. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) time-of-flight spectrometer Fast Imaging Plasma Spectrometer (FIPS) has detected many planetary ion species of which He<sup>+</sup>, the Na<sup>+</sup>-group (including Na<sup>+</sup>, Mg<sup>+</sup> and Si<sup>+</sup>) and the O<sup>+</sup>-group (including O<sup>+</sup> and several water group ions) are the most abundant. The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) UltraViolet and Visible Spectrometer (UVVS) has also detected Ca<sup>+</sup> ions in the nightside plasma sheet. Models of the planetary ion distribution inside Mercury's magnetosphere have mostly concentrated on the abundant Na<sup>+</sup> and H<sup>+</sup> ion populations. Comparison with FIPS data has been limited to the first two MESSENGER flybys and no comparison has been made with MASCS/UVVS observations.</div><div> </div><div>We have developed a Monte Carlo test-particle model which describes the ion density distribution produced from photo-ionization of several neutral species in Mercury's exosphere. The global ion density and energy distribution of Ca<sup>+</sup>, Mg<sup>+</sup>, Na<sup>+</sup>, O<sup>+</sup> and He<sup>+</sup> will be presented here. We will review the influence of the interplanetary magnetic field (IMF) B<sub>x</sub> and B<sub>y</sub> components on the global structure of the ion density distribution, the composition of the nightside plasma sheet and the evolution of the Na<sup>+</sup> ion density along the Mercury year.</div>

scholarly journals Density, Energy and Phase Space Density Distribution of Planetary Ions He+, O+ and Na+ in Mercury's Magnetosphere

2021 ◽  
Author(s):  
A. L. Elisabeth Werner ◽  
François Leblanc ◽  
Jean-Yves Chaufray ◽  
Ronan Modolo ◽  
Sae Aizawa ◽  
...  
Keyword(s):  
Phase Space ◽  
Density Distribution ◽  
Test Particle ◽  
Space Environment ◽  
Particle Model ◽  
Phase Space Density ◽  
Ion Density ◽  
Space Density ◽  
Upstream Solar Wind ◽  
The Impact

<p>The Mercury plasma environment is enriched in planetary ions from the tenuous neutral exosphere. We have developed a test-particle model which describes the full equation of motion for planetary ions produced from photo-ionization of the neutral exosphere. The new test-particle model is coupled to a Monte Carlo test-particle model of the neutral exosphere (Exospheric Global Model; EGM; Leblanc et al. 2017) and two hybrid-kinetic models: LatHyS (Modolo et al. 2016) and AIKEF (Müller et al. 2011). This coupling will allow us to consider the impact of non-adiabatic energization on the ion density distribution as well as the connection to seasonal asymmetries in the neutral exosphere.</p><p>We compare the density, energy and phase space density distribution of He+, O+ and Na+ from our model with observations from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) time-of-flight spectrometer Fast Imaging Plasma Spectrometer (FIPS; Raines et al. 2013). Our results indicate the presence of several interesting high-density structures both inside and outside FIPS observable energy range (E = 0.05 -13 keV), the properties of which are likely very sensitive to the upstream solar wind conditions. We present how these results may aid the interpretation of FIPS data and future measurements by BepiColombo.</p>

scholarly journals Synthetic Fast Ion Diagnostics in Tokamaks: Comparing the Monte Carlo Test Particle Code ASCOT against Experiments

2016 ◽  
Vol 69 (3) ◽  
pp. 620-627 ◽  
Author(s):  
Simpp Äkäslompolo ◽  
Tain Kurki-Suonio ◽  
Sepp Sipilä ◽  
ASCO Group
Keyword(s):  
Monte Carlo ◽  
Test Particle ◽  
Monte Carlo Test ◽  
Fast Ion

scholarly journals A physico-chemical model to study the ion density distribution in the inner coma of comet C/2016 R2 (Pan-STARRS)

2020 ◽  
Author(s):  
Susarla Raghuram ◽  
Anil Bhardwaj ◽  
Damien Hutsemékers ◽  
Cyrielle Opitom ◽  
Jean Manfroid ◽  
...  
Keyword(s):  
Density Distribution ◽  
Electron Impact ◽  
Emission Intensity ◽  
Impact Ionization ◽  
Excitation Source ◽  
Resonance Fluorescence ◽  
Ion Density ◽  
Physico Chemical ◽  
Intensity Ratios ◽  
Ion Emission

Abstract The recent observations show that comet C/2016 R2 (Pan-Starrs) has a unique and peculiar composition when compared with several other comets observed at 2.8 au heliocentric distance. Assuming solar resonance fluorescence is the only excitation source, the observed ionic emission intensity ratios are used to constrain the corresponding neutral abundances in this comet. We developed a physico-chemical model to study the ion density distribution in the inner coma of this comet by accounting for photon and electron impact ionization of neutrals, charge exchange and proton transfer reactions between ions and neutrals, and electron-ion thermal recombination reactions. Our calculations show that CO$_2^+$ and CO+ are the major ions in the inner coma, and close to the surface of nucleus CH3OH+, CH3OH$_2^+$ and O$_2^+$ are also important ions. By considering various excitation sources, we also studied the emission mechanisms of different excited states of CO+, CO$_2^+$, N$_2^+$, and H2O+. We found that the photon and electron impact ionization and excitation of corresponding neutrals significantly contribute to the observed ionic emissions for radial distances smaller than 300 km and at larger distances, solar resonance fluorescence is the major excitation source. Our modelled ion emission intensity ratios are consistent with the ground-based observations. Based on the modelled emission processes, we suggest that the observed ion emission intensity ratios can be used to derive the neutral composition in the cometary coma only when the ion densities are significantly controlled by photon and photoelectron impact ionization of neutrals rather than by the ion-neutral chemistry.

Crossover scaling in semidilute polymer solutions: a Monte Carlo test

1991 ◽  
Vol 1 (1) ◽  
pp. 37-60 ◽  
Author(s):  
Wolfgang Paul ◽  
Kurt Binder ◽  
Dieter W. Heermann ◽  
Kurt Kremer
Keyword(s):  
Monte Carlo ◽  
Polymer Solutions ◽  
Monte Carlo Test

Test particle model predictions of SEP electron transport and precipitation at Mars

2021 ◽  
Author(s):  
R. D. Jolitz ◽  
C. F. Dong ◽  
A. Rahmati ◽  
D. A. Brain ◽  
C. O. Lee ◽  
...  
Keyword(s):  
Electron Transport ◽  
Test Particle ◽  
Particle Model ◽  
Model Predictions

scholarly journals WN4 effect on longitudinal distribution of different ion species in the topside ionosphere at low latitudes by means of DEMETER, DMSP-F13 and DMSP-F15 data

2009 ◽  
Vol 27 (7) ◽  
pp. 2893-2902 ◽  
Author(s):  
L. Bankov ◽  
R. Heelis ◽  
M. Parrot ◽  
J.-J. Berthelier ◽  
P. Marinov ◽  
...  
Keyword(s):  
Density Distribution ◽  
Major Ions ◽  
Local Times ◽  
Longitudinal Distribution ◽  
Topside Ionosphere ◽  
Regular Feature ◽  
Ion Density ◽  
F Region ◽  
Longitudinal Variations ◽  
Ion Species

Abstract. Plasma probe data from DMSP-F13, DMSP-F15 and DEMETER satellites were used to examine longitudinal structures in the topside equatorial ionosphere during fall equinox conditions of 2004 year. Since the launch of DEMETER satellite on 29 June 2004, all these satellites operate close together in the topside ionosphere. Here, data taken from Special Sensor-Ion, Electron and Scintillations (SSIES) instruments on board DMSP-F13, F15 and Instrument Analyser de Plasma (IAP) on DEMETER, are used. Longitudinal variations in the major ions at two altitudes (~730 km for DEMETER and ~840 km for DMSP) are studied to further describe the recently observed "wavenumber-four" (WN4) structures in the equatorial topside ionosphere. Different ion species H+, He+ and O+ have a rather complex longitudinal behavior. It is shown that WN4 is almost a regular feature in O+ the density distribution over all local times covered by these satellites. In the evening local time sector, H+ ions follow the O+ behavior within WN4 structures up to the pre-midnight hours. Near sunrise H+ and later in the daytime, He+ longitudinal variations are out of phase with respect to O+ ions and effectively reduce the effect of WN4 on total ion density distribution at altitudes 730–840 km. It is shown that both a WN4 E×B drift driver and local F-region winds must be considered to explain the observed ion composition variations.

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