Empirical models of ion density distribution in the dayside Martian ionosphere

2021 ◽  
Author(s):  
J. ‐P. Huang ◽  
Y. ‐T. Cao ◽  
J. Cui ◽  
Y. ‐Q. Hao ◽  
X. ‐S. Wu ◽  
...  
Keyword(s):  
Density Distribution ◽  
Empirical Models ◽  
Ion Density ◽  
Martian Ionosphere

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.

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.

Plasma diagnostics by laser spectroscopic electric field measurement

2005 ◽  
Vol 77 (2) ◽  
pp. 345-358 ◽  
Author(s):  
U. Czarnetzki ◽  
D. Luggenhölscher ◽  
V. A. Kadetov ◽  
H. F. Döbele
Keyword(s):  
Electric Field ◽  
Density Distribution ◽  
Field Measurements ◽  
Distribution Functions ◽  
Plasma Parameters ◽  
Ion Density ◽  
Versatile Tool ◽  
Low Temperature Plasmas ◽  
Energy Distribution Functions ◽  
Laser Spectroscopic

Laser spectroscopic electric field measurements have the potential to become a versatile tool for the diagnostics of low-temperature plasmas. From the spatially and temporally resolved field distribution in the sheath close to electrodes or surfaces in general, a broad range of important plasma parameters can be inferred directly: electron temperature; ion density distribution; displacement-, ion-, electron-diffusion current density; and the sheath potential. Indirectly, the electron and ion energy distribution functions and information on the ion dynamics in the sheath can also be obtained. Finally, measurements in the quasi-neutral bulk can also reveal even the plasma density distribution with high spatial and temporal resolution. The basic concepts for analysis of the field data are introduced and demonstrated by examples in hydrogen discharges.

Computation of the Removal Function for Ion Beam Figuring Curved Surface

2016 ◽  
Vol 13 (10) ◽  
pp. 7025-7031 ◽  
Author(s):  
Wa Tang ◽  
Weijie Deng ◽  
Xiaolin Yin ◽  
Donglin Xue ◽  
Ligong Zheng ◽  
...  
Keyword(s):  
Density Distribution ◽  
Gaussian Distribution ◽  
Material Removal ◽  
Ion Beam ◽  
Surface Profile ◽  
Curved Surface ◽  
Space Distribution ◽  
Computation Method ◽  
Ion Density ◽  
Ion Beam Figuring

Ion beam figuring (IBF) is a deterministic method for final figuring process of optical surface. The removal functions of IBF should be measured and calibrated strictly to guarantee the accuracy of the figuring results. The incident parameters of ion, surface profile and ion density distribution on the surface are the main factors which affect the material removal rate within the removal function. For the curved surfaces these factors vary from point to point so that the removal functions keeps changing when figuring curved surface especially for steep surface. Unlike the first two factors, the ion density distribution can’t be described by mathematic expression directly. Moreover, the ion is not in Gaussian distribution on the curved surface any more, which will result in variation of removal functions. Faraday cup is used to get the ion space distribution. So that the ion density on an arbitrary point can be obtained exactly. Based on the material removal features, revision method is proposed to fix the difference of the removal functions between the curved surface and the flat surface. Through experiments and theoretical analysis, the removal functions changes distinctly and not in Gaussian distribution. The computation method can fit the variety of the removal function effectively.

The ion density distribution in a magnetized plasma sheath

Vacuum ◽  
2008 ◽  
Vol 83 (1) ◽  
pp. 205-208 ◽  
Author(s):  
Xiu Zou ◽  
Minghui Qiu ◽  
Huiping Liu ◽  
Lijie Zhang ◽  
Jinyuan Liu ◽  
...  
Keyword(s):  
Density Distribution ◽  
Plasma Sheath ◽  
Magnetized Plasma ◽  
Ion Density

scholarly journals Study on the layered dusty plasma structures in the summer polar mesopause

2010 ◽  
Vol 28 (9) ◽  
pp. 1679-1686 ◽  
Author(s):  
◽  
◽  
◽  
◽  
Keyword(s):  
Density Distribution ◽  
Gravity Wave ◽  
Dusty Plasma ◽  
Layer Structure ◽  
Thin Layers ◽  
Ion Density ◽  
Ice Particles ◽  
Summer Echoes ◽  
Polar Mesosphere Summer Echoes ◽  
Formation And Evolution

Abstract. Traditional hydrodynamic equations are adopted to build a one-dimensional theoretical model to study the effect of gravity wave on layered dusty plasma structures formation and evolution near the polar summer mesospause region associated with polar mesosphere summer echoes (PMSE). The proposed mechanism gives consideration to the charged ice particle motion by the gravity wave modulation, making a significant contribution to the vertical transport of heavy ice particles and convergence into thin layers. And numerical results show that the pattern of the multi-layer structure depends on the ration of the initial ice particles density distribution to the vertical wavelength of the gravity waves, the ice particle size and the wind velocity caused by gravity wave. Also, the variation of ion density distribution under the influence of gravity wave has also been examined. Finally, the electron density depletions (bite-outs) layers has been simulated according to the charge conservation laws, and the results are compared to the ECT02 rocket sounding data, which agree well with the measuring.

Trapped ion density distribution in the presence of He-buffer gas

1981 ◽  
Vol 25 (3) ◽  
pp. 249-251 ◽  
Author(s):  
H. Schaaf ◽  
U. Schmeling ◽  
G. Werth
Keyword(s):  
Density Distribution ◽  
Buffer Gas ◽  
Ion Density ◽  
Trapped Ion

Ion Density Distribution in an Inductively Coupled Plasma Chamber

2004 ◽  
Vol 6 (2) ◽  
pp. 2233-2236 ◽  
Author(s):  
Chen Junfang ◽  
Zhao Wenfeng ◽  
Wu Xianqiu ◽  
Fan Shuangli ◽  
Fu Silie
Keyword(s):  
Density Distribution ◽  
Inductively Coupled Plasma ◽  
Ion Density ◽  
Plasma Chamber ◽  
Inductively Coupled

scholarly journals Charged particles density distribution in the cathode fall region of the glow discharge in helium

2021 ◽  
Vol 2119 (1) ◽  
pp. 012111
Author(s):  
V A Pinaev
Keyword(s):  
Distribution Function ◽  
Glow Discharge ◽  
Density Distribution ◽  
Electron Distribution Function ◽  
High Energy ◽  
Cathode Fall ◽  
Mechanism Of Formation ◽  
Ion Density ◽  
The Poisson Equation ◽  
High Energy Electrons

Abstract In the present work, the mechanism of formation and propagation of the group of high energy electrons in the cathode regions of a glow discharge in helium is discussed. Using the method of the Monte Carlo collisions simulation, the beam electron energy distribution function in the cathode fall region of a glow discharge has been determined in the gas pressure range of 30−70 Pa. It is shown that the electron distribution function at the end of the cathode fall region contains a lot of electrons which have no any collisions and have energies close to the cathode fall potential. On the basis of the obtained results the distribution of the ion density was simulated using the Poisson equation. It is shown that the ion density distribution stays almost constant in the cathode fall region. The beam and ion density increased with the pressure growth.

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