الفهرس 
Space plasma - why bother?Only 14 pages are availabe for public view
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Abstract
A highly structured plasma environment, with a large number of
readily available energy resources, has been revealed by the In Situ
measurements in the Martian Ionosphere. The energetic growth in
plasma suggests that it is not compatible with the Thermodynamic
equilibrium. A wide range of plasma wave characteristics arises due
to large deviations from thermodynamic equilibrium. In this way, a
large number of wave modes and unstable fluctuations may be supported by the Martian plasma. The main features of fully nonlinearly
low-frequency electrostatic wave modes, such as ion acoustic solitary
waves and double layer waves in plasmas that are relevant to the Martian Ionosphere will be investigated by this thesis. In order to model
ionospheric plasma and study how its variability affects the fundamental features of these waves, this methodology is based upon the use of
hydrodynamical modeling as well as observations by Mars Atmosphere
and Volatile Evolution (MAVEN). Three chapters are included in this
thesis, describing them as follows:
Chapter I, shows a short overview of Mars, where its typical features and plasma environment are found. Besides, a summary of the
major space missions that explored it.
In Chapter II, We investigated how variations in number density
in plasma affect the propagation of low-frequency electrostatic waves
in the planet’s ionosphere. We use a collisionless inhomogeneous unmagnetized plasma model with two positive cold ion species (O+, H+)
with nonthermal electrons for this purpose. the basic equations are
reduced to one evolution equation. The latter has been analyzed and
solved numerically to obtain an arbitrary amplitude shock wave profle as well as the possible regions for the existing waves. We’ve put
forward a negative potential, which is consistent with the compressive
wave profle. An interpretation of the electrostatic waves, which can
be found in Mars’ ionizing atmosphere, is based on fndings from this
investigation. We’re going to be able to explain how the gas is lost
from the ionosphere if we can observe this wave in Mars’ Ionosphere.
In Chapter III, We investigated the propagation properties of fully
ivnonlinear ion-acoustic solitary waves and double-layer waves in the
Martian ionosphere. The plasma model consists of three positive ions
(H+, O+, and O2+) and superthermal electron distribution. Sagdeev
pseudo-potential is obtained for arbitrary amplitude ion-acoustic waves.
The effects of plasma parameters on the nature of the solitary waves
and double layer waves are investigated. The velocity of the wave phase
has been established to be supersonic, and this is in agreement with
the observations.