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Sources of thermonuclear neutrons with magnetic confinement
Published in S. V. Ryzhkov, A. Yu. Chirkov, Alternative Fusion Fuels and Systems, 2018
The β (beta) ratio is one of the main characteristics for magnetic plasma confinement systems and determines the operating modes of many installations, especially when it comes to thermonuclear perspectives of the system and primarily as a power plant. The maximum value of energy content in fast ions corresponds to the maximum value of β. And it, as well as the energy confinement time, depends on the magnitude of the external magnetic field and temperature that enter the ion gyroradius ρi=0.00456Timi/ZiB, where mi is the mass of the ion in atomic mass units, Zi is the ion charge.
Nonlinear Dust Kinetic Alfvén Waves in a Dust-Ion Plasma with Ions Following q-Nonextensive Velocity Distribution
Published in B. Raneesh, Nandakumar Kalarikkal, Jemy James, Anju K. Nair, Plasma and Fusion Science, 2018
It is well-known that Alfvén wave is nondispersive in the ideal magnetohydrodynamic description. However, the wave can be dispersive for its oblique propagation to the direction ambient magnetic field in plasma when shear Alfvén waves are either affected by the ion gyroradius (for Q<<ß<<1; Q is the electron-to-ion mass ratio, and β is the thermal to magnetic pressure ratio), or by the electron inertia length (for ß<<Q). The resulting dispersive Alfvén waves are often known as kinetic Alfvén wave (hereafter KAW) and inertial Alfvén wave in the former and the latter cases, respectively. The dispersive character of KAWs when balanced with nonlinear steepening may lead to the formation of nonlinear structures like solitary KAWs and double layers. The data received from space satellites [1, 2] has revealed solitary like structures by strong electromagnetic spikes which could possibly be interpreted as KAWs with dip or hump type solitary structures. The study of nonlinear phenomena of KAWs in plasma has drawn much attention because of their relevance in explaining electromagnetic fluctuations and nonlinear structures observed in space, astrophysical, and laboratory plasmas.
Introduction
Published in Igor G. Kondrat’ev, Alexander V. Kudrin, Tatyana M. Zaboronkova, Electrodynamics of Density Ducts in Magnetized Plasmas, 2019
Igor G. Kondrat’ev, Alexander V. Kudrin, Tatyana M. Zaboronkova
Let the following conditions be satisfied for the plasma parameters and the amplitude of an alternating (antenna-launched) electromagnetic field: (i) their spatial variations along and across an ambient static magnetic field are much greater than the electron mean free path and the ion gyroradius, respectively; (ii) their temporal variations are slow on the scale of the mean time between two collisions of one particle; (iii) the pressure of the plasma is much less than that of the ambient magnetic field. Besides, we assume that the quasi-neutrality is fulfilled to a good accuracy, so that one can write for the plasma density, N,
Kinetic Alfvénic cnoidal waves in Saturnian magnetospheric plasmas
Published in Waves in Random and Complex Media, 2021
Manpreet Singh, Kuldeep Singh, N. S. Saini
Over the last few decades, kinetic Alfvén waves (KAWs) have attracted a great attention of space plasma physicists because of their occurrence in space environments [1–3]. KAWs play an important role in the transport of energy and particles in a number of space and astrophysical plasma environments [4–10]. KAWs are formed when the perpendicular wavelength becomes approximately equal to the ion gyroradius. At small scale, Alfvén waves are significantly damped [11], and an electric field parallel to the external magnetic field appears. This electric field is formed due to the finite electron pressure in the parallel direction. The magnetic field is considered to be strong enough such that the plasma beta (β) lies in the range . Due to this strong magnetic field, the electrons having small gyroradius (relative to ions) keep on following the magnetic lines of force while the ions deviate from the magnetic field lines. In such a condition, an obliquely propagating ion density perturbation is observed.
Dust acoustic solitary waves in a five component cometary plasma with dust charge variation
Published in Radiation Effects and Defects in Solids, 2021
T. W. Neethu, S. Shilpa, A.C. Saritha, N. S. Philip, C. Venugopal
The electron current decreases by a factor compared to that in the absence of a magnetic field as the electron gyroradius is comparable to the electron collection radius on dust grains due to magnetic field, and the ion gyroradius is still much larger than the ion dust attraction size [ i.e. the ion current to the grain will remain the same as in an unmagnetized plasma] (57, 58, 74). On the hydrodynamic time scale, the dust grain can quickly reach local equilibrium and the currents from the electrons and ions to the dust get balanced, given by (5, 74), Using Equations (10)–(13) in the above current balance Equation (14), we get, where , , , , , , , and .
Influence of FLR correction on Jeans instability in rotating radiative QMHD fluid model
Published in Radiation Effects and Defects in Solids, 2021
D. L. Sutar, G. Ahmed, R. K. Pensia
Additionally, the strong magnetic field plays a vital role in specific astrophysical problems the same as the development of intergalactic clouds into self-gravitating star formation. Mestel and Spitzer (6) have investigated the impact of magnetic fields on dust cloud formation. The presence of a magnetic field is introduced into rotating quantum plasma by some new scales, such as Larmor radius (gyroradius). The finite ion Larmor radius (FLR) correction is based on where is Larmor radius and is a special scale for the plasma field, and is defined by a simple extension component for several of those equations explaining magnetosphere of plasma dynamics. Linear and relatively high-order situations in build-up to the charge separation and energization of the molecules and then to the producing of viscosity excluding the collision. In that relation, the equations array for quantum magnetohydrodynamics (QMHD) to derive the index of quantum magnetized plasma by taking into account the zero Larmor radius of electron and ions, the frequency is generally lower than the electron-ion gyration frequency. The zero Larmor radius does not hold numerous intergalactic states of affairs, e.g. in the laboratory and astrophysical plasma. In a particular situation, the FLR of ion is introduced, it was applied pressure tensor form in the momentum transfer equation of the rotating QMHD array of equations and this pressure tensor is responsible for changing the system dynamics.