Whistler waves guided by ducts with enhanced density in a collisional magnetoplasma

Abstract

UDC 533.951We study the guided propagation of whistler waves along cylindrical ducts with enhanced density in a collisional magnetoplasma. It is shown that under certain conditions, the presence of comparatively small dissipative losses due to electron collisions in a plasma medium can lead to significant changes in the dispersion characteristics and field structures of whistler modes guided by such ducts compared with the case of a collisionless plasma. We present the results of numerical calculations showing such changes in the properties of whistler modes.

Whistler Waves' Propagation in Plasmas With Systems of Small‐Scale Density Irregularities: Numerical Simulations and Theory

“…The dispersion equation can be obtained from the boundary conditions at the duct surface ρ = a . Such equation was considered previously for ducts with enhanced plasma density, under the condition f ce ≪ f pe (Es'kin et al, ; Zaboronkova et al, ). Here we discuss the properties of the leaky modes, which can be guided by a duct with small density enhancement under the condition .…”

“…An analytical solution can be obtained for a uniform density profile only, when and N e 0 are constant values. Note that the properties of modes guided by a sharp‐walled uniform duct differ only slightly from those of modes propagating in a smooth‐walled duct if the wall thickness is smaller than the transverse scale of the fields of the quasi‐parallel whistler part of the leaky modes (Bakharev et al, ; Es'kin et al, ).…”

Нестійкість Трубчастого Електронного Пучка У Разі Обдування Плазмового Твердотільного Циліндра, Який Розміщено У Сильному Поздовжньому Магнітному Полі

“…It should be noted that interest to open guide systems containing magnetoactive components has been renewed recently. One of the directions in this domain is the study of excitation and propagation of helicon-type waves in cylindrical plasma structures located in free space [19][20][21] or background magnetoactive plasma [26][27][28][29] in parallel to the external constant magnetic field. In particular, increased attention is paid to waves that play an important role in high-frequency helicon discharges [19,20].…”

Whistler eigenmodes of magnetic flux tubes in a magnetoplasma

“…These studies have been motivated by the fact that the guided whistler waves are encountered in many cases, including not only the near-Earth space [1][2][3][4], but also tokamaks [9] and low-temperature laboratory plasmas [10][11][12][13][14][15], and can significantly affect the efficiency of whistler wave excitation by electromagnetic sources [16][17][18]. Whistler wave propagation in density ducts was considered theoretically in many works [14][15][16][17][18][19][20][21][22][23][24]. However, there exists very little theory of the phenomena caused by the guidance of whistler-mode waves in structures that are formed by variation of other plasma parameters, for example, an external dc magnetic field.…”