Space Charge Waves in Cylindrical Plasma Columns

Abstract

When a plasma is of finite transverse cross section, space-charge waves may propagate even in the absence of a drift motion or thermal velocities of the plasma. Some of the properties of these space charge waves have been investigated by regarding the plasma as a dielectric and solving the resulting field equations. The effect of a steady axial magnetic field is considered, but motion of heavy ions and electron temperature effects are neglected. Waves are found to exist at frequencies low compared with the plasma frequency as well as waves with oppositely directed phase and group velocities (backward waves). Many of the features of these waves have been verified experimentally by measuring phase velocity and attenuation of waves along the positive column of a low pressure mercury arc in an axial magnetic field. Measurements of electron density have been made using these waves and the results are compared with those obtained by other methods. An interesting feature of these measurements, of value in plasma diagnostics, is that they can be made with frequencies which are small compared with the plasma frequency.

Complex Surface Wave Modes of Plasma Column Loaded Closed Cylindrical Waveguide

“…The quasi-static approximation for plasma column loaded cylindrical waveguides was presented in detail by Trivelpiece and Gould [11][12][13]. In their study, the resulting modes are slow modes and are transverse magnetic (TM).…”

“…The surface waves in partially stationary plasma of finite transverse cross section were observed for the first time by Trivelpiece and Gould [11][12][13]. They obtained the field equations by using quasistatic approximation and also presented analytically and experimentally two types of propagation.…”

“…The plasma column loaded closed cylindrical waveguides have been tackled in different studies using the quasistatic approximation [11][12][13][14]46] or the exact solution [16,[47][48][49][50][51] or both [15,52]. In these studies, the propagation characteristics of the structures have been presented on the frequency-propagation constant (ω-γ) plane called the Brillouin diagrams, because these diagrams are easily interpreted and therefore more useful to engineers and physicists [48].…”

Application of Perfectly Matched Layer Absorbing Boundary Conditions for Propagation of Surface Wave on the Long Plasma Cable

“…Since it has been found that surface wave plays an important role in sustaining an overdense plasma (3) , therefore, several works have been performed in this area (4) (5) . Usually for the computer simulation of surface wave produced plasma, the Finite Element Method (FEM) (6) or the Finite Difference Time Domain Method (FD-TD) (7) are employed.…”

Landau damping of electron plasma waves in the linear and trapping regimes

“…T-G waves are longitudinal electrostatic plasma oscillations (Langmuir waves), modified by the cylindrical boundary [4]. Landau damping occurs when resonant electrons absorb energy from the wave; these electrons have axial velocity v, = vph, where Vph is the wave phase velocity.…”