Resonance properties of a single dust particle in a stratified glow discharge

Abstract

The forced vertical oscillations of a single dust particle trapped in a standing striation are investigated. The particle oscillations associated with the displacement of the striation are induced by square wave modulation of the discharge current. Amplitude−frequency characteristics with respect to pressure are measured. The resonance frequency, the logarithmic decrement and the amplitude of resonance peak are determined. In order to obtain the eigenfrequency value, the phase shift of the forced dust particle oscillations is measured and the velocity resonance investigated. The calculation of the dust particle charge is made with the help of the eigenfrequency. A quantitative description of the resonance behaviour of the dust particle based on the theory of the forced harmonic oscillator is made. The Q-factor of a dusty plasma system is measured for the first time, and the obtained value compared with Q-factors of dusty plasma oscillatory systems previously investigated in rf plasma.

Nonlinear oscillations of a single dust particle as the basis of the method for the DC plasma diagnostics

“…This approach is normally valid in the limit γ ω 0 and is justified for our case. The value of eigenfrequency obtained under the same experimental conditions in [4] is ω 0 2π =21.8 ± 2.6 Hz, the damping constant calculated with the help of the Epstein formula [8] takes the value of γ = 15 s −1 at pressure p = 0.16 Torr. The dependence of the amplitude A on ε and F 0 is given by equation [7]…”

“…The discharge current modulation was realized with the help of the experimental technique suggested in [3,4]. The detailed description of the experimental setup is presented in figure 1 published in [3,4]. A stratified glow discharge was produced in neon at pressure p = 0.16 Torr and currents 2-3 mA.…”

“…Second, accurate knowledge of the relation between the characteristics of the discharge plasma and the parameters of the dust particles is necessary. Under the condition of DC discharge the investigations of the linear dust particle oscillations conducted in [3,4], were used to solve this problem.…”

The vibrational properties of the dust trap created in standing striation

“…The value of eigenfrequency coincides with the values obtained under the same experimental conditions in ref. [], at the error level. The values of damping constant β are in good agreement with that obtained with the help of the relaxation oscillation and with the value of the Epstein damping rate …”

Complex plasma in a stratified glow discharge in a strong magnetic field

“…An electric field close to that in real striations was modeled in [55] as E(z) ∼ {exp[exp(2πz/L)] − 1.3}. Then, in [56,57], a similar dependence E(z) was presented by a simpler and more convenient expression, which we also use in our model:…”