Motion behavior of micron-sized dust particles in pulse-modulated radio frequency N2/O2/Ar discharges

A one-dimensional (1D) fluid model is introduced to investigate the charging, transport, and motion behavior of micron-sized dust particles in pulse-modulated radio frequency (RF) capacitively coupled N2/O2/Ar discharges. The effects of modulation frequency and duty cycle on the plasma characteristics and particle behavior are investigated, and the effects of particle size and initial conditions on particle motion behavior are discussed in detail. It is found that, under the same average power, reducing the duty cycle or modulation frequency significantly increases the plasma density, and a large number of negative ions can be obtained at the electrodes. Furthermore, the falling speed and displacement of particles can be effectively reduced by lowering the modulation frequency. It is also observed that the size, initial position, and initial velocity of the injected particles significantly affect particle velocity and trajectory.