Dust acoustic waves in a direct current glow discharge

TLDR

The study experimentally investigates dust acoustic waves in a dc glow discharge plasma. A 3 cm anode disk in a 60 cm chamber with 100 mTorr nitrogen creates a glow discharge; dust is trapped electrostatically, DA waves are driven by a 5–40 Hz anode modulation, and wavelengths are measured from single‑frame video of scattered light. The measured dispersion relation matches theoretical predictions.

Abstract

An experimental investigation of dust acoustic (DA) waves in a dc glow discharge plasma is described. The glow discharge is formed between a 3 cm anode disk and the grounded walls of a 60 cm diameter vacuum chamber which is filled with nitrogen gas at a pressure of about 100 mTorr. Dust located on a tray in the chamber is attracted into the plasma where it is trapped electrostatically. The dust acoustic waves were produced by applying a modulation signal (5–40 Hz) to the anode. The wavelength of the DA waves was measured from single frame video images of scattered light from the dust grains. The measured dispersion relation is compared with theoretical predictions.