Dust-induced modulation of the atomic emission in a dusty Argon discharge

The spectral emission of argon atoms in a dusty rf discharge plasma has been determined. For that purpose, the spatially and temporally resolved emission of the argon atoms during the rf cycle was measured using a gated intensified charge-coupled device camera. While dust particles of 2–3¿¿µm diameter trapped in the sheath lead to an increased plasma emission during the sheath expansion phase, larger particles of 10–12¿¿µm diameter result in a decreased emission. This behavior is explained by the combined action of electron density reduction due to the charging dynamics in the sheath and the increase of electron temperature to compensate plasma losses at the dust