Interaction force in a vertical dust chain inside a glass box

TL;DR

This study investigates how rf power influences the interaction forces, charge, and screening length of dust particles in a confined plasma within a glass box, revealing that increased power reduces both charge and screening length.

Contribution

It provides experimental insights into how rf power affects dust particle charge and plasma screening length inside a glass confinement, highlighting ion trapping effects.

Findings

Screening length decreases with increased rf power.

Dust particle charge decreases as rf power increases.

Ion trapping may significantly influence sheath behavior.

Abstract

Small number dust particle clusters can be used as probes for plasma diagnostics. The number of dust particles as well as cluster size and shape can be easily controlled employing a glass box placed within a GEC rf reference chamber to provide confinement of the dust. The plasma parameters inside this box and within the larger plasma chamber have not yet been adequately defined. Adjusting the rf power alters the plasma conditions causing structural changes of the cluster. This effect can be used to probe the relationship between the rf power and other plasma parameters. This experiment employs the sloshing and breathing modes of small cluster oscillations to examine the relationship between system rf power and the particle charge and plasma screening length inside the glass box. The experimental results provided indicate that both the screening length and dust charge decrease as rf power inside the box increases. The decrease in dust charge as power increases may indicate that ion trapping plays a significant role in the sheath.