On the heterogeneous character of the heartbeat instability in complex (dusty) plasmas

TL;DR

This paper proposes a hypothesis that the heartbeat instability in complex plasmas results from periodic critical transformations at the boundary of the void, driven by electron and ion loss on microparticles, aligning with experimental observations.

Contribution

It introduces a novel hypothesis linking the heartbeat instability to boundary transformations similar to sheath formation, supported by experimental consistency.

Findings

The hypothesis aligns with measured stability parameters.

The plasma glow intensity and microparticle dynamics match the model.

Heartbeat instability can be excited by laser modulation.

Abstract

A hypothesis on the physical mechanism generating the heartbeat instability in complex (dusty) plasmas is presented. It is suggested that the instability occurs due to the periodically repeated critical transformation on the boundary between the microparticle-free area (void) and the complex plasma. The critical transformation is supposed to be analogous to the formation of the sheath in the vicinity of an electrode. The origin of the transformation is the loss of the electrons and ions on microparticles surrounding the void. We have shown that this hypothesis is consistent with the experimentally measured stability parameter range, with the evolution of the plasma glow intensity and microparticle dynamics during the instability, as well as with the observed excitation of the heartbeat instability by an intensity-modulated laser beam, tuned to the atomic transition of a working gas.