Thermal runaway in two-dimensional complex plasma crystals

TL;DR

This study investigates how localized laser heating causes melting and thermal runaway in two-dimensional plasma crystals, revealing a threshold-dependent behavior similar to explosive reactions in reactive matter.

Contribution

It demonstrates the role of fluid mode-coupling instability in inducing thermal runaway in plasma crystals, a novel insight into their melting dynamics.

Findings

Below threshold, melted areas recrystallize.

Above threshold, melting expands rapidly, destroying order.

Thermal runaway behavior resembles explosive reactions.

Abstract

The full melting of a two-dimensional plasma crystal was induced in a principally stable monolayer by localized laser stimulation. Two distinct behaviors of the crystal after laser stimulation were observed depending on the amount of injected energy: (i) below a well-defined threshold, the laser melted area recrystallized; (ii) above the threshold, it expanded outwards in a similar fashion to mode-coupling instability induced melting, rapidly destroying the crystalline order of the whole complex plasma monolayer. The reported experimental observations are due to the fluid mode-coupling instability which can pump energy into the particle monolayer at a rate surpassing the heat transport and damping rates in the energetic localized melted spot, resulting in its further growth. This behavior exhibits remarkable similarities with impulsive spot heating and thermal runaway (explosion) in ordinary reactive matter.