Interaction of a supersonic particle with a three-dimensional complex plasma

TL;DR

This study investigates how a supersonic particle interacts with a three-dimensional complex plasma in microgravity, revealing Mach cone formation, particle charge estimations, and localized heating effects at the microscopic level.

Contribution

It provides detailed experimental observations of Mach cone structures and particle dynamics in 3D complex plasma under microgravity conditions, using high-resolution imaging.

Findings

Mach cones with M ≈ 1.5 - 2 observed in plasma

Particle charge estimations compared with standard theories

Localized heating behind the supersonic projectile

Abstract

The influence of a supersonic projectile on a three-dimensional complex plasma is studied. Micron sized particles in a low-temperature plasma formed a large undisturbed system in the new 'Zyflex' chamber during microgravity conditions. A supersonic probe particle excited a Mach cone with Mach number M $\approx$ 1.5 - 2 and double Mach cone structure in the large weakly damped particle cloud. The speed of sound is measured with different methods and particle charge estimations are compared to calculations from standard theories. The high image resolution enables the study of Mach cones in microgravity on the single particle level of a three-dimensional complex plasma and gives insight to the dynamics. A heating of the microparticles is discovered behind the supersonic projectile but not in the flanks of the Mach cone.