Particle ordered structures in a strongly coupled classical thermal plasma

An ordered structure of macroscopic particles has been experimentally observed in a classical neutral thermal plasma using a laser time-of-flight system. The strongly coupled thermal plasma consists of Ce${\mathrm{O}}_2$ particles and electrons emitted by the latter under atmospheric pressure and temperature of 1700 K. The particles are charged positively and suspended in a plasma flow. Their charge is about ${10}^{4}e$ and the calculated value of a Coulomb coupling parameter ${\gamma }_p$ is > 120, which corresponds to a strongly coupled plasma.