Pyrometric investigation of nanoparticles condensation process in gaseous and superfluid helium

Abstract

The work is devoted to the study of thermal radiation accompanying the condensation of products of pulsed laser ablation of a tungsten target in vacuum, superfluid and gaseous helium. Pyrometric measurements have shown that the radiation characteristics depend on the medium. The obtained data imply that the sources of radiation in vacuum and gas are predominantly submicron particles, while in superfluid helium (He II) they are nanometer particles. These conclusions have been confirmed by electron microscopy data.