The formation and transport phenomena of nanometre-sized particles in a dc plasma

Lisa Wörner (1, 2) , Eva Kovacevic (1) , Johannes Berndt (1) , Hubertus M. Thomas (3) , Markus H. Thoma (2) , Laifa Boufendi (1) , Gregor Morfill (3)

1 GREMI - Groupe de recherches sur l'énergétique des milieux ionisés
2 MPE - Max Planck Institute for Extraterrestrial Physics
3 MPE - Max-Planck-Institut für Extraterrestrische Physik

The growth of nanoparticles in low-temperature plasmas is often accompanied by the formation of complex particle patterns and intricate transport processes. This paper deals with the formation and growth of nanoparticles operated in a mixture of argon and acetylene. The experiments are performed in a cylindrical dc discharge, the so-called PK-4 facility that shall be launched to the International Space Station (ISS) in 2014. The experiments show that the particles are formed in a localized region close to the anode and are transported as still localized dust structures ('dust bullets') along the glass tube. The formation of new particles triggers an oscillatory process that is characterized by the periodic appearance and subsequent removal of dust particles. The frequency of this process, as well as the size of the particles within each 'dust bullet', can be controlled by means of the neutral gas flow. This behaviour can be understood by analysing the size-dependent forces acting on the growing particles.

Domaines: Physique des plasmas [physics.plasm-ph]

Lisa Wörner, Eva Kovacevic, Johannes Berndt, Hubertus M. Thomas, Markus H. Thoma, et al.. The formation and transport phenomena of nanometre-sized particles in a dc plasma. New Journal of Physics, 2012, 14, pp.023024. ⟨10.1088/1367-2630/14/2/023024⟩. ⟨hal-00690916⟩