Speaker
Armelle Michau
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.3013.pdf
Charge Fluctuations of small Particles
A. Michau1, S. Prassanna1, K. Hassouni and S. Longo2
1
LSPM, UPR 3407 CNRS, Université Paris 13, 93430 Villetaneuse, France
2
Department of Chemistry, University of Bari, via E. Orabona 4, 70126 Bari, Italy
The charge distribution of small particle and in particular for particle less than 10 nm is
critical for aerosol dynamics while it controls particle coagulation [1] . Particle charge
distribution is well described by Gaussian distribution [2] but this assumption is no more
valid for such small particle. In this study we developed a Fokker Planck method using
Monte Carlo simulation to describe the charge state of particle in a plasma.
The model captures gaussian distribution for large particle. However for small particle sizes
the distribution is very narrow, large fraction of them are neutrals [3] and cannot be described
by a gaussian.
0.6 2 nm 0.6 50 nm
0.5 0.5
0.4 0.4
frequency
frequency
0.3 0.3
0.2 0.2
0.1 0.1
0.0 0.0
-4 -3 -2 -1 0 1 -10 -9 -8 -7 -6 -5 -4 -3 -2
q q
Figure 1 : charge distribution for ne=ni, Te/Ti=3 for two particle size.
This charge fluctuation effect has been studied for different plasma conditions and has to be
taken into account when considering for coagulation in dusty plasmas.
1. Michau, A., C. Arnas, and K. Hassouni, Aerosol dynamics in a sputtering DC discharge. Journal of
Applied Physics, 2017. 121(16): p. 163301.
2. Matsoukas, T. and S.K. Friedlander, Dynamics of aerosol agglomerate formation. Journal of Colloid
and Interface Science, 1991. 146(2): p. 495-506.
3. Bouchoule, Dusty plasmas: physics, chemistry & technological impacts in plasma processing 1999:
John Wiley and Sons Ltd.
