Kinematics of charged nanometric particles in silent discharges

N Jidenko (1, 2) , J.-P. Borra (3)

1 CNRS - Centre National de la Recherche Scientifique
2 LPGP - Laboratoire de physique des gaz et des plasmas
3 LPGP - Laboratoire de physique des gaz et des plasmas

1 mm plane-to-plane configurations with or without dielectric barriers on the metallic electrodes are used to investigate AC electric precipitation of charged submicronic particles of controlled electrical mobility injected in a laminar flow. The collection efficiency is calculated from concentration measurement for different voltages. Below air ionisation threshold, experimental and theoretical collection efficiencies are consistent. Above air ionisation threshold, the current and collection efficiency increase with frequency and voltage related to the number of microdischarges per second and per surface unit. This study intends to check the influence of surface polarisation by microdischarges development on the collection of charged particles. Comparison between theory of collection in homogeneous AC field without microdischarge on the one hand, and measured collection efficiency with microdischarges on the other hand, proves that surface polarisation by microdischarges does not improve the collection efficiency, but enables either an increase of charge by ions repulsion from the surface, whatever the frequency is or a improved mixing at 60 kHz.

Domaines: Sciences de l'ingénieur [physics]

N Jidenko, J.-P. Borra. Kinematics of charged nanometric particles in silent discharges. Journal of Physics D: Applied Physics, 2005, 38 (4), pp.617-620. ⟨10.1088/0022-3727/38/4/014⟩. ⟨hal-03217040v2⟩