Theory of Sub-micron and Ultra-fine Dust Particle Bipolar Charging under Dielectric Barrier Discharge Plasma Conditions
Résumé
The objective of the present study is to develop a theory of sub-micron and ultrafine particles by bipolar charging under dielectric barrier discharge (DBD) environments. The DBD generates streamer or Trichel pulse corona discharge forming electron-rich non-thermal plasmas. The mean free path of electrons under DBD atmospheric pressure condition is much longer than the diameter of sub-micron particles. The electron charging speed is usually much faster than negative ions since electron mobility is few 100 times of ions, hence charged particle may be collected to wall during the initial electron-positive ion plasma stage. In this work, bipolar charging model will be based on electron under free molecular condition and the ions under transition to continuum conditions. The effect of particle size, DBD operating voltage and frequency will be discussed in detail.