Rapid transport of nano-particles having a fractional elementary charge on average in capacitively-coupled rf discharges by amplitude-modulating discharge voltage.
We have observed transport of nano-particles having, on average, a fractional elementary charge in single pulse and double pulse capacitively-coupled rf discharges both without and with an Amplitude Modulation (AM) of the discharge voltage, using a two-dimensional laser-light scattering method. Rapid transport of nano-particles towards the grounded electrode is realized using rf discharges with AM. Two important parameters for the rapid transport of nano-particles are the discharge voltage and the period of AM. An important key of the rapid transport is fast redistribution of ion current over the whole discharge region; that is, fast change of spatial distribution of forces exerted on nano-particles. The longer period of the modulation is needed for rapid transport for the larger nano-particles. The higher discharge voltage of the modulation is needed for rapid transport of nano-particles having a smaller mean charge. Local perturbation of electric potential using a probe does not bring about global rapid transport of nano-particles, whereas it leads to their local transport near the probe.
Shiratani
Masaharu
M
Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan. siratani@ed.kyushu-u.ac.jp
Koga
Kazunori
K
Iwashita
Shinya
S
Nunomura
Syota
S