Controlled particle generation in an inductively coupled plasma

By injecting pulses of acetylene into an inductive argon/helium discharge, carbon clusters with diameters in the range of 10-50 nm are produced. These particles cause an instability of the plasma, which becomes visible as an oscillation of the emission intensity. The particles are analyzed ex situ using atomic force microscopy and scanning electron micrographs. A unique linear dependence between particle size and oscillation time period is found. Thereby the oscillation phenomenon can serve as monitor signal to control the size of plasma produced particles.