Modeling of argon–acetylene dusty plasma

Abstract

The properties of an Ar/C 2 H 2 dusty plasma (ion, electron and neutral particle densities, effective electron temperature and dust charge) in glow and afterglow regimes are studied using a volumeaveraged model and the results for the glow plasma are compared with mass spectrometry measurements. It is shown that dust particles affect essentially the properties of glow and afterglow plasmas. Due to collection of electrons and ions by dust particles, the effective electron temperature, the densities of argon ions and metastable atoms are larger in the dusty glow plasma comparing with the dust-free case, while the densities of most hydrocarbon ions and acetylene molecules are smaller. Because of a larger density of metastable argon atoms and, as a result, of the enhancement of electron generation in their collisions with acetylene molecules, the electron density in the afterglow dusty plasma can have a peak in its time-dependence. The results of numerical calculations are in a good qualitative agreement with experimental results.

Effects of process conditions on the chemistry of an Ar/C2H2 dust‐forming plasma

“…Using the volume‐averaged model, we have analyzed how the Ar/C 2 H 2 plasma properties depend on different process conditions (absorbed power, EEDF, input flux of C 2 H 2 and nanoparticle density). The study has been carried out for the conditions similar to our experiments on nanoparticle growth . Main processes responsible for the generation and loss of different ions and neutral species have also been analyzed and are presented in the Supporting Information.…”

“…Main processes responsible for the generation and loss of different ions and neutral species have also been analyzed and are presented in the Supporting Information. In most cases studied here, the EEDF is considered to be Druyvesteyn‐like as it is typical for radio‐frequency laboratory plasmas at n e < 10 11 cm −3 and Pd > 0.2 Torr × cm, where d ≈ L /2 is the dimension of the reactor in centimeter, that is, for the conditions of our experiments . As grown nanoparticles may affect the EEDF, the study of its variation on the plasma properties is also of particular interest.…”

“…The model takes into account the most important neutral species and positive ions evidenced in our experiments on nanoparticle growth in an Ar/C 2 H 2 plasma (Figure ). The details of the experiments can be found elsewhere …”

“…In the past two decades, plasmas used for the formation of carbonaceous dust particles have been intensively investigated both by experimental measurements and numerically . The experiments have shown that dust particle growth strongly depends on the concentrations of C 2 H − ions, which are supposed to act as the main species for the initiation of dust formation and C 2 H neutral radicals .…”

“…Moreover, processes responsible for the production and loss of different ions and neutrals in the discharge are analyzed, to identify the most important ones. The numerical study is carried out for process conditions similar to our experiments on nanoparticle growth using a global (volume‐averaged) model. The zero‐dimensional (0D) model approach has shown to be effective for the analysis of chemically active gas dischargers at low pressures .…”