Please use this identifier to cite or link to this item:
|Title:||Capacitively coupled radio-frequency discharges in nitrogen at low-pressure|
|Author(s):||Alves, L. L.|
Pintassilgo, C. D.
Es-Sebbar, E. T.
|Abstract(s):||This paper studies ccrf discharges (at f=13.56 MHz frequency) in pure nitrogen, produced within cylindrical parallel-plate reactors similar to GEC reference cells  (associated with the GREMI and the LATMOS setups, the latter corresponding to the PAMPRE experiment ), at 100-300 V applied voltages and 0.1-1 mbar pressures. Under these conditions, the neutral gas is found close to room temperature (~350 K) . The discharges are studied using both experiments and simulations. Experiments include the measurement of the following quantities: (i) the applied voltage, using a high-voltage probe; (ii) the self-bias voltage; (iii) the effective power coupled to the plasma, taking into account circuit losses; (iv) the average electron density, using a resonant-cavity technique; (v) the intensities of radiative transitions with the nitrogen second-positive system and first-negative system, and with the 881.5 nm atomic line of argon, using optical emission spectroscopy diagnostics. The comparison between model results and measurements shows the influence in results of the nitrogen kinetics, particularly via the interaction of species with the reactor walls. Simulations use an hybrid code that couples a 2D time-dependent fluid module , describing the dynamics of charged particles (electrons and positive ions N2+ and N4+), and a homogeneous (0D) kinetic module, describing the production and destruction of nitrogen (atomic and molecular) neutral species. The coupling between these modules adopts the local mean energy approximation  to define space-time dependent electron parameters for the fluid module and to work-out space-time average rates for the kinetic module. Model results yield the self-consistent dc-bias voltage, the effective power coupled to the plasma, and the 2D spatial distributions for (i) the densities and fluxes with the charged particles and the electron mean energy, (ii) the densities of the most relevant nitrogen species, and (iii) the rf plasma potential.|
|Description:||Apresentação em poster|
|Appears in Collections:||CDF - FCT - Comunicações/Communications (with refereeing)|