Kinetic study of a N2-CH4 afterglow plasma for production of N-containing hydrocarbon species of Titan's atmosphere

We present the results from a self-consistent kinetic model simulating the afterglow of a flowing microwave discharge in pure N2 in which CH4 is introduced in the post-discharge. The simulation is carried out for a discharge operating at 433 MHz, in a tube of 1.9 cm inner radius, at the pressure range 26.6-133 Pa. In the post-discharge the CH4 is primarily dissociated into CH3 and CH2 due to collisions with the metastables N2(A3Σu+) and N2(a′1Σu-) coming from the discharge, while HCN is obtained from collisions of CH3 and CH2 with N(4S) atoms. Our calculations show that numerous species existing in Titan's atmosphere are then formed as a result of a complex interplay kinetics. The time-evolution of the species is investigated along the afterglow as well as the possibility of these species being precursors to the formation of organic aerosols.