Using a combination of the Monte Carlo models of fast electrons,of molecular ions(N_2^++) and of atomic species (N^+,N_f),the influence of the discharge pressure (P) and voltage(V_c) on the energy distributions of fast atomic species (N^+,N_f) produced by e^--N_(2s) and N_2^+-N_(2s) dissociation reactions at the cathode in a nitrogen do glow discharge was investigated.Boththe angular distributions and the density distributions along the radius of the species (N^+,N_f)produced by the two dissociations at the cathode were calculated.The results show that:(1)there is an optimum discharge condition for P and V_c in order to obtain the species (N^+,N_f)at the cathode with high a density and energy,(2) when the voltage is above 800 V,the species(N^+,N_f) bombarding the cathode are mainly produced by the N_2^+-N_(2s) dissociation,whereas whenthe voltage is below 300 V,they are mainly produced by the e^--N_(2s) dissociation,and (3)at highvoltages the incident angles of a considerable number of N_f into the cathode are quite small.Thedensity of the species (N^+,N_f) at the cathode increases with the voltage,and when the pressuregoes up to about 133 Pa,it decreases with the increasing pressure.
