The process of matrix isolation of nitrogen atoms in solidN2is studied by the method of condensation from the gaseous phase. In order to vary the flow rates of nitrogen atoms and molecules at the sample surface over a wide range,N2–Hemixtures of various compositions have been passed through the gas discharge zone. It is found that the EPR line width for N atoms inN2increases upon a decrease in the nitrogen flow rate from the discharge zone to a cold substrate. It is shown that this increase is due to an increase in the concentration of atomic nitrogen in the matrix leading to an enhancement of the dipole–dipole interaction between atoms. It is established that a decrease in the intensity of recombination of atoms in the course of diffusion at the sample surface due to a decrease in the surface density of these atoms plays a decisive role in the growth of the concentration of matrix-isolated atoms in the experiments. It is found that for a constant flow rate of atoms from the discharge, their concentration in the matrix increases and attains saturation upon an increase in the discharge intensity. The dependence of concentration on the discharge intensity is attributed to a change in the degree of dissociation of molecular nitrogen in the discharge. ©1998 American Institute of Physics.