The model of defects transformation in the heat-stable defect centers possessing donor properties of gallium arsenide irradiated with neutrons was proposed. The nature of these centers determined by the interaction of artificial radiation defects with impurities and defects in the crystal equilibrium. It was shown that irradiation by neutrons at temperatures above room temperature can be used not only for studying the nature and patterns of defects, but also as a way to change the directional properties of crystals.