Uniformly enhanced small-angle X-ray scattering intensities of amorphous SiO₂, measured following irradiation at room temperature with low-fluence 320 keV H⁺ and He⁺ beams, suggest that the radiation-induced defect structure is compatible with the presence of essentially totally preserved instantaneously produced interstitial-like O and Si atoms and complementary O and Si vacancy-like sites.