Core structure of latent heavy ion tracks in {100} LiF derived by small-angle X-ray scattering

Radial electron densities within 27-111 mu m-long ion damage trails, 'latent ion tracks', created in {100} LiF by irradiation with GeV Pb and U projectiles, have been derived by means of small-angle X-ray scattering. The tracks exhibit continuous electron density decreases of 49-74% along the centers of their 2.3-3.4 nm-diameter cores. Structural alteration under the intense ion-deposited electronic excitation has been attributed to two successive processes: (a) local breakdown of the LiF lattice into fluorine molecules and Li atoms, and (b) release of the fluorine gas and of at least a portion of the voluminous Li atoms through the low-density tracks.