Behaviours of titanium deuteride targets have been studied experimentally by implantation with 150 kV and 210 kV deuterons extracted from an electrostatic accelerator. Surface morphologies, phase structures and irradiation defects are investigated by scanning electron microscope, X-ray diffraction analysis and slow positron annihilation technology. It is found that surfaces of titanium deuteride targets undergo a significant selective melting. Although there must be a prominent desorption of D atoms from the targets, we have not, in diagrams of X-ray diffraction analysis, observed compelling evidence of phase transformation. Running of the neutron generator is fairly stable, such that the neutron generation rate is almost not altered. Experimental profiles of irradiation defects with slow positron annihilation technique are compared with those obtained by SRIM, and the correlations between the two are discussed. (c) 2013 Elsevier Ltd. All rights reserved.