A toroidal Alfven eigenmode (TAE) has been observed driven by alpha particles in the Joint European Torus (JET). The observation was made in dedicated deuterium-tritium experiments where radio-frequency (RF) heating was absent, in the so-called “afterglow” period when neutral beam heating was removed. Agreement with reduced and perturbative models is comparable to previous results in reference deuterium discharges where TAEs are readily excited with RF. These results obtained for elevated safety factor and monotonic magnetic shear support similar findings on the Tokamak Fusion Test Reactor (TFTR) where Alfven cascades and their possible transition to TAEs was observed.