The effect of swift heavy ion irradiation (SHII) on quasicrystalline Al65Cu20Fe15 is reported for the first time. This particular quasicrystal is chosen for this study, so that the effect of electronic excitations on the intrinsic electronic
properties of quasicrystals can be studied. It is found that irradiation at 77 K improves the quasicrystalline order and
results in icosahedral grain growth. These results provide experimental support to the view that the quasicrystal structures can be described as hierarchy of overlapping connecting clusters.