Observation of Ultrasound from Heavy-Ion Irradiations ―― Ion-Beam Seismology(Current Topic)

Abstract

Dynamical processes inside of bulk solids induced by penetrating fast heavy ions are studied through the observation of ultrasonic waves. Applying a seismological method, the relation between the mass motion inside a solid and the elastic wave is described. Our experiment is presented where solid samples were irradiated with a single-bunch ion beam of 3.8-GeV Ar ions and ultrasonic waveforms were observed with piezoelectric sensors at different directions from the beam spot. The analyses of the position dependence of the ultrasonic waveform thus obtained show that the Ar-ion irradiation induces a nearly isotropic expansion confined in the bulk.