In order to clarify the mechanism of secondary nucleation of iceinduced by ultrasound

experiments on ice crystals in degassed sucrose solutions and untreated solutions have been carried out using a novel ultrasonic cold stage device. For each experiment

the ultrasonic waves operated at a power output of 120W. The results show that the ice dendrite crystals growing in a sucrose solution can be broken up into smaller fragments when ultrasound was applied for 2 s

but the pre-existing ice dendrite crystals in a degassed sucrose solution are still unbroken when ultrasound was applied for 6 s. These findings confirm that cavitation induced by ultrasound is a major factor for the fragmentation of ice crystals.