Note: A new optical method for the detection of bubble nucleation in superheated droplet detector

A superheated droplet detector (SDD) consists of a large number of micron-sized superheated liquid drops suspended in a gel medium. The vaporization of a superheated drop is associated with the emission of an acoustic signal. A novel optical method is developed for the detection of this acoustic signal. In this method, a probe-bubble picks up the acoustic signal, and the oscillation of the probe-bubble is detected by employing a laser and phototransistor. The method can detect vaporization of an individual superheated drop in real-time and can be used for studying the response of SDDs to ionizing radiations.