Towards sub-100psec timing trough sonoluminescence light

Abstract

The increasing importance of positron lifetime spectroscopy in semiconductor defects studies, where defect and bulk lifetimes are often too close to be clearly resolved, places renewed importance on the drive towards achieving better instrumental resolution. Time resolutions (fwhm's) of 100ps or less, without significant loss of efficiency, would be highly desirable. The best resolution achieved to date on 22Na energy windows, is 124ps using a modified form of the XP2020UR photomultiplier coupled to NE111 scintillator [1]. In this Conference, we present timing investigations made with the newly discovered picosecond light emission from sonoluminescence. Sonoluminescence is the process in which an ultrasonic standing wave is used to produce flashes of light from a trapped water bubble [2]. The spectrum of the emitted light has a broadband spectrum and has repetitive pulse duration of less than 50ps. In this respect, sonoluminescence light can be usefully employed to study the sources of time jitter in photomultiplier and constant fraction discriminator combinations. We present provisional data on this present promising approach.