Low-temperature photoacoustic detector with fibrescope as light window

摘要

A low-temperature photoacoustic detector is reported in this paper, which can operate up to the temperature of liquid nitrogen. The use of the fibrescope as a window solved the difficulty of the light entering the low-temperature cell. We have also been successful in increasing the signal-to-noise ratio by putting the microphone in the sample cell. The experiment for the high-T_(c) superconductor indicates that the photoacoustic signal was enhanced considerably during the process of the superconducting transition.