A large area avalanche photodiode (LAAPD) has been investigated as a possib
le photosensor for detecting liquid xenon scintillation. The LAAPD proved t
o be operational at the temperature of liquid xenon (down to -105 degrees C
) with the dark current significantly reduced with respect to that at room
temperature (less than 1 pA versus 30 nA at 20 degrees C). The bias voltage
needed to achieve a certain gain is found to decrease linearly with decrea
sing temperature at a rate of 2.3 V/degrees C.