  EXO-200 uses 468 large area avalanche photodiodes (LAAPDs) for detection of
scintillation light in an ultra-low-background liquid xenon (LXe) detector. We
describe initial measurements of dark noise, gain and response to xenon
scintillation light of LAAPDs at temperatures from room temperature to 169K -
the temperature of liquid xenon. We also describe the individual
characterization of more than 800 LAAPDs for selective installation in the
EXO-200 detector.
