Developing a Single-Phase Liquid Argon Detector with SiPM Readout

Liquid argon is used as a target material in several current and planned experiments related to dark matter direct searching and neutrino detection. SiPM is becoming the standard for scintillator detectors because of its advantages over traditional PMT. In this paper, we developed a single-phase liquid argon detector with SiPM readout and evaluated its light yield with an Am-241 gamma source. After eliminating the effect of SiPM cross-talks and after-pulses, we achieve the light yield of 12.5 +/- 3.4 photoelectrons per keVee primarily generated by the argon scintillation, which is one of the best results for a liquid argon detector. In addition, we provide an experimental method to estimate the effect of cross-talks and after-pulses on light yield using dark noise data. Finally, we quantitatively give the relationship between the light yield and the decay time of the slow component of a liquid argon detector.