The liquid-argon scintillation pulseshape in DEAP-3600

Understand

DEAP-3600 is a liquid-argon scintillation detector looking for dark matter.

• Scintillation events in the liquid argon (LAr) are registered by 255 photomultiplier tubes (PMTs), and pulseshape discrimination (PSD) is used to suppress electromagnetic background events.
• The excellent PSD performance of LAr makes it a viable target for dark matter searches, and the LAr scintillation pulseshape discussed here is the basis of PSD.
• The observed pulseshape is a combination of LAr scintillation physics with detector effects.