The liquid-argon scintillation pulseshape in DEAP-3600
Abstract
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. We present a model for the pulseshape of electromagnetic background events in the energy region of interest for dark matter searches. The model is composed of a) LAr scintillation physics, including the so-called intermediate component, b) the time response of the TPB wavelength shifter, including delayed TPB emission at (ms) time-scales, and c) PMT response. TPB is the wavelength shifter of choice in most LAr detectors. We find that approximately 10\% of the intensity of the wavelength-shifted light is in a long-lived state of TPB. This causes light from an event to spill into subsequent events to an extent not usually accounted for in the design and data analysis of LAr-based detectors.
Keywords
Cite
@article{arxiv.2001.09855,
title = {The liquid-argon scintillation pulseshape in DEAP-3600},
author = {The DEAP collaboration and P. Adhikari and R. Ajaj and G. R. Araujoand M. Batygov and B. Beltran and C. E. Bina and M. G. Boulay and B. Broerman and J. F. Bueno and A. Butcher and B. Cai and M. Cárdenas-Montes and S. Cavuoti and Y. Chen and B. T. Cleveland and J. M. Corning and S. J. Daughertyand K. Dering and L. Doria and F. A. Duncan andM. Dunford and A. Erlandson and N. Fatemighomi and G. Fiorillo and A. Flower and R. J. Ford and R. Gagnon and D. Gallacher and E. A. Garcés and P. García Abia and S. Garg and P. Giampa and D. Goeldi and V. V. Golovko and P. Gorel and K. Graham and D. R. Grant and A. Grobov and A. L. Hallin and M. Hamstra and P. J. Harvey and C. Hearns and A. Ilyasov and A. Joy and C. J. Jillings and O. Kamaev and G. Kaur and A. Kemp and I. Kochanek and M. Kuźniak and S. Langrock and F. La Zia and B. Lehnert and N. Levashko and X. Li and O. Litvinov and J. Lock and G. Longo and I. Machulin and P. Majewski and A. B. McDonald and T. McElroy and T. McGinn and J. B. McLaughlin and R. Mehdiyev and C. Mielnichuk and J. Monroe and P. Nadeau and C. Nantais and C. Ng and A. J. Noble and G. Oliviéro and C. Ouellet and S. Pal and P. Pasuthip and S. J. M. Peeters and V. Pesudo and M. -C. Piro and T. R. Pollmann and E. T. Rand and C. Rethmeier and F. Retière and E. Sanchez García and T. Sánchez-Pastor and R. Santorelli and N. Seeburn and P. Skensved and B. Smith and N. J. T. Smith and T. Sonley and R. Stainforth and C. Stone and V. Strickland and B. Sur and E. Vázquez-Jáuregui and L. Veloce and S. Viel and J. Walding and M. Waqar and M. Ward and S. Westerdale and J. Willis and A. Zuñiga-Reyes},
journal= {arXiv preprint arXiv:2001.09855},
year = {2020}
}