WNPPC2024 - 61st Winter Nuclear Particle Physics Conference

PICO-500 Detector Calibrations

16 Feb 2024, 21:00

15m

Salon AB (Hotel Chateau Bromont)

Contributed Oral Dark Matter Searches Evening 3 - Feb. 16, 2024

Speaker

Michaela Robert (Queen's University)

Description

PICO-500 is a WIMP dark matter bubble chamber detector in its early stages of construction underground at SNOLAB. It is the upscaled successor of PICO-40L, which is currently operational with the objective of detecting dark matter or improving the world leading spin-dependent WIMP search limits set by PICO-60 in 2016. PICO-500 will have almost an order of magnitude greater sensitivity with a ~250 litre active volume of superheated C${}_3$F${}_8$ (freon) inside a quartz vessel with bellows to enable expansion and compression of the fluid. Its detection method is based on the Seitz model, in which recoiling freon nuclei from incoming WIMP scatters results in localized boiling if the energy deposition, within a critical radius, is in excess of the threshold energy. As was done for PICO-40L and PICO-60, the operating threshold of PICO-500 will be optimized for sensitivity to dark matter, and insensitivity to electron recoils caused by gammas and electrons entering the detector. The electron recoil sensitivity will be probed by introducing an 18 MBq ${}^{60}$Co gamma source into the detector and measuring the bubble nucleation rate. Cross-verification between data and simulations from PICO-40L calibrations, as well as enhancements to the calibration system for PICO-500, will contribute to an exceedingly precise understanding of the PICO-500 detector response.

Presentation materials

PICO-500 Detector and Calibration - WNPPC 2024.pdf

PICO-500 Detector and Calibration - WNPPC 2024.pptx