Speaker
Scott Fallows
(University of Alberta)
Description
The PICO collaboration searches for dark matter particles with superheated fluid detectors operated under conditions in which they are insensitive to the electron recoils that constitute the traditionally dominant background for direct detection searches. By measuring the acoustic energy emitted during bubble formation, these detectors are also able to discriminate against alpha particle backgrounds. The current target fluid, C$_3$F$_8$, allows for excellent sensitivity to the spin-dependent WIMP-proton cross section due to its high density of $^{19}$F. The chamber can be operated with other target fluids with relatively minor changes to detector operations, allowing study of the coupling of dark matter to ordinary matter in the case of a positive signal.
The PICO-60 experiment has been upgraded since the completion of the previous run in May 2014. The original 20 L CF$_3$I target fluid has been exchanged for 40 L of C$_3$F$_8$. There have been corresponding upgrades to the stereoscopic camera system to allow imaging of the doubled volume and detailed studies of bubble growth, as well as many hardware improvements focused on eliminating the particulate contamination that was one source of backgrounds in the detector. This talk presents the status of the experiment and these upgrades.
Primary author
Scott Fallows
(University of Alberta)
