PICO-2L was the first detector installed at SNOLAB by PICO, demonstrating that bubble chambers can be used to search the parameter space of low mass dark matter. The picture shows the installation of the internal system into the pressure vessel. The clear jar houses the target fluid, which is coupled to a hydraulic system via the stainless-steel bellows. With the flange lowered in place the target volume sits in view of the stereoscopic camera, which is setup to detect bubble formation.
The first run of PICO-2L lasted from October 2013 to May 2014. Results from this run have been published here.
PICO-2L started a second data taking phase in February of 2015 with a new, all synthetic quartz vessel and a new set of piezoelectric sensors. Run 2 ended in November 2015, and in January 2016 PICO reported the 2L bubble chamber was background free.
PICO 2L was decommissioned in 2016.