The DEAP-3600 Sphere pushed the physical envelope of thermoforming thick acrylic. 84 inches in diameter and 4.5 inches thick. The design and engineering team developed the tooling necessary to create this sphere.
DEAP (Dark matter Experiment using Argon Pulse-shape discrimination) is a direct dark matter search experiment which uses liquid argon as a target material. DEAP utilizes background discrimination based on the characteristic scintillation pulse-shape of argon. A first-generation detector (DEAP-1) with a 7 kg target mass was operated at Queen’s University to test the performance of pulse-shape discrimination at low recoil energies in liquid argon. DEAP-1 was then moved to SNOLAB, 2 km below Earth’s surface, in October 2007 and collected data into 2011.
DEAP-3600 was designed with 3600 kg of active liquid argon mass to achieve sensitivity to WIMP-nucleon scattering cross-sections as low as 10−46 cm2 for a dark matter particle mass of 100 GeV/c2. Reynolds Polymer’s proprietary acrylic was used in the construction of the sphere.