The Search for Dark Matter – DEAP-3600 – Acrylic Art
A stand off view of the completed DEAP-3600 detector acrylic vessel. Standing proudly on a rotator frame before it undergoes a rigorous round of cleaning and then annealing. Bonded acrylic tends to be stressed acrylic, the bonds and the material around them tend to have a great deal of locked in stress. If the vessel was to be cooled to cryogenic temperatures, it would certainly crack and fail at one of the light guide bonds.
To insure this does not happen, the stress must be removed. This is done via heating the vessel and annealing the acrylic. The bonds have been done in such a way to leave a small bulge of material on the outside, and such, any locked in stress, through the process of annealing will move outwards and end within those bulges. Once that is complete the bulges are machined away and polished, and we are left with a vessel free from stress, ready for cleaning and dressing.
Taken with my Mamiya 645, 70mm, hand held
The vessel here looks very yellow due to white balance, and that not all of the protective paper wrapping on the acrylic has been removed yet