If you’ve been to Science North recently, you may have noticed a large stainless steel sphere taking up residence outside Sudbury’s science centre.
The piece on display is the inner vessel of a dark matter experiment called MiniCLEAN, installed at SNOLAB.
SNOLAB is a world-class science facility located deep underground in the operational Vale Creighton nickel mine, situated near Lively.
MiniCLEAN stands for (mini Cryogenic Low-Energy Astrophysics with Nobel liquids) and the inner vessel was installed at SNOLAB between 2013 and 2019.
It was a research and development component of a global program to test new technologies for dark matter searches.
Studying dark matter is challenging since it doesn't behave like the ordinary matter in that it does not absorb, reflect or emit light. It is because of this challenge that one-of-a-kind components, like the inner vessel, to devise methods of detecting dark matter particle interactions.
The experiment consisted of the inner vessel on display at Science North, which is made of ultra-clean stainless steel that held 500 kilograms of liquid argon or neon and was surrounded by 92 sensitive photodetectors watching for particle interactions in the vessel.
The entire vessel was then located in a large cylindrical water tank over two stories tall (25 feet tall, 18 inches in diameter) to provide additional shielding from unwanted particle interactions.
You can now see the MiniCLEAN inner vessel just outside the science centre’s main entrance.
