'Snowball chamber' helps scientists use supercooled water to search for dark matter

After watching YouTube videos of people in the world, it's about this concept solidified for Matthew M. Szydagis, an assistant professor of physics at the University of Albany, New York State University, especially when he saw it again during the Disney movie "Frozen."

During the 2019 American Physical Society April Meeting in Denver, Szydagis will describe how it works. Read more at https://arxiv.org/abs/1807.09253.

"All of my work is motivated by the search for dark matter," he said, "we're sure we're out there because we can observe its indirect gravitational effects," Szydagis said. "It makes up a significant fraction of the universe, but we have yet to uncover direct, conclusive and unambiguous evidence of it within the lab."

If water is clean enough-low in impurities, such as dust particles and a place in a smooth container, Szydagis explained, it can be cooler than its freezing point of 0 C (32 F) without freezing.

"This is called 'supercooling' and can be easily superheated in the microwave, it's simply the reverse," he said. "The water ends up, in either of these cases, in a state of metastability, or unstable nor quite stable."

A disturbance can trigger the transition phase, freezing and crystallization, in this case. "This is not ordinary freezing," he added. "We are having cold water as cold as -20 C (-4 F) .It is not the same as depression, like when you salt your sidewalk, because the water was pure and not contaminated with impurities on purpose. "

The group has some forms of microscopically (subatomically) it causes it to freeze if it's supercooled first. "Some particles like neutrons can even scatter multiple times within the water," Szydagis said. "We were able to show this not only with commercially available sources of particles, but also a 'radioactive red' plate with orange-based uranium-based paint from the 1950s."

They created a new detector based on the supercooled water, dubbed the "snowball chamber" because that matches well with "bubble" and "cloud" chambers, which are technologies from the early to mid-20th century that use boiling and condensation.

Supercooled water certainly is not new; it has been studied for many years by chemists and condensed matter physicists, down to -40 C (-40 F). There are even more than 100 years old.

"But we managed to discover a new property of supercooled water," Szydagis said. "To our great surprise, we found that some particles (neutrons) but not others (gamma rays) trigger freezing. it and see 'approach-the scientific method in their most basic form, not only do we have a new detector of

The group of many other potential for their discovery, including detecting nuclear weapons in homeland security, understanding cloud formation, and providing clues to some mammalian species hibernate, supercooling their blood somehow.