Sudbury’s SNOLAB announces breakthrough in detecting neutrinos

Scientists at the underground SNOLAB in Sudbury have observed a rare neutrino interaction. Researchers say the experiment allows them to study elusive particles

It takes eight minutes for neutrinos to travel from the sun to the Earth, and trillions pass through our bodies every second.

They are produced during nuclear reactions -- including those that take place in the sun -- and are notoriously difficult to detect.

That’s because neutrinos don’t typically interact with other particles. But there has been a breakthrough in detecting them at Sudbury’s SNOLAB.

The lab is located deep underground at Vale’s Creighton Mine, with the Canadian Shield protecting experiments from cosmic rays that bombard the Earth’s surface.

“For the first time, scientists have succeeded in also observing them transform carbon atoms into nitrogen inside a vast underground detector,” SNOLAB said in a news release Dec. 12.

The discovery was made by Oxford researchers at SNOLAB, part of their SNO+ Experiment using the SNO+ detector located two kilometres underground.

Shielded from cosmic rays

The deep location “was crucial to shield the lab from cosmic rays and background radiation that would mask the faint neutrino signals,” said the news release announcing the breakthrough.

Christine Kraus, a senior research scientist at SNOLAB, told CTV News in an interview this week that the research is all about “trying to understand what the universe is made of (and) what happened early in the universe.”

“Why does it look like what it looks like now?” said Kraus.

“And to do that, we want to go to the smallest parts so called subatomic particles. And we particularly look for neutrinos and interactions with light trails.”

“This particular measurement used 250 days of detector time to see five separate events,” said Ryan Bayes, a postdoctoral researcher at SNOLAB.

‘Bizarre particles’

“And what I mean by those events is a neutrino comes in, interacts with a special carbon atom, produces a special hydrogen atom, and afterwards … the nitrogen atom decayed. So this is a very, very, very rare type of event.”

SNOLAB said that “neutrinos are bizarre particles that are essential for understanding stellar processes, nuclear fusion, and the evolution of the universe.”

The discovery builds on Nobel Prize-winning research that led to SNO’s lead investigator, Dr. Arthur B. McDonald, sharing in the 2015 prize in physics.

Kraus said that project opened “the door for new research into neutrino properties and their role in the universe.”

“This is the first time we have observed this particular interaction. So it speaks for the development of our new technology,” she said.

“This would really tell us that there’s something very exciting that happened as the universe was created, because our universe exists out of matter particles, not antiparticles. And we don’t understand why that is in principle, naively, they should be created equal, same amounts.”

Kraus said the discovery was a team effort between researchers and many more.

“As this gets more known, I think there might be more job opportunities for people,” she said.

“It brings up on the map, people will read that name because our experiment is called SNO+, so Sudbury Neutrino Observatory is in the name.”

The research is nowhere near complete because, in science, when one answer is found, dozens more questions emerge when it comes to figuring out the physics of the universe.