It sounds like a James Bond villain’s lair, but SNOLAB’s operations are aimed at the greater good – namely, solving fundamental mysteries of the universe’s existence.
Greater Sudbury’s hidden gem is in Vale’s Creighton nickel mine, where a team of 150 researchers work alongside another 1,000 physicists from around the world in laboratories located approximately two kilometres underground.
Although some components of the laboratory space have been in operation for a couple of decades, the expanded laboratory as we know it today is celebrating its 10th anniversary this year.
While SNOLAB has teamed up with researchers and 46 North Brewing for a special beer to mark their 10th year, the occasion also offers an opportunity to highlight both their history and horizons.
The facility, after all, is billed as the deepest and cleanest lab in the world, and includes 5,000 square metres of clean lab space used for various experiments that require the unique environment the facility is able to offer.
It’s a space that created an environment that assisted in the furthering of neutrino research, which earned Sudbury Neutrino Observatory researcher Art McDonald the Nobel Prize in physics in 2015, who received the award alongside Dr. Takaki Kajita of the Super-Kamiokande detector in Japan. Their work demonstrated that neutrinos, subatomic particles, carry a mass.
Fortified against cosmic rays
SNOLAB is located two kilometres underground off an existing Vale mine, where the laboratory space is largely shielded from cosmic rays.
“When you go down two kilomtres you can spend an entire 40-hour workweek and not be hit by a single cosmic ray,” SNOLAB interim executive director Clarence Virtue said, adding that although some cosmic rays penetrate that deep into the Earth’s crust, it’s approximately 0.3 cosmic rays per metre squared per day.
The surface of the Earth, in comparison, has 50-million times more cosmic rays bombarding it on a regular basis.
Cosmic rays, he explained, are “energetic particles, protons, photons, that typically interact in the upper atmosphere of the earth and create a shower of other particles from the interactions they have high in the atmosphere.”
These cosmic rays interfere with the types of experiments that take place at SNOLAB, which is why the research space is located where it is.
Initially just the SNO (standing for the Sudbury Neutrino Observatory) the first wing of the facility opened a couple decades ago to study (as the name suggests) neutrinos.
Researchers partnered with Inco (later Vale) to open the research space off of an existing mining operation, taking advantage of an area whose minerals were of little economic interest to the company. They travel two kilometres underground in a cage alongside miners – a three-minute ride Virtue said travels the height of approximately four CN Towers.
“The cage is really moving,” he said, adding that once they reach the desired depth it’s a one-mile walk to the research space.
“The entire lab is a clean room, so we go two kilometres deep to get away from the cosmic rays, but there’s all kinds of natural radioactivity just in normal materials.”
Including the initial SNO space, SNOLAB now consists of three large cavities whose current incarnation is marking its 10th anniversary this year.
There are several other facilities such as this all over the world, but this is the only facility in Canada and one of only two in North America. Most are situated within mountains, including the Gran Sasso National Lab currently under construction in Italy, which is being built off of an existing road tunnel.
Since cosmic rays bombard the Earth from all angles, including the sides of mountains, a laboratory located underground is the most ideal location, Virtue said.
The Laboratori Nazionali del Gran Sasso, for example, will “have 100 times the number of cosmic rays going through that lab compared to us.”
There’s a wide range of experiments taking place in these labs, and not all experiments need the very best, deepest lab. That said, there’s particular interest in SNOLAB when it comes to certain experiments that require the best environment clear of cosmic rays.
Accomplishments and work in progress
The initial Sudbury Neutrino Observatory research into neutrinos proved groundbreaking, confirmed that neutrinos have mass and “changed our understanding of the innermost workings of matter and proves crucial to our view of the universe.”
This, according to SNOLAB’s website, which offers a rundown of scientific awards that came as a result of their researchers’ work.
Neutrinos, Virtue explained, are the second-most abundant known particles and are tied into the history of the universe dating back to the Big Bang.
Something upset the balance between matter and antimatter at the time of the big bang, which resulted in everything we see today, he said, adding that “the entire universe, including us, is made up of that matter that was somehow generated during the Big Bang.”
Although early successes in the field of studying neutrinos resulted in a Nobel Prize and the construction of SNOLAB — a $70-million construction project — research into the particles is ongoing and includes a more than 10-year experiment counting to measure the neutrinos that come out of a supernova explosion within the Milky Way galaxy.
Although supernova explosions take place approximately once per second in the universe, only three per century take place in our galaxy, so the experiment might take some time to see results. When it does take place, however, researchers hope to learn more about the nature of supernovas via the “astronomical number of neutrinos” they produce.*
The two cavities dug out and opened 10 years ago to expand the SNO facility beyond its initial cavity and into the SNOLAB we know today are largely dedicated toward the study of dark matter, which is only theoretical at this point in time and has yet to be seen by any researcher.
“Convincing the world that you have seen dark matter, which has been hypothesized to exist, that’s basically Nobel Prize material,” Virtue said. “This is one of the very best places in the world to do that.”
Understanding dark matter will help us understand the universe, he added.
“We observe things in the universe we can’t attribute to the things we already know about, and there’s very strong evidence that there is extra mass out there in galaxies that is not visible and is not made of the things we already know of.”
It’s presumably a particle of some nature, he said, adding that “we can’t really conceive of it being anything other than a particle.”
Thus far, researchers at SNOLAB have ruled out areas of parameter space but have yet to actually see dark matter.
“The history to date has been literally dozens of experiments ruling out regions in that two-dimentional plane,” he said, adding that although theorists have many theories they’ve yet to empirically determine anything about dark matter.
With the detectors sensitive to cosmic rays and SNOLAB the best research space in the world clear of cosmic rays, the site has become a central pillar in the research into dark matter.
On the neutrino front, a case is currently being made for an experiment projected to cost between $300 and $400 million at SNOLAB, the funding and politics for which are currently being worked out.
The key question they seek to answer relates to the nature of neutrinos and whether it’s its own antiparticle.
“It’s fundamental knowledge, it’s fundamental science,” Virtue said. “It’s a really in-depth better understanding of how the universe came to be, why things are the way they are.”
SNOLAB an active research space
Various experiments are taking place at SNOLAB at any given time, although the COVID-19 pandemic has limited the number of people working underground.
As it stands, between 30 and 35 people are underground during a day shift, but this number would typically total between 40 and 50.
These include the 150 people on staff and the group of 1,000 members of a user community of physicists from around the world, including those from more than 30 countries.
“Typical shifts, there could be anywhere from 10, 15, 20 users on the shift along with the SNOLAB staff, but it really depends on what’s going on underground,” Virtue said.
Most of the experiments taking place underground run for three to five years 24/7 in order to produce a result, while the next generation of tests are running for 10 years.
It’s a unique facility recognized throughout the world as an ideal place to study neutrinos and dark matter, which history’s most famous theoretical physicist, Dr. Stephen Hawking, visited in 2012.
While the search for funding remains ongoing, the province announced a $12-million pledge last year to help launch their 2023-29 strategic plan, which is slated to include “the vision to be the leading international laboratory in deep underground science, hosting the world’s most advanced experiments that provide insight into the nature and evolution of the universe.”
Large-scale, multi-year experiments are ongoing, but various other efforts with more immediate implications also take place, including an effort that began early in the pandemic to create a simple emergency ventilator.
A considerable part of dark matter research involves gas management and handling in developing the sophisticated control systems to make that control possible, which directly correlated with the development of ventilator technology.
“SNOLAB has been well supported by the public and (we) want to contribute back,” then- executive director Nigel Smith said at the time. “This is obviously for the benefit of Canadians and the benefit of the world as well. It would be unconscionable not to engage everything that we can to support solutions in this crisis.”
Celebrating 10 years at SNOLAB
To celebrate its 10th anniversary, SNOLAB and researchers from the REPAIR collaboration have teamed up with 46 North Brewing for a special Cosmic Rays beer, available at their tasting room at Kelly Lake Road and in growlers.
The yeast used in the brew was cultured underground at SNOLAB by the REPAIR collaboration, which is an effort of the Northern Ontario School of Medicine to study the effect of low-level background radiation on living organisms.
“We know that too much radiation is harmful,” Virtue said, adding that on the flipside is radiation therapy in cancer treatment that kills cells selectively.
“It is essential that there’s some background level of radiation interfering with our genetics, with our biology for life to have developed the way that it did?”
Cosmic Rays is a charity beer with a portion of the proceeds from sales being donated to the Northern Cancer Foundation.
Although world-renowned in the scientific community for its contributions to the field of science, Virtue said efforts like this are aimed at helping let the general community know they exist.
“It’s a bit of hidden gem in Sudbury, and absolutely more people should know about that.”
* This story has been updated to reflect that three supernovas occur in our galaxy per century. An incorrect timeframe originally appeared in this story.
Tyler Clarke covers city hall and political affairs for Sudbury.com.
