LAKE VERMILION— More details on the planned deployment of a neutrino detector in the waters off Vermilion’s Ely Island later emerged this week in response to questions posed by the Timberjay.
The installation of the detector is an initiative of the federal Defense Advanced Research Projects Agency, or DARPA, a research and development branch of the Defense Department, and the agency has been working closely with Fermilab for at least the past two years to move the project forward. It is now expected to be deployed in mid-to-late October, according to Tracy Marc, media relations manager with Fermilab.
A separate experiment, coordinated by the University of Minnesota-Duluth and the Brookhaven Laboratory, will be deployed later this year in Lake Superior.
The Lake Vermilion experiment will entail ten separate cylindrical modules, called Muon Underwater Modules, or MUMs, and each MUM will be enclosed within its own metal framework that will measure 22-1/2 feet long, and approximately 10 feet in height and width. Two flat-panel detectors will be placed within each MUM.
The MUMs will be buoyant so they are suspended approximately one meter off the bottom. The water depth at the deployment site is approximately 35 feet, so the top of the MUMs will be approximately 22 feet below the water surface.
According to DNR area hydrologist Kim Boland, who worked with Fermilab on the issuance of a public waters work permit for the project, Fermilab officials will use heavy concrete anchors attached by cables to the frameworks of each MUM to keep the devices from floating to the surface. Fermilab officials anticipate that mud and silt at the site will engulf the concrete anchors and provide a relatively firm attachment to the lake bottom.
As part of their permit, said Boland, the DNR is requiring Fermilab to ensure navigability around the device. Since the north side of Ely Island in Big Bay is popular with both walleye and muskie anglers, Fermilab officials say the location of the MUMs will be identified with buoys. The Timberjay has confirmed that Fermilab officials have contacted the St. Louis County Sheriff’s Office about the deployment of buoys, since navigation aids are under the purview of the sheriff. St. Louis County Sheriff Gordon Ramsay confirmed that officials from the lab did reach out earlier this summer about the process for deploying buoys, but have yet to hear anything since.
Researchers have identified a cabin site on the north side of Ely Island, which is expected to serve as the base of operations for the electronics associated with the detector and they have built a shed designed to house most of that gear, which still needs to be hauled to the island site.
Some residents who live in the vicinity of Ely Island have raised concerns about energy use and the noise that might be associated with the detectors, but Fermilab’s Marc insists the project will be almost totally silent. Marc noted that the energy draw from each of the MUMs is expected to be about 300 watts. That’s about a third the electrical draw of a typical toaster. She said researchers have been in communication with Lake Country Power, which serves Ely Island, and that the project will require no upgrades to the island’s existing service.
“The system uses a power amount typical of a small house,” said Marc.
According to Marc, the electronics shed is insulated to ensure minimal sound is audible outside and there would be little noise in either case. “The only noise-generating devices in the enclosure would be several personal computers,” Marc said. The shed is being outfitted with air conditioning to ensure computing equipment is kept cool, which could potentially generate sound. But Marc said researchers expect to gather data from the detectors from November of this year to February 2027, so it’s unlikely the air conditioner would ever be needed.
Meanwhile, the detecting device within each MUM is made of plastic, according to Marc, has no moving parts, and will be silent.
Why Lake Vermilion?
The researchers identified Lake Vermilion as the best location for their research to give the experiment the best sensitivity to the neutrinos Neutrino Main Injector, or NuMI, beam at Fermilab, located outside Chicago. Fermilab built the beam 25 years ago for neutrino oscillation experiments using a massive underground detector located at the 27th level of the Soudan Mine.
Neutrinos are neutral subatomic particles that have nearly zero mass. They can pass through normal matter without interacting because, at the atomic level, matter is mostly empty space. This ability to pass through matter is why neutrinos are often referred to as “ghost particles.” They travel through the universe at close to the speed of light and can only be detected with current technology in those rare instances when they make contact with a much more massive atomic particle, such as a proton, possibly in a water molecule located near the detector. When that happens, they emit varying types of energy, which researchers study to better understand them.
Possible applications
More importantly for DARPA’s purposes is the ability of neutrinos to potentially allow for nearly instantaneous communication on opposite sides of the planet, underwater, or even into deep space. While DARPA has not explained the ultimate goal of its proposal, a technology-focused online news source, known as TheDebrief, described the current research as “a game changer for underwater military surveillance.”
According to the publication, DARPA has “quietly launched an ambitious new initiative to develop technologies to detect and observe underwater human-made neutrinos, or “ghost particles.” DARPA has not revealed the purpose behind the research, but the TheDebrief suggests that DARPA “may be exploring using neutrinos for long-range underwater communication or detecting clandestine nuclear activities, including tracking enemy nuclear submarines.”
Traditional methods of communication with submarines can be extremely challenging, as they are limited in range and are subject to interference from saltwater and underwater disturbances. While neutrinos may offer a means of communicating long distances or underwater in the future, any direct application is still likely years away.