LAKE VERMILION— A proposal to construct a large neutrino detector under the surface of Lake Vermilion’s Big Bay is moving forward quickly with plans to install the device at a site just north of Ely Island sometime after Labor Day.
The proposal, which has been developed with little public awareness or involvement, 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.
According to Fermilab, the project is described as an underwater neutrino detector project, which is currently being built for installation sometime in the next several weeks.
Fermilab officials did answer some questions about the detector posed by the Timberjay, but did not respond prior to deadline to inquiries about the size and shape of the device, nor how the site would be indicated on the lake to prevent anglers from potentially snagging parts of the detector or associated underwater power lines. A diagram included in a Fermilab document available online shows a rack containing ten large-diameter cylinders, although the diagram does not include recognizable dimensional data.
Fermilab did undertake geotechnical work at the site, which apparently raised some concerns. “To our astonishment, there is a roughly 150-foot-deep valley filled with sediment in the area we were planning to deploy,” stated Alan Bross, Fermilab’s lead official on the detector. “We are still trying to figure out what to do.”
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.
While the Fermilab team had explored western Lake Superior as a possible location for the detector, they settled on Lake Vermilion due largely to the existence of the neutrino main injector, or NuMI, beam at Fermilab, located outside Chicago. Fermilab built the beam 25 years ago for neutrino oscillation experiments using underground detectors at Soudan and Ash River, both of which are located in the path of the neutrino beam.
Fermilab would use the existing beam and the newly built Lake Vermilion detector to help observe the behavior of accelerator-sourced neutrinos in open water. While Fermilab officials haven’t confirmed the size of the detector, such devices need to have substantial mass in order to interact, even occasionally, with these high-energy particles.
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, that is located within an operating neutrino 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. According to the TheDebrief, neutrinos’ ability to pass through matter at high speed makes them excellent candidates for long-range, instantaneous communication systems in underwater environments since they can travel vast distances through water with minimal alteration, offering a revolutionary approach to secure, long-distance communication for naval operations, although such technology is likely still years away. A 2012 study, however, documented, for the first time, the use of a neutrino beam to send a simple message.