IceCube Neutrino: Observatory That Hunts Most Elusive Particle in the Universe Set for $37 Million Upgrade

The IceCube Neutrino Observatory is a unique detector buried deep within ice at the South Pole that's designed to observe some of the strangest particles in the universe. Now, the facility is set to receive a $37 million upgrade in order to enhance its capabilities, with the intention of providing fascinating new insights into the nature of the cosmos.

Operated by an international collaboration of scientists, the observatory—which is spread out over a cubic-kilometer of ice—is used to search for neutrinos: invisible, nearly massless subatomic particles which rarely ever interact with normal matter due their lack of electrical charge. Neutrinos travel across the universe at near-light-speed, often passing right through entire planets, stars and galaxies unhindered. Indeed, hundreds of billions of these neutrinos ghost through our bodies every second.

But despite being the second most ubiquitous particles in the universe after photons,—particles of light—neutrinos are not well understood compared to other types of matter, precisely because of the fact that they don't interact with other forms.

Understanding more about these elusive subatomic particles could cast new light on some of the most extreme phenomena in the universe—where neutrinos are produced—such as exploding stars, gamma-ray bursts, neutron stars and black holes, according to the IceCube website. They act as a kind of "astronomical messenger," travelling in straight lines from their source without being affected by other matter. Thus they can provide information on events which take place in the far reaches of the universe.

Studying neutrinos can help scientists to explore some of the enduring mysteries in physics, such as the properties of the neutrino, the origin of cosmic rays and the nature of the 96 percent of material in the universe that we cannot see—dark matter (23 percent) and dark energy (73 percent.)

"Neutrinos are the last unexplored corner of the Standard Model of physics," Kael Hanson, IceCube Upgrade Principal Investigator from the University of Wisconsin-Madison—which is responsible for the maintenance and operations of the detector—said in a statement. "Neutrinos have properties the Standard Model can't account for," he noted, referencing the best available model to describe the behaviour of subatomic particles and the fundamental forces of the universe.

Clearly, detecting neutrinos is a tricky business. In order to do this, IceCube—which is primarily funded by the National Science Foundation (NSF)—observes the light emitted by secondary charged particles "that are produced when a single neutrino crashes into a proton or neutron inside an atom," according to the observatory website.

But to be able to do this, a large volume of transparent material is required to capture the light given off by just one of these extremely rare events—which can extend for more than a kilometer.

This is why the observatory was built at the South Pole, the only place on the planet which hosts sufficient quantities of a suitable, large, transparent material—i.e. clear, pure and stable water ice—and the required scientific infrastructure to support research.

At this site, scientists and engineers, installed more than 5,000 individual light detectors in eighty-six 1.5-mile-deep holes in the ice. Now, the NSF and other international partners have approved funding to expand the observatory's current detection capabilities—with the upgrades due to be installed between 2022 and 2023.

The main aim is to boost the observatory's ability to study the oscillation properties of neutrinos, which can cause them to change from one type to another (there are three known types.) Understanding these changes may help to shine light on the neutrino's properties and refine the Standard Model of particle physics.

"The goal of the upgrade is to improve the performance of the detector at both high and low energies. At low energies, it will allow us to go to the next level with our neutrino oscillations," Tyce DeYoung, IceCube Upgrade Co-Principal Investigator from Michigan State University, said.

The second aim is to gain a better understanding of the ice around the detector which will provide better observations of those neutrinos with higher energies—which are created by extreme astronomical phenomena.

"This will help not only the Upgrade achieve goal one but also can help IceCube get better resolution as a telescope for high-energy neutrinos coming from our galaxy or beyond," Hanson told Newsweek. "We archive all raw data from IceCube —about half a petabyte per year—so we can go back, apply the better ice models to archival data and within about a year of reprocessing can release an improved IceCube neutrino catalog to the astronomical community."

IceCube also detects lower-energy neutrinos which may originate from far less extreme sources, such as the collision of subatomic particles in the Earth's atmosphere.

The latest upgrades will be the first in a series of extensions to the existing IceCube facility, which together will provide even more sensitivity and precision than is currently available.

Scientists hope that such additions will lead to further significant discoveries, such as the one announced in July, 2018 when IceCube scientists revealed that they had traced the origin of an extremely-high-energy neutrino to a blazar—a supermassive black hole at the heart of a galaxy spewing out a jet of material in the direction of Earth—around 5.7 billion light-years away.

This find potentially revealed, for the first time, a source of cosmic rays—subatomic particles of various types that travel through space at near-light-speed and constantly bombard earth—whose origin has long-puzzled scientists.

"IceCube has been extremely successful both in being completed on time and on budget but the science has been pouring out too which excites the researchers analyzing the data: in 2013 we finally achieved our main mission of measuring astrophysical neutrinos and then in 2017 we achieved for the first time a joint observation of a single object, TXS 0506, a distant blazar, coincident with satellite and ground based radio, optical, and gamma ray telescopes," Hanson said. "This single event has produced a wealth of papers explaining aspects of the physics of this object."

This article was updated to include additional comments from Kael Hanson.

IceCube Neutrino Observatory
The IceCube Neutrino Observatory is located at NSF’s Amundsen-Scott South Pole Station. RAFFAELA BUSSE, ICECUBE / NSF
IceCube Neutrino: Observatory That Hunts Most Elusive Particle in the Universe Set for $37 Million Upgrade | Tech & Science