Unveiling the Mystery: Nuclear Power Station’s Ghostly Glow Found in Water 150 Miles Away!

Deep beneath the surface of Ontario, Canada, a tank filled with pure water made a remarkable discovery. A tiny particle, called an antineutrino, zipped through the water, marking a breakthrough in particle detection.

This event was special because it used water to spot an antineutrino coming from a nuclear reactor over 240 kilometers (150 miles) away. This 2023 study opens the doors for future experiments that can utilize simple and safe materials for detecting these elusive particles.

Neutrinos, the bigger family to which antineutrinos belong, are fascinating yet strange. They are incredibly abundant in the universe and are known as “ghost particles.” Why? Because they hardly interact with anything, easily passing through matter, including planets and stars.

Antineutrinos are the counterparts of neutrinos. While most antiparticles have an opposite charge to their particle twins, neutrinos and antineutrinos are unique. Scientists distinguish them by their creation process: an electron neutrino appears with a positron, while an electron antineutrino is born with an electron.

Antineutrinos come from nuclear beta decay, a type of radioactive decay where a neutron turns into a proton, releasing an electron and an antineutrino. When an electron antineutrino interacts with a proton, it can create a positron and a neutron, a reaction known as inverse beta decay.

Detecting these particles is tricky. Scientists typically use large tanks filled with liquid, fitted with photomultiplier tubes, to capture faint light from charged particles, known as Cherenkov radiation. This radiation occurs when particles travel faster than light in the liquid, similar to a sonic boom.

Nuclear reactors generate many antineutrinos, but they are low-energy, making detection challenging. Enter SNO+, the world’s deepest underground lab, more than 2 kilometers (1.24 miles) below the surface. The thick rock above shields the lab from cosmic rays, allowing scientists to analyze clearer signals.

Initially filled with ultra-pure water for calibration back in 2018, the lab analyzed 190 days of gathered data. They found signs of inverse beta decay, producing light at a specific energy level of 2.2 megaelectronvolts.

Unlike standard water detectors, which usually need higher energy levels to recognize signals, the SNO+ setup could detect down to 1.4 megaelectronvolts, giving a 50 percent chance of spotting 2.2 megaelectronvolt signals. The researchers were hopeful. A candidate signal suggested it was likely generated by an antineutrino, with a confidence level of 99.7 percent.

This discovery indicates that water could potentially be used to monitor nuclear reactors’ output effectively.

Furthermore, the SNO+ collaboration aims to deepen our understanding of neutrinos and antineutrinos. Currently, there’s a big question: are they the same particle? Finding a rare decay could answer this mystery, and SNO+ is on the hunt.

“It amazes us that pure water can measure antineutrinos from reactors across great distances,” said physicist Logan Lebanowski from the SNO+ collaboration and the University of California, Berkeley. “We put in a lot of effort to extract signals from 190 days of data, and the result is quite rewarding.”

This significant research was featured in Physical Review Letters.