There is 700 meters Underground near the city of Jiangmen in southern China, a giant ball – 35 meters in diameter and filled with over 20,000 tons of fluid – just started a mission that will last decades. This is JunoUnderground Neutrino Observatory, a recent huge -scale experiment, studying some of the most mysterious and elusive particles known to science.
Neutrino are The most abundant particles In the universe of mass. These are basic particles, which means that they do not break down into smaller components, which makes them very diminutive and very delicate. They also have zero electric charge; They are neutral – hence their name. All this means that very often they do not interact with other matters they contact, and can go through it without influence, which makes it hard to observe them. For this reason, they are sometimes called “ghost molecules”.
They also have the ability to move (or “oscillating”) between three different forms, also known as “flavors”: Electron, MU and Tau. (It should be noted that neutrine with electron flavor is different from electrons; the latter are a different type of basic particle, with a negative charge.)
The fact that oscillate Neutrin was proven by physicists Takaki Kajita and Arthur Bruce McDonald. In two separate experiments, they observed that neutrine with electrons flavored oscillates to neutrinas with a mi- and tau flavor. As a result, they showed that these particles have mass and that the mass of each taste is different. For this purpose they won Nobel Prize in the field of physics in 2015.
Explanation about the oscillations of Neutrin with the Fermi National Accelerator laboratory.
But an essential, but still unknown fact is how these masses are ordered – which of three flavors has the largest mass, and at least. If physicists understood the mass of neutrinas better, it could facilitate better describe the behavior and evolution of the universe. Juno enters here.
Unique experiment
Neutrin cannot be seen in the case of conventional particle detectors. Instead, scientists must look for scarce signs of their impact with other matter – and this is what Giant Juno ball It is for. Called a scintor, he is filled with a sensitive inner liquid consisting of a solvent and two fluorescent compounds. If neutrino passes through this matter enters it, it will cause a flash of delicate. In the area of the liquid there is a massive stainless steel network, which supports a immense number of highly sensitive delicate sensors, called photoptomultiplier tubes, capable of detecting even one photon produced by interaction between neutrino and liquid, and transforming it into a measurable sales signal.
“Juno’s experiment raises the heritage of its predecessors, with the difference that it is much larger,” says Gioacchino Ranucci, deputy head of the experiment and former boss of Borexino, another experiment with hunting at neutrino. Ranucci explains that one of the main features is that Juno can “see” both neutrino and their counterparting counterparting: Antineutrinos. The former are usually produced in an atmosphere of earth or a distribution of radioactive materials in the skin of the earth, otherwise it comes from space – from stars, black holes, supernova and even a great explosion. Antineutrinos, however, are artificially produced, in this case by two nuclear power plants near the detector.
“When they propagate, neutrinos and anti -members still oscillate, transforming into each other,” says Ranucci. Juno will be able to capture all these signals, explains, showing how they oscillate, “with precision never achieved before.”