Neutrino

Context:

Scientists have shown that the geometry of space-time can cause neutrinos to oscillate.

What are neutrinos?

A neutrino is a subatomic particle that is very similar to an electron, but has no electrical charge and a very small mass, which might even be zero. Neutrinos are one of the most abundant particles in the universe. Because they have very little interaction with matter, however, they are incredibly difficult to detect. Nuclear forces treat electrons and neutrinos identically; neither participate in the strong nuclear force, but both participate equally in the weak nuclear force. Particles with this property are termed leptons. In addition to the electron (and it’s anti-particle, the positron), the charged leptons include the muon (with a mass 200 times greater than that of the electron), the tau (with mass 3,500 times greater than that of the electron) and their anti-particles.

Wolfgang Pauli first postulated the existence of the neutrino in 1930.

Three Types of Neutrinos

1. “Electron neutrino” is associated with the electron
2. “Muon neutrino”
3. “Tau neutrino”

• In 2015, the Nobel prize in physics was awarded to Takaaki Kajita and Arthur B. Mcdonald for discovering neutrino oscillations demonstrating that neutrinos have mass.
• Neutrinos are the least harmful of all elementary particles, as they almost never react with solid bodies.
• The mass of a neutron is 1.67×10 to the power -27 kg while the mass of a neutrino is of the order of 1×10 to the power -37kg. Hence, a neutrino is about 17 billion times lighter than a neutron. 

Why detect them?

Neutrinos hold the key to several important and fundamental questions on the origin of the Universe and the energy production in stars. Another important possible application of neutrinos is in the area of neutrino tomograph of the earth, that is detailed investigation of the structure of the Earth from core on wards. This is possible with neutrinos since they are the only particles which can probe the deep interiors of the Earth.

Why should the laboratory be situated underground?

Neutrinos are notoriously difficult to detect in a laboratory because of their extremely weak interaction with matter. The background from cosmic rays (which interact much more readily than neutrinos) and natural radioactivity will make it almost impossible to detect them on the surface of the Earth. This is the reason most neutrino observatories are located deep inside the Earth’s surface. The overburden provided by the Earth matter is transparent to neutrinos whereas most background from cosmic rays is substantially reduced depending on the depth at which the detector is located.

India-based Neutrino Observatory (INO)

• INO Project is aimed at building a world-class underground laboratory with a rock cover to conduct basic research on neutrino.
• The Tata Institute of Fundamental Research is the nodal institution. The observatory is to be built jointly with the Department of Atomic Energy and the Department of Science and Technology.
• The observatory will be located underground so as to provide adequate shielding to the neutrino detector from cosmic background radiation.
• The operation of INO will have no release of radioactive or toxic substances. It is not a weapons laboratory and will have no strategic or defence applications.
• The project location was initially decided to be located in the Nilgiris but later, on grounds that it was too close to tiger habitat, was moved to a cavern under a rocky mountain in the Bodi West Hills.
• Department of Science and Technology and the Department of Atomic Energy jointly support the project.

Indian Neutrino Observatory (INO) – Importance

1. It will be the largest experimental facility to come up in the country. It will facilitate the development of cutting-edge technology and build sophisticated instruments.
2. This observation will tell us more about the properties of neutrino particles, whose main source is the Sun and the Earth’s atmosphere.
3. Neutrinos may have a role to play in nuclear non-proliferation through the remote monitoring of nuclear reactors.
4. This will also help in developing a model of physics beyond the so-called Standard Model of Particle Physics.
5. Understanding neutrinos could help in detection of oil and mineral deposits.
6. They may open up a faster way to send data than the current ‘around the earth’ model, using towers, cables or satellites as they can pass through the Earth.
7. It would also have a great impact on diverse fields such as nuclear and particle physics, astrophysics and cosmology, medical imaging etc.
8. Neutrinos are the information bearers of the universe — which are almost never lost in their path. Efforts in studying neutrinos at INO may help unravel the deepest mystery of the universe

Source: PIB