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. Of the four fundamental forces in the universe, neutrinos only interact with two — gravity and the weak force, which is responsible for the radioactive decay of atoms.
Features of Neutrinos
- They have very little interaction with matter and hence 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 its antiparticle, 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.
- Having nearly no mass, the neutrinos zip through the cosmos at almost the speed of light.
Significance of Neutrinos
- Just as archaeologists study broken clay pieces to construct a story about the society that produced them, physicists examine neutrinos to learn more about the events and processes from which these subatomic particles have their origins.
- Neutrinos play a role in many fundamental aspects of our lives:
. they are produced in nuclear fusion processes that power the sun and stars
. they are produced in radioactive decays that provide a source of heat inside our planet
. they are produced in nuclear reactors
- Neutrinos are believed to be a vital ingredient in a star’s supernova process. These explosions spread heavy elements throughout space, elements that are needed to create the universe we live in.
- Neutrinos also provide a tool to study the structure of nucleons (protons and neutrinos), to learn how matter evolved from simple particles into more complex composites of particles, creating everything around us.
India Based Neutrino Observatory
- The India-based Neutrino Observatory (INO) Project is aimed at building a world-class underground laboratory with a rock cover of approx. 1200 m for non-accelerator based high energy and nuclear physics research.
- The project includes construction of an underground laboratory and associated surface facilities at Pottipuram in Bodi West hills of Theni District of Tamil Nadu.
- It also includes construction of an Iron Calorimeter (ICAL) detector for studying neutrinos, consisting of 50000 tons of magnetized iron plates arranged in stacks with gaps in between where Resistive Plate Chambers (RPCs) would be inserted as active detectors.
- The proposed magnetized ICAL detector will detect the atmospheric neutrinos and antineutrinos over a wide range of energies and path lengths.
