GRAPES-3 Experiment:
The GRAPES-3 experiment discovered a new feature in the cosmic-ray proton spectrum at about 166 tera-electron-volt (TeV) energy while measuring the spectrum spanning from 50 TeV to a little over 1 peta-electron-volt (PeV).
- Gamma Ray Astronomy PeV EnergieS phase-3 (GRAPES-3) is designed to study cosmic rays with an array of air shower detectors and a large area muon detector.
- It is located in Ooty, India.
- It is operated by the Tata Institute of Fundamental Research.
- It aims to probe the acceleration of cosmic rays in different astrophysical settings.
- Its objectives are to study:
- The origin, acceleration and propagation of >1014 eV cosmic rays in the galaxy and beyond.
- Existence of “Knee” in the energy spectrum of cosmic rays.
- Production and/or acceleration of the highest energy (~1020 eV) cosmic rays in the universe.
- Astronomy of multi-TeV γ-rays from neutron stars and other compact objects.
- Cosmic rays were discovered more than a century ago.
- They are considered to be the most energetic particles in the universe.
