Speaker
Description
The GRAPES-3 experiment, located in Ooty, India, consists of an array of 400 plastic scintillator detectors spread over an area of 25,000 m² and a 560 m² tracking muon telescope, operating since year 2000. Together, these instruments enable the detection of extensive air showers in the 1 TeV – 10 PeV energy range and the measurement of the angular flux of muons with energies above 1 GeV, covering 2.3 sr sky. Using these measurements, GRAPES-3 contributes a broad range of research topics, including the energy spectrum and nuclear mass composition of primary cosmic rays, solar and heliospheric phenomena, and particle acceleration in the atmosphere during thunderstorms. This talk will present an overview of the GRAPES-3 detectors along with key scientific results obtained in recent years. The highlights include (i) the measurement of a 1.3 GV electric potential in a massive thundercloud, (ii) the use of a geomagnetic storm to probe a localized weakness in the geomagnetic shield, (iii) the observation of a hardening in the proton energy spectrum at 166 TeV, and (iv) the detection of small-scale cosmic-ray anisotropy at TeV energies.
Ref: https://www.tifr.res.in/grapes3/publications.html