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GRAPES- 3

Topics Covered:

  1. Awareness in space.

 

GRAPES- 3

 

What to study?

For Prelims and Mains: GRAPES- 3- features and objectives of the programme, about muons and their significance in studying thunderclouds.

 

Context: For the first time in the world, researchers at the GRAPES-3 muon telescope facility in Ooty have measured the electrical potential, size and height of a thundercloud that passed overhead on December 1, 2014.

 

Why study properties of thunder clouds?

Learning about the properties of thunderclouds can be useful in navigation of aircraft and preventing short circuits.

 

How muons were used?

Muons and other particles are produced when cosmic rays bombard air particles surrounding the earth. The muons produced can have positive or negative charge. When a positively charged muon falls through a cloud, it loses energy. If its energy falls below 1 giga electron volt (GeV), which is the threshold of detection of the GRAPES-3 muon telescope, it goes undetected.

On the contrary, a negatively charged muon gains energy when falling through the cloud and gets detected. Since there are more positive than negative muons produced in nature, the two effects don’t cancel out, and a net change in intensity is detected.

 

About GRAPES 3:

The GRAPES-3 experiment (or Gamma Ray Astronomy PeV EnergieS phase-3) located at Ooty in India started as a collaboration of the Indian Tata Institute of Fundamental Research and the Japanese Osaka City University, and now also includes the Japanese Nagoya Women’s University.

GRAPES-3 is designed to study cosmic rays with an array of air shower detectors and a large area muon detector.

It aims to probe acceleration of cosmic rays in the following four astrophysical settings. These include acceleration of particles to, (i) ~100 MeV in atmospheric electric fields through muons, (ii) ~10 GeV in the Solar System through muons, (iii) ~1 PeV in our galaxy, (iv) ~100 EeV in the nearby universe through measurement of diffuse gamma ray flux.

 

Sources: the hindu.