TIFR Current Affairs

GRAPES-3 Telescope upgraded to detect solar storms

The GRAPES-3 experiment at TIFR’s (Tata Institute of Fundamental Research) Cosmic Ray Laboratory in Ootacamund in Tamil Nadu is getting upgraded to detect solar storms.

GRAPES-3 (Gamma Ray Astronomy PeV EnergieS phase-3) experiment had detected the effect of a solar storm that hit the earth in June 2015.

Key Facts
  • GRAPES-3 has an important role in understanding the propagation of storms from the L1 point (Lagrange point 1) to its impact on the Earth.
  • The upgraded detector will have an increased coverage and improved capacity to determine the direction of incident cosmic rays.
  • It will play a major role in getting precise information about the propagation of storms in the last million miles (from the L-1 point) of their journey from the Sun to the earth.
Background

The Sun is at a distance of 150 million kilometres from the earth. Satellites are placed at a distance of nearly 1.5 million kilometres, at the so-called L1 point (between Earth and Sun), where they orbit the Sun along with the Earth. The satellites act as an early warning system as the charged particles from a solar storm first impact the satellites before hitting the earth.

About GRAPES 3 experiment

The GRAPES-3 experiment is located at Ooty in India. It was started as a collaboration of the TIFR and the Japanese Osaka City University, and now also includes the Japanese Nagoya Women’s University. It is specially 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 four astrophysical settings.

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TIFR Researchers discovery challenges theory of superconductivity

Researchers’ team from Tata Institute of Fundamental Research (TIFR) have discovered that bismuth semi-metal in bulk form becomes a superconductor.

The team was lead by Dr. S. Ramakrishnan of the Department of Condensed Matter Physics and Material Sciences at TIFR, Mumbai. 

What researchers have discovered?

They have discovered that when temperature of bismuth semi-metal in bulk form is lowered to 530 microKelvin (about -273 degree C), it becomes a superconductor. It acts as superconductor at temperature three orders of magnitude higher than the theoretical prediction.

Significance
  • This landmark discovery challenges the conventional understanding of superconductivity based on Bardeen-Cooper-Schrieffer (BCS) theory.
  • It cannot explain the superconductivity seen in bismuth as it only explains superconductivity in most low Tc (critical temperature) superconductors.
  • The discovery demands a new theory and a new mechanism to understand superconductivity in bismuth.
  • It provides an alternative path for discovering new superconducting materials which are very different from the conventional superconductors.
What are Superconductors?

Superconductors are materials that conduct electricity with no resistance whatsoever. In order to achieve superconducting state, the element should have mobile electrons, and these electrons should come together to form pairs, known as Cooper pairs.

Unusual phenomenon in bismuth

Unlike other elements in the periodic table, bismuth has unusual phenomenon. Bismuth has only one mobile electron per 100,000 atoms. Whereas, the metallic superconductors have one mobile electron per atom. Since carrier density of bismuth is so small, it was believed that bismuth will superconduct. Thus, superconductivity in bismuth is puzzling.

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