Prof Sunil K Gupta
Dept of High Energy Physics Tata Institute of Fundamental Research Mumbai

Abstract: The GRAPES-3 experiment is a unique scientific facility located in 
the beautiful mountains of Ooty at an altitude of 2.2 km above sea level. 
The primary objective is to study the highest energy processes 
occurring in the universe. This is done through a systematic study of 
composition of primary cosmic rays below and above the `knee', sources
 of multi-TeV gamma rays, diffuse flux of gamma rays and the solar 
accelerator through the impact of coronal mass ejections, solar flares 
etc. A team of 50 scientists from a dozen institutions and universities 
from India and Japan constitute the core group of GRAPES-3. 
The GRAPES-3 experiments consist of an array of 400 large plastic 
scintillator detectors and a huge (560 sq.m.) area tracking muon 
detector. To achieve the scientific objectives extensive in-house 
development of the necessary instrumentation including plastic 
scintillator and high-speed signal processing electronics has been 
carried out. The development of some of these high performance 
instruments have the potential to complete change the nature of 
scientific problems that can now be addressed. During the colloquium 
some of these aspects would be highlighted.