MUMBAI: Unknown to many, the world’s largest magnet, weighing 50,000 tonnes, is being designed at the Bhabha Atomic Research Centre (Barc) at Trombay these days. It will be several times bigger than the one in the Compact Muan Solenoid detector at CERN in Geneva.The magnet will play a major role in the Rs 1,500-crore India-based Neutrino Observatory coming up 4,300 ft below a cave in a mountain not far from Madurai, Tamil Nadu.Vivek Datar, head of Barc’s nuclear physics division, told TOI on Monday that in terms of sheer dimensions the magnet being designed at the Trombay centre would be the largest in the world. “It will be iron-based, weighing 50,000 tonnes, while the weight of the one at CERN ranges between 4,000 and 5,000 tonnes.” Other sources indicated the magnet’s weight was 12,500 tonnes.Datar said the current plan envisaged the magnet having three modules and work on the engineering model was expected to be completed in about three years. “We plan to do this near Madurai University,” he said.He said currently four departments at Barc were involved in the magnet project but the number would increase to six later. A formal green signal from the Atomic Energy Commission is awaited.Naba Mondal, chief spokesperson of the observatory project at Tata Institute of Fundamental Research (TIFR), said the Neutrino Observatory would be a major facility relating to the area of basic sciences and would help scientists and students in fields like particle physics, astrophysics and space sciences. “This project is part of the 12th Five Year Plan of the department of atomic energy and the department of science and technology, and we have received the approval for initiating pre-project activities,” he said. Mondal said if the programmes went on schedule, construction of the observatory would start in six to eight months and it should be completed by 2018.About 100 scientists and 26 institutions are part of the Neutrino Observatory project. The institutions include Barc and TIFR, the Institute of Mathematical Sciences in Chennai, the Saha Institute of Nuclear Physics and the Variable Energy Cyclotron Centre, both in Kolkata.