India digs deep to bury neutrino-hunting chamber

India is joining the world of exotic particle research, announcing US$235 million worth of funding for a neutrino observatory in the country's south.

Approval for the India-based Neutrino Observatory (INO), proposed in 2013, means construction of the underground complex can now begin.

The 1,300 metre deep cavern under the village of Pottipuram will be home to a 50,000 tonne iron calorimeter (ICAL) acting as the detector. The ICAL is to be made of 30,000 resistive plate chambers separated by iron plates.

Physics World reports that the INO will look for evidence of the neutrino mass hierarchy, trying to work out which of the three known neutrino mass states is the heaviest and which is the lightest.

Project director Naba Mondal said an understanding of the mass hierarchy will provide insights into questions like the matter-antimatter asymmetry that allows the universe we live in to exist.

Other experiments planned for the INO include searching for dark matter, and looking for evidence of a process called neutrinoless double-beta decay. If it exists, this decay mode allows two neutrons to decay into two protons and two electrons – but it's never been observed.

As well as the INO experiment – the largest cavern will be 130 metres long, 26 metres wide and 30 metres high, with two smaller caverns for the secondary experiments – India will set up an Inter-Institutional Institute for High-Energy Physics 110 km away in Madurai.

INO director Naba Mondal says India will seek international participation in the project, and noted that the country hasn't conducted research like this since 1992, when the Kolar Gold Field project ended.

India spent about US$73m on its Mars Orbiter Mission, justifying it partly as a demonstration of the capabilities it can offer global industry. This project's rather larger price tag may be another such demonstration. ®