The groundbreaking ceremony for the Jiangmen Underground Neutrino Observatory happened on January 10. This means construction on Asia’s two biggest neutrino experiments will have started in the span of a week, after the India-based Neutrino Observatory was given the go-ahead by the government on January 5.
Where the INO uses a device called the iron calorimeter to ‘trap’ and study neutrinos, the JUNO will use a liquid scintillator neutrino detector: a large container filled with a pristine liquid and lined with sensors. LSNDs are used to count the number of a neutrinos emerging from particular sources, which in JUNO’s case will be two nuclear power plants (comprising 10 reactors with an output of 35.8 GW) situated 53 km from the observatory.
JUNO will also be China’s second big neutrino experiment. The first is the Daya Bay Reactor experiment, which – also using an LSND – studies neutrinos produced by cosmic muons. In 2012, it announced an important result concerning the mass hierarchy of the three types of neutrinos, placing the JUNO in good stead on two fronts, so to speak: with designing and operating an LSND and with using such an installation to get results. Thus, the Institute of High Energy Physics responsible for JUNO already has over 300 scientists from 45 institutions in nine countries working with it.
India, on the other hand, has little to count on on that front, which is why the INO is still soliciting collaborators despite showing no signs of any flaws in its design or effective implementation. The lack of experience also shows in a more subtle, but no less telling, way: in the press releases crafted by the respective organisations. While the TIFR/IMSc statement issued for the INO stuck to the point, the IHEP statement for JUNO expressed confidence about getting results, too.
Both INO and JUNO, once simultaneously operational in 2020, will be extending the study of the neutrino mass hierarchy problem on a grand scale. At the INO calorimeter’s heart will sit the world’s most massive electromagnet while the JUNO’s LSND will comprise the world’s most voluminous LSND tank. At the same time, the two observatories don’t signify the dawn of experimental neutrino physics in Asia; the Kolar Gold Fields neutrino experiment in India took care of that in 1964.