The India-based Neutrino Observatory (INO) project has been facing a barrage of questions from environmentalists, politicians and others ever since the project was cleared. One of the queries concerns the actual experiments planned and the nature of neutrinos themselves — whether the experiment will use artificially manufactured neutrino beams and on the safety to humans and the environment if such neutrinos are used.

The concern about the use of artificially manufactured neutrino beams is rooted in a 2004 paper by Naba Mondal, Project Director of INO. He had written that in order to receive neutrinos from neutrino factories all around the world at a later date that they are setting up the magnetic detector. Dr. Mondal clarified to this Correspondent that the statement was made in the preliminary stages of formulating the experiment, when it was not known what source of neutrinos would be needed.

The team had planned for this method for its second phase of operation in order to measure one of the parameters associated with “neutrino oscillations.”

However, China, using neutrinos from their Daya Bay nuclear reactor, has by now already measured this parameter, so the need and the plan for this phase of operation of the INO experiment no longer exist.

Even if such a beam were to be used, it would have had no harmful effects, he stressed. “A human being can stand in the path of such a neutrino beam for his or her lifetime, say eighty years, and only one neutrino will perhaps interact with the body,” he said, quantising his argument that even if such a beam were to be commissioned, it would have no side-effects.

To mention two experiments using neutrino beams, the Fermilab experiment has been beaming neutrinos to Minnesota (Soudan Mine) which is nearly 735 km away for about 15 years; beams from CERN in Geneva reach the Gran Sasso laboratory in Italy (over 700 km away), this has been running for about seven years. The U.S. is developing an experiment called the Long Baseline Neutrino Facility to beam neutrinos from Fermilab to Homestake mines (in the U.S.) in which scientists from various countries including India are participating.

“Sending a neutrino beam for experiments to a faraway detector is nothing new. If there were any danger with such beams, will the U.S, Japan and Italy have allowed this? In any case, INO will use only atmospheric neutrinos,” said Dr Mondal.

In this context, it is necessary to look at the nature of neutrinos. It is not correct to say that naturally occurring neutrinos have only low energies.

Neutrinos coming from the atmosphere, such as cosmic rays have very high energies, just as the extragalactic neutrinos detected at the IceCube experiment in the South Pole. So when we say we are being bombarded by neutrinos, it also includes neutrinos of high energies. In this sense, making the distinction between “natural” and “artificial” neutrinos is meaningless.

As a matter of fact, neutrinos may even play a role in maintaining peace. They can be used to monitor nuclear reactors to check if anyone is making away with stores of plutonium which can be used in making nuclear weapons. This is a part of ongoing research in France.