A stack of dusty electronic boards and tangled wires lie in a large air-conditioned room in Madurai. The stack is hooked up to a monitor that displays arrays of ticking numbers and counts elementary particles called muons that have arrived from the upper reaches of the atmosphere. There they originate from the impact of cosmic rays, highly-energetic particles from outer space. The cosmic rays also produce other particles, including the charge-less and nearly massless neutrinos.
The setup sits at the temporary premises of the Inter-Institutional Centre for High Energy Physics (IICHEP) that’s tucked away on a nondescript road by the side of the Madurai Kamaraj University. A modest sign on the gate announces the centre’s association with the India-based Neutrino Observatory (INO), the country’s most sophisticated particle physics experiment yet.
It’s hard to believe that this dusty stack is the most visible and proximate artefact of a fifteen-year long saga. At the heart of this saga lies the humble neutrino, the most feebly interacting of all the stable fundamental particles in nature, which ironically now stands accused of being a radiation hazard.
On January 5, 2015, the Union Cabinet sanctioned Rs.1,500 crore for the construction of the INO’s laboratory under a hill in the Theni district of Tamil Nadu. Within 15 days, Vaiko, the leader of the Marumalarchi Dravida Munnetra Kazhagam (MDMK) party in Tamil Nadu, filed a writ petition against the project in the Madurai bench of the Madras High Court, claiming that it would “bring unimaginable and terrible disaster to the mankind (sic) and the environment”.
Stephen Inbanathan was present when Vaiko personally came to argue his case at the High Court. There were no locals at the hearing, only members of Vaiko’s party and a few lawyers. “There will be radiation and this will affect people. What sin have these people committed? Are they guinea pigs?” he recalls Vaiko saying.
Inbanathan, a materials scientist at the American College in Madurai, first became involved with the INO as part of the outreach efforts, communicating with the locals in Tamil and coordinating the groundwork required in Madurai for the IICHEP. He is now a part of the scientific collaboration as well.
Ruling on Vaiko’s petition, the Madurai bench of the Madras High Court passed an interim order on March 26, 2015, that required clearance from the Tamil Nadu Pollution Control Board (TNPCB) to be obtained before construction work at the site could begin. This was, in fact, an explicit requirement in the environmental clearance that was granted for the project in June 2011. After a small delay, the application to the TNPCB was submitted in May 2015 – the scientists say they had to await financial sanction from the Cabinet before applying for the clearance. The TNPCB, despite being required to respond within 45 days, has neither granted nor denied clearance till date. Until it does, the High Court stay will remain.
An even longer delay has stalled the construction of the IICHEP facility that would serve as the research, training and development centre for the INO. The Bhabha Atomic Research Centre (BARC), part of the collaboration of 24 institutions across India working on the INO, had in 2012 purchased 33 acres of land in Madurai for construction of the IICHEP, not far from its present temporary office. There was a requirement to convert the zone from “residential” to “mixed educational”, a lengthy and rather cumbersome procedure. The zone conversion had to be publicised in the newspapers to allow for response in case of any opposition. And there was no opposition, Inbanathan says.
The Madurai Collector then convened a meeting involving local officials and the Town Planning Committee where Inbanathan was asked to present a brief about the project. That was in 2014. “They passed the application and sent it to Chennai,” he says. “There it is gathering dust now.”
Neither of these incidents were the first time that plans for the INO have suffered a setback.
In 2005, a report was submitted to the Scientific Advisory Committee of the then-PM Manmohan Singh identifying a site in Singara, also in Tamil Nadu. Another three years passed by before the MoEF granted its environmental clearance. Protests by environmental activists followed, which prompted the Chairman of the Atomic Energy Commission at the time, Anil Kakodkar, to meet the then-CM of Tamil Nadu M. Karunanidhi to seek his help in seeing the project through. He was told that the concerns of the activists had to be taken into account. They were about the site being in an ecologically fragile zone, being on the periphery of the Mudumalai Tiger Reserve and also being close to an elephant corridor.
Conservation scientists who spoke to The Wire felt that the PUSHEP hydroelectric project that had already come up in the area had presented a far greater potential for disturbing the ecology of the region. They also felt that the physicists had been naïve in not having anticipated the protests by the activists.
Jairam Ramesh, who was the environment minister at the time, asked the Tiger Conservation Authority for a report on whether the tigers would indeed be affected. He was to reportedly visit the site but that never materialised. In November 2009, Ramesh rejected the chosen site in Singara on the basis of the “very weighty reasons” the aforementioned report gave about the project’s impact on the wildlife and ecology of the area. The present site in Theni was then suggested as a possible alternative by the Geological Survey of India.
It was fifty years ago, and some four hundred kilometres to the north of Theni, that atmospheric neutrinos were first reported at an observatory deep underground in the Kolar Gold Fields. The muon had already been discovered in the cosmic rays that shower us day and night. Homi Bhabha, a pioneer in the study of cosmic rays and already the head of the Atomic Energy Commission, asked his young PhD student B.V. Sreekantan to go to Kolar and measure how the number of muons detected would change with the depth.
That was 1951. The men eventually went down to a depth of almost three kilometres, measuring the muon flux. “For two months, they didn’t find a single cosmic ray muon. Then they realised they can look for neutrinos at this depth because there’s no more background. That’s how they started the atmospheric neutrino experiment,” says Naba Mondal of the Tata Institute of Fundamental Research (TIFR), who was at Kolar in the early 1980s working on a different experiment, and is now the director of the INO.
Frederick Reines, an American physicist who had discovered the neutrino escaping a nuclear reactor in 1956, was also hunting for them in cosmic rays. He came to Kolar and talked to the mining authorities on his own, without informing the Indian physicists, says Mondal. “Bhabha was very upset. He called Sreekantan and said we have to do this ourselves. And they did.”
Reines’ group, working in a gold mine in South Africa, discovered atmospheric neutrinos first. But the Indian physicists working at Kolar, collaborating with colleagues in the UK and Japan, published first – on August 15, 1965 – two weeks before their competitors.
It was, as a review put it, “a historic race which had no losers but two winners.” Kolar was host to other experiments in later years until the mines turned unproductive, were shut down and became flooded with water in the early 1990s.
A meeting to commemorate the half century of the detection of atmospheric neutrinos was held at the Royal Society in London in December last year. Attended by perhaps a hundred guests, including the 2015 physics Nobel laureate Arthur McDonald, the meeting was organised by Durham University, which along with Osaka City University were partner institutions of TIFR in the Kolar experiment. It was a genteel half-day affair where medals were given and recollections were made. Brajesh Choudhary, a professor at Delhi University, was present. It was a mixed feeling being there as a neutrino physicist, he later told The Wire, since no such event was organised in India despite the major contributions of its scientists.
Choudhary is another member of the INO collaboration who also works with Fermilab in the US and CERN in Europe. The Wire had asked him prior to his trip about the court case and delays. “The Tamil Nadu government is killing a national project for political gains,” he put it bluntly, “Yes, these things are happening.”
If the application in Chennai had come through and the construction at the IICHEP completed, it would have allowed the assembling of a prototype detector tenth the size of the one to be set up at the INO. This would be made out of the same detectors that are used to track muons at the temporary premises of the IICHEP in Madurai. Called resistive plate chambers, or RPCs, each of these detectors has two parallel glass plates separated by a sealed gap of two millimetres that contains a gas mixture. When a charged particle passes through the mixture, it amplifies the signal by producing more charged particles.
The INO proposes to embed 30,000 such detectors in a 50,000-tonne magnetised iron structure called an Iron Calorimeter (ICAL), which would be as tall as a five-storey building. As the work at Kolar had shown, experiments to observe atmospheric neutrinos could be placed underground to filter out much of the cosmic rays that would otherwise form the background radiation. But instead of going underground, the INO proposes to build a cavern inside a hill in the Theni district, with about a kilometre of rock above shielding it from cosmic rays. Left in the open, the instrument is a muon detector; taken underground or otherwise shielded, it becomes a neutrino telescope. This is possible because on the rare occasion a neutrino does interact with matter, a charged particle is produced and which can be detected.
Neutrinos are the most abundant particles in the universe after photons, the particles associated with light. Those neutrinos created copiously in the Big Bang still surround us. Neutrinos are also produced from the decay of radioactive elements present naturally around us in the soil, inside the earth, and even in the food we eat. They could also be byproducts of the nuclear fission of radioactive elements inside nuclear power stations. But on Earth, the dominant source is the Sun, sending out 10 billion neutrinos through every squared centimetre. They are produced as part of the nuclear fusion processes that power the Sun. Explosions called supernovae that mark the death of massive stars are yet another source.
When physicists began studying a type of neutrinos produced in the Sun, called electron neutrinos, in the mid-1960s, they encountered a mystery. Only about one-third of the expected number were found to be arriving on Earth. This so-called solar neutrino problem baffled scientists for more than thirty years till experiments found that the total number of neutrinos – when one included the other two kinds of neutrinos, muon and tau neutrinos – added up to the expected number. Follow-up experiments ruled out alternative explanations and the conclusion was that neutrinos were changing from one type to the other while travelling from the Sun to the Earth, a process called neutrino oscillation. The phenomenon, however, implied that neutrinos must have a rest mass, contrary to the Standard Model’s prediction that they were massless. It was an indication that the model was incomplete.
Since the 1960s, physicists have meticulously built up the Standard Model, a framework of mathematical and physical rules to describe the properties and behaviour of fundamental particles in a self-consistent way. It contains a web of theories and equations connecting the character of each particle with another. Even if one strand of this web snaps, the entire model will have to be reworked because reconnecting the strand in a different way will reconfigure all other strands. And discovering that neutrinos had mass was one such moment. It highlighted the need for physicists to relook everything else they didn’t know about neutrinos – including, but especially, the neutrino-mass hierarchy. Now that neutrinos were known to have masses, and that they came in three kinds, which neutrino was the heaviest and which the lightest? Other questions were: Why did they come in three types and not two or four? Why is it so very light? And is the neutrino its own antiparticle?
At the mathematical heart of this problem was a 3 × 3 matrix – a grid of nine values that fit into different equations to yield answers for different questions. Of them, six were particularly relevant to determining the mass hierarchy.
Three of them, called mixing angles, determine how the three flavours of neutrinos mix. One of these angles, called theta-13 (pronounced theta-one-three), was determined in 2012. But the fundamental problem of neutrino mass hierarchy remains, and the principal goal of the INO is to solve it.
It turns out that neutrino oscillation is different if the neutrino travels through matter as opposed to a vacuum. Because of this matter effect, the number of muon neutrinos reaching the detector from below, after having passed through the earth, will be different from the number that reaches it from above, after having travelled through only the atmosphere. Moreover, this up/down ratio differs for antineutrinos.
What makes the INO unique is its ability to distinguish the muons and anti-muons that the neutrinos and antineutrinos, respectively, would generate in their rare interactions with the atoms of the detectors. Their opposite electric charges mean that the muons and anti-muons would leave distinct tracks due to the magnetic field applied on the ICAL. This distinction enables the physicists to determine the oscillation probabilities and hence the relative ordering of the mass states.
Neutrinos also pass through the ground unhindered. The strong nuclear force that binds together the constituents of atomic nuclei does not affect leptons, the family of particles of which the electron is the most familiar member. The neutrino is also a lepton. Carrying no electric charge, neutrinos don’t interact via the electromagnetic force. And gravitation, being a very feeble force, is not important at subatomic scales. This leaves the weak force as the only mechanism by which neutrinos interact with matter. As far as they’re concerned, matter is pretty much open space.
Last year’s Nobel Prize for physics was awarded jointly to the leaders of two neutrino observatories, in Canada and Japan, for discovering neutrino oscillations. One of them, Arthur McDonald, present at the Royal Society London in December to commemorate the fifty years of atmospheric neutrinos, was in Mysore this January at the Indian Science Congress. “In your lifetime, you will perhaps have one atom changed by a neutrino,” he said at a talk, trying to describe the impact of the particle on human beings, “which will have no influence on you whatsoever.”
Vaiko argued otherwise in his affidavit. A reading of the petition reveals that many of the allegations are the same as those originally made by the Kerala-based activist V.T. Padmanabhan, who has a long history of grievances with the Department of Atomic Energy (DAE). It is a distrust shared by G. Sundarrajan, a graduate in engineering and one of the trustees of Poovulagin Nanbargal, an environmental organisation. Its name is Tamil for “friends of flora”.
Less than a month after Vaiko read his affidavit in the Madurai court, Sundarrajan filed an appeal at the National Green Tribunal (NGT) against the environmental clearance that had been granted to the project in June 2011. The Wire met him in Chennai this January.
The organisation (he objects to the ‘NGO’ descriptor) is run out of a bookstore and publishes a magazine in Tamil. In tandem with the NGT case, Poovulagin Nanbargal had emblazoned its February 2015 magazine cover with a photo of the INO site and a prominent nuclear radiation symbol hanging beside it. “Both the national parties do not have any chance to come to power in Tamil Nadu,” he says at one point, “so they want to dump all the destructive projects in Tamil Nadu.”
An environmental clearance can be appealed before the NGT only within a window of 30 days. Sundarrajan bases his appeal, filed more than three years later, partly on the claim that the clearance granted in June 2011 wasn’t advertised in the local newspapers, as is the requirement. But copies of the advertisement published in local newspapers in the same month, both in English and in Tamil, were seen by The Wire.
It becomes apparent, both from our conversation and from the NGT appeal, that Poovulagin Nanbargal sees the INO as a continuation of what it perceives as the high-handed policies and the often opaque nature of the DAE. Sundarrajan says the attitude is handed down from Homi Bhabha. “He was very bold enough (sic) to say that the success of Indian atomic energy establishment lies in its caste system,” Sundarrajan said, “He was very arrogant. So it is [in] their DNA.” The Wire was not able to independently confirm the veracity of the statement attributed to Bhabha.
It appears that the DAE’s insensitive functioning, from Jaduguda to Kudankulam, has come back to haunt them. Jadugoda has been mined for decades for uranium, reportedly poisoning the area. The violent crackdown by the government on protesters against the Kudankulam nuclear power plant in 2012, which left at least one person dead, seems to have polarised the activists. Another issue is that the Atomic Energy Regulatory Board, the oversight body for nuclear plants, itself comes under the DAE, creating further distrust. “Close down DAE,” says Sundarrajan at another point. “We don’t want that department.”
But the DAE is also a major funder of basic science in India, powering institutes like the TIFR in Mumbai and the Institute of Mathematical Sciences (IMSc) in Chennai. The latter is at the forefront of the INO collaboration and is an unlikely institution to be caught in legal proceedings. A senior scientist, affiliated neither with the IMSc nor the INO, described the researchers there as “down-to-earth fellows who keep a low-profile and do good work”. The celebrated physicist E.C.G. Sudarshan was once its director, and the institute, which celebrated its 50th anniversary in 2012, has quietly built its reputation. The lobby of the main building has a blackboard on which is inscribed the Hindi word of the week. On the day The Wire visited, the word was vishwas, Hindi for belief.
The activists appear keen to extend the DAE’s tainted image to D. Indumathi, a physicist at IMSc and one of the spokespersons for the INO, and others. This is a particularly jarring accusation given that, more than most physicists, she has been active in outreach as a member of the Tamil Nadu Science Forum and also runs a children’s science magazine.
Because of her fluency in Tamil, Indumathi led much of the outreach efforts at the villages surrounding the site in Theni and at the colleges in nearby towns. Numerous TV interviews and explainers later, she’s been forced to cope with it through desperate humour. “If you don’t laugh about it, you’ll go mad,” she says.
A sense of the kind of questions Indumathi may have had to go through comes when Sundarrajan uses the phrase ‘artificial neutrinos’ at the meeting. Choudhary, the Delhi University professor, seems to mentally splutter when The Wire puts this coinage to him. “A particle is a particle,” he says, slightly at a loss for words, “There is no artificial neutrino, it is a neutrino.”
What Sundarrajan is referring to and contrasting is neutrinos that come from sources like cosmic rays and neutrinos produced through specific techniques, for example, smashing protons onto a graphite target at accelerators such as at Fermilab in the US. But it’s emblematic of the carelessness with which words are used and science is glossed over.
This claim is repeated in Vaiko’s petition, too, wherein he says there’s a difference between natural and “factory-produced” or “artificial” neutrinos. The contention is that neutrinos produced at such so-called factories are radioactive (and that they are going to be beamed to Theni, zapping it in a kind of cruel experiment). This exasperates Choudhary. “Anyone who tells that [the] neutrino gives radiation is either ignorant of basic physics or is on some kind of hallucinatory drugs,” he says.
Sundarrajan cites a 1999 paper titled “Potential hazards from Neutrino Radiation at Muon Colliders” to make his case. The paper, however, talks about potential radiation from the flux produced in a muon collider in the neighbourhood of the accelerator site. The neutrinos themselves are going to be detected thousands of kilometres away. It is as if, Choudhary told The Wire, “a bullet is fired in Chennai and I am worried about it in Delhi.”
Muon colliders don’t exist at present and still face technical challenges. Long baseline experiments such as at Fermilab use beam neutrinos produced by conventional particle accelerators. Protons accelerated to a high energy are made to strike a target, producing charged particles known as pions that then decay to muons and neutrinos. Before they leave the accelerator site, the muons either decay to produce more neutrinos or filter out leaving only neutrinos to travel to the far-end detector. Atmospheric neutrinos are born in a similar process, except that the initial high-energy protons arrive from outer space.
This idea of the INO as a far-end detector of a beam of neutrinos from elsewhere is what has activists alarmed. There were proposals on paper in the mid-2000s where INO was to be a detector for a neutrino beam sent from Fermilab in the US, or from CERN in Switzerland. The long distance travelled by the neutrinos, termed a long baseline, would have helped in determining the mass hierarchy by allowing easier observation of their oscillations.
However, in 2012, the Daya Bay Chinese neutrino experiment showed a much larger value for theta-13 than expected. This meant that a long baseline wouldn’t be required. “The larger the value [of theta-13], the smaller the distance you need to travel,” says Choudhary. Put another way, “If the probability of oscillation is low, then you need to allow longer distance. Now the probability is not that low.”
This means that the plans for the INO to receive a neutrino beam are now shelved. “There is no discussion today on the table for the next 20 years of sending a beam to India,” says Choudhary, “and there is nothing in future.”The INO whitepaper, available on the arXiv server and dated May 2015, does not mention the long baseline concept at all in its abstract.
Apart from radiation, there’s a second cluster of surprising fear-mongering – concerns that the construction of the tunnel and the cavern would cause earthquakes. There is, for instance, an attempt to draw parallels with another underground laboratory in Italy, Gran Sasso. As a rebuttal to Padmanabhan’s allegations in Current Science pointed out, this is comparing chalk and cheese – the rock in Gran Sasso is limestone whereas that in Theni is a much harder type known as charnockite. One allegation is that the construction of the tunnel and the cavern would disrupt the groundwater aquifers. This is again an irrelevant issue as the tunnel will be constructed under the hill, not underground. In any case, charnockite is not a rock that sustains aquifers.
Yet another allegation is that earthquakes could be triggered because the region falls in a ‘shear zone’. The region, in fact, falls in seismic zone 2, the safest zone in India, not 35 as claimed by Vaiko in the petition – no such classification even exists. It led the secretary of the DAE, Sekhar Basu, to remark in the counter-affidavit upon the “utter carelessness with which the allegations have been levelled.”
Kusala Rajendran, a geologist at the Indian Institute of Science, confirmed that the Western Ghats do not have any active geological faults, and to allege that an earthquake would be induced by localised blasting near the surface is baffling. There are several hydroelectric power projects in the nearby Idukki district of Kerala, just over the hill on the other side, with kilometres of tunnels.
A legitimate issue regarding the environmental clearance emerged after the filing of the writ petition and the NGT appeal. A rule change that came into effect on July 1, 2010, required that the final environmental impact assessment report submitted for any project must be prepared by a consultant that is accredited by the Quality Council of India. For the INO, an ecological impact assessment, the final report of which was submitted in November 2010, was done by the Salim Ali Centre for Ornithology and Natural History (SACON). And this, the activists pointed out, wasn’t accredited. Scientists from the INO collaboration say that this is fine because they themselves presented the SACON report – along with a Detailed Project Report prepared by TANGEDCO and a geotechnical report prepared by the Geological Survey of India – before the expert appraisal committee for environmental clearances. Legal experts consulted by The Wire, however, say that the requirement of accreditation for the consultants that prepared the individual reports still applies.
“Withdraw that report, get a new environmental report, put this new environmental report before the public. Let the public decide,” says Sundarrajan. “Who am I to tell the people of Theni, it’s not me.”
The day The Wire was in Theni, there appeared a news report about Udayakumar, an activist who led the protests against the Kudankulam nuclear project, who spoke on the INO at a function in the district. He alleged that the DAE secretly plans to use the INO site as a nuclear waste dump, seemingly deriving from earlier suspicions that the Kolar mines were to be used for this purpose. He went further and claimed that this is all part of a conspiracy involving the US. Vaiko made similar allegations in his affidavit, claiming that the project’s “mandate is to provide information on the quality of neutrinos detected at INO… more or less like a hospital undertaking drug trials.”
Past the district centre of Theni, one comes to the town of Bodinayakanur. This is the assembly seat occupied by O. Panneerselvam, who was briefly Chief Minister of Tamil Nadu when Jayalalithaa was jailed. “People will not vote for him if he allows the project to come up,” Sundarrajan had told The Wire. He added that he doubts the TNPCB clearance will come through before the elections, which have now been set for May.
Travelling further, the road narrows as one leaves the national highway. Vehicles drive over millet stalks laid out on the road for threshing. On either side, clusters of windmills dot the green landscape. As we leave the state highway and approach the villages that neighbour the INO site, we see numerous roadside shrines and several small temples. Reports surfaced last year of police preventing villagers from celebrating festivals at one of these temples. Then we come across a trail that, The Wire was told, would bypass the villages and lead directly to the site. But construction of that road is yet to begin. Finally we arrive at the bus stop in the village of T. Pudukottai, where a trail leads off the tarred road to the INO site.
The immense, broad peak, blanketed by green in its lower reaches, dominates our view once we reach a clearing at the end of the trail. To get closer, one has to cross a dry stream across which lies a partially constructed pillar for a bridge. Beyond that is a fenced area of 66 acres which would contain the entrance to the tunnel that burrows into the tallest peak.
There’s a gate, which, on the day The Wire visited, was open. Villagers led their herd of goats into and out of it. The smell of fresh dung permeated the area.
The peak which is proposed to be tunnelled into is flanked on its right by a shorter one. The Wire was told that there’s a temple on top of this shorter peak, but it isn’t visible from below. In March last year, after the Madras HC passed an order staying the construction, the villagers were reportedly stopped by the police from going up to the shrine to offer prayers. Mondal and Inbanathan say they don’t know why the police were present at all and that they made it clear there are no restrictions on entering the fenced area, for now. They also say the shrine can be accessed by an alternative route that doesn’t pass through the fenced area.
It is clear that once the construction begins, the villagers would lose access to a part of their grazing land. The scientists say these concerns had indeed been raised during their interactions before the environmental clearance was granted in 2011, and that the villagers were convinced that there will be no restrictions on grazing on the land outside the fenced area. It is curious that these issues have resurfaced after four years. The villagers also appeared worried by claims by Vaiko and the activists that radioactive contamination of the area would destroy all the vegetation and that women would suffer miscarriages.
In 2009, when the site at Singara was being debated, G. Rajasekharan, former director of IMSc, wrote in The Hindu warning that the moment was passing. Not long afterward, a group of international scientists, some of them Nobel laureates, wrote to the PM saying, “any further significant delay will be very detrimental to the success of the whole project, and may indeed make the project moot.” This is because the INO is hardly alone in its pursuit; there is today a “neutrino industry”, as one physicist puts it. With the delays, it may be too late for the INO to be the first to determine the mass hierarchy. An ongoing beam experiment in the US, named NOvA, or a reactor experiment being built in China, JUNO, have become likelier candidates to nail it down first.
However, as with Kolar, there will still be value in doing the experiment. The data from the INO would complement, and add to, those from other experiments worldwide. Beyond that, there is value in building a frontline science experiment from scratch, entirely indigenously. “Even if we can’t discover first,” says Indumathi, “to build something hands-on is so important.”
Choudhary, who collaborates extensively with US and European high energy experiments, agrees. Those experiments are not designed by Indian physicists and students don’t get to work on the hardware, being mostly involved in data analysis. “When we go abroad we are a cog in the wheel,” he says. “We are not the engine.”
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