മലയാളം ലിങ്കില് ക്ലിക് ചെയ്ത് വായിക്കാം
കോലാര് ഖനികളില് നിന്നും പൊട്ടിപ്പുറത്തേക്കുള്ള ദൂരത്തിനിടയില് സംഭവിക്കുന്നത് - ഇന്ത്യാധിഷ്ഠിത ന്യൂട്രിനോ നിരീക്ഷിണാലയത്തെ കുറിച്ച് നിരീക്ഷാലയത്തിന്റെ വക്താവ് പ്രൊഫസ്സര് നബ കെ. മണ്ഡലുമായി നടത്തിയ അഭിമുഖ സംഭാഷണം.
പ്രൊഫസ്സര് നബ കെ. മണ്ഡല്/ഡാലി
1.A long awaited dream of indian scientific community of having an India based Neutrino Observatory (INO) is going to be fulfilled in this 12th plan. Could you give a brief summary about the background of the project and how it was conceived ?
The India-based Neutrino Observatory (INO) is a proposed pure-Science underground laboratory. Its primary goal is to study the properties and interactions of weakly interacting particles, called neutrinos. Neutrino is the second most abundant particle in the universe. The most abundant being the photon – quanta of light. There are roughly 300 neutrinos in every cubic cm of our universe. Originally neutrinos were thought to be massless. However recent experiments elsewhere in the world have shown that neutrinos have tiny mass. This discovery has wide ranging implications in our understanding of astrophysics as well as particle physics. As a result, neutrino physics is the most exciting area of research in particle physics today. India has a long tradition in neutrino research. In fact,the first ever detection of cosmic ray produced neutrino took place in a deep underground laboratory at Kolar Gold fields. Unfortunately the KGF mines closed down around 1990. However in view of the importance of the neutrino physics, it was widely felt by the Indian scientific community that we must revive neutrino research in India. The issue was raised again in a meeting of the particle physics community held at Institute of Mathematical Sciences, Chennai in January 2000. In 2002, a proposal was presented to the Department of Atomic Energy, Govt. of India which laid out an ambitious goal of establishing an Indian-based Neutrino Observatory, outlining the physics goals, possible choices for the detector and their physics reach. An MoU was signed by seven Indian institutes as early as August 2002 started this project. In 2005 a project report detailing the project was submitted by INO collaboration to DAE and DST requesting R & D funds. The project was also discussed by the Scientific Advisory Council to the Prime Minister chaired by eminent Indian scientist Prof. C. N. R. Rao on 27th August, 2005 and approved. Over the next 6-7 years the INO collaboration was involved in various R & D efforts and was also looking for a suitable site with the help from Geological Survey of India.
2. As you said, an neutrino observatory is not new for India. It was in Kolar gold mines we first detected the atmospheric neutrino. Could you tell us about this old laboratory which had been working under T.I.F.R?
Dr. Homi Bhabha who founded Tata Institute of Fundamental Research was instrumental in creatingthe underground laboratory at KGF to study cosmic rays way back in 1952. He asked the former Director of TIFR, Prof. B.V.Sreekantan then a Ph.D. student working with him to go to KGF, setup the underground laboratory and study the properties of muon, a cosmic ray particle not well understood till that time. Prof. M.G.K.Menon, another former director of TIFR later joined Prof. Sreekantan and along with few other scientists formed an excellent group conducting experiments at various depths at KGF . Looking at the possibility of doing front ranking experiments in particle physics using cosmic rays, scientists from UK and Japan joined them in KGF and together they built a detector which was used to detect the atmospheric neutrino in 1965. This laboratory apart from detecting the atmospheric neutrinos was also used to look for the stability of the proton and to search for magnetic monopoles.
3.What is the reason behind the closing of the lab at Kolar gold mines?
Kolar gold mines was one of the deepest and oldest mine in the world. It was operational for morethan 120 years. During the last 10-15 years of its existence, the mine was making heavy lossescontinuously due to reducing deposits and increasing costs of mining gold bearing rocks fromdeep levels. Every mine in the world has to have a life span. KGF was no exception. So by 1990 the Bharat Gold Mines limited decided to close down the mining activities at KGF in a phased manner. Closing down activities at KGF started in 1991 and completed in 2001. As a result the Underground laboratory was also closed down.
4. How long has it taken, after closing of Kolar lab, to formulate the idea and work out the plans for another neutrino observatory in India? What are the difficulties that came across during the process?
The discussion for developing a new underground laboratory in India started as soon as it became clear to the scientific community that KGF is going to be closed down. The first discussion meeting took place in 1989 itself. Since then this question has come up, off and on in many discussions. However the idea of setting up a new underground lab in India to study neutrinos got a boost after the discovery of neutrino mass. It was realised that a new set of experiments are required to completely understand the properties of neutrinos and its implication in astrophysics and particle physics. In 2002, the INO collaboration was formed. A committee was setup with scientists, engineers and geologists to identify a suitable location for setting up a new underground laboratory.We also started various R & Ds needed to finalise the detector configuration and to develop the required technologies in house.
5. What are the benefits to Indian scientific community, once INO is materialized?
What does one expect from a mega science project like INO ? Certainly excitement for carrying out front ranking research in the area of neutrino physics is the prime motivation. The magnetised detector that we are going to setup will address one of the key questions in the field of neutrino physics today. i.e. mass hierarchy. This in turn will guide us to pick up correct theory beyond our current knowledge in particle physics. How the matter behaved at extremely high energies as it existed at the early stage of our universe. In the process of building this massive detector we will develop various cutting edge technologies, state of the art particle detectors, the massive 50 kton magnet, sophisticated electronics, online monitoring and data acquisition system. Students will have the opportunity to participate in building each of these components from scratch. In fact some of them are already doing that. Industries will be involved in a big way in developing many of these tools. So the benefits will go beyond just doing front ranking basic research. It will create an ambiance of developing technology, doing things with your own hands. A culture that is lacking in India.
Another important aspect of such a mega science project is that no single institute in the country has the ability or resources to do it alone. It has to be a collaborative enterprise. In fact already about 25 research institutes, IITs, universities from all over India have joined hands to make INO a success. Everybody is pitching in with the resources and expertise they have. Some are developing detectors, some electronics, some are working on various engineering aspects and some are optimising the detector through computer simulation. This culture of collaboration and cooperativeness is another benefit that emerge out of such large mega science project.
We do hope when we complete the INO project, we will have a scientifically richer nation.
6. It is not only Indian Scientific Community who are putting their hope on INO. The International community too is looking forward to INO. What are the main expectations of the International scientific community from INO?
INO-ICAL detector is complementary to the other existing as well as proposed neutrino detectors in the world. Because it is a magnetised detector, it will be able to separate out the neutrino events and anti-neutrino events. This in turn will be useful to understand the mass ordering of the neutrinos, i.e. which one of the three neutrinos is the lightest and which one is the heaviest. At the present time out of all the proposed and existing neutrino detectors around the world, INO –ICAL is most suitable to answer this question. The global neutrino community is therefore looking forward to INO finding this answer.
7.Were there any international interventions for establishing INO? If so, what are they?
Most important aspect of any scientific research is the international peer-review. Whenever an individual or a group of scientists proposed an experiment it is customary to get it reviewed by a group of international experts . INO project was also reviewed by an international set of experts.
It was based on the review reports of these international experts, INO project was taken up by Indian funding agencies for funding. In addition at one stage a set of renowned scientists in the field of particle physics including Nobel laureates wrote to Indian Prime Minister supporting the project. These are only indications of the importance of INO-ICAL detector in the minds of world experts.
8.The iron calorimeter (ICAL) detector that will be installed in the INO will be the worldś most massive detector. What are the other research possibilities expected in the fields other than neutrino research during ICAL´s indigenous development?
The INO project will also lead to (i) Human Resounce Development in basic science research, (ii)contribute to the creation of highly skilled scientists for participation in future particle physics and astroparticle physics experiments. Development of various kinds of particle detectors and associated instrumentations in collaboration with local industry is a part of the INO project. Detectors developed by particle physicists over the years have found wide application in areas such as medical imaging, material science, industrial control and in geological survey. Application of particle detectors in medical imaging is a central goal of the INO project.
9.Indian scientific community is waiting for INO with high hope, as it is expected to make a lot contributions in the field of basic science. Inspite of these hopes and expectations, some people have been raising their fears and suspicions. For example, the article by V.S Achuthanandan in the Hindu and couple of other articles in various magazines after that. What are the measures taken by you, as a INO spokesperson, to clear these fears and anxieties?
It is very unfortunate that some people without any expertise in the field of particle physics or even physics are generating unwarranted fear in the minds of the people by misquoting and misreporting the findings of some technical papers out of context. These people also gave misleading information to Shri V.S. Achuthanandan. As soon as we heard about these unfortunate developments, we decided to conduct an extensive outreach program to inform the people of Kerala and specially to the science students of the state about the true nature of our project. Myself and the convener of our INO outreach program Prof. D. Indumathi from Institute of Mathematical sciences visited several universities and colleges in Kerala over four days and gave seminars explaining the true nature of this project. I also gave several interviews to reporters both from the visual as well as print media explaining the project details.
10.One of the main allegations about the INO project, which is going to be built under Department of Atomic Energy, is that it is quite secretive. Is it right? Are there any public awareness reports on this project? If so, where do we get those?
These are false allegations. In fact all information about the INO project is publicly available in our web page. www.ino.tifr.res.in.In this web page, one can find our responses to FAQs (Frequently asked Questions) about the project. It covers all aspect of the project including its science goal, its impact ( or nonimpact) on the environment, the details about the INO detector, why we need to conduct this experiment underground - everything were mentioned. We even have an outreach page there where we explain the project in various regional languages. Everything about INO project are in public domain.
11.What will be the environmental and socio-economical impact of INO? Have INO or any other agency done any studies on these ? If so, what are they?
The site has been chosen and approved taking into account environmental and ecological factors, geological stability, and physics requirements. The Salim Ali Centre for Ornithology and Natural History (SACON), Coimbatore, prepared the Environmental Impact Assessment (EIA) report for this project. This report is also available in the INO Web page. The project has been discussed in detail at various levels with experts from the Tamil Nadu State Environment and Forest Department and the Ministry of Environment and Forests (MOEF), Government of India. A formal presentation was made to the Experts Committee of MOEF in January 2011. Based on these, the project has now been given both environmental and forest clearances.
12. It is stressed in the INO website that the entire site for the INO project is in Theni district of Tamil nadu. Still some people continue to argue that ´740´meters of tunnel, main cavern and three other observatories would be in Kerala. Their argument is based on the Sackon environmental impact studies which report that INO tunnel will lead to Kerala after 1700 meters of travel. Could you please give a detailed description of the site, cavern measurements and observatory site plan?
INO underground tunnel and the caverns are all located entirely inside Tamil Nadu close to the Kerala state border. It is a national project. Scientists from 25 research institutes, universities as well as IITs from all over the country are involved in this national basic science project. Why should govt. of India will secretly locate this laboratory inside Kerala ? This lab will be there for the next 50 years so. It is ridiculous to suggest that we are locating the lab inside Kerala without informing Govt. of Kerala.
13. Even if the INO project is completely inside Tamilnadu, it is very near to Idukki in Kerala. Don´t you think that environmental and socio-economical impact studies on these places are also necessary?
The Idukki dam is about 40 km from the project location. There will be absolutely no impact on the Idukki or any other dam due to the construction activities of the INO project. To appreciate the impact of tunnelling on dams, or more correctly non-impact, consider Pykara dam in the Nilgiris which is about 10-15 kms from the PUSHEP underground hydro-electric project which was commissioned recently in 2004. Nearly 13 kms of tunnels were constructed under the northern edge of Nilgiri mountains for the PUSHEP project below Glenmorgan forebay bringing waters from Pykara dam. No danger to Pykara dam was envisaged and has been reported. Furthermore, the Singara heritage power house built in 1932 is about 200m from the main access tunnel portal to the underground project. No damage was caused to this heritage dam during the construction of the tunnels and the underground powerhouse which took more than ten years to complete.
14. Singara and Suruli in Tamilnadu itself has been recommended as two other potential sites for INO. Why is Theni preferred over these two sites?
In fact the INO site selection committee originally identified Singara as the best site to locate the project. However in 2008, this site was declared as the buffer zone for the Tiger reserve and we were asked to find an alternate site. Both Suruli as well as Pottipuram sites were suggested to us by the Tamil Nadu forest department and Geological Survey of India. Since Suruli site was also close to an wildlife sanctuary, we opted for the Pottipuram site which is away from any wildlife sanctuary and also there will be no occupation of forest land.
15. INO caverns are designed to get a cover of more than 1000 meters of rock all around to house the detector and control equipments. For materializing this design, it is calculated that, INO will have to break approximately 8 lakh tons of rock. Blastings could cause vibrations up to 3 in the richter scale. The area around the Idukki dam which is close to the INO site has been known to be prone to quakes of 5.3 richter scale. Is it possible that the rock blasting could increase the probability of quakes in this area?
The tunnel and the underground caverns will be constructed using the technique of controlled blasting. This is normal for the construction of any road tunnel or even underground metro in big cities around the world. If one look at the FAQs in the INO website, there is a detailed graph on the magnitude of ground vibration due to controlled blasting. Infact while the blasting for the main cavern will take place, the ground vibration just at the top of the mountain which is just 1 km away from the blast site will be less then 1mm/sec for a couple of second. There is no way any one will feel the effect even few km away. The Idukki dam is at least 40 km away from the INO site. To give you another piece of information, there are more than 300 open stone quarries in the Idukki district alone ( as per Kerala Govt. statistics). All stone quarries use uncontrolled blasting techniques. If they are not a threat to the Dams in the area, how come INO construction which will mostly take place deep inside the rock can have any effect on the Dams in the area ?
16. What is the normal energy range of a neutrino? How do neutrinos from different sources differ in energy? Could you tell us about these different neutrinos and about their interactions. What is the probability that high energy neutrinos could lead to any sort of radiations ?
There are various sources of neutrinos with varying energy ranges. The neutrinos produced by the sun have energies in the range of 100 Kev to 20 MeV. Neutrinos produced by the cosmic rays in the earth’s atmosphere have energies in the range of 1 to 100 GeV with a falling spectrum. Neutrinos expected from any future neutrino factory will be also in the GeV energy range . There is no scope of neutrinos to be the source of any harmful radiation because neutrinos interact extremely weekly with matter. Yes neutrinos of higher energy will have higher probability to interact, but at the energies we are talking here for either atmospheric or neutrinos from a factory, they are extremely feeble. To give an example a neutrino need to zip through 10¹⁸ people placed one behind the other, it get it interact.
17.What would be the energy range of neutrinos, that are going to be observed in INO?
INO will observe atmospheric neutrinos with energies in the range of few to several tens of GeV. Even if we manage to get neutrino beam from a factory, its energy will again be in the range of 10-15 GeV.
18. Is it true that the interaction of high energy neutrinos with matter can produce hadron showers?
Hadron is just the name of one class of elementary particles like proton, neutron ( not neutrinos), pion etc. Similarly electrons, muons, neutrinos belongs to a separate class of particles called leptons. Hadron showers are the end product of high energy particle collisions. Millions of such hadron showers are being produced in our atmosphere due to cosmic rays colliding with air nucleus in our atmosphere every second. In fact we conduct experiments to detect such showers on the surface of the earth. Now since neutrino is also an elementary particle, in principle a very high energy neutrino can also produce a hadron shower. However as mentioned earlier since the neutrino hardly interact, its probability to produce a hadron shower is extremely small.
19. How are these hadron showers and particle showers produced? What is the intensity of radiation during those showers?
As mentioned above, hadron/particle showers are produced when energetic particles mostly hadrons collide with each other. Such showers are produced in particle accelerators when energetic beam of particles collide with each other. It also happens when energetic cosmic rays collide with air nucleus in the atmosphere of the earth. These showers are the source of cosmic radiation that reaches earth’s surface. The total radiation dose due to cosmic ray produced hadron showers are much below the limits prescribed for human body. More importantly, these showers exit whether you like it or not. Neither atmospheric neutrinos nor the factory produced neutrinos are sources of hadron shower of any consequence.
20. What will happen to the iron of the calorimeter after interacting with the neutrino? What will happen to the neutrinos which are not interacting with the detector?
Could you give us some numbers like the number of neutrinos that would be detected by the calorimeter? How does the radiation effects due to these compare with other natural radioactivity?
Nothing will happen to the iron of the calorimeter after interacting with neutrinos. It will remain as it is. In fact once the experiment is over, one can reuse the iron for other purpose. Most of the neutrinos will just go through the detector without any interaction. We expect about a thousand of atmospheric neutrino events per year inside the INO-ICAL detector. There is absolutely no radiation effect associated with these neutrino events. So no need to compare it with oher radiation sources.
21. Is there an area called neutrino health physics?
I have no idea what is the meaning of neutrino health physics. Neutrinos has nothing to do with health.
22.Are there any safety issues anticipated once INO is in the working mode? If so, what are the precautions INO would be implementing in this respect?
There will be normal safety issues like in any other research laboratory. We are mostly concerned with the fire issues. We need to be careful about accidental fire. Other than this we do not anticipate any safety issues.
23. Is there any sort of pollution expected from neutrino experiments?
No pollution is expected from neutrino experiments.
24. What are the experiments planning to be done in the INO other than neutrino observations, for eg. in biology and physics?
Other than INO-ICAL, there are two more proposals for setting up experiments in the INO lab. One is also using neutrinos, called neutrinoless double beta decay experiment. The other one is to detect dark matter. In fact since the underground lab will have fewer cosmic rays reaching there can be used for developing novel materials, to conduct special experiments in biology which may need low radiation environment. You should remember that inside the laboratory we will have much less radiation than in the surface of the earth.
25. Is it possible to use neutrino beams to inactivate a distant nuclear bomb? Are there any studies published on this aspect? What are possibilities of using a neutrino beam as a weapon?
I have seen a paper on using neutrino beams to inactivate a distant nuclear bomb. However in my opinion and in the opinions of many other specialists it is completely impractical.
26. Which are the foreign countries and foreign institutes collaborating with the INO project?
At present INO is a completely an Indian project. However, we are looking for International collaborations. Just as CERN is an international collaboration INO also looking for it.
27. What about the ´Hawai collaboration¨?
Sandip Pakvasa from Hawai- who is a theoretical neutrino physicist of Indian Origin (from baroda) is a strong supporter and enthusiast of INO project. who would like to see India developing such world class scientific project.
28.Could you please explain the so-called neutrino factory? Is there any relation between neutrino factory and the INO?
A neutrino factory is a particle accelerator complex proposed by the global neutrino physics community where beam of neutrinos pointing to a particular direction will be produced. The neutrino beam produced at the neutrino factory complex will travel through the earth and be detected in a neutrino detector several thousand kilometres away. Such a facility will be extremely useful to understand some of the fundamental properties of neutrinos, which in turn will help us to unravel some of the mysteries of nature like absence of antimatter in the universe.INO-ICAL detector can act as a neutrino detector for factory produced neutrinos if such a neutrino factory is built either in Europe or in Japan. So INO collaboration is interacting with the global neutrino community to pursue this possibility.
29. You are a member or IDS-NF steering group. The fourth plenary meeting of IDS was conducted at TIFR in September 2009. INO, IDF-NF, neutrino factory .. is there any ´relationship´ among them?
I have already mentioned that if a Neutrino Factory comes in Europe or in Japan then INO could act as a far detector for such a neutrino factory during its second phase. The International Neutrino physics community had setup a committee to coordinate neutrino factory related R & D activities in the world. This is how particle physics research is done internationally. This committee is called “International Design Study Group for the Neutrino Factory“ (IDS-NF). Since INO is also interested to get a neutrino beam from such a factory, if it is built either in Europe or in Japan, I have been made a member of this international committee. The full membership of this committee is available at the IDS-NF webpage hosted by Rutherford Lab, UK.
If one looks at the membership of this committee, one can realize that it is international in character, just as science is international. Scientists involved in basic research all over the world belong to a global community. They collaborate and communicate with each other all the time. IDS-NF meets periodically in different parts of the world. In this spirit of international cooperation and collaboration, we hold the 4th meeting of IDS-NF in India in 2009.
30. As a last question, it was V.S Achuthanandanś Hindu article that brought INO into the discussions. After that article you met V.S and has talked to him. What did he say? What is his stand on INO now?
From the new paper reports in September, 2012, we realised that Shri V.S.Achuthanandan has some misunderstanding about the INO project. So we met him during our last visit to Kerala and explained to him the true nature of the project. How the current generation of students interested in basic research will be benefited in having such a world class science laboratory in our country itself. After we explained the details of the INO project to him, he now has a very clear understanding on the true nature of the project. I found him a very pro-science person. He is certainly in favour of establishing such science labs in the country. His earlier opposition was due to some misinformation given to him by some one.