# India-based Neutrino Observatory

India-based Neutrino Observatory (INO) is a particle physics research project under construction to primarily study atmospheric neutrinos in a 1,300 meters (4,300 ft) deep cave under Ino Peak near Theni, Tamil Nadu, India. This project is notable in that it is anticipated to provide a precise measurement of neutrino mixing parameters. The project is a multi-institute collaboration and one of the biggest experimental particle physics projects undertaken in India.[1][2][3][4]

The project was originally to be completed in 2015 at an estimated cost of 1,500 crores, has been cleared by the Ministry of Environment (India) for construction in the Bodi West Hills Reserved Forest in the Theni district of Tamil Nadu. Although delayed, the project is underway as of 2015.[5][6]

When completed, the main magnetised iron calorimieter (ICAL) experiment include the world's most massive magnet, four times larger than the 12,500-tonne magnet in the Compact Muon Solenoid detector at CERN in Geneva, Switzerland.[7][8]

## History and recent developments in the project

The possibility of a neutrino observatory located in India was discussed as early as 1989 during several meetings held that year. Since then this question comes up, off and on, in many discussions. The issue was raised again in the first meeting of the Neutrino physics and Cosmology working group during the Workshop on High Energy Physics Phenomenology (WHEPP-6) held at Chennai in January 2000 and it was decided then to collate concrete ideas for a neutrino detector.

Further discussions took place in August 2000 during a meeting on Neutrino Physics at the Saha Institute of Nuclear Physics, Kolkata, when a small group of neutrino physics enthusiasts started discussing the possibilities. The Neutrino 2001 meeting was held in the Institute of Mathematical Sciences, Chennai during February 2001 with the explicit objective of bringing the experimentalists and theorists in this field together. The INO collaboration was formed during this meeting. The first formal meeting of the collaboration was held in the Tata Institute of Fundamental Research, Mumbai, during 6 and 7 September 2001 at which various subgroups were formed for studying the detector options and electronics, physics goals and simulations, and site survey.

In 2002, a document was presented to the Department of Atomic Energy, (DAE) which laid out an ambitious goal of establishing an India-based Neutrino Observatory, outlining the physics goals, possible choices for the detector and their physics. Since then many new and fast paced developments have taken place in neutrino physics. The award of the Nobel Prize in Physics (2002) to the pioneers in neutrino physics is a measure of the importance of this field.

As a result of the support received from various research institutes, universities, the scientific community and the funding agency, the Department of Atomic Energy, a Neutrino Collaboration Group (NCG) was established to study the possibility of building an India-based Neutrino Observatory (INO). The collaboration was assigned the task of doing the feasibility studies for which funds were made available by the DAE. A memorandum of understanding (MoU) was signed by the directors of the participating institutes on August 30, 2002 to enable a smooth functioning of the NCG during the feasibility period. The NCG has the goal of creating an underground neutrino laboratory with the long-term goal of conducting decisive experiments in neutrino physics as also other experiments which require such a unique underground facility.[1]

On 20 November 2009, Ministry of Environment (India) Minister Jairam Ramesh in a letter to Anil Kakodkar, Secretary, Department of Atomic Energy and Chairman, Atomic Energy Commission of India, denied permission for the Department of Atomic Energy to set up the India-based Neutrino Observatory (INO) project at Singara in Nilgiris, as it falls in the buffer zone of the Mudumalai Tiger Reserve (MTR). Jairam Ramesh said that based on the report of Rajesh Gopal, Additional Principal Chief Conservator of Forests (PCCF) and Member-Secretary of the National Tiger Conservation Authority (MS-NTCA), the Ministry cannot approve the Singara site. The report says:

"The proposed project site falls in the buffer zone of Mudumalai Tiger Reserve and is in close proximity to the core/critical tiger habitats of Bandipur and Mudumalai Tiger reserves. It is also an elephant corridor, facilitating elephant movement from the Western Ghats to the Eastern Ghats and vice versa. The area is already disturbed on account of severe biotic pressure due to human settlements and resorts and that the construction phase of the project would involve transport of building materials through the highways passing through the core area of the Bandipur and Mudmulai Tiger Reserves.[9]

Instead, he suggested an alternate site near Suruli Falls, Theni District in Tamil Nadu. The Minister said this site did not pose the same problems that Singara posed and environmental and forest clearances should not be a serious issue. He also assured the DAE that the Ministry would facilitate necessary approvals for the alternative location. Dr Naba K Mondal of the Tata Institute of Fundamental Research, who is the spokesperson for the INO project said:

"But Suruliyar too is in a reserved forest area that is dense and would require cutting down of trees, something that was not required at Singara. Can the government assure us that forest clearance for this site will be given," he asks. "Alternatively, we can move to the nearby Thevaram, which is about 20–30 km away from the Suruliyar falls. This forest area has only shrubs but there is no source of water here and water will have to be piped over a distance of 30 km,"[9][10]

On 18 October 2010, the Ministry of Environment & Forests approved both environment and forest clearance for setting up the observatory in the Bodi West Hills Reserved Forest in the Theni district of Tamil Nadu.

As of February 2012, the land was allocated to the INO collaboration by the government of Tamil Nadu and the excavation work was about to start. Naba K Mondal, chief spokesperson of INO project and a senior scientist at the Tata Institute of Fundamental Research, Mumbai, told The Hindu that the pre-project work will start in April 2012 and 66 crores has been sanctioned for the work. The first task will be to have a road connectivity from Rasingapuram to Pottipuram village. The project is expected to be completed in 2015 at an estimated cost of 1,500 crores.[7][8]

On 18 September 2012, Kerala’s octogenarian Opposition leader and CPI(M) central committee member VS Achuthanandan expressed anxiety over establishing a neutrino observatory on the Theni-Idukki border between Tamil Nadu and Kerala, citing environmental and radiological issues.[11] Soon the INO collaboration clarified on all the issues raised by him and the responses are on the INO website.

On 5 January 2015, Union Cabinet headed by Prime Minister Narendra Modi approved to set up the India-based Neutrino Observatory (INO).[12]

On 20 February 2015, The southern bench of National Green Tribunal ordered notices to the central and state governments on a petition challenging the environmental clearance granted to the India-based Neutrino Observatory (INO) project. [13]

On 26 March 2015, The Madurai bench of the Madras high court restrained the central government from commencing the work on the proposed India-based Neutrino Observatory (INO).The court directed the government to get permission from the Tamil Nadu Pollution Control Board (TNPCB) before commencing the work.[14]

## Participating Institutes

Memorandum of Understanding (MoU) spelling out the operational aspects of the project and the mode of utilisation of available funds was signed by seven primary project partners: Tata Institute of Fundamental Research (TIFR), Mumbai, Bhabha Atomic Research Centre (BARC), Mumbai, Institute of Mathematical Sciences (IMSc), Chennai, Saha Institute of Nuclear Physics (SINP), Kolkata, Variable Energy Cyclotron Centre (VECC), Kolkata, Harish Chandra Research Institute (HRI), Allahabad and Institute of Physics (IOP), Bhubaneswar.[1]

Thirteen other project participants include: Aligarh Muslim University, Aligarh, Banaras Hindu University, Varanasi, Calcutta University (CU), Kolkata, Delhi University (DU), Delhi, University of Hawaii (UHW), Hawaii, Himachal Pradesh University (HPU), Shimla, Indian Institute of Technology, Bombay (IITB), Mumbai, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, North Bengal University (NBU), Siliguri, Panjab University (PU), Chandigarh, Physical Research Laboratory (PRL), Ahmedabad, Sálim Ali Centre for Ornithology and Natural History (SACON), Tamil Nadu and Sikkim Manipal Institute of Technology, Sikkim.

## Design

Chart showing 3 neutrinos and interacting particles, according to the Standard Model of Elementary Particles

The primary research instrument will consist of a 50,000 ton magnetised iron particle physics calorimeter with glass Resistive Plate Chamber (RPC) technology as the sensor elements.[1]

The ICAL design is mostly based on the monolith experiment that could not go beyond the proposal Stage. The detector was expected to start collecting data in the year 2012. The location of INO has attracted a lot of attention from the neutrino physics community as the distance between INO and CERN is very close to "Magic Baseline" – a distance at which the effect of the CP phase on the measurement of ${\displaystyle \theta _{13}}$ is minimal.[15] The project has been hit by lack of skilled manpower and opposition by environmentalists. In 2008, INO started a graduate training programme leading to PhD Degree in High Energy Physics and Astronomy to deal with the shortage of particle physicists. [16]

The Primary goals of the ICAL are the following: [17]

1. Unambiguous and more precise determination of Neutrino oscillation parameters using atmospheric neutrinos.
2. Study of matter effects through electric charge identification, that may lead to the determination of the unknown sign of one of the mass differences.
3. Study of charge-conjugation and charge parity (CP) violation in the leptonic sector as well as possible charge-conjugation, parity, time-reversal (CPT) violation studies.
4. Study of Kolar events, possible identification of very-high energy neutrinos and multi-muon events.

The ICAL detector consists of 6 centimeters (2.4 in) thick Iron plates as passive material, with RPCs in between as active material.

A prototype of the ICAL detector with 14 layers, measuring 1 m × 1 m × 1 m is already operational in the VECC, Kolkata. The 35 ton prototype is set up over ground to track cosmic muons. [18]

## Location

The originally proposed site was at Singara 11°32′N 76°36′E﻿ / ﻿11.533°N 76.600°E, 5.5 kilometers (3.4 mi) south-west of Masinagudi in the Nilgiri Hills of South India. The site has been changed due to protests from environmental groups. The INO will now be built 10 km east of Theni in southern India at 9°58′N 77°16′E﻿ / ﻿9.967°N 77.267°E[6]:2 Bodi West Hills in Theni district, Tamil Nadu state.[19]

## Notes and references

1. ^ a b c d Mondal, Naba K. (January 2004). "Status of India-based Neutrino Observatory (INO)" (PDF). Proceedings Indian National Science Academy. 70, A: 71–77. Retrieved 2008-04-03.
2. ^ Mondal, Prof. N K (July 2008). "FAQ on INO" (PDF). Institute of Mathematical Sciences, Chennai. Retrieved 2009-04-03.
3. ^ The Hindu (2005). "India gets ready with ambitious science project". Retrieved 2008-07-12.
4. ^ Youtube, Rajya Sabha TV (2014). "A Question of Science". Retrieved 2014-08-14.
5. ^ Majumder, Gobinda (4 March 2015). Status and perspectives of India based neutrino observatory (INO) (PDF). XVI International Workshop on Neutrino Telescopes. Venice.
6. ^ a b Acharya, B S (5 May 2015). Status of India-Based Neutrino Observatory (INO) (PDF). IceCube Particle Astrophysics Symposium (IPS2015). Madison, Wisconsin.
7. ^ a b http://www.ino.tifr.res.in/ino/neutrino-press-release.pdf
8. ^ a b http://www.newscientist.com/article/dn19620-indian-neutrino-lab-to-boast-worlds-biggest-magnet.html
9. ^ a b Ramachandran, R. (2009-11-21). "Ministry's 'no' to Neutrino Observatory project in Nilgiris". The Hindu. Chennai: Kasturi and Sons Ltd. pp. Front Page. Retrieved 9 December 2009.
10. ^ Madhusudan, M. (2009-11-22). "Centre no to neutrino observatory in Nilgiris". Sunday Pioneer. New Delhi: Pioneer Syndication Services. Retrieved 9 December 2009.
11. ^ "V S Achuthanandan flays proposed Neutrino observatory". The New Indian Express. 18 September 2012. Retrieved 2 May 2013.
12. ^ "Indian Neutrino Observatory set for construction". Physics World. Jan 7, 2015.
13. ^ http://timesofindia.indiatimes.com/city/chennai/Green-tribunal-issues-notices-to-Centre-state-on-neutrino-project/articleshow/46318216.cms
14. ^ Saravanan, L (26 March 2015). "Madras HC restrains Centre from commencing work on India-based Neutrino Observatory". The Times of India. Retrieved 2015-09-06.
15. ^ Agarwalla, S; Sanjib Kumar Agarwallaa; Sandhya Choubeya & Amitava Raychaudhuria (28 May 2007). "Neutrino mass hierarchy and θ13 with a magic baseline beta-beam experiment". Nuclear Physics B. ScienceDirect, Elsevier B.V. 771 (1–2): 1–27. Bibcode:2007NuPhB.771....1A. arXiv:. doi:10.1016/j.nuclphysb.2007.02.012.
16. ^ Unknown (2008). "Education updates". Retrieved 2008-08-17.
17. ^ INO collaboration (2007). "INO feasibility Study" (PDF). Retrieved 2008-07-10.
18. ^ B. Satyanarayana (2009). "INO prototype detector". Retrieved 2009-07-25.
19. ^ Michael Banks (19 October 2010). "Green light for Indian neutrino observatory". Retrieved 2010-10-19.