NEUTRINOS are teeny, tiny, nearly massless particles
that travel at near lightspeeds. Born from violent astrophysical events like
exploding stars and gamma ray bursts, they are fantastically abundant in the
universe, and can move as easily through lead as we move through air. But they
are notoriously difficult to pin down.
"Neutrinos are really pretty strange particles when you
get down to it," says John Conway, a professor of physics at University of
California, Davis. "They're almost nothing at all, because they have almost no
mass and no electric charge...They're just little whisps of almost nothing."
Ghost particles, they're often called.
But they are one of the universe's essential
ingredients, and they've played a role in helping scientists understand some of
the most fundamental questions in physics.
For example, if you hold your hand toward the sunlight for
one second, about a billion neutrinos from the sun will pass through it, says
Dan Hooper, a scientist at Fermi National Accelerator Laboratory and an
associate professor of astronomy and astrophysics at the University of Chicago.
This is because they're shot out as a byproduct of nuclear fusion from the sun -
that's the same process that produces sunlight.
"They're important to our understanding of the kind of
processes that go on in the sun, and also an important building block for
the blueprint of nature," Hooper said.
Particle physicists originally believed that neutrinos were
massless. But in the 1990s, a team of Japanese scientists discovered that they
actually have a smidgen of mass. This tiny bit of mass may explain why the
universe is made up of matter, not antimatter. Early in the process of the Big
Bang, there were equal amounts of matter and antimatter, according to Conway.
"But as the universe expanded and cooled, matter and antimatter were mostly
annihilated. And a slight symmetry favored matter over antimatter. We
think neutrinos may have something to do with that process.... And it's a
puzzle, why we're made out of matter and not antimatter."
Studying neutrinos is difficult. They're tough to detect
since they interact so weakly with other particles. But the newly-completed
IceCube Neutrino Observatory will study neutrinos inside a cubic kilometer block
of ice in Antarctica. Here's how: when the neutrinos interact with atoms inside
the deep arctic ice detectors, they sometimes give off puffs of energy.
"As neutrinos pass through and interact, they produce charged
particles, and the charged particles traveling through the ice give off light,"
Conway said. "That's how they're detected. t's like having a
telescope for neutrinos underground."
Fermilab National Laboratory has an experiment that hurls a
beam of neutrinos 400 miles underground from Wisconsin to Northern Minnesota in
about two milliseconds, and the lab is also planning a massive linear
accelerator called Project X that will study the subatomic particles by sending
them even farther.
"If 100 years ago, I told someone that the universe was
filled with massless, chargeless particles with no energy, I wonder if they'd
have believed you," Conway said. "Who knows where we'll be 100 years from now."
INDIA-BASED NEUTRINO OBSERVATORY
(INO) is a proposed particle physicsresearch project to
primarily study atmospheric neutrinos in a 1,300 meters (4,300 ft) deep cave
under Ino Peak near Pudukkottai, Tamil Nadu, India. This project is notable in
that it is anticipated to provide a precise measurement of neutrino mixing
parameters. The project is amulti-institute collaboration and one of the biggest
experimental particle physics projects undertaken in India.
The project, expected to be completed in 2015 at an estimated
cost of $250 million, 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. When completed, the INO will house 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.
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 firstformal meeting of
the collaboration was held in the Tata Institute of Fundamental Research,
Mumbai, during September 6 and 7th, 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 paceddevelopments 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
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.On November 20, 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- ased 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, AdditionalPrincipal 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
EasternGhats 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
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
"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,"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. The
project is expected to be completed in 2015 at an estimated cost of $250
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.
Thirteen other project participants include: Aligarh
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.
The primary research instrument will consist of a 50,000 ton
magnetized ironparticle physics calorimeter with glass Resistive Plate Chamber (RPC)
technology as the sensor elements.
The INO 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 θ13 is minimal. The project has been hit
by lack of skilled man power and opposition by environmentalists. In 2008,
INO started a graduate training program leading to Ph.D. Degree in High Energy
Physics and Astronomy to deal with the shortage of particle physicists.
The Primary goals of the INO are the following
Unambiguous and more precise determination of Neutrino
oscillationparameters using atmospheric neutrinos.
Study of matter effects through electric charge
identification, that may lead to the determination of the unknown sign of
one of the mass differences.
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.
Study of Kolar events, possible identification of
very-high energy neutrinos and multimuon events.
The INO 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 INO detector with 14 layers, measuring 1m x 1m x 1m is already
operational in the VECC, Kolkata. The 35 ton prototype is set up over ground to
track cosmic muons.
The location of the site was supposed to be Singara 11°32′N
76°36′E 5.5 kilometers (3.4 mi) southwest 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 at 9°57′14.299″N 77°16′47.561″E Bodi West
Hills in Theni district, southern India.