One news i heard that it is a biggest of all and also some scientists from kolakata also have the hands in that experiment....I shall continue later abt this
What is CERN?
CERN, the European Organization for Nuclear Research, is one of the world’s largest and most reputed institutions for scientific research. It was founded in 1954 and straddles the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures with a mission of providing “collaboration among European States in nuclear research of a pure scientific and fundamental character” without any “concern with work for military requirements”. CERN is run by 20 European Member States, but many non-European countries are also involved in different ways. Scientists come from around the world to use CERN’s facilities. India is an observer state at CERN, scientists from some 580 institutes and universities around the world use CERN’s facilities. CERN employs around 2500 people.
The Laboratory’s scientific and technical staff designs and builds the particle accelerators and ensures their smooth operation. They also help prepare, run, analyze and interpret the data from complex scientific experiments. Some 10,000 visiting scientists, half of the world’s particle physicists, come to CERN for their research. They represent 580 universities and 85 nationalities. The business at CERN is fundamental physics, finding out what the universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature. The tools used at CERN are particle accelerators and detectors. Accelerators boost beams of sub atomic particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.
CERN's accelerators and detectors require leading edge technologies. Industrial spin-offs in several domains are now incorporated in our daily lives. Cancer therapy, medical and industrial imaging, radiation processing, electronics, measuring instruments, new manufacturing processes and materials, the WWW, these are just some of the many technologies developed at CERN during research in particle physics.
Actually how many phases are there in this experiment? What happens at each phase?
Experiments in High Energy Physics have progressively evolved into being very complex to enormously complex. The Large Hadron Collider (LHC) is a machine that was conceived in the early eighties when its predecessor accelerator (Large electron positron Collider, LEP) was being built. It was the foresight of scientists in those days (1982) who decided that the tunnel should be 27 km in circumference so that a future upgrade would be possible, and the overheads of digging the tunnel were minimized. LEP was operational from 1989 to the year 2000, followed by LHC installation and commissioning commenced in full swing. It saw first beams on Sep 10, 2008 with live coverage on Eurovision. This historic event marks a transition from over two decades of preparation to a new era of discovery.
On Sep 10th the first beam of protons started steering around the tunnel. How much time these protons take to get accelerated to the velocity of light?
On September 10 at 10:28 the first proton beams were steered successfully around the 27 km path around the LHC tunnel. The same evening the second beam of protons were triumphantly exiting the finish line in the counter clockwise direction. Starting up a major new particle accelerator takes much more than flipping a switch. Thousands of individual elements have to work in harmony, timings have to be synchronized to under a billionth of a second, and beams finer than a human hair have to be brought into head-on collision. This initial success puts a tick next to the first of those steps, and over the next few weeks, as the LHC’s operators gain experience and confidence with the new machine, the machine’s acceleration systems will be introduced, and the beams will be brought into collision to allow the research program to begin.
In parallel, since 1989 itself, scientists have been designing experiments with ‘the digital cameras for sub atomic viewing’ which will be able to “see” these collisions. Millions of digital cameras put together in an onion like structure meaning many layers cover hermetically the collision point, so that we don’t let any information leak from the collision. All particles are formed for a trillionth of a second from the energy of the smashing particles, remember the famous equation from Einstein E=mc2? And then in a trillionth of a second disappear back into energy. Capturing this process closely is the business of the four experiments located on the LHC. These experiments flagged the passage of the “beam” on 10th of September, and with that instant began an epoch of ‘data taking’ during which scientists will continue to work 24 hours 7 days a week to ‘catch’ each and every collision that will happen in the LHC machine. For some scientists like me, this is one experiment for my career and lifetime.
Experiments at the LHC will allow physicists to complete a journey that started with Newton’s description of gravity. Gravity acts on mass, but so far science is unable to explain the mechanism that generates mass. Experiments at the LHC will provide the answer. LHC experiments will also try to probe the mysterious dark matter of the universe – visible matter seems to account for just 5% of what must exist, while about a quarter is believed to be dark matter. They will investigate the reason for nature’s preference for matter over antimatter, and they will probe matter as it existed at the very beginning of time.
LHC is the largest machine in the world, the precise circumference of the LHC accelerator is 26659 m, with a total of 9300 magnets inside. Not only is the LHC the world’s largest particle accelerator, just one-eighth of its cryogenic distribution system would qualify as the world’s largest fridge. All the magnets are precooled to minus 193.2°C (80 K) using 10 080 tonnes of liquid nitrogen, before they are filled with nearly 60 tonnes of liquid helium to bring them down to -271.3°C (1.9 K). At full power, trillions of protons will race around the LHC accelerator ring 11 245 times a second, travelling at 99.99% the speed of light. Two beams of protons will each travel at a maximum energy of 7 TeV (tera-electronvolt), corresponding to head-to-head collisions of 14 TeV. Altogether some 600 million collisions will take place every second.
To avoid colliding with gas molecules inside the accelerator, the beams of particles travel in an ultra-high vacuum – a cavity as empty as interplanetary space. The internal pressure of the LHC is 10-13 atm, ten times less than the pressure on the Moon!
The LHC is a machine of extreme hot and cold. When two beams of protons collide, they will generate temperatures more than 100 000 times hotter than the heart of the Sun, concentrated within a minuscule space. By contrast, the 'cryogenic distribution system', which circulates superfluid helium around the accelerator ring, keeps the LHC at a super cool temperature of -271.3°C (1.9 K) – even colder than outer space!
To sample and record the results of up to 600 million proton collisions per second, physicists and engineers have built gargantuan devices that measure particles with micron precision. The LHC's detectors have sophisticated electronic trigger systems that precisely measure the passage time of a particle to accuracies in the region of a few billionths of a second. The trigger system also registers the location of the particles to millionths of a metre. This incredibly quick and precise response is essential for ensuring that the particle recorded in successive layers of a detector is one and the same.
The data recorded by each of the big experiments at the LHC will fill around 100 000 dual layer DVDs every year. To allow the thousands of scientists scattered around the globe to collaborate on the analysis over the next 15 years (the estimated lifetime of the LHC), tens of thousands of computers located around the world are being harnessed in a distributed computing network called the Grid.
When can we say that this experiment is over?
Technically speaking it is foreseen that the experiments that are being conducted using the LHC machine will continue for at least 15 to 20 years. Breakthrough discoveries are expected in a few years, while finer analyses will continue for many many years.
What are the benefits the world will enjoy when this experiment is successfully completed?
This is an experiment which has followed directly from the curiosity of mankind, a look back over the last 100 years of physics reveals an era of finding answers to an amazing set of questions. Some answers feed directly into technological growth leading to a complete transformation of our lives: the story of the transistor illustrates one transformation. Life without computers is now as unthinkable just like a computer without miniaturized silicon components which came straight from the physicist’s laboratory.
Some areas of scientific research, such as particle physics and cosmology, seem remote from everyday life and unlikely to bring immediate practical applications. Are they worth the effort in human and material resources? This research may take us far away from the conditions of everyday life, but because it continually pushes at boundaries in thinking and in technology it is a springboard for many new developments.
Fundamental science is where new ideas and methods begin that later become commonplace - from the electric light, which originated in 19-century curiosity about electricity, to the World Wide Web, invented at CERN to allow international teams of particle physicists to communicate more easily. No amount of applied research on the candle would have brought us the electric light; no amount of R&D on the telephone would have brought about the Web. Science needs the space for curiosity and imagination. Benefits follow naturally.
After the completion of the experiment, can we reuse the equipment established at the LHC site?
Definitely, most of the hardware that was dismantled from LEP has been used elsewhere, either at CERN or at laboratories where students have profited from it.
How many Indian scientists are involved in this prestigious, once in a generation experiment?
Over 100 scientists collaborate with CERN from India from Institutions comprising
Aligarh University
BARC Bhabha Atomic Research Centre Mumbai
Institute of Physics, Bhubaneswar
Panjab University Chandigarh
University of Rajasthan
University of Jaipur
University of Jammu
University of Delhi
SINP Kolkata
TIFR Tata Institute of Fundamental Research
VECC Variable Energy Cyclotron Centre Kolkata
Any other information which clears the fears unnecessarily spread about this experiment among the common people....
The LHC can achieve energies that no other particle accelerators have reached before. The energy of its particle collisions has previously only been found in Nature. And it is only by using such a powerful machine that physicists can probe deeper into the key mysteries of the Universe. Some people have expressed concerns about the safety of whatever may be created in high-energy particle collisions. However there are no reasons for concern. Accelerators only recreate the natural phenomena of cosmic rays under controlled laboratory conditions. Cosmic rays are particles produced in outer space in events such as supernovae or the formation of black holes, during which they can be accelerated to energies far exceeding those of the LHC.
Cosmic rays travel throughout the Universe, and have been bombarding the Earth’s atmosphere continually since its formation several billion years ago. Despite the impressive power of the LHC in comparison with other accelerators, the energies produced in its collisions are greatly exceeded by those found in some cosmic rays. Since the much higher-energy collisions provided by nature for billions of years have not harmed the Earth, there is no reason to think that any phenomenon produced by the LHC will do so. Cosmic rays also collide with the Moon, Jupiter, the Sun and other astronomical bodies. The total number of these collisions is huge compared to what is expected at the LHC. The fact that planets and stars remain intact strengthens our confidence that LHC collisions are safe. The LHC’s energy, although powerful for an accelerator, is modest by nature’s standards. Although the energy concentration (or density) in the particle collisions at the LHC is very high, in absolute terms the energy involved is very low compared to the energies we deal with every day or with the energies involved in the collisions of cosmic rays. However, at the very small scales of the proton beam, this energy concentration reproduces the energy density that existed just a few moments after the Big Bang—that is why collisions at the LHC are sometimes referred to as mini big bangs.
Massive black holes are created in the Universe by the collapse of massive stars, which contain enormous amounts of gravitational energy that pulls in surrounding matter. The gravitational pull of a black hole is related to the amount of matter or energy it contains — the less there is, the weaker the pull. Some physicists suggest that microscopic black holes could be produced in the collisions at the LHC. However, these would only be created with the energies of the colliding particles (equivalent to the energies of mosquitoes), so no microscopic black holes produced inside the LHC could generate a strong enough gravitational force to pull in surrounding matter.
If the LHC can produce microscopic black holes, cosmic rays of much higher energies would already have produced many more. Since the Earth is still here, there is no reason to believe that collisions inside the LHC are harmful.
Black holes lose matter through the emission of energy via a process discovered by Stephen Hawking. Any black hole that cannot attract matter, such as those that might be produced at the LHC, will shrink, evaporate and disappear. The smaller the black hole, the faster it vanishes. If microscopic black holes were to be found at the LHC, they would exist only for a fleeting moment. They would be so short-lived that the only way they could be detected would be by detecting the products of their decay.
Radiation is unavoidable at particle accelerators like the LHC. The particle collisions that allow us to study the origin of matter also generate radiation. CERN uses active and passive protection means, radiation monitors and various procedures to ensure that radiation exposure to the staff and the surrounding population is as low as possible and well below the international regulatory limits.
For comparison, note that natural radioactivity — due to cosmic rays and natural environmental radioactivity — is about 2400 μSv/year in Switzerland. A round trip Europe–Los Angeles flight accounts for about 100 μSv. The LHC tunnel is housed 100 m underground, so deep that both stray radiation generated during operation and residual radioactivity will not be detected at the surface. Air will be pumped out of the tunnel and filtered. Studies have shown that radioactivity released in the air will contribute to a dose to members of the public no more than 10 μSv/year.
