THE LARGE HADRON COLLIDER
1) What is l.h.c? 4
2) Design 5
3) Aim of l.h.c 6-7
4) How does l.h.c work? 8-9
5) Where is l.h.c? 10-11
6) Who benefits? 12
7) Latest news from l.h.c 13
Indian contributions in l.h.c 14
9) Future scope 15 10) Bibliography 16
WHAT IS LHC?
The Large Hadron Collider (LHC) is the world’s largest and highest-energy particle accelerator, intended to collide opposing beams of protons or lead ions, each moving at approximately 99.999999% of the speed of light
The LHC was built by the European Organization for Nuclear Research (CERN) with the intention of testing various predictions of high-energy physics, including the existence of the hypothesised Higgs boson and of the large family of new particles predicted by supersymmetry. It lies underneath the Franco-Swiss border between the Jura Mountains and the Alps near Geneva, Switzerland. It is funded by and built in collaboration with over 10,000 scientists and engineers from over 100 countries as well as hundreds of universities and laboratories.
On 10 September 2008, the proton beams were successfully circulated in the main ring of the LHC for the first time. On 19 September 2008, the operations were halted due to a serious fault between two superconducting bending magnets.Owing to the already planned winter shutdown, the LHC will not be operational again until the spring of 2009. The LHC was officially inaugurated on 21 October 2008, in the presence of political leaders, science ministers from CERN’s 20 Member States, CERN officials, and members of the worldwide scientific community.
Design
Map of the Large Hadron Collider at CERN
The LHC is the world’s largest and highest-energy particle accelerator.The collider is contained in a circular tunnel, with a circumference of 27 kilometers (17 mi), at a depth ranging from 50 to 175 meters underground.
The 3.8 m wide concrete-lined tunnel, constructed between 1983 and 1988, was formerly used to house the Large Electron-Positron Collider. It crosses the border between Switzerland and France at four points, with most of it in France. Surface buildings hold ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.
Aim of L.H.C:
The LHC will allow scientists to probe deeper into the heart of matter and further back in time than has been possible using previous colliders.
Researchers think that the Universe originated in the Big Bang (an unimaginably violent explosion) and since then the Universe has been cooling down and becoming less energetic. Very early in the cooling process the matter and forces that make up our world ‘condensed’ out of this ball of energy.
The LHC will produce tiny patches of very high energy by colliding together atomic particles that are travelling at very high speed. The more energy produced in the collisions the further back we can look towards the very high energies that existed early in the evolution of the Universe. Collisions in the LHC will have up to 7x the energy of those produced in previous machines; recreating energies and conditions that existed billionths of a second after the start of the Big Bang.
The results from the LHC are not completely predictable as the experiments are testing ideas that are at the frontiers of our knowledge and understanding. Researchers expect to confirm predictions made on the basis of what we know from previous experiments and theories. However, part of the excitement of the LHC project is that it may uncover new facts about matter and the origins of the Universe.
One of the most interesting theories the LHC will test was put forward by the UK physicist Professor Peter Higgs and others. The different types of fundamental particle that make up matter have very different masses, while the particles that make up light (photons) have no mass at all. Peter’s theory is one explanation of why this is so and the LHC will allow us to test the theory.
How does the LHC work?
The LHC accelerates two beams of atomic particles in opposite directions around the 27km collider when the particle beams reach their maximum speed the LHC allows them to ‘collide’ at 4 points on their circular journey.
Thousands of new particles are produced when particles collide and detectors, placed around the collision points, allow scientists to identify these new particles by tracking their behavior.
The detectors are able to follow the millions of collisions and new particles produced every second and identify the distinctive behavior of interesting new particles from among the many thousands that are of little interest.
As the energy produced in the collisions increases researchers are able to peer deeper into the fundamental structure of the Universe and further back in its history. In these extreme conditions unknown atomic particles may appear.
Where is the LHC?
Most, if not all, research teams are contributing to GridPP.
UK LHC centres:
- · Brunel University,
- · Imperial College – University of London,
- · Lancaster University,
- · Oxford University,
- · Queen Mary – University of London,
- · Royal Holloway – University of London,
- · STFC Rutherford Appleton Laboratory,
- · University College London,
- · University of Birmingham,
- · University of Bristol,
- · University of Cambridge,
- · University of Durham,
- · University of Edinburgh,
- · University of Glasgow,
- · University of Liverpool,
- · University of Manchester,
- · University of Sheffield,
- · University of Sussex,
- · University of Swansea,
- · University of Warwick,
- · University of the West of England
Who benefits?
There are two types of benefit that the LHC project produces for the UK. The less easily measured benefits are:
- new understanding of the physical world,
- training of world class scientists and engineers,
- maintenance of a vibrant, world class UK research base and,
- A leading role in a major international project.
More easily appreciated are the knowledge, expertise and technology that are spun off from the LHC and can be directly applied to development of new medical, industrial and consumer technologies.
The science of the LHC is far removed from everyday life, but the fact that the science is so extreme constantly pushes the boundaries of existing technical and engineering solutions. Simply building the LHC has generated new technology.
The LHC is not primarily about building a better world. Rather, it allows us to test theories and ideas about how the Universe works its origins and evolution. The questions asked, and answers found, are so fundamental that the information from LHC experiments will only be applied many years in the future, if at all. However, this is an experiment and one of the surprises from the experiment may be new science that can be applied almost immediately.
Latest News from the LHC
CERN has confirmed that a fault in an electrical connection between two magnets caused the incident on the 19th September, which has temporarily shut down preparation of the LHC for experiments. The fault led to mechanical damage and a release of liquid helium, which contributed to further damage to the affected sub-sector of the machine. All of the safety systems operated as expected and no one was put at risk. CERN has the spares and resources available to complete replacement and repair during the scheduled CERN-wide, maintenance shutdown over winter. Checks and modifications will ensure that similar failures do not occur elsewhere once the LHC restarts in Spring 2009.
What had been an exceptionally smooth early commissioning phase for the LHC, following first injection of proton beams on the 10th September, was halted by a technical failure on the 19th September . The first few days of commissioning beams in the LHC had encountered some technical problems, which had been resolved. However, the damage caused by failure of an electrical connection (during a test) has required that the affected sector be warmed up for repair.
Indian Contributions in LHC
India has contributed to the construction and commissioning of CERN’s most ambitious particle accelerator project the “Large Hadron Collider” (LHC) and is now engaged in other activities, namely, CTF 3 and LINAC-4. The contributions to LHC span from hardware, software, expert manpower support for evaluation of some of the LHC sub-systems and commissioning support of various subsystems of LHC.
Details of Indian Contributions
1 50000 litres Liquid Nitrogen tanks.
2 Superconducting corrector magnets
i) Sextpole (MCS)
ii) Decapole and Octupole (MCDO)
3 Precision Magnet Positioning System (PMPS) Jacks
4 Quench Heater Protection Systems (QHPS)
5 Integration of QHPS units into racks
6 Control electronics for circuit breakers of energy extraction system
7 Local protection units (LPU)
8 SC Dipole magnet tests/measurements,expert support in Man years
9 LHC Hardware Commissioning of Cryogenics, Power converters, Protection systems, Controls. Man years
10 Data management software upgrade, Data analysis software/documentation projects
11 Development of JMT-II software
12 Software development-slow control of Industrial Systems of LHC
13 Design and calculations for Vacuum system for beam dump line
14 Analysis of cryo-line jumper and magnet connections
Future scope:
The LHC is still new, but its successor – the International Linear collider (ILC) – is already being discussed. So why build two high energy colliders that operate on the same principles?
The LHC is a ‘discovery’ machine, a general purpose tool that will open up new areas of physics and demonstrate the existence, or not, of predicted new laws and particles. The ILC is a precision instrument that will allow scientists to explore in detail the discoveries made by the LHC.
The ILC is still at the planning stage, no location for the machine has been agreed and much feasibility testing has to be conducted before the construction phase.
Bibliography
Websites:
1) www.google.com
2) www.wikipedia.com
3) www.lhc.ac.in
