From UPSC perspective, the following things are important :
Prelims level : Large Hadron Collider (LHC)
Mains level : Not Much
The world’s most powerful particle collider, the Large Hadron Collider (LHC), will begin smashing protons into each other at unprecedented levels of energy beginning July 5.
What is the LHC?
- The Large Hadron Collider is a giant, complex machine built to study particles that are the smallest known building blocks of all things.
- Structurally, it is a 27-km-long track-loop buried 100 metres underground on the Swiss-French border.
- In its operational state, it fires two beams of protons almost at the speed of light in opposite directions inside a ring of superconducting electromagnets.
- The LHC’s second run (Run 2) began in 2015 and lasted till 2018. The second season of data taking produced five times more data than Run 1.
- The third run will see 20 times more collisions as compared to Run 1.
How does it work?
- The magnetic field created by the superconducting electromagnets keeps the protons in a tight beam and guides them along the way as they travel through beam pipes and finally collide.
- Just prior to collision, another type of magnet is used to ‘squeeze’ the particles closer together to increase the chances of collisions.
- The particles are so tiny that the task of making them collide is akin to firing two needles 10 km apart with such precision that they meet halfway.
Extreme conditions involved
- Since the LHC’s powerful electromagnets carry almost as much current as a bolt of lightning, they must be kept chilled.
- The LHC uses a distribution system of liquid helium to keep its critical components ultracold at minus 271.3 degrees Celsius, which is colder than interstellar space.
- Given these requirements, it is not easy to warm up or cool down the gigantic machine.
What is the latest upgrade?
- Three years after it shut down for maintenance and upgrades, the collider was switched back on this April.
- This is the LHC’s third run, and it will operate round-the-clock for four years at unprecedented energy levels of 13 tera electron volts.
Note: A TeV is 100 billion, or 10-to-the-power-of-12, electon volts. An electron volt is the energy given to an electron by accelerating it through 1 volt of electric potential difference.
Targets this year
- It now aims to be delivering 1.6 billion proton-proton collisions per second.
- The last time, the proton beams will be narrowed to less than 10 microns — a human hair is around 70 microns thick — to increase the collision rate.
- ATLAS is the largest general purpose particle detector experiment at the LHC.
- The Compact Muon Solenoid (CMS) experiment is one of the largest international scientific collaborations in history, with the same goals as ATLAS, but which uses a different magnet-system design.
Previous runs & ‘God Particle’ discovery
- Ten years ago, in 2012, scientists at CERN had announced to the world the discovery of the Higgs boson or the ‘God Particle’ during the LHC’s first run.
- The discovery concluded the decades-long quest for the ‘force-carrying’ subatomic particle, and proved the existence of the Higgs mechanism, a theory put forth in the mid-sixties.
- This led to Peter Higgs and his collaborator François Englert being awarded the Nobel Prize for physics in 2013.
- The Higgs boson and its related energy field are believed to have played a vital role in the creation