Download CERN PARTICLE ACCELERATOR

CERN
PARTICLE ACCELERATOR
HOW THE ACCELERATORS AT WORK TO PUSH PARTICLES NEARLY TO THE
SPEED OF LIGHT
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
WHAT ARE THE ACCELERATORS?
• The accelerators at CERN include a series of machines which successively aim
to raise the speed of particles to almost that of light.
• There are 6 accelerators, some linear and some circular.
• The protons pass through them successively, each time becoming faster, and
as we will explain, heavier.
• The aim of the accelerators is to raise the speed and mass of the protons, and
eventually to collide them and detect the results.
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
• http://images.iop.org/objects/ccr/cern/48/6/18/CCELHC1_07-08.jpg
1. LINAC 2 – THE LINEAR ACCELERATOR
• The linear accelerator is the first accelerator in the complex
• The hydrogen atoms, whose electrons are stripped off, are turned into protons
• The linear accelerator, uses an electric field to begin the acceleration and directed
movement of these nuclei
• Electromagnets are used to guide the movement of these protons
• By the time they leave Linac 2, the particles will have reached a third of the speed of light
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
2. PROTON SYNCHROTRON BOOSTER - PSB
• After the Linac 2, the protons are divided into four circular rings
• Each ring is 150 meters in circumference
• The reason for having circular paths, is that the linear ones are now impractical
• An electric field is pulsated, speeding the particles
• There are powerful electromagnets at right angles with the rings, which bend the beam
• Here, the beam reaches speeds up to 91.6% of that of light
• In the end, the beams are squeezed together before they are passed along the next step
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
3. PROTON SYCHROTRON – PS
• This is a circular path which is 628 metres in circumference
• The proton beam passes through the PS for 1.2 seconds
• During this time, it is accelerated to 99.9% of the speed of light, where they have approached the
limiting speed of light
• In the PS, the particles reach their point of transition: where the extra energy they are provided with is
converted into mass, and no longer speed
• The energy provided is in the form of a pulsating field
• The energy of each proton here is 25 GeV (electron volts measure the microscopic kinetic energy f each
proton)
• The protons are now 25 times heavier than in their normal state
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
4. SUPER PROTON SYNCHROTRON - SPS
• This is a circular path which is 7 kilometres in circumference
• The energy of each proton reaches 450 GeV
• The particles here are injected every 30 minutes
• Around 2208 packets of protons
• They are injected into the next accelerator in two different packets, with opposite directions
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
5. LARGE HADRON COLLIDER – LHC
• The circumference is 27 kilometres
• It has two vacuum pipes which run in opposite directions
• Ultra sophisticated kickers, which synchronise incoming packets with those already circulating
• The pipes cross over in four detector cabins and the particles collide there
• Extra energy is given to the protons
• Their speed is so high, that the circle round the ring over 1100 times/second, getting extra energy from
the pulsating energy field
• Their energy is now 7 TeV
• They are 7000 heavier then at rest
• The magnetic force bends their trajectory, guiding them through the pipes, providing 12 000amps
through its superconducting eletromagnets
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty
Elisabeta Hoxhaj, Nikita Tokarev, Patrik Räty