|
|
|
|
|
Circular accelerators were the first type of accelerator invented in 1929. In fact, the first cyclotron (shown above) was only 4 inches (10 cm) in diameter. American physicist Ernest O. Lawrence and his student Stanley Livingston built the first circular particle accelerator: the cyclotron.Lawrence's cyclotron used two D-shaped magnets (called Dee) separated by a small gap. The magnets produced a circular magnetic field. An oscillating voltage created an electric field across the gap to accelerate the particles (ions) each time around. As the particles moved faster, the radius of the their circular path became bigger until they hit the target on the outermost circle. Lawrence's cyclotron was effective, but could not reach the energies that modern circular accelerators do. Things have come a long way since then - CERN's Large Electron Positron collider, the most powerful accelerator at the laboratory today, is some two million times more powerful than Lawrence and Livingstone's cyclotron, is 27 kilometers in circumference, and is buried 100 metres below ground. |
|
A Simple Explanation Circular Particle Accelerators
|
| For circular accelerators, the particles are accelerated along a circular path using electric and magnetic fields. They go around and around until the desired energy is achieved, at which point they are made to collide. Like linear accelerators, there are two types of collisions utilized, one being the fixed target collision, seen below. |
 |
| The second type is the circular collider, which involves
two oppositely charged particles being accelerated in opposite directions
around the collider and then made to collide when they have enough energy.
Because two moving beams collide with each other,
much higher energy collisions are made to occur. Currently, the accelerators
capable of the highest energy collisions are circular colliders. |
 |
| A problem with circular accelerators is that as the particles go around the loop, they radiate away a great deal of energy. A large percentage of the energy the accelerator gives the particles goes to compensate the lost energy. The amount of energy loss depends on the mass of the accelerated particle, and how sharp the curve is. The heavier the particle, the less energy it radiates away, thus these types of accelerators are more suited for use with protons and antiprotons. Also the bigger the circumference of the accelerator, the less the energy loss will be, therefore accelerators with large circumferences are better. |
|
.I am indebteded to Jeremy Verkaik of the Department of Physics and Astronomy at The University of York, Toronto, Canada for the use of the Accelerator demonstrations.
|
 |
|
"What goes
around, comes around"
|
 |
|
|
Office
|
Quiz
|
