Quantum World Uncategorized

How does Particle Accelerator work ?

Particle Accelerators have been around since the 1970s, and have been theorized since the discovery  of the cathode ray tube in the 1890s. The two most basic types are the circular and
linear accelerators.

The purpose of both of these is to accelerate particles like protons, neutrons,  electrons, etc. to very high velocities to either collide with each other or strike an external target. But have you ever amazed how  it does work and which concepts  scientist does  use to accelerate particle .

The Large Hadron Collider is an 18-mile (27km) ring containing powerful magnets lying beneath the French-Swiss border at the Cern laboratory in Geneva.
This is Large Hadron collider , world’s biggest particle accelerator built by CERN.                          Image Credit / CERN

1) Why build these expensive machines? 

Aside from being very cool, these inventions have helped advance fields of all sorts ranging from medicine (chemotherapy, etc.), to the common industry of circuitry, and even national security. When people think of particle accelerators, they think commonly of the discovery of new elementary particles such as the mysterious and elusive Higgs-Boson particles  . It is so much more than that. Strides in nuclear physics leading to the discovery of harvesting fission and fusion reaction energies have been one such huge accomplishment. It can even go as far as to say it has lead us to open our horizons in the direction of discovery of the beginnings of our
universe.

2) How Do Particle Accelerators Work? 

As mentioned before, the purpose is to accelerate these particles to very high velocities. You start with the source. The source provides the particles to be accelerated. For example, a radioactive isotope can provide the elementary particles such as alpha rays (helium nucleus) and beta rays (electrons). Then, the beam of particles travel through a metal pipe while in a vacuum. This vacuum is very important for providing the particles with no obstructions in their path. Electromagnets control the direction of the particles along their path. Oscillating electric fields boost and accelerate these particles leading to either a collision or projection at a target depending on the objective.

Circular Accelerators

Circular accelerators accelerate particles along a circle with an increasingly larger radius. The schematics are the same as described above except the intensity (or voltage) of the electric fields and magnetic fields are increased with each successive rotation to increase the size of the circular orbit (to increase the radius). Circular accelerators are commonly used for particle collisions and for fixed target experiments. However, in a circular accelerator, a process called
bremsstrahlung occurs. This is when the radiation produced by the accelerating particles decelerates it and you lose as much energy as you produce while accelerating it leading to an equilibrium phase. Furthermore, for protons, you would need super strong magnetic fields to curve the path requiring massive cryogenic systems.

Linear Accelerators

. Linear accelerators propel particles along a straight (linear) path. While circular accelerators have its problems accelerating a particle past a certain equilibrium phase, linear accelerators
have no such obstructions. Hypothetically it can accelerate it as fast as it wants requiring you only to add increasingly more powerful magnets and electric fields along its path. However these accelerators can loose particles along the route if certain particles fail to act upon the influence of the electromagnetic fields at the precise moment needed. Usually these
accelerators are used for fixed target experiments. The downside other than its impressive ability to loose particles is how much space it requires. Practically speaking, very long linear accelerators are not possible as we do not have the resources for it. What a shame.

3) Why Care? 

So you might be thinking, “what good is any of this to me?” Well, if the accomplishments mentioned above weren’t enough, just understand that a lot of what you see around you today may not be possible. Treatments undiscovered, consumer products potentially twice the size
and less efficient, security compromised. As our next generation, know what you’re voting for. We need to delegate more money towards advances in such fields for the betterment of our
society. Vote for you. Vote for science.

Preethi is a high school student in United States who is interested in Physics. She loved to discuss any topic related to the subject. In her free time, she loves watching PBS Spacetime and listening to pop music. She hopes to someday major in some area of physics.