Particle accelerators can show us the secrets of the universe! Or possible create a black hole that sucks up Earth. But what are particle accelerators?
Before we talk about particles, we have to talk about magnets. Magnetism is a set of physical phenomena resulting from magnetic fields. Most familiar is that a magnetic field applies a force to an object, like sticking a magnet to a fridge. Magnetic fields are the result of electrical currents or of the so-called magnetic moment of elemental particles. Let’s leave that last one alone for now.
You can create an electromagnet by wrapped insulated copper wire around an iron core – for example, a nail. When you run a current through the wire, it will start to give off a magnetic field. One end of the nail will be the north pole, the other the south pole.
And, yes, these ends are called ‘north pole’ and ‘south pole’ because of those locations on Earth. The molten metal in the Earth’s core generates a magnetic field with it’s magnetic poles roughly at the north and south pole.
So, what does this have to do with a particle accelerator?
Magnetism and charged particles
A current generates a magnetic field, but a magnetic field also effects charged particles. A magnetic field applies force to a charged particle like an electron or proton. So, not only does a current produce a magnetic field, a magnetic field also produces a current.
A transformer – not the robots – basically consists of two sets of wire coils. A current is run through one of the coils. This produces a magnetic field, which in turn produces an electric current in the other coil at a different voltage.
When you create a long tunnel of magnets, you can use the magnetic fields in the tunnel to apply a force to a particle. Applying force to something will make it accelerate. In other words, a particle accelerator does exactly what the name says, it accelerates particles using magnetic fields.
The two basic types of accelerators are the linear accelerator, which is a straight tunnel of electromagnets, and the circular particle accelerator, which is a circle of them. I’m oversimplifying a bit. If you’re interested in the details, you should read a full book on the subject.
Why would we want an accelerator?
There are a couple of reasons you could want to accelerate particles. The most common reason is that you want to study what happens to particles when they interact at high energy levels. This type of research can help in understanding how the sun works, how to create better power plants, and perhaps understanding physics more fundamentally.
The Large Hadron Collidor is the largest circular accelerator which is used in this type of research. It makes the particles it accelerates collide at high energy levels. One thing that made possible was discovering the theoretically predicted Higgs boson.
Slightly more directly practical is the use of particle accelerators in medicine. Particle accelerators are used in radiation therapy. A bit of a side-step, but an MRI scanner uses magnetic field’s effects on particles to generate a 3D image of somebody’s interior.
Accelerators are also used to produce radioactive isotopes, which can be used for medical imaging and certain therapies.
And, as a science fiction author, I like to imagine the use of accelerators to create particle beam weapons. Particle beam weapons would use an accelerator to speed up a stream of subatomic particles and fire that at a target. Although we have no idea yet if this even possible in a handgun, or if it will ever be economically feasible, it’s fun to speculate. As a result, science fiction literature is filled with them.
Particle accelerators, like the name implies, accelerate particles using magnetic fields. That’s useful for a variety of reasons.