Particle accelerators, sometimes known by the nickname "atom smashers," allow scientists to accelerate tiny subatomic particles, such as electrons or protons, to near the speed of light. Then they allow a particle to collide with an atom, smashing it into pieces so they can learn about what's inside of it.
A particle accelerator is a device that uses electric fields to propel electrically charged particles to high speeds and magnetic fields to contain them.
The Large Hadron Collider, a 17-mile-round atom-smasher on the French-Swiss border that sits nearly 600 feet below, has been 14 years and several billion dollars in the making. The machine is designed to rev up opposing beams of particles to nearly the speed of light and smash them together. A few scientists are concerned that the collisions will create tiny black holes that destroy the earth.
Over the years, particle accelerators have revealed that the internal structure of the atom is more complex than scientists had imagined.
Experts estimate there are over 30,000 particle accelerators in use around the world.
Scientists first learned about subatomic particles, such as protons, neutrons, and electrons, in the early 20th century. Particle accelerators were invented in the 1930s to allow scientists to learn even more about the internal structure of the atom. Scientists also believe particle accelerators can help us understand the forces that existed at the very creation of the universe.
There are two basic types of particle accelerators:
Linear - In a linear accelerator, particles travel in a straight line from one end to the other.
Circular - In a circular accelerator, particles travel repeatedly around a loop.
Particle accelerators use different types of technology. For example, electric fields are used to accelerate particles as they travel through a vacuum inside a metal pipe. To create calculated collisions, large electromagnets precisely direct the particles to their targets, which could be thin pieces of metal or another beam of particles. After the collision takes place, sophisticated particle detectors are used to detect and record the radiation and particles produced.
The results of particle acceleration experiments have been used for many other purposes, including medical research, development of new technologies and products, and even national security.
The Large Hadron Collider (LHC) accelerates two beams of protons in opposite directions around the tunnels. The beams of protons are steered by a system of electromagnets about 100,000 times stronger than Earth's magnetic field. To counteract the heat produced in the process, the world's largest cryogenic system keeps the electromagnets cooled to a temperature of -456º F!
In 1930, a young scientist in California named Ernest Lawrence, inspired by a sketch of a hypothetical accelerator in a research journal, and built the contraption. Lawrence applied 2,000 volts of electricity and boosted hydrogen electron molecules up to 80,000 volts. It opened the door to particle physics and the era known as "big science," employing hundreds of people to tackle some of science's weightiest problems.
In 1966, electrons and positrons began zipping down the 2-mile-long Stanford Linear Accelerator, the longest atom-smasher of its type in the world.
In 1974, the world's biggest cyclotron, called TRIUMF, is located in the suburbs of Vancouver in Canada. A 59-foot-diameter magnet spins protons up to three-quarters the speed of light and then spits them out on a path to one of several destinations. There, they are smashed into ever-smaller particles for a host of experiments.
The Tevatron, which went into action in 1983, preceded the Large Hadron Collider as the champion of particle accelerators. The 4-mile-round track sits underground amid cow pastures in suburban Chicago and smashes beams of protons and antiprotons together at energies up to 1.8 trillion electron volts, or 1.8 TeV.
In 2000, The Relativistic Heavy Ion Collider (RHIC, pronounced "rick") on Long Island in New York smashes beams of gold ions together in pursuit of a mysterious dense state of matter called a quark-gluon plasma that existed a millionth of a second after the Big Bang.
How do particle smashers work?
Particle smashers use electric fields to speed up and increase the energy of a beam of particles, which are steered and focused by magnetic fields.
The particle source provides the particles, such as protons or electrons, that are to be accelerated. The beam of particles travels inside a vacuum in the metal beam pipe. The vacuum is crucial to maintaining an air and dust free environment for the beam of particles to travel unobstructed. Electromagnets steer and focus the beam of particles while it travels through the vacuum tube.
Electric fields spaced around the accelerator switch from positive to negative at a given frequency, creating radio waves that accelerate particles in bunches.
Particles can be directed at a fixed target, such as a thin piece of metal foil, or two beams of particles can collide. Particle detectors record and reveal the particles and radiation that are produced by the collision between a beam of particles and the target.
Scientists have used the LHC to try to recreate the conditions immediately following the Big Bang at the beginning of the universe.
In 2012, scientists using the LHC discovered the Higgs boson, the subatomic particle believed to hold the key to understanding how particles get their mass.