A particle accelerator is a machine that accelerates and collides beams of charged particles, such as electrons, protons, and ions, of atomic and sub-atomic size. These machines allow scientists to study the particles that make up all matter in the universe by colliding them together or into a target. Particle accelerators use electric fields to speed up and increase the energy of a beam of particles, which are steered and focused by magnetic fields. There are two basic types of particle accelerators: linear accelerators and circular accelerators. Linear accelerators propel particles along a linear, or straight, beam line, while circular accelerators propel particles around a circular track.

Particle accelerators are used in a wide variety of applications, including fundamental research, particle therapy for oncological purposes, radioisotope production for medical diagnostics, ion implanters for the manufacture of semiconductors, and accelerator mass spectrometers for measurements of rare isotopes such as radiocarbon. They are also used in industry to make materials more durable in extreme temperatures or resistant against chemicals.

The particles injected into an accelerator are referred to as a “beam,” and a series of electromagnets steers and focuses the beam of particles. In a linear accelerator, the particles shoot straight toward a fixed target, while in a circular accelerator, the particles travel around a ring, constantly gaining speed. Circular accelerators can speed particles up in less overall space than a linear accelerator, but they tend to be more complex to build and operate.

The Department of Energy Office of Science supports particle accelerators and research that uses these devices primarily through its High Energy Physics and Nuclear Physics programs. There are currently more than 30,000 accelerators in operation around the world.

In summary, a particle accelerator is a machine that accelerates and collides beams of charged particles, allowing scientists to study the particles that make up all matter in the universe. They use electric fields to speed up and increase the energy of a beam of particles, which are steered and focused by magnetic fields. Particle accelerators are used in a wide variety of applications, including fundamental research, particle therapy for oncological purposes, radioisotope production for medical diagnostics, ion implanters for the manufacture of semiconductors, and accelerator mass spectrometers for measurements of rare isotopes such as radiocarbon.