How Particle Accelerators Work

Scientists use particle accelerators to study the HOW A origins of our universe, investigate the subatomic structure of PARTICLE ACCELERATOR the world around us and advance research in medicine, environmental clean-up and more. WORKS THE PARTICLES On a basic level, particle accelerators produce a beam of charged particles that can be used for a variety of research purposes. Most often, the beam of particles is comprised of protons or electrons, charged subatomic particles. Sometimes, whole atoms of elements like gold or uranium, which are much heavier, are used. Proton A stable subatomic particle with a positive charge. Neutron A neutral subatomic particle with no electric charge. Electron A stable subatomic particle with a negative charge, which is regarded as the basic unit of electric charge. Atom The smallest unit into which matter can be divided while still maintaining the characteristic properties of a chemical element. THE ACCELERATOR In a circular particle accelerator, the particles are repeatedly propelled through a circular pipe. With each pass, the strength of the electric fields increases, accelerating the beam of particles. When the particles have reached the desired energy level, a target is placed into their path, where a particle detector observes the collision. Particle Source Beam Pipe The particle source provides the particles, such as protons or electrons, that are to be accelerated. The beam of particles travels in a vacuum inside this metal pipe. It is important to maintain an air and dust free environment for the beam of particles to travel unobstructed. Electromagnets Electromagnets steer and focus the beam of particles while it travels through the vacuum tube, Electric Fields Electric fields spaced around the accelerator switch from positive to negative at a given frequency, creating radio waves that accelerate particles in bunches. 5 Targets Particles can be directed at a fixed 6. Particle detectors record and reveal the Detectors target, such as a thin piece of metal foil, or two beams of particles can particles and radiation that are produced by the collision between a beam of particles and the target. be collided. WHY PARTICLE ACCELERATORS MATTER Discovery Science Medicine Industry Security Particle accelerators are essential tools of discovery for particle and nuclear physics and for sciences that Tens of millions of patients receive accelerator-based diagnoses and therapy each year in hospitals and clinics around the world. Worldwide, hundreds of industrial processes use particle accelerators -- from the manufacturing of computer chips to the cross-linking of plastic for shrink wrap and beyond. Particle accelerators play an important role in national security, including cargo inspection, stockpile stewardship and materials characterization. use x-rays and neutrons. ENERGY.GOV