What is an electronvolt?

• Charged particles tend to speed up in an electric field, defined as an electric potential - or voltage - spread over a distance
• One electron volt (eV) is the energy gained by a single electron as it accelerates through a potential of one volt
• It is a convenient unit of measure for particle accelerators, which speed particles up through much higher electric potentials
• The first accelerators only created bunches of particles with an energy of about a million eV
• The LHC can reach beam energies a million times higher: up to several teraelectronvolts (TeV)
• This is still only the energy in the motion of a flying mosquito
• But LHC beams include trillions of these particles, each travelling at more than 99.99% of the speed of light