The gas pedal is a device that can artificially accelerate a beam of charged particles to a high energy. It is an important device for the study of atomic nuclei and elementary particles, and in recent years, it has been increasingly widely used in industry, agriculture and health care. According to the shape of the orbit of the particle movement, can be divided into two categories of linear and circular gas pedal, the former has a high-pressure multiplier, electrostatic gas pedal and linear gas pedal, the latter has an electron induction gas pedal, cyclotron, proton synchrotron and so on.
Currently the world's largest particle gas pedal is the United States Fermi National Accelerator Laboratory, a proton synchrotron, which can accelerate the proton to 500GeV (1GeV on behalf of the 1 billion electron-like). The beam strength has reached 2 times 1013 protons/pulse. In fact, this big gas pedal is composed of four gas pedals: 750keV pre-injector, 200MeV linear gas pedal, 8GeV fast enhancer and 500GeV main gas pedal. The pre-injector, also known as the high voltage multiplier, is a low-energy, strong-flow gas pedal used to generate a beam of protons. The protons are accelerated from here, accelerating the negative hydrogen ions drawn from the ion source to 750 keV; the linear gas pedal, which consists of nine sections, with a total length of about 150 meters, is installed in an underground tunnel, and its function is to accelerate the beam generated in the pre-injector to 200 MeV; the beam comes out of the linear gas pedal, and then, through the intermediate-energy transport section, it arrives at the fast enhancer. This is also a synchrotron that accelerates 15 times per second. When negative ions are injected through a thin film, they are stripped of their outer electrons and become protons. After several accelerations, the energy is up to 8 GeV, and the beam is then drawn out for injection into the main gas pedal. The main gas pedal has a diameter of 2 kilometers and is a concrete tunnel with a horseshoe-shaped cross-section, laid underground at a depth of about 7 meters. Its function is to accelerate protons to high energies and complete the final acceleration. The normal operating energy is 400 GeV, with a maximum energy of 500 GeV. It is planned to build a superconducting main gas pedal ring on top of the main gas pedal, which is expected to increase the energy to 1,000 GeV.