It has since served as a pre-accelerator for the Intersecting Storage Rings (ISR) and the Super Proton Synchrotron (SPS), and is currently part of the Large Hadron Collider (LHC) accelerator complex.

In addition to protons, PS has accelerated alpha particles, oxygen and sulfur nuclei, electrons, positrons, and antiprotons.

When early in the 1950s the plans for a European laboratory of particle physics began to take shape, two different accelerator projects emerged.

One machine was to be of standard type, easy and relatively fast and cheap to build: the synchrocyclotron, achieving collisions at a center-of-mass energy of 600 MeV.

After a visit to the Cosmotron at Brookhaven National Laboratory in the US, the group learnt of a new idea for making cheaper and higher energy machines: alternating-gradient focusing.

At this point the relative increase in particle velocity changes from being greater to being smaller, causing the amplitude of the betatron oscillation to go to zero and loss of stability in the beam.

This was solved by a jump, or a sudden shift in the acceleration, in which pulsed quadruples made the protons traverse the transition energy level much faster.

The PS was approved in October 1953, as a synchrotron of 25 GeV energy with a radius of 72 meter, and a budget of 120 million Swiss franc.

[4] By the end of 1965 the PS was the center of a spider's web of beam lines: It supplied protons to the South Hall (Meyrin site) where an internal target produced five secondary beams, serving a neutrino experiment and a muon storage ring; the North Hall (Meyrin site) where two bubble chambers (80 cm hydrogen Saclay, heavy liquid CERN) were fed by an internal target; when the East Hall (Meyrin site) became available in 1963, protons from the PS hit an internal target producing a secondary beam filtered by electrostatic separators to the CERN 2 m bubble chamber and additional experiments.

[7] Together with the construction of the Intersecting Storage Rings (ISR), an improvement program for the PS was decided in 1965, also making space for the Gargamelle and the Big European Bubble Chamber experiments.

During this period the demand for heavier ions to be delivered as a primary beam to the SPS North experimental hall (Prévessin site) also increased.

Other straight sections are reserved for beam observation stations and injection devices, targets, and ejection magnets.

As the alignment of the magnets is of paramount importance, the units are mounted on a free floating ring of concrete, 200 meters in diameter.