PS proton sourceAcceleratorCERN-OBJ-AC-005First proton source used at CERN's Proton Synchrotron (PS) which started operation in 1959. The PS was CERN’s first synchrotron. Activated in 1959, it was initially CERN's flagship accelerator, but when the laboratory built new accelerators in the 1970s, the PS’s principal role became to supply particles to the new machines. In the course of its history, it has juggled many different kinds of particles, feeding them directly to experiments or to more powerful accelerators. It is CERN's oldest accelerator still functioning today (2025). It is part of the accelerator chain that supplies proton beams to the Large Hadron Collider. With a circumference of 628 metres, the PS has 277 conventional (room-temperature) electromagnets, including 100 dipoles to bend the beams round the ring. The accelerator operates at up to 26 GeV. In addition to protons, it has accelerated alpha particles (helium nuclei), oxygen, sulphur, argon, xenon and lead nuclei, electrons, positrons and antiprotons. The source is a Thonemann type. In order to extract and accelerate the protons at high energy, a high frequency electrical field is used (140Mhz). The field is transmitted by a coil around a discharge tube in order to maintain the gas hydrogen in a ionised state. An electrical field pulse, in the order of 15kV, is then applied via an impulse transformer between anode and cathode of the discharge tube. The electrons and protons of the plasma formed in the ionised gas in the tube, are then separated. Currents in the order of 200mA during 100 microseconds have been obtained with this type of source.1959http://cds.cern.ch/record/43855http://cds.cern.ch/record/43855oai:cds.cern.ch:43855diagram / "Synchrotron a protons" (extrait du rapport annuel1957 du CERN)The object was part of CERN 40th anniversary exhibition. AA quadrupole magnetAcceleratorCERN-OBJ-AC-019Focusing magnet used for the AA (antiproton accumulator).Making an antiproton beam took a lot of time and effort. Firstly, protons were accelerated to an energy of 26 GeV in the PS and ejected onto a metal target. From the spray of emerging particles, a magnetic horn picked out 3.6 GeV antiprotons for injection into the AA through a wide-aperture focusing quadrupole magnet. For a million protons hitting the target, just one antiproton was captured, 'cooled' and accumulated. It took 3 days to make a beam of 3 x 10^11 - three hundred thousand million - antiprotons. About focusing magnets (quadrupoles): Quadrupole magnets are needed to focus the particle beams and squeeze them so that more particles collide when the beams cross. Particle beams are stored for about 10 hours in the LHC. During this time, the particles make four hundred million revolutions around the machine, travelling a distance equivalent to the diameter of the solar system.1980http://cds.cern.ch/record/43890http://cds.cern.ch/record/43890oai:cds.cern.ch:43890 antiproton targetAcceleratorCERN-OBJ-AC-020Antiproton target used for the AA (antiproton accumulator). Making an antiproton beam took a lot of time and effort. Firstly, protons were accelerated to an energy of 26 GeV in the PS and ejected onto a metal target. From the spray of emerging particles, a magnetic horn picked out 3.6 GeV antiprotons for injection into the AA through a wide-aperture focusing quadrupole magnet. For a million protons hitting the target, just one antiproton was captured, 'cooled' and accumulated. It took 3 days to make a beam of 3 x 10^11 - three hundred thousand million - antiprotons.1980http://cds.cern.ch/record/43891http://cds.cern.ch/record/43891oai:cds.cern.ch:43891Target and focusing horn fixed onto the same holder. engMagnetic Focusing HornAcceleratorCERN-OBJ-AC-031This magnetic focusing horn was used for the AA (antiproton accumulator). Its development was an important step towards using CERN's Super Proton Synchrotron as a proton - antiproton collider. This eventually led to the discovery of the W and Z particles in 1983. Making an antiproton beam took a lot of time and effort. Firstly, protons were accelerated to an energy of 26 GeV in the PS and ejected onto a metal target. From the spray of emerging particles, a magnetic horn picked out 3.6 GeV antiprotons for injection into the AA through a wide-aperture focusing quadrupole magnet. For a million protons hitting the target, just one antiproton was captured, 'cooled' and accumulated. It took 3 days to make a beam of 3 x 10^11 -, three hundred thousand million - antiprotons.1974http://cds.cern.ch/record/43971http://cds.cern.ch/record/43971oai:cds.cern.ch:43971Focusing horn and antiproton target fixed onto the same holder. magnetic hornAcceleratorCERN-OBJ-AC-022Neutrinos and antineutrinos are ideal for probing the weak force because it is effectively the only force they feel. How were they made? Protons fired into a metal target produce a tangle of secondary particles. A magnetic horn like this one, invented by Simon Van der Meer, selected pions and focused them into a sharp beam. Pions decay into muons and neutrinos or antineutrinos. The muons were stopped in a wall of 3000 tons of iron and 1000 tons of concrete, leaving the neutrinos or antineutrinos to reach the Gargamelle bubble chamber. A simple change of magnetic field direction on the horn flipped between focusing positively- or negatively-charged pion beams, and so between neutrinos and antineutrinos.1999-07-27T22:00:00Zhttp://cds.cern.ch/record/43925http://cds.cern.ch/record/43925oai:cds.cern.ch:43925