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Particle beams circulate for around 10 hours in the Large Hadron Collider (LHC). During this time, the particles make four hundred million revolutions of the machine, travelling a distance equivalent to the diameter of the solar system. The beams must travel in a pipe which is emptied of air, to avoid collisions between the particles and air molecules (which are considerably bigger than protons). The beam pipes are pumped down to an air pressure similar to that on the surface of the moon. Much of the LHC runs at 1.9 degrees above absolute zero. When material is cooled, it contracts. The interconnections must absorb this contraction whilst maintaining electrical connectivity.

The Time-Of-Flight system of ALICE consists of 90 such modules, each containing 15 or 19 Multigap Resistive Plate Chamber (MRPC) strips. This detector is used for identification of charged particles. It measures with high precision (50 ps) the time of flight of charged particles and therefore their velocity. The curvature of the particle trajectory inside the magnetic field gives the momentum, thus the particle mass is calculated and the particle is identified The MRPC is a stack of resistive glass plates, separated from each other by nylon fishing line. The mass production of the chambers (~1600, covering a surface of 150 m2) was done at INFN Bologna, while the first prototypes were bult at CERN.

Connection between two superconducting magnets Cryostat - Keeping the magnets cold The Large Hadron Collider superconducting magnets are cooled by liquid helium to 1.9 degrees above absolute zero, or around 300 degrees below the ambient temperature in the tunnel. To keep them cold, each 30 000 kg magnet sits inside a cryostat that isolates it from the tunnel. Inside the cryostat, air is pumped out to reduce heat in-flow. Bellows - Allowing expansion and contraction When the magnets are cooled, they contract: normally 15 metres long, each magnet shrinks by 4.5 cm on its way down to 1.9 degrees above absolute zero. One side of each 30 000 kg magnet is held stationary, while the other is left free to move. Stainless steel bellows such as these absorb the contraction. Notice that every single join needs to allow for such movement, even the electrical connections. Helium Pipe - The cooling supply This pipe carries superfluid helium at 1.9 degrees above absolute zero, around 300 degrees below room temperature. As helium is cooled and put under pressure, it becomes a superfluid, with excellent thermal conductivity, ensuring the temperature is the same everywhere in the circuit. However this gives engineers an extra challenge as superfluids have unusual quantum properties. They can even creep upwards – if there are leaks in the circuit a superfluid will find them! The Large Hadron Collider is cooled by sector, of which there are eight in total. Cool down of one sector takes around 6 weeks. When the accelerator is brought back to room temperature for maintenance works, CERN recuperates the helium and stores it, so it can be reused. Niobium Titanium Cable - Bringing current to the magnets This cable carries the 13 000 amps to the Large Hadron Collider magnets. It is made from a Niobium-Titanium superconductor which is embedded in copper, to ensure an electrical connection is maintained even if the superconductor warms up and stops conducting. This happens at around 10 degrees above absolute zero. The LHC is cooled to 1.9 degrees above absolute zero, to keep the current perfectly stable. Look at the joins in the cable, called splices. They allow the wires to move over each other and retain an electrical connection, when the magnet contracts during cooling. Beam-Pipe Fingers - Keeping the electrical connection Fingers of copper slide over the beam-pipe in every connection between magnets in the Large Hadron Collider. These fingers retain an electrical contact whilst the magnets contract during cooling. The beam-pipe has double layers. The outer layer is slightly colder than the inner one so that any residual gas molecules, left behind in the tube after pumping, are drawn outwards through small holes so they cannot be disturbed by the passing proton beam. Diode - Removing the current There are many mechanisms in place to prevent friction between cable windings that might generate heat and stop the superconductor from conducting. In the eventuality the magnets do stop working, around 13 000 amps of current needs to be taken out of the system. This happens via diodes situated at the extremity of every magnet. The diode conducts a current pulse ramping in less than a second up to 13 000 amps and then slowly decaying down to zero. This process raises their temperature by several hundred degrees, so the diodes are cooled by the LHC Helium circuit.

The magnetic field must be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. 50’000 tonnes of steel sheets are used to make the magnet yokes that keep the wiring firmly in place. The yokes constitute approximately 80% of the accelerator's weight and, placed side by side, stretch over 20 km.

This brass block was part of the CMS experiment. Its role was to slow down particles before their energy was measured. The Compact Muon Solenoid (CMS) experiment is one of two large general-purpose particle physics detectors built on the Large Hadron Collider (LHC).

The electromagnetic calorimeter used in LHCb is a sandwich of lead plates and scintillating tiles. Incoming particles interact with the lead, creating a shower of new particles. This shower goes on to interact with the plastic tiles where its energy is transformed into tiny flashes of light, called scintillations. All this light is then collected in optical fibres which transport it to a photomultiplier tube that converts the light signal into a pulse of electrical current. The resulting signal reveals the energy of the original particle. 3300 such modules combine to make up the first layer of LHCb calorimeters.

The discovery of the Higgs boson by the ATLAS and CMS experiments was announced in CERN’s main auditorium in July 2012. Here, finally, was the missing piece in the standard model describing our universe. For some, it was the culmination of over 40 years’ work. This champagne bottle was drunk by members of CERN’s Theoretical physics group on the occasion.

This antimatter trap is used at the Antimatter decelerator to study atoms of antimatter. Electrically-charged antimatter can be trapped in this device, also called a Penning trap. The Penning trap requires an ultrahigh vacuum. Inside the trap, magnetic fields force the charged antiparticles to spiral around the magnetic field lines, and electric fields confine them along the magnetic axis. Even though at the beginning of the universe, antimatter has been produced in equal quantity with matter, it now seems to have completely disappeared.

CELESTA (CERN Latch-up Experiment Student Satellite) will be the first CERN-driven microsatellite, developed in collaboration with the University of Montpellier in the framework of a collaboration agreement defined and signed in 2015. The project, supported through the KT Fund, has two main objectives: one is developing and flying a space version of CERN radiation monitor (RadMon) coupled with a latch-up experiment; the second is showing that the space radiation environment of Low Earth Orbit can be reproduced in the CERN High energy AcceleRator Mixed field facility (CHARM). This would open the use for space system qualification activities, and provide a radiation monitor module for future missions.

A beautiful module of tracker from the CMS experiment, made up of silicon.