CAVIAR (CAMAC Video Autonomous Read-out), developed about 1980 at CERN in Geneva, was a multi-purpose microcomputer for the interactive development, in-line control and monitoring of experiments in high-energy physics. The CAVIAR machine was used in conjunction with a CAMAC system, consisting of a set of I/O modules assembled in a 19" crate. Some of the CAMAC-modules (for instance, analog-to-digital converters) would directly be connected to measuring devices, while another module would give access to a host (mainframe) computer through a high-speed link. The CAVIAR uses a Motorola 6800 microprocessor with 32 kB of solid-state RAM. In 29 kB EPROM the BAMBI (BASIC-like) interpreter is stored. Using the BAMBI graphics commands, graphs and histograms can be shown on the built-in miniature monitor screen. An alphanumeric terminal is connected to CAVIAR for programming and entering commands. The Super-CAVIAR (shown in the picture) is an enhanced version of CAVIAR with 64 kB RAM, 84 kB EPROM and other improvements.

The crystals used in CMS’s electromagnetic calorimeter may look like simple bricks of glass, but they are in fact mostly metal and are heavier than steel! Lead tungstate crystal with a touch of oxygen in this crystalline form is highly transparent and scintillates when electrons and photons pass through it. This means it produces light in proportion to the particle’s energy. CMS contains nearly 80’000 such crystals, each of which took two days to grow. This technology developed at CERN has applications in medical imaging, for example improving cancer diagnosis. The Compact Muon Solenoid (CMS) is a general-purpose detector at the Large Hadron Collider (LHC).

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.

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.