wire chamber or spark chamber?
Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.
OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers
Zonder titelBoxes of bubble chamber film showing photographs of particle collisions. The particle tracks were then analysed on scanning tables (see object CERN-OBJ-DE-029). We have a selection of bubble chamber film available for loan, including some from the Big European Bubble Chamber (BEBC).
The UA2 central calorimeter measured the energy of individual particles created in proton-antiproton collisions. Accurate calibration allowed the W and Z masses to be measured with a precision of about 1%. The calorimeter had 24 slices like this one, each weighing 4 tons. The slices were arranged like orange segments around the collision point. Incoming particles produced showers of secondary particles in the layers of heavy material. These showers passed through the layers of plastic scintillator, generating light which was taken by light guides (green) to the data collection electronics. The amount of light was proportional to the energy of the original particle. The inner 23 cm of lead and plastic sandwiches measured electrons and photons; the outer 80 cm of iron and plastic sandwiches measured strongly interacting hadrons. The detector was calibrated by injecting light through optical fibres or by placing a radioactive source in the tube on the bottom edge.
The 3.70 metre Big European Bubble Chamber (BEBC) was dismantled on 9 August 1984. One of the biggest detectors in the world, it produced direct visual recording of particle tracks. 6.3 million photos of interactions were taken with the chamber in the course of its existence.
<3> pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.
Gargamelle was the name given to a big bubble chamber built at the Saclay Laboratory in France during the late 1960s. The experiment ran at CERN from 1970 - 1976 and in 1973 found the first experimental evidence of the particles responsible for transmitting the weak force. The weak force, one of the 4 fundamental interactions at work in the universe, has long been the subject of research at CERN. The force is responsible for radioactivity and is the reason why the sun shines. Gargamelle observed what is known as neutral currents, the process of a neutrino and electron transforming into a muon and a neutrino by exchanging an electrically neutral force carrier. The interaction was triggered by a beam of neutrinos and recorded by photographing the trail of bubbles left behind in the freon that filled the experiment's main chamber. Gargamelle has been conserved and is now displayed in the Microcosm garden.
<2> scintillators with their support.
Three pieces. Wire chambers used for the beams at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.
Zonder titel