TOTEM

TOTal Elastic and diffractive cross section Measurement

The TOTEM experiment studies forward particles to focus on physics that is not accessible to the general-purpose experiments. Among a range of studies, it will measure, in effect, the size of the proton and also monitor accurately the LHC's luminosity.

To do this TOTEM must be able to detect particles produced very close to the LHC beams. It will include detectors housed in specially designed vacuum chambers called 'Roman pots', which are connected to the beam pipes in the LHC. Eight Roman pots will be placed in pairs at four locations near the collision point of the CMS experiment.

Although the two experiments are scientifically independent, TOTEM will complement the results obtained by the CMS detector and by the other LHC experiments overall.

The TOTEM experiment involves 50 scientists from 10 institutes in 8 countries (2006).

TOTEM detector

• Size: 440 m long, 5 m high and 5 m wide
• Weight: 20 tonnes
• Design: Roman pot and GEM detectors and cathode strip chambers
• Location: Cessy, France (near CMS)