The interactions between electrons and protons lead to the emission of quarks and gluons from the proton which materialize in the visible world as jets of particles. The process is called "fragmentation" and is not yet fully understood. Careful measurement of these jets needs special detectors like the H1 calorimeter which constists of a stack of lead and steel plates submerged in 70 m3 of liquid argon. The jets are absorbed mainly in the steel plate calorimeter and produce electrical signals which can be recorded. The signal thus produced measure the energy and direction of these jets. Electrons and photons are absorbed by lead portions of the calorimeter and their energy and direction can also be deduced.
A view into the cryostat housing the H1-calorimeter.
The structure of the absorberplates in the calorimeter can be seen. The gaps between the steel plates are filled with liquid argon, cooled to a tenoerature of -183 degrees Celsius.
The calorimeter is constructed of a series of wheels and these are slid into the detector on special rails.
