Installing the H1 calorimeter

28 October 1998

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This week's image is of the H1 detector in its very early stages of construction in the North Hall of the Hadron Electron Ring Accelerator (HERA) at the DESY laboratory in Hamburg. The picture shows the first ring-shaped component of H1's calorimeter, which measures the energy flow in particle collisions, being installed into the large cryostat that keeps the device at -183 ºC.

Since its completion in 1992, the H1 detector has been recording the products of high energy electron-proton collisions to facilitate the study of the inner structure of the proton. These 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 H1 calorimeter is designed to detect and measure these jets and other energetic particles emitted. It consists of stacks of lead and steel plates, immersed in 70 m³ jacket of liquid argon (cooled to a temperature of -183 ºC), which are divided into small cells so that the particle jets can be very well localised in space. The complete cylindrical structure surrounds the interaction zone, ensuring that few particles escape undetected

Credit: DESY/H1

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