Forward calorimetry at hadron collider

Calorimeter has been an essential element of High Energy Physics Experiment for decades. As beam energies of hadron colliders reached the multi-TeV range, hermeticity of the calorimetric system became a high priority issue. Additional requirements arose from increased luminosity. The Forward Calorimeter (covering rapidity η >3) must to provide high quality measurements of hadronic jets (energy and position) at extremely high rate and at the same time withstand a harsh radiation environment. The Liquid Argon Tube Forward Calorimeter was developed at the University of Arizona to fulfill those requirements. Prototypes of the electromagnetic section (15X₀, later 25X₀) were tested at BNL and CERN secondary beams in 1993 and 1995. Data acquired in those tests allowed us to study such vital parameters of the calorimeter as response uniformity, energy and position resolution. An energy range from 2 GeV to 200 GeV and angles from 0.6° to 5.6° were covered. Observed results (together with extensive Monte-Carlo simulation studies of the Forward Region) allowed the Liquid Argon Tube Calorimeter to be chosen among several competing designs as the Baseline for the Forward Calorimeter of the ATLAS multi-purpose detector at the LHC (CERN)