The H lliquidargoncalorimeter system

Theliquid argon calorimeter ofthe H1 detector presently taking data at the HERAep collider at DESY,Hamburg, isdescribed. Themainphysics requirements andthe mostsalient design features relevant to this calorimeteraregiven. Theaimto havesmoothandhermetic calorimetric coverage over thepolarangularrange4° <0< 154° is achieved by asingle liquidargon cryostat containing calorimeter stacks structured in wheels andoctants for easy handling. Theabsorber materialsused