Performance of the ATLAS liquid argon forward calorimeter in beam tests

One of two ATLAS Forward Calorimeters, consisting of threemodules, one behind the other, was exposed to particle beams ofknown energies in order to study the detector performance with andwithout the presence of upstream material in the beam, and at theinner edge of the acceptance where shower energy containment isincomplete. Data were taken in the H6 beamline at CERN usingelectron and hadron beams with energies from 10 to 200 GeV.Results related to the intrinsic detector calibration, based on datataken with a minimal amount of material in front of the detector,have been previously published, but are updated here. This paperfocuses on studies of data taken with additional upstream materialin place. The effects of this additional material on the linearityand resolution of the response are presented. The response at theinner edge of the acceptance is also investigated. For all analyses,results based on a GEANT4 simulation of the beam-test setup anddetector response are also presented.