Performance of the ATLAS liquid argon forward calorimeter in beam tests

One of two ATLAS Forward Calorimeters, consisting of three modules, one behind the other, was exposed to particle beams of known energies in order to study the detector performance with and without the presence of upstream material in the beam, and at the inner edge of the acceptance where shower energy containment is incomplete. Data were taken in the H6 beamline at CERN using electron and hadron beams with energies from 10 to 200GeV. Results related to the intrinsic detector calibration, based on data taken with a minimal amount of material in front of the detector, have been previously published, but are updated here. This paper focuses on studies of data taken with additional upstream material in place. The effects of this additional material on the linearity and resolution of the response are presented. The response at the inner edge of the acceptance is also investigated. For all analyses, results based on a GEANT4 simulation of the beam-test setup and detector response are also presented.