ATLAS activities with Carleton involvement - Testbeam Analysis 2003

The ATLAS Forward Calorimeter (FCal) was tested in 2003 to beams of electrons, pions and muons within the energy range of 5 GeV to 200 GeV at the CERN SPS, in Geneva, Switzerland. The ATLAS Forward Calorimeter has been designed to cover a pseudorapidity range from n =3 to 5. The Forward Calorimeter is situated in a very high particle flux region. In order to avoid charge build up, a small LArg gap was chosen using a paraxial rod and copper tube structure. The FCal has three depth compartments: FCal1 is an electromagnetic calorimeter compartment with a gap size of 250 microns while FCAL2 and FCal3 are hadronic compartments with 375 and 500 microns gap sizes respectively.

The three modules were setup in a cryostat at the H6c test beam area at CERN. The idea was to determine the elementary calorimeter performance parameters like the electromagnetic calibration for the three modules, and the hadronic response of the combined setup.

The left plot shows the response of the FCal1 to electrons as a function of energy. The residual with respect to the fit are shown on the right.

The energy resolution for electrons as a function of energy.