Uniformity of the CALICE Fe-AHCAL response to pions

The CALICE Analog Hadron Calorimeter (AHCAL) is segmented in the central part into $3 \times 3$ cm$^2$ plastic scintillator tiles. The uniformity of the calorimeter response to pions ($\pi^+$) across the surface of the tiles was studied with test beam data obtained in 2007 at the CERN H6 beamline in the energy range from 30 to 80 GeV. The relative deviation of the response as function of the impact position of the incoming pion (1 mm steps) was used to determine the homogeneity of the signal. The response of the test beam calorimeter was found to be independent of the impact position of the pion to better than 0.8%.