Systematic investigation of the electromagnetic filtering effect as a tool for achieving the compensation condition in silicon hadron calorimetry

In a calorimeter with silicon readout, the use of a combination of low-Z (Fe) and high-Z (Pb) materials as absorbers allows the transformation of the electron energy distribution of the incident showers in two media with different critical energies via the filtering effect. As a result, the visible electromagnetic energy and consequently the value of the e/mip ratio can be substantially reduced as a function of the thickness of the high-Z (Pb) material present in the absorber. Measurements of this effect for a set of Si/Fe+Pb calorimeter configurations are presented and discussed. The filtering effect makes possible the achievement of the compensation condition.