ELECTROMAGNETIC FILTERING EFFECT IN SILICON CALORIMETRY

In a calorimeter with silicon readout, the use of a combination of low-Z (Fe) and high-Z (Pb) materials as absorbers enables 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 electromagnetic energy value can be substantially reduced as a function of the thickness of 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. A direct consequence of the filtering effect is to enable the achievement of the compensation condition.