Compensation condition in Si/U hadronic calorimeter

The first prototype of a Si/U hadronic calorimeter was designed and developed. It consists of silicon mosaics, located next to uranium plates 10-mm thick and 50×50 cm² in area. The total calorimeter depth is six interaction lengths. Measurements performed with the Si/U calorimeter at the CERN PS (at 2, 4 and 6 GeV) support the view that the signal equalization, which provides the condition e /h=1, can be obtained with a silicon readout by tuning the calorimeter response to the electromagnetic component of the hadronic shower. This can be achieved by inserting, in front and/or back of the silicon detector, low-Z absorber (G10 plates). The fiberglass absorbs soft electrons, thus reducing the total energy sensed. The low- Z absorber is used to reduce the response of the electromagnetic component in a hadronic shower, while the pure hadronic component is expected to be only slightly affected