Introduction

In this exercise we will use LCDD, an extension of the standard Geant4 GDML format, to describe a complete detector setup, including sensitive detectors and readout. Since we are using XML to configure Geant4 there is no need to write any C++ code.  We can use a version of SLIC which has been pre-built with support for GDML included. In this example we will use a simple test beam like calorimeter consisting of lead glass blocks of 1 cubic cm. For each calorimeter cell we read out the Ionization loss as well as the energy deposited by cherenkov photons.