First results of the engineering prototype of the CALICE tile hadron calorimeter

A new prototype of a tile hadron calorimeter (HCAL) for the International Linear Collider (ILC) detector is currently developed within the CALICE collaboration. The aim is to improve the energy resolution by measuring details of the shower development (particle flow). The prototype is based on scintillating tiles that are read out by novel silicon photo-multipliers (SiPMs). The full prototype will contain about 2500 detector channels (one layer) and takes into account all engineering design aspects that are demanded by the intended operation at the ILC. For technical manageability reasons, the detector is subdivided into basic units (HCAL Base Unit: HBU) with typically 144 detector channels. In order to reduce the amount of non-absorbing material in the calorimeter, the thickness of the inner detector modules is optimized to only 5.4 mm. The presentation will focus on the first electrical and mechanical integration experiences of the first two realized HBUs. The operation with a newly developed data acquisition, based on a commercial FPGA board and two newly developed mezzanine modules, is described. Additionally, first results for an integrated light-calibration system (LCS) are shown, addressing the critical distribution of the fast trigger signals (pulse width of about 40 ns) to all channels. The LCS is used for calibration and gain monitoring, addressing the temperature and bias dependencies of the SiPMs gains.