System aspects of the ILC-electronics and power pulsing

The requirements for the electronics of an experiment at the international linear collider (ILC) are driven by the bunch structure of the accelerator - short trains (1ms) with bunch to bunch lag of 0.3μs interrupted by long empty intervals (199ms) - and the precision physics. Based on developments of the CALICEcollaboration a system for high granular dense calorimetry is presented. The talk covers the system aspect: — of compact sensors as Si-diodes and multi-pixel Geiger mode photo sensors, — of the electromechanics with components embedded into the PCB’s, — of integrating the functionality needed nearby the sensor into low power ASIC’s, — of a DAQ-chain, in which each channel triggers on its own and the data selection is installed into PC’s and — of calibrating the calorimeter. With the high number of 100 million channels the power consumption and cooling have to be investigated carefully. Calculations demonstrate, that active cooling inside the calorimeters can be avoided. But essential for this goal is using the low duty cycle (0.5%) of the accelerator to power cycle the major consumers and designing an ASIC for low power (25μW/channel). For the power cycling a concept is developed, which keeps the current fluctuation local to avoid EMIproblems and to supply the in-detector electronics with DCcurrent through wires weith moderate cross section. Some of the ideas are already realized in a prototype for physics and component studies. The setup integrates 14 thousand channels and was installed for two month at CERNtestbeam. 200 million of electrons and pions are collected and 15T-Byte of data are stored. The data nicely show the details of a shower development needed to prove the particle flow algorithm for high energy resolution