First prototype of a silicon microstrip detector with the data-driven readout chip FSSR2 for a tracking-based trigger system

We developed and characterized the first prototype of a silicon microstrip detector system to be used in the forward region (high rapidity) of high energy physics experiments. This detector features an innovative readout integrated circuit, the second version of the Fermilab Silicon Strip Readout chip (FSSR2), which, being completely data-driven, allows for the direct use of the detector information at the lowest level of the trigger. All the particle hits on the detector can be read out in real time without any external trigger and any particular limitation due to deadtime. The chip services 128 strips providing the address, the time-stamp and a 3 bit amplitude information for all hits. Several programmable features are included in the chip, such as an internal pulser, a baseline restorer, and a selectable signal peaking time and gain. The performance in terms of noise and threshold dispersion have been measured with and without sensor connected to the chip and at different values of peaking time and gain, confirming that the FSSR2 meets the design requirements. The electronic calibration has been crosschecked with a radioactive source of 241Am.