Crosstalk characterisation of the readout electrodes for the ALLEGRO ECAL

This report presents an initial study of signal cross-talk in a prototype readout electrode developed for a noble liquid electromagnetic calorimeter of the Future Circular Collider (FCC). Different signal tracing and shielding configurations were tested using direct signal readout and readout with a fanout board. The influence of the readout setup on signal amplitude and oscillations was also evaluated. Results show that x-talk is highest in neighbouring cells, with logical tracing exhibiting strong localised x-talk and optimised tracing showing a more even distribution. Towers with wider vertical shielding, particularly tower 13, demonstrated the lowest x-talk, confirming the effectiveness of this approach while highlighting the trade-off with capacitance and noise. These measurements provide a useful basis for future detector design studies.