Beam splash effects on ATLAS silicon microstrip detectors evaluated using 1-w Nd : YAG laser

On an incident of accelerator beam loss, the tracking detector located close to the beam line is subjected to receive intensive radiation in a short period. We used a 1-W focused Nd : YAG laser and simulated the effects on the ATLAS microstrip detector. The laser corresponds to intensity of up to 1 × 10 9 mips / pulse with a pulse width of about 10 ns. We observed breaks on Al strips on extreme conditions, depending on the laser intensity and bias voltage applied to the silicon sensor. The break can be interpreted as the oxide breakdown due to a large voltage locally created across the oxide by the intensive signal charges. The robustness of the Semiconductor Tracker (SCT) module including readout ASICs is also evaluated.