Occupancy reduction in silicon strip detectors with the APV25 chip

The occupancy of a silicon detector is defined as the number of hit channels at any random moment. High occupancy can become problematic in a system with large off-time background signals which do not belong to the triggered event, yet are seen in the readout data. One solution to this problem is to reduce the area per channel, which implies an increase in the total number of channels and eventually leads to a pixel detector. The other option is to reduce the shaping time at the cost of signal-to-noise. We present an advanced method which can be applied using the APV25 front-end chip. Using multiple sampled points along the shaping curve, the hit timing can be reconstructed with high precision.