Percival soft X-ray CMOS Imager for Photon Science – Status and Prospects

Percival is a CMOS-based imager with 2 megapixels, also called P2M, designed for photon science experiments. The first generation of the P2M sensor showed some performance issues. Specifically, ADCs in full-speed operation mode are affected by crosstalk and show a non-linear and uncorrectable response. A firmware hack to the readout and data acquisition system has been introduced to partially overcome these effects, at the cost of limiting the frame rate to 83 Hz. Moreover, a non-uniform dark response of the sensor pixels is observed, explained by non-uniform bias currents across the chip: two opposite edges of the sensor cannot be digitized when applying biases that have the centre of the sensor operating normally. These issues are addressed in the re-submission of the chip. In this contribution, we present the current status of the detector and the first results from the re-designed sensor.