Speaker
Description
Inter-pixel capacitance (IPC) is an important parameter which needs to be measured accurately so that the required corrections can be applied to the measured conversion gain and hence all the derived detector performance characteristics. Different methods such as auto-correlation, absolute capacitance, hot-pixel, cosmic ray hits or single-pixel reset methods can be used to measure the inter-pixel capacitance of a detector. However, these methods measure the average IPC over the array or do not show if there are any variations in the IPC along the columns or the rows of the detector. A robust method has been used at ESO on a H4RG detector to determine if any variation of IPC across the array by implementing multiple column / row resets. We find the IPC indeed show variation across the array and the measured IPC is also dependent on readout / reset method employed. In addition, the glue voids at pixel level presents ice-crystal shaped filament features as they have a different gain and coupling to their neighboring pixels. The complex behavior of IPC would need to be taken into account in the detector modelling so that its effect on science can be assessed. This talk will present the measurement method used and the IPC results from an engineering H4RG-15 detector.
