The development and application of the test system for the silicon pixel modules in HEPS-BPIX

Abstract

HEPS-BPIX is a prototype of photon counting pixel detector developed for the High Energy Photon Source. It consists of 16 silicon pixel modules which should be tested individually to ensure the function and performance. Due to various factors such as the non-uniformity of the processes and voltage drop, the response of each pixel in the silicon pixel module is not identical completely. The response difference of pixels can be minimized by the threshold calibration. This system is developed for the quality test and calibration of the silicon pixel modules. The system consists of a mother board, a control board and a data acquisition (DAQ) system. The mother board provides necessary resources including power supplies and the fanout of calibration signals. Besides, it can be used to test the connectivity by monitoring the power states. The control board reads data out and provides the clock, trigger and configuration data for the silicon pixel module. The DAQ system sends the control commands and receives the readout data through an Ethernet link. Compared with the previous readout system, this designed system has a lower noise level and better scanning curves making the calibration more accurate. And it has been successfully applied to the comparison experiments of the through silicon via and wire-bonding silicon pixel modules. The results show that this test system can be used to the quality test and calibration of the silicon pixel modules. In addition, the system can be adapted to the measurement of different pixel array detector modules.