Performance monitoring techniques for semiconductor pixel detectors in long-term operations

Abstract: Semiconductor pixel detectors are widely used in various applications, many of which require sustained stability of the detector performance over extended periods of operations. However, the presence of irreversible and temporary degradations can impact the detector performance during prolonged use. Thus, continual monitoring of the detector performance that can be affected by degradation effects become necessary. This paper presents a cost-effective examination procedure for real-time monitoring and regular inspections of pixel detectors during prolonged operations. The real-time monitoring method monitors the charge drifting process without introducing additional background by utilizing the cosmic muons to detect temporary effects caused by shifts in operating conditions such as ambient temperature. On the other hand, the offline inspection regularly evaluates the per-pixel spectral characteristics including baseline and gain using simple radioactive sources to evaluate the level of irreversible degradation. The monitoring procedure is validated on a Timepix3 detector equipped with a CdTe sensor which proves its effectiveness.