Speaker
Description
The realization of 4D tracking with simultaneous micrometer spatial and picosecond temporal resolution relies not only on sensor technology but also on a precise understanding and calibration of the readout electronics. While Trench-Isolated Low-Gain Avalanche Detectors (TI-LGADs) offer the necessary segmentation and intrinsic gain, this high level of segmentation necessitates a dedicated readout ASIC which adds additional complexity to the system and needs to be understood to a high level in order to achieve the best possible performance.
To show the limit of the achievable timing resolution, we will present results gathered via a femtosecond Two Photon Absorption (TPA) laser and testbeam measurements with the Timepix4 beam telescope. The results are obtained with two generations of FBK TI-LGADs on Timepix4. The Timepix4 ASIC has a pitch of 55 micron, and measures both the time of arrival (ToA) and the charge in the form of the time over threshold (ToT). The TDC bins are 195 ps which gives a temporal resolution of 56 ps. The combination of laser and testbeam measurements give us the tools to fully characterize both sensor and ASIC and to determine the best way to correct for effects such as timewalk and clock corrections to achieve our optimal temporal resolution.
The results show that we can achieve an excellent timing performance. We will focus on identifying the factors limiting the temporal resolution and discuss the potential for further improvement.