Speaker
Description
This contribution reports on the results of large-area (2 cm$^2$) small pitch (55 μm) inverse Low-Gain Avalanche Detectors (iLGAD), bonded to Timepix3 readout chips. The ilGAD sensors were produced by Micron Semiconductor Ltd with the goal to obtain good gain uniformity and minimise the fill-factor issue present with traditional small-pitch LGAD designs. We have conducted detailed performance evaluations using both laboratory-based X-ray calibrations and beam tests. An XRF setup has been used to obtain energy calibration and to identify the optimal operating settings of the new devices, whereas the extensive beam tests allowed for a detailed evaluation of the tracking and general detector performance. The beam-tests were performed at the CERN SPS North Area H6 beamline, using a 120 GeV/c pion beam. The reference tracking and time-stamping is achieved by a Timepix3-based beam telescope setup.
The results show a gain of around 5 with very good uniformity, measured across the whole gain area, as well as a hit time resolution limited by the Timepix3 readout binning of 1.5 ns. The contribution of time-walk effects to the time resolution is largely reduced, compared to sensors without gain. Furthermore, it is shown that the gain opens the possibility of a good X-ray energy resolution down to 4.5 keV.
