Timepix3 detectors are the latest generetion of hybrid active pixel detectors of the Medipix family. Such detectors consist of an active sensor layer wich is flip-chip bump-bonded the readout ASIC, segmenting the detector into a square matrix of 256 x 256 pixels (pixel pitch 55 µm). Ionizing radiation interacting in the active sensor material creates charge carriers, which drift towards the pixelated electrode, where they are collected. In each pixel, the time of the interaction (time resulution 1.56 ns) and the energy deposition are measured.
We demonstrate with measured data (120 GeV pions, cosmic muons) how the time information can be used for “4D“ particle tracking, with the three spatial dimensions and the energy losses along the particle trajectory (dE/dx). Since the coordinates in the detector plane are given by pixelation (x,y), the x- and y-resolution is determined by the pixel pitch. The z-coordinate is reconstructed by evaluating the charge carrier drift times (z) with a resolution, experimentally proven to be better than 40 µm for a Timepix3 equipped with a 500 µm thick silicon sensor. Due to the data-driven readout scheme, the track information can be obtained in real-time.