Timepix3: first measurements and characterization of a hybrid-pixel detector working in event driven mode

Abstract

Timepix3 is a hybrid pixel detector readout chip. It features a data driven readout mode where the chip sends out a data packet containing pixel coordinate, time over threshold and time of arrival immediately after the hit is processed by the pixel. The maximum hit rate is 40 Mhits/cm 2 /s with a minimum time step in the arrival time measurement of 1.56 ns. The pixel matrix consist of 256 × 256 square pixels at a 55 µm pitch and the pixel front end noise is 61 e − RMS. In this paper we present the first radiation measurements with Timepix3 bump bonded to a 300 µm thick silicon sensor. The chip is calibrated per pixel, using internal test pulses and the calibration is verified using X-ray fluorescence. The energy resolution, threshold dispersion and gain dispersion is measured. The energy resolution in time over threshold mode under normal operation conditions is 4.07 keV FWHM at 59.5 keV. At 10.5 keV an energy resolution of 0.72 keV FWHM was achieved in photon counting mode and in time over threshold mode, by optimizing the energy response, we achieved a 1.38 keV FWHM. We also investigate the time walk and present first results on using the time information for track reconstruction.

3D reconstruction of particle tracks in a 2 mm thick CdTe hybrid pixel detector

“…For proper time-stamping, the time-walk effect has to be corrected for. This can be done by test pulses [24] or experimentally [3,5]. In the presented work, the latter method was used.…”

Towards a new generation of pixel detector readout chips

“…A global shutter is used to stop or activate detection but, as long as the shutter is open, data is continuously driven off chip as soon as it is generated. Using this mode spectroscopic X-ray imaging is also possible [7], but at a significantly lower flux than that permitted by Medipix3. On the other hand, much more information is available for analysis as the time stamp permits off-line clustering and the number of energy bins used can be chosen a posteriori according to the needs of the application.…”

“…The data shown in figure 4 has been reconstructed to shown the 3D view of the charge in the silicon sensor[7].…”

Ionizing Energy Depositions After Fast Neutron Interactions in Silicon

“…The chip design allows a simultaneous measurement of the time and the energy in each pixel. Details on the chip design and measurements of the detector performance can be found in [4], [17], [18].…”

“…This time interval was calibrated to ionizing energy depositions in the silicon by using the photo-electron signal after the illumination with X-rays of known energy [19]. With a counter of 40 MHz clock frequency, energy resolutions of about 4 keV could be achieved for the photo peak of a 241 Am-source at 59.5 keV [18].…”