Speaker
Description
Abstract
Timepix3 is a hybrid pixel detector readout chip that features an event driven mode. Upon incident particle hits, it sends processed pixel coordinate, time-over-threshold and time-of-arrival to the readout [1].
Timepix3 modules with planar and 3D sensors where studied with different x-ray sources, low and high-energy hadrons at test beams. This paper will report on the comparative spectral analysis of the two detectors and discuss their performances.
Summary
3D sensors compatible with Timepix3 where fabricated at CNM Barcelona, Spain and bump-bonded at Advacam, Finland. The structure of 3D sensors, where electrodes are processed inside the silicon bulk is known to affect the spectral response of x-ray and charged hadrons due to the presence of the electrodes themselves and the special electric field layout. In particular 3D are shown to be less prone to charge sharing than planar sensors. In this study we will use the Timepix3 features to study the detailed spectral response of the 3D sensors at different energies and particle incident angles to understand the spatial response of the sensor when compared to a planar one.
Comparisons studies of 3D and planar sensors include cluster size, as can be seen in Figure 1, cluster energy, pixel energy versus induced charge, and effects of 3D electrodes on the overall detection efficiency. The studied angles with respect to the incident beam are 0, 45, 60, and 70 degrees. Data were collected at the SPS facility of CERN, with 40GeV/c pion beams and at the Van Der Graaf facility in Prague with low energy proton and with radioactive sources at Manchester and Prague. For test beams the detectors were configured in a telescope arrangement of 2 synchronized planar and 3D-Timepix3 detectors and Readout with the Katherine software.
As an example of the results that will be shown, in Figure 2 top the Landau distribution of 40 GeV pions at zero degrees incident angle collected with the 3D sensors (main figure cluster size>2, insert cluster size>=1). At the bottom, images of the corresponding event distributions on the sensor for the low energy peaks and for the main landau peak for cluster size greater than 2. We will analyse these finding and report correlations with the geometrical response of the sensor.
[1] T Poikela et al 2014 JINST 9 C05013
