Speaker
Description
A beam telescope based on the Timepix3 ASIC was built in order to perform
detailed studies of VELO Upgrade prototypes using charged particle beams. The
telescope consists of 8 planes of hybrid pixel detectors with 300 um p-on-n
silicon sensors.
Tracks measured with the telescope have excellent spatial resolution, reaching under 2 um due to the
small (55x55 m2) pitch, per-pixel measurements of the deposited charge, and
the orientation of the detector planes in order to maximally profit from charge
sharing.
In addition to precise spatial measurements, the Timepix3 ASIC operates with a
640 MHz oscillator that allows hit time-stamping in steps of 1.56 ns, giving a
potential time-measurement resolution of 450 ps per plane. It is of great
interest for future pixel trackers to investigate how precise time measurements
can be combined to give optimal track time precision. Detailed studies have
been performed to investigate the temporal resolution of individual telescope
planes and the track timestamp obtained through the combination of the 8
planes.
In order to control systematic effects and provide an independent time
measurement, two scintillators mounted on fast PMTs were placed at
opposing ends of the telescope. Their signals are treated by constant fraction
discriminators to minnimise jitter. The combination of this setup and
the track timestamps results in a temporal resolution of approximately 200 ps,
which has allowed the assessment of new prototypes with more promising
technologies for precise timing. The sub-nanosecond precision of the track time
allows the study of timing structures within the pixel chip, along with
measurements of other potential systematic effects. Complementary studies are
being performed in the lab with a laser setup and preliminary results will be
presented.
In this presentation the most recent results on the temporal resolution of the
Timepix3 telescope will be presented, together with the timing performance of
new sensor prototypes.
| Submission declaration | Original and unpublished |
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