Nov 18 – 20, 2019
CERN
Europe/Zurich timezone

Effects of trapping on the collected signals from subsequent laser pulses in irradiated silicon sensors

Nov 20, 2019, 10:20 AM
20m
30/7-018 - Kjell Johnsen Auditorium (CERN)

30/7-018 - Kjell Johnsen Auditorium

CERN

30/7-018
190
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Speaker

Leena Diehl (Albert Ludwigs Universitaet Freiburg (DE))

Description

During studies on the signal formation in silicon strip sensors, irradiated and annealed until the occurring of the phenomena of charge multiplication, it was observed that previously flowing free carriers changed the detector response. In particular, it was inferred that trapping of free carriers produced by a laser pulse changes the electric field distribution.
The impact of subsequent laser pulses distant even several microseconds on the signals was then studied by means of Edge- and Top-Transient Current Technique. A strong reduction of the collected charge and a change in the signal shape have been observed for different laser pulse repetition times and intensities, temperatures and sensor irradiation fluences.
The results confirm that trapping processes change the electric field distribution. This phenomenon known as “polarization effect” has been observed in other materials or in silicon at very low temperatures. In this work the consequences of this effect on the measured signals are shown at operation temperatures (-15°C-30°C).

Authors

Leena Diehl (Albert Ludwigs Universitaet Freiburg (DE)) Riccardo Mori (Albert Ludwigs Universitaet Freiburg (DE))

Co-authors

Marc Hauser (Albert Ludwigs Universitaet Freiburg (DE)) Ulrich Parzefall (Albert Ludwigs Universitaet Freiburg (DE)) Liv Wiik-Fuchs (Albert Ludwigs Universitaet Freiburg (DE)) Karl Jakobs (Albert Ludwigs Universitaet Freiburg (DE))

Presentation materials