Ultra-Fast Silicon Detectors & Beyond: a Decade of Developments Chasing Accurate 4D Tracking

by Roberta Arcidiacono (Università del Piemonte Orientale, Italy)

Wednesday 24 Apr 2024, 11:15 → 12:45 Europe/Zurich

Ecole de physique

In the past decade, there has been growing interest in the development of silicon sensors able to simultaneously accurately measure the time of passage and the position of impinging charged particles. 

Two design innovations have radically changed the performance of silicon sensors, transforming them into high-resolution timing detectors, capable of meeting the high demands of future 4D trackers: the introduction of internal moderate gain and of intrinsic charge sharing. The internal gain mechanism leads to large signals and improved time resolution, while charge sharing eliminates the necessity for extremely small pixels to achieve excellent spatial resolution.

In this seminar, I will outline the journey that led to the current state-of-the-art silicon sensors for 4D-tracking, beginning with the UFSD (Ultra-Fast Silicon Detectors) sensors, based on the LGAD technology, with excellent timing capability.  Excellent spatial resolution is achieved with thin LGAD coupled with a resistive read-out (also called RSD sensors). The goal of this device is to achieve a spatial resolution of a few micrometres using large pixels (150-200 micrometres), concurrently providing an excellent time resolution (~30 ps). 

LGAD- and RSD-based silicon sensors are now adopted, or considered, in several future experiments and are the basis for several future 4D-trackers.

UFSD_beyond_UNIGE.pdf