Novel silicon readout shapes for time-of-flight detectors

Scientists at ETP are collaborating with INFN Torino and CERN to develop a silicon sensor with precise temporal and spatial resolution called the Resistive Silicon Detector (RSD/ AC-LGAD). This is an n-in-p sensor with an internal gain layer and resistive layer near the surface. As charged particles traverse the sensor, they induce signals that are shared between readout electrodes. This concept of resistive charge sharing enables large distances between electrodes while maintaining spatial and temporal precision. 

In future collider experiments such as the FCC-ee, such a sensor can be used as a Time-of-Flight detector as part of a system which will identify the type of particle traversing the detector. This is a fundamental component to enable future experiments to perform precise studies of the Standard Model of particle physics. Such a system would require many square meters of silicon detectors. The standard Low Gain Avalanche Diode (LGAD) technology currently used in timing layers must be divided into pixels, using LGADs in a Time-of-Flight system would result in a large channel count and overall detector cost. Thus, an alternative sensor geometry is needed to maintain a low number of readout channels (less power, less cooling, and less cost).

This paper describes a novel readout shape geometry which could be expanded for future use in these large Time-of-Flight systems. This novel RSD will have precise timing and precise, one dimensional spatial resolution. The results were presented by ETP at the TREDI conference in Perugia, Italy and are now published in JINST.