The development of ultra-thin, wafer-scale, flexible silicon pixel sensors: ITS3, the next generation inner tracker for ALICE

by Magnus Mager (CERN)

Thursday 7 May 2026, 15:00 → 16:00 Europe/Rome

Aula Magna

This presentation will first introduce ALICE and its main physics goals (study of quark-gluon plasma in heavy-ion collisions) together with the main observables and required detection techniques that are particularly challenging in view of the long-term physics program called ALICE3. In order to face with this demanding program, the collaboration started a strong R&D on CMOS sensors. Over the last 1-2 decades, monolithic CMOS particle sensors have become the technology of choice in applications where highest resolutions and lowest material budgets are key: with pitches in the order of 20 μm, they contain sensing elements and readout circuitry in only a few 10 μm thickness. Together with a very low power consumption this allows to build very light and precise detectors, which translates into excellent system-level performances. A large commercial interest in this technology - it is the same process that is used for image sensors - drives a rapid development, providing ever smaller feature sizes and higher integration densities, very much to the benefit of their application as particle detectors. At the same time, several specific optimizations have been developed to increase radiation hardness and speed, as well as to lower power consumption. The latest incarnation, the sensor for the new inner tracker, "ITS3", of ALICE pushes the technology further in a number of aspects that will be discussed in the Colloquium. "MOSAIX", the final prototype of the ITS3 sensor, has just been fabricated and marks a major milestone in the field. Results from the R&D program will be presented, showing that it will allow to achieve the final vertexing and tracking performances of the whole inner tracker detector. Finally, an outlook towards future applications and developments of monolithic CMOS sensors is given.