Achievements of the ATLAS Upgrade Planar Pixel Sensors R&D Project

TL;DR

This paper reviews the progress of the ATLAS Planar Pixel Sensor R&D Project, demonstrating advancements in radiation-hard pixel sensors for the HL-LHC upgrade, including beam tests, sensor design improvements, and simulation comparisons.

Contribution

It provides a comprehensive overview of recent developments in planar pixel sensor technology, including irradiation testing, edge passivation techniques, and large-area prototyping efforts.

Findings

Beam test results show sensors withstand high fluences (>10^16 n_eq/cm^2).

Successful development of edgeless n-in-p pixel assemblies with irradiation.

Sensor design improvements and low-cost hybridisation concepts are progressing.

Abstract

In the framework of the HL-LHC upgrade, the ATLAS experiment plans to introduce an all-silicon inner tracker to cope with the elevated occupancy. To investigate the suitability of pixel sensors using the proven planar technology for the upgraded tracker, the ATLAS Planar Pixel Sensor R&D Project (PPS) was established comprising 19 institutes and more than 90 scientists. The paper provides an overview of the research and development project and highlights accomplishments, among them: beam test results with planar sensors up to innermost layer fluences (> 10^16 n_eq cm^2); measurements obtained with irradiated thin edgeless n-in-p pixel assemblies; recent studies of the SCP technique to obtain almost active edges by postprocessing already existing sensors based on scribing, cleaving and edge passivation; an update on prototyping efforts for large areas: sensor design improvements and concepts for low-cost hybridisation; comparison between Secondary Ion Mass Spectrometry results and TCAD simulations. Together, these results allow an assessment of the state-of-the-art with respect to radiation-hard position-sensitive tracking detectors suited for the instrumentation of large areas.