Characterization and Performance of Silicon n-in-p Pixel Detectors for the ATLAS Upgrades

TL;DR

This paper evaluates silicon n-in-p pixel detectors for the ATLAS upgrade, demonstrating their radiation hardness, electrical performance, and suitability for high-fluence environments in future collider experiments.

Contribution

It presents the development and comprehensive characterization of n-in-p pixel sensors and modules, including irradiation effects and preliminary tracking performance results.

Findings

Sensors maintain performance after irradiation

Charge collection efficiency remains high post-irradiation

Preliminary testbeam results show promising tracking efficiency

Abstract

The existing ATLAS Tracker will be at its functional limit for particle fluences of 10^15 neq/cm^2 (LHC). Thus for the upgrades at smaller radii like in the case of the planned Insertable B-Layer (IBL) and for increased LHC luminosities (super LHC) the development of new structures and materials which can cope with the resulting particle fluences is needed. N-in-p silicon devices are a promising candidate for tracking detectors to achieve these goals, since they are radiation hard, cost efficient and are not type inverted after irradiation. A n-in-p pixel production based on a MPP/HLL design and performed by CiS (Erfurt, Germany) on 300 \mu m thick Float-Zone material is characterised and the electrical properties of sensors and single chip modules (SCM) are presented, including noise, charge collection efficiencies, and measurements with MIPs as well as an 241Am source. The SCMs are built with sensors connected to the current the ATLAS read-out chip FE-I3. The characterisation has been performed with the ATLAS pixel read-out systems, before and after irradiation with 24 GeV/c protons. In addition preliminary testbeam results for the tracking efficiency and charge collection, obtained with a SCM, are discussed.