Beam Test Studies of 3D Pixel Sensors Irradiated Non-Uniformly for the ATLAS Forward Physics Detector

TL;DR

This paper reports on beam test studies of 3D pixel sensors irradiated non-uniformly, demonstrating their suitability for the ATLAS Forward Physics detector with improved radiation hardness and reduced dead area.

Contribution

It presents the electrical characterization and beam test results of 3D pixel sensors specifically irradiated non-uniformly for the ATLAS AFP upgrade.

Findings

Sensors maintain performance after non-uniform irradiation

Reduced dead area achieved in 3D pixel sensors

Validation of 3D sensors for high-radiation environments

Abstract

Pixel detectors with cylindrical electrodes that penetrate the silicon substrate (so called 3D detectors) offer advantages over standard planar sensors in terms of radiation hardness, since the electrode distance is decoupled from the bulk thickness. In recent years significant progress has been made in the development of 3D sensors, which culminated in the sensor production for the ATLAS Insertable B-Layer (IBL) upgrade carried out at CNM (Barcelona, Spain) and FBK (Trento, Italy). Based on this success, the ATLAS Forward Physics (AFP) experiment has selected the 3D pixel sensor technology for the tracking detector. The AFP project presents a new challenge due to the need for a reduced dead area with respect to IBL, and the in-homogeneous nature of the radiation dose distribution in the sensor. Electrical characterization of the first AFP prototypes and beam test studies of 3D pixel devices irradiated non-uniformly are presented in this paper.