# Performance of active edge pixel sensors

## TL;DR

This paper evaluates active edge pixel sensors designed for high-radiation environments like the HL-LHC, demonstrating their high efficiency and extended detection volume at the edges through beam tests.

## Contribution

It presents the design, production, and beam test performance of thin active edge pixel sensors with reduced insensitive areas for the ATLAS upgrade.

## Key findings

- High hit-efficiency at the detector edges
- Extended detection volume beyond pixel region
- Effective performance despite guard rings

## Abstract

To cope with the High Luminosity LHC harsh conditions, the ATLAS inner tracker has to be upgraded to meet requirements in terms of radiation hardness, pile up and geometrical acceptance. The active edge technology allows to reduce the insensitive area at the border of the sensor thanks to an ion etched trench which avoids the crystal damage produced by the standard mechanical dicing process. Thin planar n-on-p pixel sensors with active edge have been designed and produced by LPNHE and FBK foundry. Two detector module prototypes, consisting of pixel sensors connected to FE-I4B readout chips, have been tested with beams at CERN and DESY. In this paper the performance of these modules are reported. In particular the lateral extension of the detection volume, beyond the pixel region, is investigated and the results show high hit-efficiency also at the detector edge, even in presence of guard rings.