Spatial resolution and efficiency of prototype sensors for the LHCb VELO Upgrade

TL;DR

This paper evaluates the spatial resolution and detection efficiency of prototype sensors for the LHCb VELO upgrade, using beam test data to analyze performance under various conditions including irradiation levels.

Contribution

It provides a detailed characterization of sensor performance, including spatial resolution and efficiency, for both irradiated and non-irradiated prototypes in the context of the LHCb upgrade.

Findings

Spatial resolution varies with bias voltage, track angle, sensor thickness, and implant size.

Irradiated sensors maintain high efficiency despite radiation exposure.

Performance data supports sensor optimization for the LHCb upgrade.

Abstract

A comprehensive study of the spatial resolution and detection efficiency of sensor prototypes developed for the LHCb VELO upgrade is presented. Data samples were collected at the CERN SPS H8 beam line using a hadron mixture of protons and pions with momenta of approximately 180 GeV/c. The sensor performance was characterised using both irradiated and non-irradiated sensors. Irradiated samples were subjected to a maximum fluence of $\mathrm{8\times10^{15}~1~MeV~n_{eq}~cm^{-2}}$, of both protons and neutrons. The spatial resolution is measured comparing the detected hits to the position as predicted by tracks reconstructed by the Timepix3 telescope. The resolution is presented for different applied bias voltages and track angles, sensor thickness and implant size.