3D silicon pixel detectors for the ATLAS Forward Physics experiment

Abstract

The ATLAS Forward Physics (AFP) project plans to install 3D silicon pixel detectors about 210 m away from the interaction point and very close to the beamline (2-3 mm). This implies the need of slim edges of about 100-200 $\mu$m width for the sensor side facing the beam to minimise the dead area. Another challenge is an expected non-uniform irradiation of the pixel sensors. It is studied if these requirements can be met using slightly-modified FE-I4 3D pixel sensors from the ATLAS Insertable B-Layer production. AFP-compatible slim edges are obtained with a simple diamond-saw cut. Electrical characterisations and beam tests are carried out and no detrimental impact on the leakage current and hit efficiency is observed. For devices without a 3D guard ring a remaining insensitive edge of less than 15 $\mu$m width is found. Moreover, 3D detectors are non-uniformly irradiated up to fluences of several 10${}^{15}$ n${}_{eq}$/cm${}^2$ with either a focussed 23 GeV proton beam or a 23 MeV proton beam through holes in Al masks. The efficiency in the irradiated region is found to be similar to the one in the non-irradiated region and exceeds 97% in case of favourable chip-parameter settings. Only in a narrow transition area at the edge of the hole in the Al mask, a significantly lower efficiency is seen. A follow-up study of this effect using arrays of small pad diodes for position-resolved dosimetry via the leakage current is carried out.

10 pages, submitted to JINST

References in corpus (2)

• Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip
• Beam Test Studies of 3D Pixel Sensors Irradiated Non-Uniformly for the ATLAS Forward Physics Detector

Cited by in corpus (11)

• Observation and measurement of forward proton scattering in association with lepton pairs produced via the photon fusion mechanism at ATLAS
• The ATLAS Experiment at the CERN Large Hadron Collider: A Description of the Detector Configuration for Run 3
• Radiation hardness of small-pitch 3D pixel sensors up to a fluence of $3\times 10^{16}$ n${}_{\mathrm{eq}}$/cm${}^2$
• Beam tests of an integrated prototype of the ATLAS Forward Proton detector
• Search for an axion-like particle with forward proton scattering in association with photon pairs at ATLAS
• 3D silicon pixel detectors for the High-Luminosity LHC
• Module production of the one-arm AFP 3D pixel tracker
• 3D sensors for the HL-LHC
• Resolution studies with the DATURA beam telescope
• Performance of the ATLAS forward proton Time-of-Flight detector in Run 2
• Missing-mass search in forward-proton-tagged dilepton events with the ATLAS detector