Speaker
Description
The current ATLAS Inner Detector (ID) is unable to efficiently handle the increased event rate and radiation dose expected at the High Luminosity LHC (HL-LHC). To address this challenge, the ID will be entirely replaced with the all-silicon Inner Tracker (ITk), designed to provide superior tracking performance in the demanding HL-LHC environment. The ITk Pixel Detector, positioned in the innermost part of the ITk, will feature two types of modules: triplet modules with radiation-hard 3D sensors in the innermost layer (L0), where fluences up to $2 \times 10^{16} \, n_{\text{eq}} / \text{cm}^2$ are expected, and quad modules with planar n-in-p sensors 100 μm thick in the second layer (L1) and 150 μm in the outer layers (L2–L4).
Test beam characterization is integral to the qualification of modules for the ITk Pixel Detector, providing valuable insights into the performance of various sensor designs under different conditions and contributing to the finalization and refinement of the detector designs. A broad range of pre-production modules – including those equipped with the latest readout chips (ITkPixV2), produced by various vendors and featuring different sensor technologies and designs – is being tested in test beams both before and after irradiation. The collected data have been reconstructed and analyzed to evaluate key performance metrics of the pixel detectors, such as hit efficiency, spatial resolution, and its reliability.
This talk presents updates from the recent 2024/2025 test beam campaigns, highlighting several important developments. Notably, data were collected for the first time from triplet modules featuring 3D sensors from FBK (Fondazione Bruno Kessler, Italy), assembled with the ITkPixV2 readout chip, marking the first test of this configuration under test beam conditions. 3D sensors from SINTEF (Norway) irradiated to fluences up to $1.7 \times 10^{16} \, n_{\text{eq}} / \text{cm}^2$ and produced with a new passivation process, demonstrated strong performance, achieving over 96% average efficiency at approximately 70 V bias and up to 98% at 100 V. These results align with those from the original design sensors and confirm that the new passivation provides comparable radiation hardness. Additionally, two FBK thin planar modules, irradiated to $0.5 \times 10^{16} \, n_{\text{eq}} / \text{cm}^2$, have been remeasured to improve data quality. By carefully resetting and reapplying noise masks at each bias point, the number of masked pixels was significantly reduced, enabling stable operation across bias voltages. A high hit efficiency of approximately 99% was achieved at a moderate bias of around 220 V, confirming the suitability of these sensors for ITk requirements.
Details
Dr. Dmytro Hohov
Laboratoire de Physique des 2 infinis Irène Joliot-Curie – IJCLab (France)
https://www.ijclab.in2p3.fr/
| Internet talk | No |
|---|---|
| Is this an abstract from experimental collaboration? | Yes |
| Name of experiment and experimental site | ATLAS ITk pixel test beam collaboration (CERN) |
| Is the speaker for that presentation defined? | Yes |