The new and complete Belle II DEPFET pixel detector: Commissioning and previous operational experience

Year: 2024

Type: article

Abstract: The Belle II experiment at the SuperKEKB collider in Tsukuba, Japan, has collected e + e − collision data between 2019 and 2022. After reaching a record-breaking instantaneous luminosity of 4.71 × 10 34 cm -2 s -1 and recording a dataset corresponding to 424 fb -1 , it completed its first planned long shutdown phase in December 2023. Aside from upgrades of the collider and detector maintenance, the shutdown was used for the installation of the two-layer Pixel VerteX Detector (PXD). As the innermost sub-detector, multiple scattering effects need to be reduced. PXD utilizes the Depleted P-channel Field Effect Transistor (DEPFET) technology, allowing for a material budget of 0.21% X 0 per layer. Each of the tracker’s 40 modules consists of an array of 250 × 768 pixels with a pitch ranging from 50 µm × 55 µm for the inner to 85 µm × 55 µm for the outer layer yielding high gain and high signal-to-noise ratio while retaining about 99% hit efficiency. This article discusses the experience of the 4-year operation of the previous single-layer PXD in harsh background conditions as well as commissioning and testing of the fully-populated PXD2 during Long Shutdown 1.

Source: Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment

DOI: 10.1016/j.nima.2024.169763

Institutions: University of Bonn, Halbleiterlabor of the Max-Planck-Society, Deutsches Elektronen-Synchrotron DESY, Justus-Liebig-Universität Gießen, Charles University, University of Göttingen

Language: English

Topic: Particle Detector Development and Performance

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,690

OpenAlex ID: W4401749432