Results from the commissioning of the ATLAS Pixel detector

TL;DR

This paper reports on the successful commissioning, calibration, and performance of the ATLAS Pixel detector, demonstrating high efficiency and low noise levels after extensive testing with cosmic-ray data before LHC collisions.

Contribution

It provides the first comprehensive results on the commissioning and calibration of the ATLAS Pixel detector, highlighting its readiness for LHC collision data collection.

Findings

96% of the detector was calibrated and tuned.

Tracking hit efficiency reached 99.8%.

Noise occupancy was at 10^-10 level.

Abstract

The ATLAS Pixel detector is a high-resolution, low-noise silicon-based device designed to provide tracking and vertexing information within a distance of 12 cm from the LHC beam axis. It consists of approximately 80 million pixel channels with radiation-hard front-end electronics connected through optical fibers to a custom-controlled DAQ system away from the detector. Following the successful installation of the detector in June 2007, an intense commissioning period was conducted in the year 2008 and more than 400,000 cosmic-ray tracks were recorded in conjunction with other ATLAS sub-detectors. By the end of the year, 96% of the detector was tuned, calibrated, and taking data at 99.8% tracking hit efficiency and with noise occupancy at the 10^-10 level. We present here the results of the commissioning, calibration, and data-taking as well as the outlook for future performance with LHC collision-based data.