The Online Calibration, Operation, and Performance of the CMS Pixel Detector

TL;DR

This paper details the calibration, operation, and performance of the CMS pixel detector, emphasizing the calibration procedures, detector operation during early LHC runs, and handling of high background events.

Contribution

It presents the calibration methods, operational procedures, and performance insights of the CMS pixel detector since its installation in 2008.

Findings

Calibration of Readout Chips' thresholds and analog response completed

Detector operated successfully during early LHC runs

Mechanisms developed for handling large beam background events

Abstract

The CMS pixel detector consists of approximately 66 million silicon pixels whose analog signals are read out by 15,840 programmable Readout Chips. With the recent startup of the LHC, the detector is now collecting data used for precise vertexing and track-finding. In preparation for data taking, the detector's Readout Chips and their supporting readout and control electronics were calibrated. The calibration that has taken place since the detector's installation in the summer of 2008 will be described. These calibrations focused on the optimization of the Readout Chips' thresholds and analog response. The operation of the detector during the early running of the LHC will also be discussed. The calibrations that are performed on a regular basis and a mechanism to handle the readout of large beam background events will be described.