The Laser calibration of the Atlas Tile Calorimeter during the LHC run 1

TL;DR

This paper details the Laser calibration system for the Atlas Tile Calorimeter during LHC Run 1, focusing on stability, calibration constant computation, and timing correction methods to ensure precise measurements.

Contribution

It introduces a comprehensive Laser calibration approach for the Atlas Tile Calorimeter, including stability analysis, calibration constant calculation, and timing correction techniques.

Findings

Electronics stability variations below 0.6%

Calibration constants determined with 0.3-0.5% uncertainty

Effective detection and correction of timing misconfigurations

Abstract

This article describes the Laser calibration system of the Atlas hadronic Tile Calorimeter that has been used during the run 1 of the LHC. First, the stability of the system associated readout electronics is studied. It is found to be stable with variations smaller than 0.6 %. Then, the method developed to compute the calibration constants, to correct for the variations of the gain of the calorimeter photomultipliers, is described. These constants were determined with a statistical uncertainty of 0.3 % and a systematic uncertainty of 0.2 % for the central part of the calorimeter and 0.5 % for the end-caps. Finally, the detection and correction of timing mis-configuration of the Tile Calorimeter using the Laser system are also presented.