Upgrade of the ATLAS Hadronic Tile Calorimeter for the High Luminosity LHC

Christophe Clement

doi:10.1134/s1063778821030091

Abstract

The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS experiment. It is a scintillating plastic tiles and steel absorbers sampling calorimeter. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMTs). The TileCal response and its readout electronics are monitored to better than 1 $$\%$$ using radioactive source, laser and charge injection systems. The TileCal electronics will undergo major upgrades for the high luminosity phase of the LHC (HL-LHC), so that the system can cope with increased radiation and can meet the requirements of a 1-MHz trigger. Digitized signals from all PMTs are sent to the back-end electronics and to the first level of trigger at 40 MHz. This will provide better precision in the trigger system and will allow the development of more complex trigger algorithms. The TileCal upgrade program has included extensive R&D and test beam studies. A Demonstrator module was inserted in ATLAS in 2019 for testing in actual detector conditions. The main features of the TileCal upgrade program and results obtained from the Demonstrator tests are discussed.

Highlights

The High Luminosity upgrade of the LHC (HL-LHC) [1] will provide an instantaneous luminosity 7.5 times larger than LHC, to reach a dataset size of 4000 fb−1 by the end of the high luminosity phase of the LHC (HL-LHC)
The ATLAS Tile Calorimeter (TileCal) is a scintillating plastic tiles and steel absorbers hadron calorimeter located at |η| < 1.7
The TileCal role is to measure the energy of hadronic jets and is crucial to the measurement of the missing transverse momentum upon which many physics analyses rely

Summary

Introduction

The High Luminosity upgrade of the LHC (HL-LHC) [1] will provide an instantaneous luminosity 7.5 times larger than LHC, to reach a dataset size of 4000 fb−1 by the end of the HL-LHC. They hold the PMTs and on-detector electronics. The “integrator read out” integrates the PMT current for calibration of the calorimeter with a 137Cs source It provides a relative measurement of the accelerator luminosity at the ATLAS collision point [5]. The Main Board has been fully qualified for the expected radiation environment at HL-LHC and has entered pre-production Both the Main Board and the Daughter Board have been designed to have two electrically independent halves. PreProcessor The TileCal PreProcessor receives the data from the Daughter Board, computes the energy and time of the PMT pulses using digital filters, and buffers the data while waiting for a trigger decision from the ATLAS trigger. Validation of high speed communication working with a prototype of the rear module has been performed successfully in the lab

Low voltage distribution

High voltage distribution and regulation

Findings

Conclusion