Challenges, Surprises, and Lessons from the ATLAS Liquid Argon Digital Trigger

by Adriana Milic (CERN)

Tuesday 8 Dec 2026, 09:00 → 10:30 Europe/Zurich

13/2-005 (CERN)

The Phase-I Upgrade of the ATLAS Liquid Argon (LAr) Calorimeter introduced
a new fully digital trigger readout system, significantly increasing the
granularity and precision of information available to the Level-1 trigger.
Developing and commissioning such a large scale custom electronics system
presented numerous technical challenges.

This seminar will provide an overview of the LAr calorimeter readout
architecture, with particular emphasis on the digital trigger readout
electronics. After introducing the main components of the system, I will
discuss the experience gained during detector commissioning and Run 3
operation. The talk will highlight practical lessons learned from operating
custom ASICs, optical links, and FPGA firmware in a demanding experimental
environment. Selected examples will illustrate how unexpected hardware and
firmware effects were identified, understood, and mitigated to achieve
reliable detector operation.

The seminar aims to provide insight into bringing complex detector
electronics from prototype to stable long-term operation, and the
engineering challenges encountered along the way.