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Trigger for Particle Physics (TRI)

Module convenor: Roman Lietava (Birmingham) and Karim Massri (CERN)

Module Code: TR

Duration (Hours): 10 hourly sessions

Start Date and Commitments

Start: on 12/1/2024 - 10 lectures on Fri 11-12

Module Details

To provide an introduction to the principles of triggers for high energy physics experiments, to study how triggers are implemented in LHC experiments, and to look at future directions in triggering. In addition the assumptions and methods for Van der Meer scans will be discussed.

Lecture Notes

You can find the lecture notes online at

Learning objectives

Motivation for triggers in high energy physics experiments

Basic trigger concepts: coincidences, dead time management

Examples: NA57; OPAL

Requirements at the LHC.

Examples: ALICE SPD and TRD triggers: ATLAS L1 calorimeter trigger

Future directions in trigger development

Luminosity measurement with Van der Meer scans.

Syllabus in more detail:

Why triggers are necessary, simple triggering scheme with time budgeting, dead time, advantages of multi-level triggers, advantages of buffering, examples from CERN fixed target experiments, timing at the CERN LEP collider, deadtimeless triggers, trigger timing in the OPAL experiment, timing in an LHC experiment, the RD-14 TTC project, LHCb restrictions, examples of LHC triggers (the ALICE pixel trigger, the ATLAS L1 Calo trigger, the ALICE TRD trigger, High Level triggers, triggering in the Auger experiment, plan for CBM experiment at GSI, continuous triggers, implementation in LHCb and ALICE, the future of triggering.