Speaker
Julian Glatzer
(CERN)
Description
The ATLAS Level-1 Central Trigger (L1CT) system is a central part of
ATLAS data-taking and is configured, controlled, and monitored by a
software framework with emphasis on reliability and flexibility. The
hardware has undergone a major upgrade for Run 2 of the LHC, in order
to cope with the expected increase of instantaneous luminosity of a
factor of 2 with respect to Run 1. It offers more flexibility in the
trigger decisions due to the double amount of trigger inputs and
usable trigger channels. It also provides an interface to the new
topological trigger system. Operationally - particularly useful for
commissioning, calibration and test runs - it allows concurrent,
independent triggering of up to 3 different sub-detector combinations.
In this contribution, we give an overview of the fully operational
software framework of the L1CT system with particular emphasis on the
configuration, controls and monitoring aspects. The software framework
allows the L1CT system to be configured consistently with the ATLAS
experiment and the LHC machine, upstream and downstream trigger
processors, and the data acquisition. Trigger and dead-time rates are
monitored coherently at all stages of processing and are logged by the
online computing system for physics analysis, data quality assurance
and operation debugging. In addition, the synchronisation of trigger
inputs is watched based on bunch-by-bunch trigger information. Several
software tools allow to efficiently display the relevant information
in the control room in a way useful for shifters and experts. The
design of the framework aims at reliability, flexiblity, and
robustness of the system and takes into account the operational
experience gained during Run 1. We present the overall performance
during cosmic-ray data taking with the full ATLAS detector and the
experience with first beams in 2015.
Author
Julian Glatzer
(CERN)
