Speaker
Dr
André dos Anjos
(University of Wisconsin, Madison, USA)
Description
The DAQ/HLT system of the ATLAS experiment at CERN, Switzerland, is being commissioned for first collisions in 2009. Presently, the system is composed of an already very large farm of computers that accounts for about one-third of its event processing capacity. Event selection is conducted in two steps after the hardware-based Level-1 Trigger: a Level-2 Trigger processes detector data based on regions of interest (RoI) and an Event Filter operates on the full event data assembled by the Event Building system. The detector readout is fully commissioned and can be operated at its full design capacity. This places on the High-Level Triggers system the responsibility to maximize the quality of data that will finally reach the offline reconstruction farms.
This paper brings an overview of the current ATLAS DAQ/HLT implementation and performance based on studies originated from its operation with simulated, cosmic particles and first-beam data. Its built-in event processing parallelism is discussed for both HLT levels as well as an outlook of options to improve it.
Author
Dr
André dos Anjos
(University of Wisconsin, Madison, USA)
