Test-beam results from the ATLAS level-1 calorimeter trigger demonstrator Bohm, C.; Brawn, I.; Bright-Thomas, P. ...
1998 IEEE Nuclear Science Symposium Conference Record. 1998 IEEE Nuclear Science Symposium and Medical Imaging Conference (Cat. No.98CH36255),
1998, Volume:
1
Conference Proceeding
The ATLAS level-1 calorimeter trigger will utilise a number of advanced technologies, many of which have already been successfully demonstrated. To evaluate the different technologies associated with ...the important areas of high-speed data transport a large demonstrator system has been designed and operated during the last two years, using signals from prototype calorimeters in the ATLAS test-beam. Using this system, inter-crate data transmission and reception have been demonstrated at over 1.4 Gbyte/s, with individual links running at up to 1.6 Gbaud. Operating with 160 Mbit/s signals across a transmission-line backplane, custom transceiver ASICs have achieved inter-module data fanout at peak rates above 800 Mbyte/s. With the addition of further modules, the system was extended to emulate a vertical slice through the ATLAS level-1 calorimeter trigger. We present here the results from these tests, including measurements of bit-error rates across different data paths.
The proposed level-1 calorimeter trigger system for ATLAS relies upon several key technologies which we have been testing in a demonstrator programme. We describe here the final phase of this ...programme, which concentrates on crucial aspects of high-speed data transmission inherent in the trigger architecture while operating with signals from prototype ATLAS calorimeters. The 36-channel trigger demonstrator system has been designed to provide a flexible infrastructure for the study of alternative techniques of communication between the calorimeters and the trigger processor, including both analogue links and high-speed digital optical and electrical links operating at up to 1.6 Gbaud. Data fan-out at 160 Mbit/s between trigger processor modules using serialising Application Specific Integrated Circuits (ASICs) driving transmission-line backplanes is also evaluated. A programmable timing system re-synchronises all channels before pipeline processing by ASICs executing an electromagnetic cluster-finding algorithm. Some preliminary results are presented from the operation of this demonstrator system installed in the ATLAS test-beam at CERN.
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