LAr Phase 1 Upgrade
The LAr calorimeter upgrade is aimed at increasing the granularity of the analog signals provided to the L1 trigger.
The upgrade involves designing, prototyping, and building a new front-end-crate base-plane and a new trigger digitizer board for the Canadian-built Hadronic EndCap Calorimeter. (A base-plane is a highly specialized multilayer circuit board with a large number of connectors, that allows for more data to be transmitted to a similar sized crate). The pre-production batch of two base-planeswas assembledin 2016, and acceptance tests were successfully completed. Subsequently, characterization tests have been carried out and confirm the high quality of the base-planes.
Compatibility tests have been carried out at CERN and full production of base-planeshas started. The quality assurance tests for full production are a shared responsibility between TRIUMF and the University of Victoria.
LAr Phase 2 Upgrade
At the HL-LHC, the average number of interactions per bunch crossing is expected to be about 200 (an order of magnitude increase compared to Run 1). The existing ATLAS trigger system will not be able to cope with the resulting high pile-up conditions and will be replaced. The existing LAr readout electronics is incompatible with this new trigger system, and the current LAr front-end electronics would reach the limit of their radiation tolerance during the HL-LHC phase. For these reasons, the entire front-end and back-end readout electronics of the ATLAS LAr calorimeter will be replaced during LS3.The resources needed are the analog design expertise of the detector group run by Leonid Kurchaninov. The frontend electronics for the Hadronic Endcap calorimeters (HEC) are different from the other LAr sub-detector components because the HEC has preamplifiers in the LAr. The second part of the project is to develop digital boards based on FPGA technology and the appropriate firmware for digital signal processing in order to determine the energy deposition in the LAr calorimeters under very high pileup conditions of 200 events per bunch crossing.
We gratefully acknowledge support from the Natural Sciences and Engineering Research Council of Canada and the the Canada Foundation for Innovation.
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