Speaker
Description
In preparation for the High-Luminosity era of the LHC, the CMS experiment will replace the existing calorimeter endcaps with a novel device - the High Granularity Calorimeter (HGCAL), having around six million readout channels. The back-end readout system is based on a common CMS-wide development: ATCA boards called "Serenity", featuring optical inputs and FPGA-based processing. The electronics system for this upgrade project is highly specialized and complex, involving multiple layers of data transfer, so the testing must be carefully planned. The strategy has been to split the efforts between vertical (start-to-end) and horizontal (parallelization) test systems. An important milestone for the former has been the development and operation of test systems to prototype one vertical slice of the future endcap electronics system. This talk will provide an overview of the HGCAL backend system design and development of vertically integrated test systems what were used as the readout element in beam tests in September, 2023.