Design, development and performance of a charge injection board for the Hexaboards of CMS HGCAL

by Dr Shilpi Jain (DHEP, TIFR)

Monday 3 Mar 2025, 14:30 → 16:30 Asia/Kolkata

AG 66 (TIFR, Mumbai)

Calorimetry at the High Luminosity LHC (HL-LHC) faces two enormous challenges, particularly in the forward direction: radiation tolerance and unprecedented in-time event pileup. To meet these challenges, the CMS Collaboration is preparing to replace its current endcap calorimeters for the HL-LHC era with a high-granularity calorimeter (HGCAL), featuring a previously unrealized transverse and longitudinal segmentation, for both the electromagnetic and hadronic compartments, with five-dimensional information (space-time-energy) read out. The proposed design uses silicon sensors for the electromagnetic section and high-irradiation regions of the hadronic section , while in the low-irradiation regions of the hadronic section plastic scintillator tiles equipped with on-tile silicon photomultipliers are used. The full HGCAL will have approximately 6 million silicon sensor channels and about 240 thousand channels of scintillator tiles. Each silicon module uses front-end “hexaboards” with HGCROC chips (2 to 6 per board) to read data. Ensuring reliable solder connections between HGCROCs and the hexaboards is critical. A contactless charge injection (CI) system is being designed to test these connections without physical contact, to preserve board integrity. This non-invasive method will ensure rapid quality control for mass production, essential for HGCAL’s deployment. This talk will discuss the design, development and performance of the CI system.