TARDIS Lab: infrastructure for characterization and assembly of highly granular silicon calorimeter modules for LUXE and future Higgs Factories

Abstract

The TARDIS Lab has been established at IFIC (CSIC-UV) to develop infrastructure and expertise in high-granularity silicon calorimetry. The laboratory provides an ISO7 clean-room environment and dedicated instrumentation for silicon sensor characterization and ultra-thin calorimeter module assembly. It supports developments of silicon-based high-granularity calorimetry concepts pursued within CERN DRD Calo (DRD6) and the FCAL Collaboration. These developments serve not only as technological prototypes of the electromagnetic calorimeters and luminometers at future Higgs-factory proposals (FCC-ee, Linear Collider Facility at CERN, International Linear Collider, etc.) but are also essential for the strong-field QED program of the LUXE experiment. We describe the laboratory infrastructure, assembly workflows and DESY test-beam validation of fully assembled calorimeter modules. The assembled ECALp modules have an average thickness of approximately 760~$μ$m, while laboratory tests of 4352 channels identified connectivity problems in only 0.5\% of them. For the two SiWECAL modules assembled in 2025, connectivity problems were observed at the level of approximately $10^{-3}$ of the instrumented pads, with no mechanical failures or sensor delamination after transport and beam operation. We also present ongoing infrastructure upgrades and production milestones for 2026-2027.