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 µm, 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 $$10^{-3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:math> 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.