Validation of Timepix4 energy calibration procedures with synchrotron X-ray beams

The Timepix4 is an application-specific integrated circuit developed by the Medipix4 collaboration. The chip is a 448 × 512 matrix that can be connected, via bump-bonding, to pixelated sensors of various materials and thicknesses, forming application specific detection systems. Among the Timepix4 operating modes, the data-driven Time-of-Arrival - Time-Over-Threshold is a particularly promising mode for spectral imaging applications: data packets are generated every time the charge created by the incoming radiation goes above a pre-defined threshold, allowing the count of the detected particles and their energy measurement. This article investigates the spectroscopic characteristics of a Timepix4 assembly equipped with a 300 μm Si sensor, using monochromatic X-ray beams in the energy range 8.5 keV–40 keV working at the SYRMEP beamline of the Elettra synchrotron. The accuracy and the energy resolution of the reconstructed energy spectra, together with an energy resolution model, will be presented.