Speaker
Description
In recent years, significant efforts have been undertaken to extend the operational range of hybrid photon-counting detectors towards the tender and soft X-ray regime. In parallel with the development of new sensor technologies — notably Low-Gain Avalanche Detectors (LGADs) and thin entrance windows (TEW) [1] — these efforts have focused on the optimization of readout ASICs, with the objectives of minimizing electronic noise and thus lowering the minimum detectable energy. In this context, DECTRIS has developed a prototype EIGER2 detector [2] tailored for tender X-ray detection using an experimental calibration with fluorescence targets down to silicon K-alpha (1.74 keV). The prototype was successfully tested at the SOLEIL Synchrotron, where it recorded its first synchrotron light, and is currently undergoing further testing and characterization. This contribution presents a subset of the characterization results obtained at SOLEIL over the energy range of 1–3 keV. The following figures of merit are addressed: Quantum Efficiency (QE), Detective Quantum Efficiency (DQE), Noise Power Spectrum (NPS), spatial homogeneity, spatial resolution as quantified by Modulation Transfer Function (MTF), and count rate performance, together with a determination of the minimum viable threshold setting.
[1] Baruffaldi, F., et al., Commun Phys 8 (2025), 321
[2] Donath, T., et al., J. Synchrotron Rad. 30 (2023), 723-738
The authors acknowledge the beamline teams of SIRIUS, METROLOGIE and MARS for allocating beamtime and their support.