Note: Nanosecond LED-based source for optical modeling of scintillators illuminated by partially coherent X-ray radiation

We developed a broad-spectrum light source specifically designed to reproduce the temporal behavior of the optical pulses emitted by scintillators for X-ray detection. Nanosecond-to-millisecond pulses are generated through a fast circuit driving Light Emitting Diodes (LEDs) and are endowed with the peculiar time features of the most employed scintillators by means of a dedicated pulse shaping stage. We implement the light source for the optical modeling of the single-shot X-ray coherence measurements with near-field speckles generated by the scattering from colloidal suspensions (heterodyne near field speckle method). Moreover, we derive a rigorous scaling law that quantitatively relates visible and X-ray signal-to-noise ratios.