Hi Friederike,
We didnt have any other way of checking the spot size but knowing the optics well, and having scanned the beam size we know where it stops measuring.
The depth of field of the imaging setup is sufficient and not smaller than the scintillator thickness.
I have considered the influence of the substrate (and literature informs me it is possible) but dont have the substrate separately to test, nor do I have the scintillator on a glass substrate.
Having spoken to Crytur, we think the scintillator is the bottleneck. Have decided to build an x-ray microscope and relax the imaging requirements, instead. Will test the x-ray micropscope hopefully this year.
Thanks for taking the time to respond.
Cheers,
Cigdem