Jana1d ago
I was even more productive yesterday and assembled this cute stack!
It’s four Hamamatsu S1337-1010BR Si photodiodes with respective amplifiers. I want to add a scintillator, a light-proof metal casing and see whether I can use this as an energy-dispersive x-ray sensor, maybe even do energy-dispersive x-ray spectroscopy
Show threadJana1d ago

the analog toolkit really lends itself to be plugged onto a different board with 2.54mm headers at the bottom, I think I will do this more often.

I could also add a dedicated B2B connector, but I don’t think this is a big need, maybe I will add a footprint for size constrained applications

Oh, and if anyone here has input on scintillators and building an energy dispersive x-ray sensor in general, feel free to chime in!

Show threadgigabecquerel8h ago
@janamarie Looks good!
Unfortunately I am very sure this won't work for EDX, or any kind of spectroscopy.
With scintillators you're counting single photons at those energies, and the diodes just leak way too much to get those tiny signals out of your regular shot noise.
Photodiodes can generally be used for x-ray detection, but with the S1337 only being PN as opposed to PIN their active region is tiny, and they have a high capacitance which just introduces noise.
Show threadJana8h ago
@gigabecquerel thanks! And aww, I almost feared something like that! Can you recommend a different diode? I’m happy to update the sensor board to try a different one
Show threadgigabecquerel7h ago

@janamarie As crappy as its reputation may be, I've seen some people pull fantastic x-ray spectra from regular old BPW-34!
But the real magic is in the preamplifier and following signal chain, the detector itself is just one part of the whole system.

check out this paper, as an example:
https://www.researchgate.net/publication/229038928_X-Ray_Spectroscopy_with_PIN_diodes

Show threadftg
@gigabecquerel @janamarie
BPW34's are amazing little devices for many things.
Friend also used one in his free space laser communications receiver.
And I know of at least one funny spectrometer build that had one.
That one also had significant thought spent on the preamp.
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