Re: X-ray detector equipment with semiconductor sensor

Fred Bartoli <mynamewithAdotinbetween@xxxxxxx> wrote in
news:46cc95c1$0$432$426a74cc@xxxxxxxxxxxx:

Le Wed, 22 Aug 2007 13:24:42 +0000, Jim Yanik a écrit:

Robert Baer <robertbaer@xxxxxxxxxx> wrote in
news:46cb5400_2@xxxxxxxxxxxxxxxxxx:

Chris Jones wrote:
lmr wrote:


I would like to know if someone have a example of a circuits that have
a commercial photodiode or phototransistor how sensors ? Send me a
link or achive with applications notes ! I am trying to development a
small x-ray dose meter for x-ray diagnostic ! Thanks for help !


This circuit claims to be able to detect 60keV photons:

http://pdfserv.maxim-ic.com/en/an/AN2236.pdf

I think that it may not be suitable for detecting high dose rates like
you would find with an X-ray tube.

Chris
Recently, i had some X-rays taken, 50 KEV and the imaging plate was
a
semiconductor (array?) with very good resolution - as good as film.


it was probably coated with a phosphor,and the silicon just reads the
light emitted from the phosphor when the Xrays strike it.

Yup, except this almost surely isn't phosphor.
I've done some interesting consulting for this product line http://
www.trixell.com/pdf/Pixium4600.pdf and they use cesium iodide because of
its high conversion efficiency.




Well,that would BE one kind of phosphor.
I did say "a phosphor". 8-)
Just an emissive coating,usually made from rare earth elements,like TV sets
use.You would select for best wavelength that the semiconductor is most
sensitive to,probably shortwave IR)

--
Jim Yanik
jyanik
at
kua.net
.