[Gate-users] Optical Photons Detection

[Vesna Cuplov]

Hello Raphael,

The system consists of an LSO crystal ideal apd behind it (x position).
>

The only information that you give us is the type of detector you use. Do
you use any phantom in your
simulation or you just send optical photons directly to your detector as a
first test?


> The problem: nearly all optical singles are located on the opposite side
> of the apd.
>
> The profiles look like this:
>
> x location: peak .. low .. low .. low  <- exactly the opposite of what i
> expected
> y location: peak .. low .. low .. peak
> z location: peak .. low .. low .. peak
>

 Could you send the x location plot? If your perfect-apd surface is defined
in between the APD and the LSO and that the LSO volume is a SD, then you
should detect your photons at that x-position. Where is your peak located?



> Another consideration is that there are nearly no optical absorptions
> meassured, just "Transportation".
>

That is normal because the LSO absorption length is 50m in Materials.xml
but you can change that to make some tests.

The surface between the crystal and the apd is described by
> "perfect_apd".
>

yes, that's correct.


> All other surfaces of the crystals are described by
> "polished_teflon_wrapped". I added both at the end of the mail.
>

what other surfaces did you define? For testing purpose you do not need to
define the other surfaces now,
they will be smooth by default, just one surface is enough to test if you
detect photons correctly.

I think it would be good if you send me your macro.

regards
vesna