[Gate-users] Materials.xml collaboration !

[Samuel BURG]

Hi Simon,
Hi all,

1)
here's some data I've collected about most used
cristals : NaI(Tl), BGO, GSO, LSO:Ce, YSO, YAP:Ce,
CsI(Tl), CsI(Na).

I have not put them in a structured XML file, as there
is still some missing data (mostly ABSLENGHT at PEAK and
RESOLUTIONSCALE).

2)
I'm also very confuesed about page 162 of the
GateUserGuide_v3.1.2, § "12.2.1 Scintillation
properties" :

Knowing number of photons follow a normal distribution
(Gauss Law), and assuming equation 12.2 [s = RS * sqrt
(E * SY)] is right, 
then equation 12.3 [RS = R at E / 2.35 * sqrt(E * SY)] is
false and should be : [ RS = R at E / (2.35 * sqrt(E *
SY)) ].

s = standar deviation
RS = ResolutionScale
sqrt = square root
E = energy (511000 eV)
SY = ScintillationYield
R at E = energy résolution @ E

as we have a normal law : FWHM = 2,354820045 * Simga

3)
Then I have had a look in the Materials.xml sample
file given with Gate 3.1.2, and found the data about
LSO:

.../...
<material name="LSO">
<propertiestable>
<property name="SCINTILLATIONYIELD" value="26000"
unit="1/MeV"/>
<property name="RESOLUTIONSCALE" value="4.41"/>
.../...

but when I use [ RS = R at E / (2.35 * sqrt(E * SY)) ]
with : 

R = 0,12
E = 511000
SY = 26000

I found RS = 0,23, witch is about 1/4.41 !

So, what do we need to put in Materials.xml for
RESOLUTIONSCALE, and how to compute it ?!?



Best regards,

Samuel Burg



--- Simon Stute <gate.stute at gmail.com> a écrit :

> Hi all,
> 
> 
> I suggest to everybody that have done some optical
> photon tracking with Gate
> to answer this mail and to post your Materials.xml
> file if it contains some
> additional material definitions. It would be nice to
> merge them and to put
> the more complete file as possible in the next Gate
> release. And I propose
> to do the job :-)
> When you post your file, could you just write the
> list of materials included
> in this file to easily avoid multiple definition ??
> 
> Thanks in advance for your collaboration,
> Simon Stute
> > _______________________________________________
> Gate-users mailing list
> Gate-users at lists.healthgrid.org
>
http://lists.healthgrid.org/mailman/listinfo/gate-users
> 



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