RE: source with organ geometry

From: Santana, Mario <msantana_at_SLAC.Stanford.EDU>
Date: Wed, 30 May 2012 08:54:26 -0700

Hi German,

This is something you could do:
- Edit the "source.f" routine to sample XFLK, YFLK and ZFLK so that they match
as closely as possible your desired volume. You could approach your volume by using
different subvolumes within which you uniformly sample XFLK, YFLK, ZFLK. Each volume
would be within and ELSE IF statement that would be chosen with a probability proportional
to its volume, i.e. you throw a random number FLRNDM() and if the number is smaller
than e.g. 0.2 you chose the subvolume that represents 20% of total volume, etc. etc.
- You want to make your sampling volume (or the combination of subsampling volumes)
slightly larger than the region from which you want to sample. Then you can set a
condition after the call to GEOREG (which is towards the end of source.f subroutine)
to check whether the coordinates that you sampled (YFLK, YFLK and ZFLK) are within
that region. If NOT, you a GOTO command will send the code back to the sampling step.
The more snugly your region fits into the sampling volume the more efficient this will be, but if you
don't have much time or you get lost with programming you could always sample within a big
sphere or cube that contains your region of interest and then just reject (with the
IF... GOTO) all points that fall out of your region.

I hope this was not too cryptic... also, I am not sure how this works with a voxelized geometry.

Mario

-----Original Message-----
From: owner-fluka-discuss_at_mi.infn.it [mailto:owner-fluka-discuss_at_mi.infn.it] On Behalf Of garenas_at_fuesmen.edu.ar
Sent: Wednesday, May 30, 2012 6:25 AM
To: fluka-discuss_at_mi.infn.it
Subject: source with organ geometry

Dear Fluka users
                  at present I am working with voxelized geometry with data taken from patient's CT scans,
and an isotope spherical source inside or outside patient's anatomy.
Is it possible perform simulations in Fluka with source geometry matching a complex organ geometry?
I mean, for instance, setting an organ geometry (maybe one already defined from voxelization)
as a source with isotropic distribution of isotopes.
In case it is possible, please tell me how can I do it.
Thank you.
Regards

German Arenas
Received on Wed May 30 2012 - 19:23:04 CEST

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