Re: [fluka-discuss]: [How to use TRACKR common variables]

From: Dr. Vittorio Boccone <dr.vittorio.boccone_at_ieee.org>
Date: Sun, 14 Sep 2014 23:47:01 +0200

On 9/3/14 9:24 AM, Kyung-Nam Lee wrote:
>
> Dear, FLUKA advanced user.
>
> I would like to calculate Dose Averaged LET at each voxel.
>
> Because given fluka scoring commands cannot give the quantity, I try
> to use user routine(comscw.f).
>
> Dose Averaged LET can be defined like this formula.
>
> cid:image002.jpg_at_01CFC77B.9AC5E8C0
>
> (LET_d: Dose Averaged LET, LET: particle LET, D: absorbed dose by ith
> particle, D_total: Total dose at voxel)
>
> For calc. of Dose averaged LET, I make a modified comscw.f file. This
> file is attached on this email.
>
> I think TRACKR common variables can be used for that work. So, the
> contents is like this.
>
TRACKR common variables contains the history of the currently
transported particle.
>
> ========================= (The partial contents of comscw.f, grammar:
> not considered exactly) =================
>
> If (ISCRNG .EQ. 1) THEN
>
> If (JSCRNG .EQ. 2) THEN
>
> COMSCW=(100.0*Dtrack(1)/Ttrack(1))*(1.602176462**(-7.0)*Dtrack(1)/RHO(MEDFLK(MREG,1)))/Rull
>
> END If
>
> END If
>
> ===============================================================================================================
>
> As you know, this code cannot be used because we cannot know D_total
> not yet.
>
Do two USRBIN one with LET*D and the second with DOSE. Do the Dtot
normalization offline.

> So, most of all, I would like to ask whether the usage of Dtrack and
> Ttrack on this code is used properly or not.
>
> I think Dtrack(i) and Ttrack(i) means energy deposition of the ith
> deposition event and length of the ith track segment, respectively.
>
I think the calculation is fine. If you are using the embedded scoring
you could just calculate the Energy deposited and
>
> But, I input "1" temporarily as a index number because I cannot know
> how to get index number "i" from commom variables.
>
> If you give proper usage about using Dtrack and Ttrack, it will be
> great help for modifying the code.
>
> Also, for Dose avg. LET, Summation value of LET_i*Dose_i at each voxel
> needs to be divided by D_total(dose at voxel).
>
You can't control that. The Voxels are just a way to create the geometry
as I mentioned in my first e-mail.
The COMSCW is just a weight which will be used to weight the value you
need for the scoring.

FLUKA will take care of propagating to the scoring structure which in
your case should be a USRBIN with Cartesian mesh.

> But, D_total cannot know unless all interactions are finished.
>
> So, I would like to ask how to handle this.
>
At this stage I would suggest you to do a USERDUMP, save all the
information of the tracks you need and do the calculation offline.
Received on Mon Sep 15 2014 - 01:37:17 CEST

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