[Gate-users] Fwd: Use phase space when Source is not in routine angle

[Consuelo Guardiola]

Hi Mery, 




I had a kind of similar problem time ago regarding the inconsistency between the results gathered from Phase Space file (PhS) outputs and experimental data. I also tried with both IAEA and root PhS types, but I did not get the same results than with my whole beam line. I tried several things that other users suggested and figured some issues out, but it never fitted the experimental data completely. 




Finally what I did was to generate a virtual source (e.g. PBS or GPS) that reproduces the PhS characteristics (e.g. emittance, divergence, spot size, etc) instead of the PhS itself. If you have some experimental data to crosscheck if it works, you could tune those values. 




Additionally, I recommend you to take a look of this macro: Radiotherapy/example4/PhS-Analysis.C It would allow you to have an idea of how customizing your macro to get from your PhS root file (as input file) those optical beam parameters to further your modelling. 




Also, it can be useful if you take a look of the post loop when I had that problem, there are some useful tips of other users that could help you: 




http://lists.opengatecollaboration.org/pipermail/gate-users/2017-March/009505.html 




I hope it helps, good luck! 

Consuelo. 


De: "Mery MB" <mery.mb.mph at gmail.com> 
À: gate-users at lists.opengatecollaboration.org 
Envoyé: Dimanche 15 Avril 2018 12:13:08 
Objet: [Gate-users] Fwd: Use phase space when Source is not in routine angle 


Dear Gate User 

I simulated a breast radiation therapy plan. As we know in breast radiation therapy, treatment is done in with two tangential field ( rotation of Gantry is around 170 degree for lateral and 298 for medial). 
I simulated all the condition of treatment (rotation of Gantry, collimator, source ) and it work properly when it is run in one step from source to phantom ( I get fluence on the way of radiation and the result was good). 

I have to run more particles to reduce the error in Phantom voxel so I run the program in two steps. In the first program I get the phase space after Flattening filter and used the phase space as a source in the second program. 
The problem is: when I use the phase space in the second program. particles come from different part of space (mess of particles) and do not have its regular characteristic!!!!!!!!!!!!!!! 


I used the below script to use phase space as a source: 


# Gamma beam 
/gate/source/addSource mysource phaseSpace 
/gate/source/mysource/addPhaseSpaceFile /home/Mery/Gate/Install/Gate/bin/Plans/conformal6MV//output1/PhSg1.root 
/gate/source/mysource/setPhaseSpaceInWorldFrame 
/gate/source/mysource/useRandomSymmetry 


When I comment two below lines the disorganization (mess) of particle is reduced but it do not omit completely. 

/gate/source/mysource/setPhaseSpaceInWorldFrame 
/gate/source/mysource/useRandomSymmetry 

I repeat this programs with two type of phase space (IAEA and root), and saw the same problem. 
Is there anyone had the same problem before? or know how can I solve this issue. 
I will be thankful if someone help me . 

Best Regards 
Mery 



_______________________________________________ 
Gate-users mailing list 
Gate-users at lists.opengatecollaboration.org 
http://lists.opengatecollaboration.org/mailman/listinfo/gate-users 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20180416/c8cebbe1/attachment.html>