[Gate-users] simulating a voxelized phantom using GATE 4.0 with the speed up options

[Niklas Rehfeld]

Hi,

> New Physics macro
> #       EM  P R O C E S S
> /gate/physics/gamma/selectFictitious volumeTrace
> /gate/physics/gamma/selectGammaConversion inactive
> /gate/physics/gamma/selectRayleigh inactive
> /gate/physics/gamma/selectPhotoelectric standard
> /gate/physics/gamma/selectCompton standard

That seems to be ok.

> #       I N A C T I V E    S E C O N D A R Y   E L E C T R O N S
> /gate/physics/setElectronCut 2. mm
> #       I N A C T I V E    X - R A Y S
> /gate/physics/setXRayCut 10. keV
> /gate/physics/setDeltaRayCut 10. keV
>
> The new macro for a voxelized phantom is
> /gate/world/daughters/name lung_phantom
> #
> #  this is the new line for regular parameterization and fictitious
> interaction
> #
> /gate/world/daughters/insert fictitiousVoxelMap
> /gate/lung_phantom/setFictitiousEnergy 10 keV
> /gate/lung_phantom/setElectronCut 50 cm
> /gate/world/daughters/insert regularMatrix     : regular navigation

Here you added two daughters! One is a fictitiousVoxelMap and the  
other is the regularMatrix! If you use  
"/gate/physics/gamma/selectFictitious volumeTrace"
you should use the fictitiousVoxelMap. If you define two daughter  
volumes at the same position the result is undefined (or at least I  
don't know what happens). The regular navigator is already implicitly  
incorporated in the fictitiousVoxelMap. The regular navigator is used  
when the energy of the photon droppes below  
"/gate/lung_phantom/setFictitiousEnergy 10 keV". For larger energies  
tracking with ficitious interactions is used.

Remove this line: "/gate/world/daughters/insert regularMatrix".

Or, if you wish to use regular navigation and no fictitious  
interactions, you can remove the lines

/gate/physics/gamma/selectFictitious volumeTrace
/gate/world/daughters/insert fictitiousVoxelMap
/gate/lung_phantom/setFictitiousEnergy 10 keV

and keep line
/gate/world/daughters/insert regularMatrix

This should active solely the regular navigation (without fictitious  
interactions). "regularMatrix" and "fictitiousVoxelMap" cannot be used  
at the same time.


Good luck, let me know if your problem persists

Niklas