Example GammaTherapy

Author

I.Gudovska, V.Ivanchenko, S.Larsson
Karolinska Institute & Hospital, Stockholm, Sweden
CERN, Geneva, Switzerland

Electron beam of 50 MeV converted on target. All charged particles removed from the beam after the target. Gamma beam irradiate a water phantom. In front of the phantom a thin CheckVolume is placed to score gamma beam properties. Inside the phantom a score volume is placed to calculate radial radiation dose distribution.

GEOMETRY

GammaTherapy application geometry consists of along z:

1. Generator of electrons directed along z-axis
2. Target1 (Be, W)
3. Target2 (W, Cu)
4. GasVolume (He) : all charged particles are killed inside
5. CheckVolume (Air) : is sensitive for scoring in front of thephantom
6. Phantom (H2O) : is sensitive for radioactive dose calculation
7. Absorber in Phantom (H2O) : is sensitive for transverse dose calculation

World volume consists of Air.

STEERING

Geometry and other parameters can be defined by G4 UI commands.

Following macro files are prepared for different targets used in the real setup: be.in (thin Be target), be_w.in (thick BeW target), cu_w.in (thick Cu W target).

Only Physics Lists from physics_list kernal library can be activated. Corresponding UI commands are following

/testem/phys/addPhysics       emstandard
/testem/phys/addPhysics       emstandard_opt3
/testem/phys/addPhysics       empenelope
/testem/phys/addPhysics       emlivermore

For interactive mode G4 visualization options and variables should be defined, then the example should be recompiled:

gmake visclean
gmake

The vis.mac file can be used an example of visualization.

HISTOGRAMS

Built in histograms are provided. Name of output root file can be defined via UI command

/testem/histoName <myName>