Geant4 physics validation: Bragg Peak P. Cirrone, G. Cuttone, F. Di Rosa, S. Guatelli, B. Mascialino, M. G. Pia, G. Russo 4th Workshop on Geant4 Bio-medical Developments, Geant4 Physics Validation INF Genova, 13-20 July 2005 Susanna Guatelli

Outline Brief summary of the Geant4 hadrontherapy application Bragg peak test: Validation of Geant4 electromagnetic and hadronic physics models Susanna Guatelli

Scope of the hadrontherapy Geant4 application Model accurately the CATANA hadrontherapy beam line Calculate the energy deposit in a water phantom Calculate the Bragg peak Scattering system Modulator & Range shifter Monitor chambers Ligth field Laser Susanna Guatelli

Bragg peak test The CATANA group performs experimental measurements of the proton Bragg peak (see Giorgio’s talk) Scope of the project: ~63 MeV proton Bragg peak validation The Geant4 simulation models accurately the set-up of the experimental measurements Comparison between the experimental measurements and the results of the simulation activating alternative electromagnetic and hadronic physics models Susanna Guatelli

Particles: p, d, t, α, ions, e-, e+, pions, neutrons, muons Physics component The user can choose: to activate EM physics only to add on top the hadronic physics to activate alternative models for both EM and hadronic physics Modularised physics component Particles: p, d, t, α, ions, e-, e+, pions, neutrons, muons Susanna Guatelli

EM Physics models The user can choose to activate for protons the following alternative models: Low Energy - ICRU 49, Low Energy - Ziegler77, Low Energy - Ziegler85, Low Energy Ziegler 2000, Standard The user can choose for d, t, α, ions the alternative models: Low Energy ICRU, In the case of Low Energy Physics, also the nuclear stopping power is activate Susanna Guatelli

EM Physics models The user can choose to activate for e-: LowEnergy EEDL, LowEnergy Penelope, Standard The user can choose to activate for e+: The user can choose to activate for gamma: LowEnergy EPDL, Susanna Guatelli

Hadronic physics Elastic scattering Inelastic scattering Alternative approaches for p, n, pions LEP ( E < 100 MeV) and Binary Ion model ( E > 80 MeV) for d, t, α Neutron fission and capture Susanna Guatelli

Hadronic physics list The user can select alternative hadronic physics lists for protons, pions and neutrons Precompound model Binary model + Precompound model ( with all the option showed above) Bertini model LEP + default evaporation + GEM evaporation + default evaporation + Fermi Break-up + GEM evaporation + Fermi Break-up Susanna Guatelli

Strategy Activate the electromagnetic physics only Add on top the hadronic physics component Simulate the Bragg peak with combinations of e.m. and hadronic physics models Alternative hadronic physics models: Precompound model only + default evaporation + GEM evaporation + default evaporation + Fermi Break-up + GEM evaporation + Fermi Break-up Binary + Precompound model Bertini model LEP model Alternative e.m. physics models: Standard physics Low Energy physics: - ICRU49, - Ziegler77, - Ziegler85, - SRIM2000 Susanna Guatelli

Bragg peak test Compare experimental Bragg peak with simulation results Quantitative analysis of the results With the Statistical toolkit Kolmogorov-Smirnov test to compare simulated and experimental set-up Susanna Guatelli

First results Susanna Guatelli

Projects for the future Physics validation of the Bragg peak at higher proton beam energies Physics validation of ion Bragg peak Open to collaboration Plan to publish a paper Susanna Guatelli