Susanna Guatelli & Barbara Mascialino G.A.P. Cirrone (INFN LNS), G. Cuttone (INFN LNS), S. Donadio (INFN,Genova), S. Guatelli (INFN Genova), M. Maire (LAPP), A. Mantero (ESA), B. Mascialino (INFN Genova), P. Nieminen (ESA), L. Pandola(INFN LNGS), S. Parlati (INFN LNGS), A. Pfeiffer (CERN), M.G. Pia (INFN Genova), L. Urban (Budapest) 1st Workshop on Italy-Japan Collaboration on Geant4 Medical Application 1st Workshop on Italy-Japan Collaboration on Geant4 Medical Application Precision Validation of Geant4 Electromagnetic Physics

It handles electrons and positrons gamma, X-ray and optical photons muons charged hadrons ions multiple scattering Bremsstrahlung ionisation annihilation photoelectric effect Compton scattering Rayleigh effect gamma conversion e+e- pair production synchrotron radiation transition radiation Cherenkov refraction reflection absorption scintillation fluorescence Auger Geant4 e.m. package Standard Package LowEnergy Package Muon Package Optical photon Package Electromagnetic Physics

Validation is fundamental in Geant4 Validations at different levels Comparisons to experimental measurements and recognised standard references Unit, integration, system testing Microscopic physics validation Macroscopic validation experimental use cases E.M. Physics Validation

Validation of Geant4 electromagnetic physics models Attenuation coefficients, CSDA ranges, Stopping Power, distributions of physics quantities Quantitative comparisons to experimental data and recognised standard references Microscopic Validation

G4Standard 1.G4 LowE NIST Photon beam (I o ) Transmitted photons (I)  2 N-L =13.1 – =20 - p=0.87  2 N-S =23.2 – =15 - p=0.08 x-ray attenuation coeff in U NIST data Penelope  2 =19.3 =22 p=0.63 Absorber Materials Absorber Materials : Be, Al, Si, Ge, Fe, Cs, Au, Pb, U Photon Mass Attenuation Coefficient

G4 Standard G4 LowE NIST-XCOM  2 N-L =13.1 – =20 - p=0.87  2 N-S =23.2 – =15 - p=0.08 X-ray Attenuation Coefficient - Al

G4 LowE Penelope NIST-XCOM  2 N-P =15.9 – =19 p=0.66 X-ray Attenuation Coefficient - Al

G4 Standard G4 LowE NIST-XCOM  2 N-L =26.3 – =23 - p=0.29  2 N-S =27.9 – =23 - p=0.22 X-ray Attenuation Coefficient - Ge

G4 LowE Penelope NIST-XCOM  2 N-P =10.1 – =21 - p=0.98 X-ray Attenuation Coefficient - Ge

G4 Standard G4 LowE NIST-XCOM  2 N-L =6.6 – =20 - p=0.99  2 N-S =14.7 – =20 - p=0.80 X-ray Attenuation Coefficient - U

G4 LowE Penelope NIST-XCOM  2 N-P =19.3 – =22 - p=0.63 X-ray Attenuation Coefficient - U

G4 Standard G4 LowE NIST-XCOM  2 N-L = 12.9– =8 - p=0.12  2 N-S =8.7 – =6 - p=0.19 Compton Scattering - Al

G4 LowE Penelope NIST-XCOM  2 N-P =2.5 – =6 - p=0.87 Compton Scattering - Al

G4 Standard G4 LowE NIST-XCOM  2 N-L =4.6 – =8 - p=0.80  2 N-S =1.8 – =8 - p=0.99 Compton Scattering - Cs

G4 LowE Penelope NIST-XCOM  2 N-P =4.6 – =8 - p=0.80 Compton Scattering - Cs

G4 LowE NIST-XCOM  2 N-L =13.6 – =11 - p=0.26 Rayleigh Scattering - Al

G4 LowE Penelope NIST-XCOM  2 N-P =7.2 – =8 - p=0.52 Rayleigh Scattering - Al

G4 LowE NIST-XCOM Rayleigh Scattering - Cs

G4 LowE Penelope NIST-XCOM Rayleigh Scattering - Cs

G4 Standard G4 LowE NIST-XCOM Photoelectric Effect - Fe

G4 LowE Penelope NIST-XCOM Photoelectric Effect - Fe

G4 Standard G4 LowE NIST-XCOM Pair Production - Si

G4 LowE Penelope NIST-XCOM Pair Production - Si

G4 Standard G4 LowE-EPDL NIST CSDA range : particle range without energy loss fluctuations and multiple scattering centre Experimental set-up Absorber Materials Absorber Materials : Be, Al, Si, Ge, Fe, Cs, Au, Pb, U  2 N-S =0.267 =28 p=1  2 N-L =1.315 =28 p=1 G4 Standard G4 LowE-EPDL NIST Electrons - Stopping Power and CSDA Range

G4 Standard G4 LowE NIST-ESTAR Electrons - CSDA Range - Al

G4 Standard G4 LowE NIST-ESTAR Electrons - CSDA Range - Pb

G4 Standard G4 LowE NIST-ESTAR Electrons - Stopping Power - Al

G4 Standard G4 LowE NIST-ESTAR Electrons - Stopping Power - Pb

Geant NIST-ESTAR Geant Regression testing Electrons - CSDA Range – Al –G4LowE

Geant NIST-ESTAR Geant Regression testing Electrons - CSDA Range – Pb –G4Standard

G4 Standard G4 LowE NIST-PSTAR Protons - CSDA Range Al

G4 Standard G4 LowE NIST-PSTAR Protons - CSDA Range Pb

G4 Standard G4 LowE Ziegler NIST-PSTAR Protons - Stopping Power Al

G4 Standard G4 LowE NIST-PSTAR Protons - Stopping Power - Pb

Geant NIST-PSTAR Geant Regression testing Protons - CSDA Range – Al – G4LowE

Geant NIST-PSTAR Geant Regression testing Protons - CSDA Range – Al – G4LowE Ziegler

Geant NIST-PSTAR Geant Regression testing Protons - CSDA Range – Al – G4Standard

Geant NIST-PSTAR Geant Regression testing Protons - CSDA Range – Pb – G4LowE

Geant NIST-PSTAR Geant Regression testing Protons - CSDA Range – Pb – G4LowE Ziegler

Geant NIST-PSTAR Geant Regression testing Protons - CSDA Range – Pb –G4Standard

e - beam Experimental set-up Electrons Transmission Tests

Angle of incidence (with respect to the normal to the sample surface) = 0° G4 LowE Lockwood et al. (1981) Incident e - beam Experimental set-up Backscattered e-Electrons Backscattering Coefficient – E=100keV

G4 LowE Lockwood et al. (1981) Angle of incidence (with respect to the normal to the sample surface)=0° Electrons Backscattering Coefficient – E=1MeV Backscattering Coefficient – E=1MeV

G4 LowE Coleman (1992) Positrons - Backscattering coefficient – 30keV

Regression testing G4 Standard G4 LowE NIST-PSTAR

Iceland Basalt Fluorescence Spectrum Counts Energy (keV) Detector response Anderson- Darling Test A c (95%) =0.752 Auger Spectrum in Cu Simulation of Auger emission from pure materials irradiated by an electron beam with continuous spectrum Auger Effect, X-Ray Fluorescence

proton straggling ions antiprotons protons Barkas Effect Much more available or in progress…

Experimental set-up validation Collaboration of Geant4 developers and research groups of different experiments ATLAS CMS Dark matter and experiments Medical Physics Space science Macroscopic Validation

Note: Geant4 validation is not always easy experimental data often exhibit large differences! Backscattering low energies - Au The Problem of Validation: Finding Reliable Data…

Geant4 electromagnetic package encompasses an ample set of physics models, specialised for particle type, energy range and detector applications Geant4 Physics Reference Manual ( Geant4 e.m. physics is subject to a rigorous testing and validation process Many detailed results are available for the validation of basic physics distributions ( Many significant contributions to the validation of Geant4 e.m. physics from test beams and application in the experiments Conclusions

A project has been recently launched for a Geant4 Physics Book To have a solid and comprehensive reference on Geant4 physics Collaborative effort involving Geant4 physics groups, experiments Main focus of the project is Geant4 physics models validation Collaboration with detector experts: valuable and welcome! Geant4 Physics Book