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Precision Validation of Geant4 Electromagnetic Physics. 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) ,
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Precision Validation of Geant4 Electromagnetic Physics 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
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 Standard Package LowEnergy Package Geant4 e.m. package Muon Package Optical photon Package Electromagnetic Physics • It handles • electrons and positrons • gamma, X-ray and optical photons • muons • charged hadrons • ions
E.M. Physics Validation • 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
Microscopic 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
Photon Mass Attenuation Coefficient 2N-L=13.1 – =20 - p=0.87 2N-S=23.2 – =15 - p=0.08 Transmitted photons (I) NIST Photon beam (Io) G4Standard • G4 LowE x-ray attenuation coeff in U NIST data Penelope c2=19.3 n=22 p=0.63 Absorber Materials: Be, Al, Si, Ge, Fe, Cs, Au, Pb, U
2N-L=13.1 – =20 - p=0.87 2N-S=23.2 – =15 - p=0.08 NIST-XCOM G4 Standard G4 LowE X-ray Attenuation Coefficient - Al
NIST-XCOM G4 LowE Penelope X-ray Attenuation Coefficient - Al 2N-P=15.9 – =19 p=0.66
2N-L=26.3 – =23 - p=0.29 2N-S=27.9 – =23 - p=0.22 NIST-XCOM G4 Standard G4 LowE X-ray Attenuation Coefficient - Ge
NIST-XCOM G4 LowE Penelope X-ray Attenuation Coefficient - Ge 2N-P=10.1 – =21 - p=0.98
2N-L=6.6 – =20 - p=0.99 2N-S=14.7 – =20 - p=0.80 NIST-XCOM G4 Standard G4 LowE X-ray Attenuation Coefficient - U
NIST-XCOM G4 LowE Penelope X-ray Attenuation Coefficient - U 2N-P=19.3 – =22 - p=0.63
Compton Scattering - Al 2N-L= 12.9– =8 - p=0.12 2N-S=8.7 – =6 - p=0.19 NIST-XCOM G4 Standard G4 LowE
Compton Scattering - Al NIST-XCOM G4 LowE Penelope 2N-P=2.5 – =6 - p=0.87
Compton Scattering - Cs 2N-L=4.6 – =8 - p=0.80 2N-S=1.8 – =8 - p=0.99 NIST-XCOM G4 Standard G4 LowE
Compton Scattering - Cs NIST-XCOM G4 LowE Penelope 2N-P=4.6 – =8 - p=0.80
NIST-XCOM G4 LowE Rayleigh Scattering - Al 2N-L=13.6 – =11 - p=0.26
NIST-XCOM G4 LowE Penelope Rayleigh Scattering - Al 2N-P=7.2 – =8 - p=0.52
NIST-XCOM G4 LowE Rayleigh Scattering - Cs
NIST-XCOM G4 LowE Penelope Rayleigh Scattering - Cs
Photoelectric Effect - Fe NIST-XCOM G4 Standard G4 LowE
NIST-XCOM G4 LowE Penelope Photoelectric Effect - Fe
NIST-XCOM G4 Standard G4 LowE Pair Production - Si
NIST-XCOM G4 LowE Penelope Pair Production - Si
Electrons - Stopping Power and CSDA Range 2N-S=0.267 =28 p=1 2N-L=1.315=28 p=1 G4 Standard G4 LowE-EPDL NIST Absorber Materials: Be, Al, Si, Ge, Fe, Cs, Au, Pb, U G4 Standard G4 LowE-EPDL NIST CSDA range: particle range without energy loss fluctuations and multiple scattering Experimental set-up centre
NIST-ESTAR G4 Standard G4 LowE Electrons - CSDA Range - Al
NIST-ESTAR G4 Standard G4 LowE Electrons - CSDA Range - Pb
NIST-ESTAR G4 Standard G4 LowE Electrons - Stopping Power - Al
NIST-ESTAR G4 Standard G4 LowE Electrons - Stopping Power - Pb
NIST-ESTAR Geant4-05-00 Geant4-05-02 Electrons - CSDA Range – Al –G4LowE Regression testing
NIST-ESTAR Geant4-05-00 Geant4-05-02 Electrons - CSDA Range – Pb –G4Standard Regression testing
NIST-PSTAR G4 Standard G4 LowE Protons - CSDA Range Al
NIST-PSTAR G4 Standard G4 LowE Protons - CSDA Range Pb
NIST-PSTAR G4 Standard G4 LowE Ziegler Protons - Stopping Power Al
NIST-PSTAR G4 Standard G4 LowE Protons - Stopping Power - Pb
NIST-PSTAR Geant4-05-00 Geant4-05-02 Protons - CSDA Range – Al – G4LowE Regression testing
NIST-PSTAR Geant4-05-00 Geant4-05-02 Protons - CSDA Range – Al – G4LowE Ziegler Regression testing
NIST-PSTAR Geant4-05-00 Geant4-05-02 Protons - CSDA Range – Al – G4Standard Regression testing
NIST-PSTAR Geant4-05-00 Geant4-05-02 Protons - CSDA Range – Pb – G4LowE Regression testing
NIST-PSTAR Geant4-05-00 Geant4-05-02 Protons - CSDA Range – Pb – G4LowE Ziegler Regression testing
NIST-PSTAR Geant4-05-00 Geant4-05-02 Protons - CSDA Range – Pb –G4Standard Regression testing
Electrons Transmission Tests Experimental set-up e- beam
Electrons Backscattering Coefficient – E=100keV Lockwood et al. (1981) G4 LowE Backscattered e- Experimental set-up Incident e- beam Angle of incidence (with respect to the normal to the sample surface) = 0°
Electrons Backscattering Coefficient – E=1MeV Lockwood et al. (1981) G4 LowE Angle of incidence (with respect to the normal to the sample surface)=0°
Coleman (1992) G4 LowE Positrons - Backscattering coefficient – 30keV
NIST-PSTAR G4 Standard G4 LowE Positrons - Backscattering coefficient – 30keV Regression testing
Auger Effect, X-Ray Fluorescence Iceland Basalt Fluorescence Spectrum Auger Spectrum in Cu Counts Energy (keV) Anderson-Darling Test Ac (95%) =0.752 Detector response Simulation of Auger emission from pure materials irradiated by an electron beam with continuous spectrum
protons antiprotons proton straggling Much more available or in progress… ions Barkas Effect
ATLAS CMS Dark matter and n experiments Macroscopic Validation • Experimental set-up validation • Collaboration of Geant4 developers and research groups of different experiments Medical Physics Space science
The Problem of Validation: Finding Reliable Data… Note: Geant4 validation is not always easy experimental data often exhibit large differences! Backscattering low energies - Au
Conclusions • Geant4 electromagnetic package encompasses an ample set of physics models, specialised for particle type, energy range and detector applications Geant4 Physics Reference Manual (www.cern.ch/geant4) • 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 (http://www.ge.infn.it/geant4/analysis/test) • Many significant contributions to the validation of Geant4 e.m. physics from test beams and application in the experiments