Low Energy Electromagnetic Physics Maria Grazia Pia, INFN Genova on behalf of the LowE WG ht t p:/ / www.ge.inf n.it / geant 4/ lowE/ index.ht ml Geant4 Workshop and Geant4 ∆ Review, CERN, October 2002 Maria Grazia Pia, INFN Genova
The process in a nutshell We have and maintain a URD Ample requirements traceability – Regular contacts with users – Still improving it: added documentation We have a process for requirements and validation results as traceability items management – in progress: traceability documentation from simple matrix to Rose model – But we would like to have a tool for it! We regularly hold WG meetings to We do analysis and design discuss and agree together our project – We validate our designs against use cases planning (GDPM approach) We do design and code reviews We have a SPI process – not enough, however… – With some spells of SPD sometimes… – main problem: geographical spread – Collaboration with Anaphe for a common Unit, package integration, system tests (tailored) process + validation (acceptance) We keep everything in CVS – we do a lot… but we would like to do more (not in our head…) – Limited by availability of resources availability of resources for core – Code, designs, tests, documents etc. testing We maintain a web site – Need a more systematic approach and better tools � Test & Analysis Project Test & Analysis Project – LowE, advanced examples, WG projects – Close collaboration with users More det ails: see t alk on Sof t ware Process in Physics, Geant 4 Review 2001 Maria Grazia Pia, INFN Genova
Recent physics activities Electron processes Auger effect – New – New parameterisations of LLNL data Fluorescence – Various bug fixes – Small fixes and improvements while re- – Tests against NIST database (range) implementing in a design iteration – Tests against Sandia database – Test beam validation in collaboration with ESA Science Payload Division Photon processes PIXE – Rather stable – Toy model – Tests of angular distributions in – Established contacts for databases, plans for progress new model Protons, ions Polarisation – Stable, minor improvements – Improvement of Compton – Bragg peak tests in progress γ conversion in progress – Antiprotons – Contacts with experiments for – Paper in progress, very close to submission common validation tests Maria Grazia Pia, INFN Genova
Photons: mass attenuation coefficient UR 1.1 E = (NIST-G4EMStandard)/NIST E = (NIST-G4LowEn)/NIST 18 16 14 12 Fe 10 8 6 4 2 Comparison against NIST data E (%) 0 -2 -4 -6 Tests by IST - Natl. Inst. for Cancer -8 Research, Genova (F. Foppiano et al.) -10 -12 -14 -16 -18 LowE accuracy ~ 1% 0.01 0.1 1 10 Photon Energy (MeV) Also water, Pb This test will be introduced into the Test & Analysis project for a systematic verification Maria Grazia Pia, INFN Genova
Photon attenuation: Geant4 vs. NIST data UR 1.1 Test and validation by IST - Natl. Inst. for Cancer Research, Genova Geant4 LowEn Geant4 LowEn Geant4 LowEn 10 NIST 1000 NIST NIST 100 µ / ρ (cm 2 /g) in iron Pb 100 water Fe µ / ρ (cm 2 /g) in water µ / ρ (cm 2 / g in lead 10 1 10 1 1 0.1 0.1 0.1 0.01 0.01 0.01 0.1 1 10 0.01 0.1 1 0.01 0.1 1 10 Photon Energy (MeV) Photon energy (MeV) Photon Energy (MeV) Low Energy EM � Delta = (NIST-G4EMStand) / NIST E = (NIST-G4EMStandard)/NIST E = (NIST - G4EM Standard)/NIST Delta = (NIST-G4LowEn) / NIST 16 E = (NIST-G4LowEn)/NIST 10 18 Standard EM E = (NIST- G4LowEn)/NIST � 14 16 8 14 12 w.r.t. NIST data 12 10 6 10 8 8 4 accuracy within 1% 6 6 4 2 4 Delta (%) 2 2 E (%) 0 E (%) 0 0 -2 -2 -2 -4 -4 -6 -6 -4 -8 -8 -6 -10 -10 -12 -12 -8 -14 -14 -16 -16 -10 -18 0.01 0.1 1 10 0.01 0.1 1 0.01 0.1 1 10 Photon Energy (MeV) Photon Energy (MeV) Photon Energy (MeV) Maria Grazia Pia, INFN Genova
Photons: angular distributions UR 1.1 Rayleigh scattering: Geant4-LowE and expected distribution (more work in progress) Maria Grazia Pia, INFN Genova
Photons, evidence of shell effects UR 1.1 Photon transmission, 1 µ m Pb Photon transmission, 1 µ m Al Maria Grazia Pia, INFN Genova
UR 1.1 Electron Bremsstrahlung New parameterisations of EEDL data library – in response to problem reports from various users – precision is now ~ 1.5 % Plans – Systematic verification over Z and energy – Need Test & Analysis Project for automated verification Maria Grazia Pia, INFN Genova
UR 1.1 Electron ionisation New parameterisations of EEDL data library – in response to problem reports from various users – precision is now better than 5 % for ~ 50% of the shells, poorer for the 50% left Plans – Systematic verification over shell, Z and energy – Need Test & Analysis Project for automated verification (all shells, 99 elements!) Maria Grazia Pia, INFN Genova
UR 1.1 Electrons: range Al Al Range in various simple and composite materials Compared to NIST database Also Be, Fe, Au, Pb, Ur, air, water, bone, muscle, soft tissue Testbed for Test&Analysis prototype Maria Grazia Pia, INFN Genova
UR 1.1 Electrons: dE/dx Ionisation energy loss in various materials Compared to Sandia database More systematic verification planned (for publication) Also Fe, Ur Maria Grazia Pia, INFN Genova
UR 1.1 Electrons, transmitted 20 keV electrons, 0.32 and 1.04 µ m Al Maria Grazia Pia, INFN Genova
UR 2.1 Protons Stopping power Z dependence for various energies Ziegler and ICRU, Fe Ziegler and ICRU, Si Ziegler and ICRU models Straggling UR 2.5 Nuclear stopping power Bragg peak (with hadronic interactions) Maria Grazia Pia, INFN Genova
UR 2.3 Antiprotons New: comparison with another theoretical model N on-linear calculation by Arista – and Lifschitz Dashed – Geant4 LowE proton Solid – Geant4 LowE Quantal Harmonic Oscillator model Dotted-dashed – Calculation by Arista and Lifschitz Points – Data from ASACUSA Maria Grazia Pia, INFN Genova
Ions UR 2.2 Ar and C ions Deuterons Maria Grazia Pia, INFN Genova
σ ν ν ν 2 d 1 h h h = + − θ φ 2 2 2 Polarisation 0 Polarisation r 2 sin cos Cross section: UR 4.1, D.1 Ω 0 ν ν ν 2 d 2 h h h 0 0 ξ = θ φ ⇒ ξ = − θ φ = 2 2 cos sin cos sin 1 sin cos N x ( ) 1 Scattered Photon Polarization ε ⊥ = θ ˆ − θ φ ˆ β ' cos j sin sin k sin N 250 eV -100 GeV 1 1 ˆ ˆ ˆ ε = − θ φ φ − θ θ φ β ' 2 N i sin sin cos j sin cos cos k cos || ξ φ N N h ν ε θ Polar angle A h ν 0 θ Low Energy Low Energy φ Azimuthal angle α z O Polar ised Compt on Compt on Polar ised ε Polarization vector C 1 MeV 10 MeV y 100 keV small ϑ small ϑ small ϑ More details: talk on Geant4 Low Energy Electromagnetic Physics large ϑ large ϑ large ϑ Other polarised processes under development Maria Grazia Pia, INFN Genova
Fluorescence UR 3.1 Experimental validation: Microscopic validation: test beam data, in collaboration with against reference data ESA Science Payload Division Spect rum f rom a Mars-simulant r ock sample Fe lines GaAs lines Scattered photons Maria Grazia Pia, INFN Genova
UR 3.1 Auger effect New process, validation in progress Auger electron emission from various materials Sn, 3 keV photon beam, electron lines w.r.t. published experimental results Maria Grazia Pia, INFN Genova
Contribution from users Many valuable contributions to the validation of LowE physics from users all over the world – excellent relationship with our user community User comparisons with data usually involve the effect of several physics processes of the LowE package A small sample in the next slides – no time to show all! Maria Grazia Pia, INFN Genova
GEANT4 Workshop, 2002 30 September – 4 October GEANT4 Medical Applications at LIP GEANT4 Medical Applications at LIP P. Rodrigues, A. Trindade, L.Peralta, J. Varela LIP – Lisbon Maria Grazia Pia, INFN Genova
Homogeneous Phantom Homogeneous Phantom P. Rodrigues, A. Trindade, L.Peralta, J. Varela, LIP � Simulation of photon beams produced by a Siemens Mevatron KD2 clinical linear accelerator � Phase-space distributions interface with GEANT4 � Validation against experimental data: depth dose and profile curves Differences Differences 10x10 cm 2 15x15 cm 2 LIP – Lisbon 10x10 cm 2 15x15 cm 2 Maria Grazia Pia, INFN Genova
Electron Transport at Low Energies Electron Transport at Low Energies P. Rodrigues, A. Trindade, L.Peralta, J. Varela, LIP � Evaluation of electron range for different GEANT4 releases GEANT4 (Low+Std) Lead Styrophoam Maria Grazia Pia, INFN Genova
Dose Calculations with 12 C Dose Calculations with 12 C P. Rodrigues, A. Trindade, L.Peralta, J. Varela, LIP � Bragg peak localization calculated with GEANT4 (stopping powers from ICRU49 and Ziegler85) and GEANT3 in a water phantom � Comparison with GSI data Maria Grazia Pia, INFN Genova
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