Low Energy Electromagnetic Physics Maria Grazia Pia, INFN Genova on behalf of the LowE WG http://www.ge.infn.it/geant4/lowE/index.html Geant4 Workshop and Geant4 D Review, CERN, October 2002 Maria Grazia Pia, INFN Genova The process in a nutshell We have and maintain a URD – Regular contacts with users We have a process for requirements management – But we would like to have a tool for it! We do analysis and design – We validate our designs against use cases We do design and code reviews – not enough, however… – main problem: geographical spread Unit, package integration, system tests + validation – we do a lot… but we would like to do more – Limited by availability of resources for core testing – Need a more systematic approach and better tools Test & Analysis Project – Close collaboration with users Full requirements traceability – Still improving it: added documentation and validation results as traceability items – in progress: traceability documentation from simple matrix to Rose model We regularly hold WG meetings to discuss and agree together our project planning We keep everything in CVS – Code, designs, tests, documents, papers etc. We have a SPI process – With some spells of SPD sometimes… – Collaboration with Anaphe for a common (tailored) process We maintain a web site – LowE, advanced examples, WG projects More details: see talk on Software Process in Physics, Geant4 Review 2001 Maria Grazia Pia, INFN Genova Recent physics activities Electron processes – – – – New parameterisations of LLNL data Various bug fixes Tests against NIST database (range) Tests against Sandia database Photon processes – Rather stable – Tests of angular distributions in progress Polarisation – Improvement of Compton – g conversion in progress – Contacts with experiments for common validation tests Maria Grazia Pia, INFN Genova Auger effect – New Fluorescence – Small fixes and improvements while reimplementing in design iteration – Test beam validation in collaboration with ESA Science Payload Division PIXE – Toy model – Established contacts for databases, plans for new model Protons, ions – Stable, minor improvements – Bragg peak tests in progress Antiprotons – Paper in progress, very close to submission Comparison against NIST data Tests by IST - Natl. Inst. for Cancer Research, Genova (F. Foppiano et al.) LowE accuracy ~ 1% E (%) Photons: mass attenuation coefficient E = (NIST-G4EMStandard)/NIST E = (NIST-G4LowEn)/NIST 18 16 14 12 10 8 6 4 2 0 -2 -4 -6 -8 -10 -12 -14 -16 -18 Fe 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 Test and validation by IST - Natl. Inst. for Cancer Research, Genova Geant4 LowEn NIST 10 Geant4 LowEn NIST Geant4 LowEn NIST 1000 water 1 Pb Fe m/r (cm 2 / g in lead m /r (cm 2 /g) in iron m /r (cm 2 /g) in water 100 100 10 1 10 1 0.1 0.1 0.1 0.01 0.1 1 0.01 10 0.01 0.01 Photon Energy (MeV) 12 10 8 6 2 0 E (%) Delta (%) 4 -2 -4 -6 -8 -10 -12 -14 -16 0.1 10 1 10 Photon Energy (MeV) Maria Grazia Pia, INFN Genova 18 16 14 12 10 8 6 4 2 0 -2 -4 -6 -8 -10 -12 -14 -16 -18 E = (NIST-G4EMStandard)/NIST E = (NIST-G4LowEn)/NIST 0.1 1 Photon energy (MeV) Low Energy EM Standard EM w.r.t. NIST data 14 0.01 1 Photon Energy (MeV) Delta = (NIST-G4EMStand) / NIST Delta = (NIST-G4LowEn) / NIST 16 0.1 E = (NIST - G4EM Standard)/NIST E = (NIST- G4LowEn)/NIST 10 8 6 4 accuracy within 1% 2 E (%) 0.01 0 -2 -4 -6 -8 -10 0.01 0.01 0.1 Photon Energy (MeV) 1 10 0.1 Photon Energy (MeV) 1 Photons: angular distributions Rayleigh scattering: Geant4-LowE and expected distribution (more work in progress) Maria Grazia Pia, INFN Genova Photons, evidence of shell effects Photon transmission, 1 mm Pb Photon transmission, 1 mm Al Maria Grazia Pia, INFN Genova 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 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 Electrons: range 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 Al 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 Electrons, transmitted 20 keV electrons, 0.32 and 1.04 mm Al Maria Grazia Pia, INFN Genova Protons Stopping power Z dependence for various energies Ziegler and ICRU models Ziegler and ICRU, Fe Ziegler and ICRU, Si Straggling Nuclear stopping power Maria Grazia Pia, INFN Genova Bragg peak (with hadronic interactions) Antiprotons Dashed – Geant4 LowE proton Solid – Geant4 LowE Quantal Harmonic Oscillator model Dotted-dashed – Non-linear calculation by Arista and Lifschitz Points – Experimental data from ASACUSA Maria Grazia Pia, INFN Genova Ions Ar and C ions Deuterons Maria Grazia Pia, INFN Genova Polarisation d 1 2 hn2 hn0 hn r0 2 2 sin 2 q cos2 f Cross section: d 2 hn0 hn hn0 Sample Methods: Low Energy Polarised Compton x 250 eV -100 GeV Integrating over f • Sample q • q - Energy Relation Energy • Sample of f from P(f) = a (b – c cos2 f) distribution cos x sin q cos f sin x 1 sin 2 q cos2 f N x hn0 O hn q a f Scattered Photon Polarization y q Polar angle f Azimuthal angle Polarization vector Maria Grazia Pia, INFN Genova 1 cos q ˆj sin q sin f k̂ sin N 1 1 ||' N î sin 2 q sin f cos f ĵ sin q cos q cos f k̂ cos N N A C ' z 100 keV 1 MeV 10 MeV small small small More details: talk on large large Geant4 Low Energy Electromagnetic Physics large Other polarised processes under development Fluorescence Microscopic validation: against reference data Experimental validation: test beam data, in collaboration with ESA Science Payload Division Spectrum from a Mars-simulant rock sample Fe lines GaAs lines Scattered photons Maria Grazia Pia, INFN Genova 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 P. Rodrigues, A. Trindade, L.Peralta, J. Varela LIP – Lisbon Maria Grazia Pia, INFN Genova 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 LIP – Lisbon 10x10 cm2 15x15 cm2 Maria Grazia Pia, INFN Genova 10x10 15x15 cm2 Electron Transport at Low Energies Evaluation of electron range for different GEANT4 releases GEANT4 (Low+Std) Styrophoam Maria Grazia Pia, INFN Genova Lead Dose Calculations with 12C 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 Geant4 low energy validation Jean-Francois Carrier, Louis Archambault, Rene Roy and Luc Beaulieu Service de radio-oncologie, Hotel-Dieu de Quebec, Quebec, Canada Departement de physique, Universite Laval, Quebec, Canada The following results will be published soon. They are part of a general Geant4 low energy validation project. Maria Grazia Pia, INFN Genova • Using Geant4, we calculated depth-dose curves for many different electron or photon sources: •Beams •monoenergetic beam •realistic clinical accelerator beam •Point sources •monoenergetic source •source with real nuclide energy spectra •and different irradiated media: •Homogeneous •water, Be, Mo or U •Heterogeneous •water/Al/lung/water •water/air/steel/air/water Maria Grazia Pia, INFN Genova Uranium irradiated by electron beam Fig 1. Depth-dose curve for a semi-infinite uranium slab irradiated by a 0.5 MeV broad parallel electron beam 1Chibani Maria Grazia Pia, INFN Genova O and Li X A, Med. Phys. 29 (5), May 2002 Multi-slab medium irradiated by photons Fig 2. Depth-dose curve for a multi-slab medium irradiated by a 18 MV realistic clinical accelerator photon beam 2Rogers D W O and Mohan Maria Grazia Pia,R,http://www.irs.inms.nrc.ca/inms/irs/papers/iccr00/iccr00.html INFN Genova Water phantom irradiated by clinac beam Fig 3. Relative dose distribution for a water phantom irradiated by a 6 MeV Clinac 2100C electron beam 3Ding G X and Rogers D W O http://gold.sao.nrc.ca/inms/papers/PIRS439/pirs439.html Maria Grazia Pia, INFN Genova Ions Independent validation at Univ. of Linz (H. Paul et al.) Geant4-LowE reproduces the right side of the distribution precisely, but about 10-20% discrepancy is observed at lower energies Maria Grazia Pia, INFN Genova Dose distribution: TG 43 protocol, experimental data (S. Paolo Hospital, Savona), G4-LowE S. Guatelli’s thesis Maria Grazia Pia, INFN Genova Application Cosmic rays, jovian electrons Solar X-rays, e, p and more! Courtesy SOHO EIT Maria Grazia Pia, INFN Genova Courtesy of S. Magni, Borexino Not only “space and medical”! Team work! Geant4 Low Energy Electromagnetic Working Group + users all over the world The validation plots in this presentation have been contributed by from 9 19 people countries Argentina, Austria, Canada, Italy, Portugal, Russia, Spain, Switzerland, UK Thanks to all! Maria Grazia Pia, INFN Genova Students Jean-Francois Carrier Stephane Chauvie Elena Guardincerri Susanna Guatelli Alfonso Mantero Pedro Rodrigues Andreia Trindade Matteo Tropeano Further physics improvements and extensions Various projects in progress – all motivated by requirements in the URD Some examples in the following slides – no time to show all! Maria Grazia Pia, INFN Genova Bremsstrahlung Models Current bremstrahlung polar angle generation scheme is independent of both atomic number, Z, and emitted photon momentum, k Does not account variations due to the screening of the nucleus by the atomic electrons At generator level, for 50 keV incident electrons with k/T=0.7 in Ag New model (2BN) to be implemented by LIP group Maria Grazia Pia, INFN Genova Polarisation theory simulation Polarisation of a non-polarised photon beam, simulation and theory Maria Grazia Pia, INFN Genova Ratio between intensity with perpendicular and parallel polarisation vector w.r.t. scattering plane, linearly polarised photons Ongoing significant effort in OOAD Maria Grazia Pia, INFN Genova Other activities in the WG Advanced examples Simulation + analysis in a distributed computing environment Test & Analysis Technology transfer Training Maria Grazia Pia, INFN Genova Technology transfer Particle physics software aids space and medicine M.G. Pia and J. Knobloch Geant4 is a showcase example of technology transfer from particle physics to other fields such as space and medical science […]. CERN Courier, June 2002 Maria Grazia Pia, INFN Genova 1. 2. 3. 4. 5. 6. 7. Talks 8. 9. in WG web 10. 11. 12. 13. 14. 15. 16. 17. The Geant4 Toolkit: simulation capabilities and application results M.G. Pia et al., 8th Topical Seminar on Innovative Particle and Radiation Detectors, Siena, 2002 Geant4: a powerful tool for medical physics E. Lamanna et al., 8th Topical Seminar on Innovative Particle and Radiation Detectors, Siena, 2002 Dose calculation for radiotherapic treatment on a distributed computing environment S. Chauvie et al., 8th Topical Seminar on Innovative Particle and Radiation Detectors, Siena, 2002 Parallel Geant4 simulation in medical and space science applications J. Moscicki et al., 8th Topical Seminar on Innovative Particle and Radiation Detectors, Siena, 2002 Simulation and analysis for astroparticle experiments A. Howard et al., 8th Topical Seminar on Innovative Particle and Radiation Detectors, Siena, 2002 Leipzig applicators Montecarlo simulations: results and comparison with experimental and manufacturer's data M. Tropeano et al., 21st ESTRO Meeting, Prague, 2002 Tools for simulation and analysis A. Pfeiffer and M.G. Pia (for the Geant4 and Anaphe Collaborations), ICHEP02, Amsterdam, 2002 The Geant4 Simulation Toolkit and Its Low Energy Electromagnetic Physics Package S. Chauvie et al., 44th Annual Meeting of the American Ass. of Physicists in Medicine, Montreal, 2002 The Geant4 Toolkit: Overview M. G. Pia, Invited lecture at the MCNEG Workshop, Stoke-on-Trent, UK, 2002 Medical applications of the Geant4 Simulation Toolkit M. G. Pia, Invited lecture at the MCNEG Workshop, Stoke-on-Trent, UK, 2002 Simulation software: applications and results in the bio-medical domain M. G. Pia et al., VII International Conference on Advanced Technologies and Particle Physics, Como, 2001 From HEP computing to bio-medical research and vice-versa: technology transfer and application results M. G. Pia et al., Plenary talk at CHEP 2001, Beijing, China, 2001 Architecture of Collaborating Frameworks A.Pfeiffer et al., CHEP2001, Beijing, China, 2001 Simulation For Astroparticle Experiments And Planetary Explorations A.Brunengo (for the Geant4 Low Energy Electromagnetic Group), CHEP2001, Beijing, China, 2001 Geant4 Low Energy Electromagnetic Physics M. G. Pia (for the Geant4 Low Energy Electromagnetic Group), CHEP2001, Beijing, China, 2001 The GEANT4 simulation toolkit G. Santin, Monte Carlo Workshop for Nuclear Medicine applications, July 2001 Geant4: simulation capabilities and application results M.G. Pia (for the Geant4 Collaboration), EPS-HEP Conference, Budapest, July 2001 Maria Grazia Pia, INFN Genova Resources Status on 1 September 2002 New collaborators: – Pablo Cirrone (INFN-LNS) – Luis Peralta, Pedro Rodrigues, Andreia Trindade (LIP, Lisbon) – Group from INFN-Gran Sasso also interested to join Maria Grazia Pia, INFN Genova We do a lot of work – and we do our best to do it well… Conclusions – a rigorous software process, continuous SPI – very effective team-work, several brilliant and motivated young collaborators We have plenty of interesting physics results in a new (and difficult) simulation domain – significant progress in the last year in a few problematic areas – don’t forget in what status we inherited the package, when the WG was created! A huge user community worldwide – excellent, constructive relationship between users and developers – more support for our activities outside the Collaboration than inside??? Many new projects in the WG, not only physics – Testing system, analysis, advanced examples, distributed computing, technology transfer More information in http://www.ge.infn.it/geant4/lowE/index.html Maria Grazia Pia, INFN Genova