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

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 (acceptance) 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 Ample 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 (GDPM approach) We have a SPI process With some spells of SPD sometimes… Collaboration with Anaphe for a common (tailored) process We keep everything in CVS (not in our head…) Code, designs, tests, documents etc. We maintain a web site LowE, advanced examples, WG projects More details: see talk on Software Process in Physics, Geant4 Review 2001

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 Auger effect New Fluorescence Small fixes and improvements while re-implementing in a 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

Photons: mass attenuation coefficient UR 1.1 Fe Comparison against NIST data Tests by IST - Natl. Inst. for Cancer Research, Genova (F. Foppiano et al.) LowE accuracy ~ 1% Also water, Pb This test will be introduced into the Test & Analysis project for a systematic verification

Photon attenuation: Geant4 vs. NIST data Test and validation by IST - Natl. Inst. for Cancer Research, Genova UR 1.1 Pb water Fe  Low Energy EM Standard EM w.r.t. NIST data accuracy within 1%

Photons: angular distributions UR 1.1 Rayleigh scattering: Geant4-LowE and expected distribution (more work in progress)

Photons, evidence of shell effects UR 1.1 Photon transmission, 1 mm Pb Photon transmission, 1 mm Al

Electron Bremsstrahlung UR 1.1 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

Electron ionisation UR 1.1 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!)

Electrons: range UR 1.1 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

Electrons: dE/dx UR 1.1 Ionisation energy loss in various materials Compared to Sandia database More systematic verification planned (for publication) Also Fe, Ur

Electrons, transmitted UR 1.1 20 keV electrons, 0.32 and 1.04 mm Al

Nuclear stopping power Protons Stopping power Z dependence for various energies Ziegler and ICRU models UR 2.1 Ziegler and ICRU, Fe Ziegler and ICRU, Si Nuclear stopping power Straggling Bragg peak (with hadronic interactions) UR 2.5

Antiprotons UR 2.3 New: comparison with another theoretical model Non-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

Ions UR 2.2 Ar and C ions Deuterons

Scattered Photon Polarization Polarisation Cross section: UR 4.1, D.1 y O z x q a f hn hn0  A C Scattered Photon Polarization 250 eV -100 GeV  Polar angle  Azimuthal angle  Polarization vector Low Energy Polarised Compton 10 MeV small  large  100 keV 1 MeV More details: talk on Geant4 Low Energy Electromagnetic Physics Other polarised processes under development

Fluorescence UR 3.1 Experimental validation: test beam data, in collaboration with ESA Science Payload Division Microscopic validation: against reference data Scattered photons Fe lines GaAs lines Spectrum from a Mars-simulant rock sample

Auger effect UR 3.1 New process, validation in progress Auger electron emission from various materials Sn, 3 keV photon beam, electron lines w.r.t. published experimental results

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!

P. Rodrigues, A. Trindade, L.Peralta, J. Varela GEANT4 Workshop, 2002 30 September – 4 October GEANT4 Medical Applications at LIP P. Rodrigues, A. Trindade, L.Peralta, J. Varela LIP – Lisbon

P. Rodrigues, A. Trindade, L.Peralta, J. Varela, LIP 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 15x15 cm2 Differences 10x10 cm2 Differences 15x15 cm2 10x10 cm2 LIP – Lisbon

P. Rodrigues, A. Trindade, L.Peralta, J. Varela, LIP 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) Styrophoam Lead

P. Rodrigues, A. Trindade, L.Peralta, J. Varela, LIP Dose Calculations with 12C 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

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.

Jean-Francois Carrier, Louis Archambault, Rene Roy and Luc Beaulieu 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 Jean-Francois Carrier, Louis Archambault, Rene Roy and Luc Beaulieu

Uranium irradiated by electron beam Jean-Francois Carrier, Louis Archambault, Rene Roy and Luc Beaulieu Fig 1. Depth-dose curve for a semi-infinite uranium slab irradiated by a 0.5 MeV broad parallel electron beam 1Chibani O and Li X A, Med. Phys. 29 (5), May 2002

Multi-slab medium irradiated by photons Jean-Francois Carrier, Louis Archambault, Rene Roy and Luc Beaulieu 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 R,http://www.irs.inms.nrc.ca/inms/irs/papers/iccr00/iccr00.html

Water phantom irradiated by clinac beam Jean-Francois Carrier, Louis Archambault, Rene Roy and Luc Beaulieu 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

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

Dose distribution: TG 43 protocol, experimental data (S Dose distribution: TG 43 protocol, experimental data (S. Paolo Hospital, Savona), G4-LowE  Protocol  Data (SV)  G4-LowE S. Guatelli’s thesis

and more! Application Not only “space and medical”! Cosmic rays, jovian electrons Solar X-rays, e, p Courtesy SOHO EIT Application and more! Courtesy of S. Magni, Borexino Not only “space and medical”!

users all over the world Team work! Geant4 Low Energy Electromagnetic Working Group + users all over the world Students Jean-Francois Carrier Stephane Chauvie Elena Guardincerri Susanna Guatelli Alfonso Mantero Pedro Rodrigues Andreia Trindade Matteo Tropeano The validation plots in this presentation have been contributed by 19 people from 9 countries Thanks to all!

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!

Bremsstrahlung Models UR A.5 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

Polarisation of a non-polarised photon beam, simulation and theory UR 1.4, 4.1 500 million events simulation Polarisation of a non-polarised photon beam, simulation and theory Ratio between intensity with perpendicular and parallel polarisation vector w.r.t. scattering plane, linearly polarised photons

Ongoing significant effort in OOAD

Other activities in the WG Advanced examples Simulation + analysis in a distributed computing environment Test & Analysis Technology transfer Training

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

Talks since last workshop in WG web 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 Talks since last workshop in WG web

Training User-centric approach: National School on Detector Technologies, Torino, Feb. 2002 Lectures + “Geant4 through an example” Geant4 & Anaphe mini-workshop, Gran Sasso Lab, July 2002 Tutorials + “Geant4 through an example” +demo Geant4 User Workshop, Salamanca, July 2002 Lectures + exercises Geant4 & Anaphe mini-workshop, INFN-LNS Lab, November 2002 Tutorials + + “Geant4 through an example” +demo “Geant4 through an example” +demo User-centric approach: Introduction to “advanced” software engineering concepts Complete (from the user’s view) training: simulation + analysis

Resources Status on 1 September 2002 New collaborators: Pablo Cirrone (INFN-LNS) Luis Peralta, Pedro Rodrigues, Andreia Trindade (LIP, Lisbon) Interest expressed by small group at INFN-Gran Sasso Lab

More information in http://www.ge.infn.it/geant4/lowE We do a lot of work and we do our best to do it well… 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 projects in the WG, not only physics Testing system, analysis, advanced examples, general electromagnetic OOAD, distributed computing, technology transfer More information in http://www.ge.infn.it/geant4/lowE Conclusions