1 / 30

Low Energy Electromagnetic Physics PART II

This article discusses the technology transfer from particle physics to fields such as space and medical science, using Geant4 as a showcase example. It covers various applications, including radiation therapy, brachytherapy, and hadron therapy simulation. The article also highlights the accuracy and flexibility of Geant4 in modeling geometries and materials, as well as its interactive facilities for visualization and analysis.

riveradavid
Download Presentation

Low Energy Electromagnetic Physics PART II

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Low Energy Electromagnetic Physics PART II Maria Grazia Pia INFN Genova Maria.Grazia.Pia@cern.ch on behalf of the Low Energy Electromagnetic Working Group Geant4 Workshop Helsinki, 30-31 October 2003 http://www.ge.infn.it/geant4/training/

  2. Technology transfer Particle physics software aids space and medicine Geant4 is a showcase example of technology transfer from particle physics to other fields such as space and medical science […]. CERN Courier, June 2002

  3. Central-Axis depth dose Profile curves at 9.8 cm depth PLATO overestimates the dose at ~ 5% level Comparison with commercial treatment planning systems M. C. Lopes IPOFG-CROC Coimbra Oncological Regional Center L. Peralta, P. Rodrigues, A. Trindade LIP - Lisbon CT-simulation with a Rando phantom Experimental data with TLD LiF dosimeter CT images used to define the geometry: a thorax slice from a Rando anthropomorphic phantom

  4. Brachytherapy Courtesy of R. Taschereau, UCSF Flexibility of modeling geometries and materials Radioactive Decay Module Low energy electromagnetic processes Interactive facilities: visualisation, analysis, UI

  5. Dose distribution Analysis of the energy deposit in the phantom resulting from the simulation Isodose curves Dosimetry Simulation of energy deposit through Geant4 Low Energy Electromagnetic package to obtain accurate dose distribution Production threshold: 100 mm 2-D histogram with energy deposit in the plane containing the source AIDA + Anaphe Python for analysis for interactivity may be any other AIDA-compliant analysis system

  6. Simulation Plato Data Simulation Plato Distance along X (mm) Distance along Z (mm) Endocavitary brachytherapy S. Agostinelli, F. Foppiano, S. Garelli, M. Tropeano Role of the simulation: precise evaluation of the effects of source anisotropy Longitudinal axis of the source Difficult to make direct measurements rely on simulation for better accuracy than conventional treatment planning software • Transverse axis of the source • Comparison with experimental data • validation of the software Effects of source anisotropy

  7. Superficial Brachytherapy Simulation Nucletron Data F. Foppiano, M. Tropeano Leipzig applicators Distance along Z (mm) Experimental validation: Geant4 Nucletron data IST data • Code reuse: • still the same application as in the previous case • only difference: the implementation of the geometry of the applicator, derived from the same abstract class • No commercial software exists for superficial brachytherapy treatment planning!

  8. Dosimetry Endocavitary brachytherapy MicroSelectron-HDR source Dosimetry Superficial brachytherapy Leipzig applicator

  9. 0.16 mGy =100% Isodose curves Dosimetry Interstitial brachytherapy Bebig Isoseed I-125 source

  10. RBE ++ tumors -- healthy tissues Distance away from seed RBE enhancement of a 125I brachytherapy seed with characteristic X-rays from its constitutive materials Goal: improve the biological effectiveness of titanium encapsulated 125I sources in permanent prostate implants by exploiting X-ray fluorescence Titanium shell (50 µm) Silver core (250 µm) Percentage 4.5 mm All the seed configurations modeled and simulated with R. Taschereau, R. Roy, J. Pouliot Centre Hospitalier Universitaire de Québec, Dépt. de radio-oncologie, Canada Univ. Laval, Dépt. de Physique, Canada Univ. of California, San Francisco, Dept. of Radiation oncology, USA

  11. Hadron Therapy Medical Applications G.A. Pablo Cirrone On behalf of the CATANA – GEANT4 Collaboration Qualified Medical Physicist and PhD Student University of Catania and Laboratori Nazionali del Sud - INFN, Italy

  12. Modulator & Range shifter Ligth field Scattering system Monitor chambers Laser CATANA hadrontherapy facility

  13. GEANT4 simulation Real hadron-therapy beam line

  14. Hadrontherapy: comparison of physics models to data Standard + hadronic Standard Processes Low Energy + hadronic Low Energy

  15. Beam Line Validation LowE e.m. + hadronic (precompound) Difference below 3% even on the peak

  16. Lateral Dose Validation Difference in penumbra = 0.5 % Difference in FWHM = 0.5 % Difference Max in the homogeneity region = 2 %

  17. Simulation of cellular irradiation with the CENBG microbeam line using GEANT4Sébastien Incertirepresenting the efforts of the Interface Physics - Biology groupCentre d'Etudes Nucléaires de Bordeaux - Gradignan IN2P3/CNRS Université Bordeaux 1 33175 Gradignan FranceEmail : incerti@cenbg.in2p3.frNuclear Science SymposiumPortland, OR, USAOctober 19-25th, 2003

  18. GEANT4 Need for a reliable simulation tool WHY A SIMULATION TOOL ? • Technical challenge : to deliver the beam ion by ion, in air, keeping a spatial resolution compatible with irradiation at the cell level, i.e. below 10 µm • A simulation tool will help to : • understand and reduce scattering along the beam line as much as possible : collimator, diaphragm, residual beam pipe pressure… • understand and reduce scattering inside theirradiation chamber : single ion detector, beam extraction into air, cell culture layer… • predict ion transport (ray tracing) in the beam line magnetic elements • dosimetry • with high flexibility and integration.

  19. ALPHAS PROTONS Reference Simulation of ion propagation in the CENBG microbeam line using GEANT4, S. Incerti et al., Nucl. Instr. And Meth. B 210 (2003) 92-97 Testing GEANT4 at the micrometer scale • horizontal error bars :  5% experimental uncertainty on the foil thickness value • vertical error bars combine statistical fluctuations obtained by varying the number of incident particles in the simulation and systematic fluctuations of the FWMH values due to the  5 % error on the foil thickness ; they range from 1% to 4% for protons and from 5% to 7% for alphas. • ICRU_R49p and ICRU_R49He electronic stopping power tables used (G4hLowEnergyIonisation) • Important issue on cuts : • - Default cutValue in PhysicsList.cc : 100 µm and above • - Max step length in target foil logic volume (UserLimits) in DetectorConstruction.cc : foil thickness / 10 • - low energy EM and standard packages give same results in the measured region of thickness

  20. Beam on target cells AIR AIR VACUUM • Beam initial energy distribution : 1 mm 10 µm In red :scattered bydiaphragm In blue : no scattering • Beam energy distribution on target : • Probability to reach a given 10 µm circular surface : • In vacuum : • Taking into account the residual air ( 5.10-6 mbar ) :

  21. GATE, a Geant4 based simulation platform, designed for PET and SPECT For the OpenGATE collaboration: Steven Staelens

  22. Geometry: scanners +sources Overview Interface with the user : scripting (macros)

  23. Solar X-rays, e, p Courtesy SOHO EIT Geant3.21 ITS3.0, EGS4 Geant4 C, N, O line emissions included low energy e/gextensions Cosmic rays, jovian electrons were triggered by astrophysics requirements X-Ray Surveys of Planets, Asteroids and Moons Induced X-ray line emission: indicator of target composition (~100 mm surface layer) Courtesy ESA Space Environment & Effects Analysis Section

  24. X-ray fluorescence, PIXE ESA Bepi Colombo mission to Mercury Analysis of the elemental composition of Mercury crust through X-ray spectroscopy Fluorescent spectrum of Icelandic Basalt (“Mars-like”) Experimental data: 6.5 keV photon beam, BESSY Courtesy of A. Owens et al., ESA many more new features, no time to mention them all...

  25. LowE at very high energy... Fluorescence is an important effect in the simulation of ultra-high energy cosmic ray experiments Courtesy of Auger

  26. Geant4 simulationof test-mass charging in the LISA mission Very long base-line: 1 million km Very high precision: < 1nm – 1pm (!)

  27. Physics List EM processes (LowE) Electrons, Gammas, etc Atomic de-excitation Hadrons (no hFluorescence) Secondaries Cuts: (250 eV), 1mm - 5mm Kill e- outside caging

  28. Courtesy of Borexino unique simulation capabilities: Credit: O. Cremonesi, INFN Milano Underground astroparticle experiments Gran Sasso Laboratory, Italy • lowE physics • fluorescence • radioactivity • neutrons • etc..

  29. Boulby Mine dark matter search Prototype Simulation Courtesy H. Araujo and A. Howard, IC London ZEPLIN III One High Energy event mirror LXe GXe PMT source

  30. ...and much more • No time to show all applications • Very good relationship between Geant4 LowE Group and its user community • valuable feedback on applications • new user requirements to extend and improve the package • Feel free to contact us! • Many user applications become (simplified) advanced examples distributed with Geant4 • to help other groups in the user community to get started

More Related