Microdosimetric GEANT4 and FLUKA Monte- - Microdosimetric GEANT4 - PowerPoint PPT Presentation

health physics health pyhsics division division risk and safety Microdosimetric GEANT4 and FLUKA Monte- - Microdosimetric GEANT4 and FLUKA Monte Carlo Simulations and Measurements of Heavy Carlo Simulations and Measurements of Heavy Ion Irradiation of Silicon and Tissue Ion Irradiation of Silicon and Tissue 1 , M. Wind 1,2 , S. Rollet 1 , M. Latocha 1,3 , P. Beck 1 , M. Wind 1,2 , S. Rollet 1 , M. Latocha 1,3 P. Beck , F.Bock 1,2 1,2 , H. B ck 2 2 , Y. Uchihori , Y. Uchihori 5 5 F.Bock , H. Bö öck 1 ARC Seibersdorf research, Health Physics Division, 2444 Seibersdorf, Austria 2 Vienna University of Technology, Atomic Institute, 1020 Vienna, Austria 3 Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Kraków, Poland 4 National Institute of Radiological Sciences, (NIRS), Inage, Chiba, JAPAN Acknowledgment: Support by ARCS (NANODOS project), NIRS, and ICCHIBAN working group. peter.beck@arcs.ac.at

Outline Outline • Simulation • Simulation of radiation effects of radiation effects • Code validation by using • Code validation by using microdosimetric microdosimetric quantities quantities • Comparison of • Comparison of measurements measurements and and simulations simulations heavy ion irradiation (silicon & tissue) irradiation (silicon & tissue) heavy ion – – microdosimetric measurements (2 2µ µm m sensitive volume) sensitive volume) microdosimetric measurements ( – – Monte Carlo simulation (FLUKA FLUKA, , GEANT4 GEANT4) ) Monte Carlo simulation ( – – peter.beck@arcs.ac.at

Why Radiation Simulation? Why Radiation Simulation? Simulation supports supports… … Simulation • understanding radiation • understanding radiation interaction mechanism interaction mechanism • irradiation test • irradiation test measurements measurements • design • design radiation hard semiconductor radiation hard semiconductor • optimize • optimize shielding shielding peter.beck@arcs.ac.at

Validation Approach Validation Approach • Validation • Validation of Monte Carlo high energy particle transport of Monte Carlo high energy particle transport • Using • Using microdosimetric microdosimetric methods methods • Compare • Compare measurements measurements with with simulations simulations absorbed dose absorbed dose – – lineal energy spectra lineal energy spectra – – dose mean lineal energy dose mean lineal energy – – peter.beck@arcs.ac.at

Monte Carlo Simulation with FLUKA & GEANT4 Monte Carlo Simulation with FLUKA & GEANT4 • • Transport Transport of of electromagnetic particles electromagnetic particles – – hadronic particles hadronic particles – – heavy ions heavy ions – – • • Energy: 20 : 20 TeV TeV to to … … Energy 10keV (all particles) 10keV (all particles) – – thermal neutrons (~ 0,1 eV thermal neutrons (~ 0,1 eV) ) – – (ph, e - - ) / FLUKA 1 keV keV (ph, e ) / FLUKA 1 – – http://www.fluka.org/index.html 250eV (ph, e) / GEANT4 250eV (ph, e) / GEANT4 – – • • Score energy deposition energy deposition Score event by event event by event – – • • Simulation of Simulation of microdosimetric microdosimetric spectra spectra http://geant4.web.cern.ch/geant4/ peter.beck@arcs.ac.at

Dosimetry - - Microdosimetry Microdosimetry Dosimetry Absorbed dose: [D] = Gy = J · kg -1 µm ~ nm Lineal energy: [ y ] = keV · µm -1 LET = MeV·cm 2 · mg -1 cm ~ mm peter.beck@arcs.ac.at

Micro- -Dosimeter (Rossi Dosimeter (Rossi- -Type) Type) Micro • • TEPC ( tissue equivalent proportional counter tissue equivalent proportional counter ) ) TEPC ( • • SEPC ( silicon equivalent proportional counter silicon equivalent proportional counter ) ) SEPC ( Source: Columbia University Electronics Tissue / Silicon Equivalent Chamber (10 µm ~ 100nm) peter.beck@arcs.ac.at

HIMAC - - Heavy Ion Medical Accelerator, Chiba, Japan Heavy Ion Medical Accelerator, Chiba, Japan HIMAC • • HIMAC HIMAC HIMAC is used for is used for cancer therapy cancer therapy – – is available for is available for scientific experiments scientific experiments during night during night – – time and weekends time and weekends • • ICCHIBAN - -8 8 ICCHIBAN Measurements in the framework of Inter Measurements in the framework of Inter – – Comparison for Cosmic- -ray with Heavy Ion ray with Heavy Ion Comparison for Cosmic Beams at Beams at NIRS NIRS Radiation study at the Radiation study at the International Space Station International Space Station – – • • Tissue & Silicon irradiation measurements Tissue & Silicon irradiation measurements O 400 MeV/u MeV/u O 400 – – Fe 300 MeV/u MeV/u Fe 300 – – peter.beck@arcs.ac.at

High Energy Particle Transport Simulation High Energy Particle Transport Simulation • • Detector geometry geometry and and material material Detector • • Source: heavy ions heavy ions Source: O 400 MeV/u O 400 MeV/u – – Fe 300 MeV/u MeV/u Fe 300 – – • • Analysis of beam characteristics beam characteristics Analysis of (shape, divergence, etc.) (shape, divergence, etc.) • • High energy particle Monte Carlo Monte Carlo High energy particle transport codes transport codes FLUKA- -2005 2005 FLUKA – – GEANT4 GEANT4 – – peter.beck@arcs.ac.at

Simulation Results: Particle fluence density Simulation Results: Particle fluence density - ³ cm - (particle · (particle ·cm ³ per unit source) per unit source) Oxygen 400 MeV/u Iron 300 MeV/u broad beam small beam • Neutron fluence rate • Neutron fluence rate • Inside tissue • Inside tissue • Electron fluence rate • Electron fluence rate • Inside silicon • Inside silicon peter.beck@arcs.ac.at

Total absorbed dose in 2µ µm sensitive silicon & tissue m sensitive silicon & tissue Total absorbed dose in 2 volume due to heavy ion irradiation volume due to heavy ion irradiation Instrument Beam Measurement FLUKA Geant 4 (Gy / source particle × 10 -10 ) MeV/u TEPC O 400 2.3 ± 0.3 2.9 ± 0.3 2.7 ± 0.3 47.0 ± 7.0 Fe 300 45.8 ± 4.6 43.3 ± 4.3 SEPC O 400 2.1± 0.3 2.8 ± 0.3 2.7 ± 0.3 Fe 300 44.4 ± 6.7 45.8 ± 4.6 42.3 ± 4.2 peter.beck@arcs.ac.at

Microdosimetric absorbed dose spectra in tissue tissue Microdosimetric absorbed dose spectra in Measurements, FLUKA, GEANT4 Measurements, FLUKA, GEANT4 Oxygen 400 MeV/u irradiation Iron 300 MeV/u irradiation peter.beck@arcs.ac.at

Microdosimetric absorbed dose spectra in silicon silicon Microdosimetric absorbed dose spectra in Measurements, FLUKA, GEANT4 Measurements, FLUKA, GEANT4 Oxygen 400 MeV/u irradiation Iron 300 MeV/u irradiation peter.beck@arcs.ac.at

Ratios of Dose Mean Lineal Energy y Ratios of Dose Mean Lineal Energy D Beam Instrument FLUKA/Meas. Geant 4/Meas. (MeV/u) TEPC O 400 1.04 ± 0.16 0.97 ± 0.15 Fe 300 1.05 ± 0.16 1.00 ± 0.15 SEPC O 400 0.89 ± 0.13 1.22± 0.18 Fe 300 1.01 ± 0.15 0.93± 0.14 peter.beck@arcs.ac.at

Ratios of dose mean lineal energy y Ratios of dose mean lineal energy D 1,6 FLUKA/Measurement 1,5 Geant4/Measurement Ratio: calculation / measurement 1,4 1,3 1,2 1,1 1,0 0,9 0,8 0,7 0,6 tissue silicon tissue silicon (O 400 MeV/u) (O 400 MeV/u) (Fe 300 MeV/u) (Fe 300 MeV/u) peter.beck@arcs.ac.at

Conclusions Conclusions • • Successful modelling of heavy ion irradiation experiments with Successful modelling of heavy ion irradiation experiments with FLUKA FLUKA – – GEANT4 GEANT4 – – • • Successful simulation of 2 Successful simulation of 2µ µm sizes m sizes silicon silicon & & tissue tissue • • Ration of calculated Ration of calculated and and measured measured total total absorbed dose absorbed dose between between 1.3 and and 0.92 0.92 (mean over all measurements (mean over all measurements 1.1 1.1). ). 1.3 • • Agreement calculated and measured dose mean lineal energy dose mean lineal energy Agreement calculated and measured within 10%. 10%. within • • FLUKA and and GEANT4 GEANT4 calculations agree within calculations agree within 5 5- -10% 10% FLUKA peter.beck@arcs.ac.at