1 / 19

Proton Transport in Liquid Water in the Upper Clinical Energy Range with Geant4-DNA

This paper explores the proton transport in liquid water at high energies using the Geant4-DNA simulation toolkit. The theoretical framework, results, and future work are discussed.

gambino
Download Presentation

Proton Transport in Liquid Water in the Upper Clinical Energy Range with Geant4-DNA

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. Covering the upper clinical energy range of Geant4-DNA for proton transport in liquid water A.D. Dominguez-Muñoz*1, M.I. Gallardo1, Z. Francis2, S. Incerti3and M.A. Cortés-Giraldo1 1Universidad de Sevilla (Seville, Spain) 2Université Saint-Joseph de Beyrouth (Beirut, Lebanon). 3CENBG / IN2P3 / CNRS (Gradignan, France). ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019 *e-mail: adominguez18@us.es

  2. Outline Motivation and goal Theoretical framework: RPWBA GOS of liquid water Results Conclusions and future work 1 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  3. Motivation and goal Max. energy Limit 100 MeV Max. energy of clinical proton therapy beams ≈250 MeV http://geant4-dna.org/ Range in liquid water ≈ 39 cm Liquid water 1 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  4. Theoretical framework: RPWBA RPWBA Relativistic Plane Wave Born Approximation Projectile Target Interaction Dirac equation Relativistic Quantum Mechanics + First Order Perturbation Excitation Interaction hamiltonian + Projectile + Two terms (Fano 1963) - - Longitudinal Ionization Target Transversal Free particle states (plane wave) Initial and final projectile wavefunction Plane Wave Approximation 2 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  5. Theoretical framework: RPWBA RPWBA Relativistic Plane Wave Born Approximation Characterized by Individual inelastic collisions Energy loss Momentum transfer Recoil energy DDCS (E>>W) Doubly differential cross section Longitudinal Transversal Generalized oscillator strength Response of the material ?? ?? GOS TGOS 3 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  6. GOS of liquid water Difficulties of computing liquid water GOS Non spherical wavefunctions Molecule Interaction between molecules Condensed phase Oxygen K-shell 4 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  7. GOS of liquid water Connecting GOS with dielectric properties [ M. Dingfelder / Radiation Physics and Chemistry 53 (1998) 1-18 ] GOS can be calculated from dielectric functions [ D. Emfietzoglou / Radiation Research 164 (2005) 202–211] Optical Oscillator Strength Drude model Red lines – Ionizations Green lines - Excitations Black line – Total sum Parameters values taken from [ D. Emfietzoglou / Radiation Research 164 (2005) 202–211] 5 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  8. GOS of liquid water Connecting GOS with dielectric properties [ M. Dingfelder / Radiation Physics and Chemistry 53 (1998) 1-18 ] GOS can be calculated from dielectric functions [ D. Emfietzoglou / Radiation Research 164 (2005) 202–211] Optical Oscillator Strength Drude model Red lines – Ionizations Green lines - Excitations Black line – Total sum Red lines – Ionizations Green lines - Excitations Black line – Total sum Parameters values taken from [ D. Emfietzoglou / Radiation Research 164 (2005) 202–211] 5 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  9. GOS of liquid water Connecting GOS with dielectric properties [ M. Dingfelder / Radiation Physics and Chemistry 53 (1998) 1-18 ] GOS can be calculated from dielectric functions [ D. Emfietzoglou / Radiation Research 164 (2005) 202–211] Q=0 5 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  10. GOS of liquid water Connecting GOS with dielectric properties [ M. Dingfelder / Radiation Physics and Chemistry 53 (1998) 1-18 ] GOS can be calculated from dielectric functions [ D. Emfietzoglou / Radiation Research 164 (2005) 202–211] Q≠0 Q=0 Total GOS 5 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  11. GOS of liquid water Connecting GOS with dielectric properties [ M. Dingfelder / Radiation Physics and Chemistry 53 (1998) 1-18 ] GOS can be calculated from dielectric functions [ D. Emfietzoglou / Radiation Research 164 (2005) 202–211] Q≠0 Q=0 Total GOS Q-extension is complex low-Q GOS ≈ constant Shell Ionization GOS Large-Q Bethe Ridge (Q=W) 5 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  12. GOS of liquid water GOS model (asymptotic behavior) [ F. Salvat / NIMB 316 (2013) 144–159 ] Small Q dominates in transverse interaction Differences between GOS and TGOS are negligible at small Q Bethe sum rule The model reproduces Bethe formula for the stopping power I-value definition Optical-Impulse approximation Large-Q (close) Low-Q (distant) Target electrons react as if they were free and at rest 6 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  13. Results Differential Cross Section (DCS) No experimental data available for our E values Comparison with G4-DNA current models Total Cross Section No experimental data available for our E values Comparison with oxygen K-shell data from PenH Stopping Power Comparison with PSTAR database 7 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  14. Results Differential Cross Section (DCS) No experimental data available for our E values Comparison with G4-DNA current models E = 1 MeV E = 10 MeV E = 100 MeV W(eV) W(eV) W(eV) –––––––G4-DNA ––––––– GOS from Dingfelderdata –––––––GOS from Emfietzogloudata 8 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  15. Results Total Cross Section No experimental data available for our E values Comparison with oxygen K-shell data from PenH Oxygen K-shell –––––––PenHdatabase ––––––– GOS from Dingfelderdata –––––––GOS from Emfietzogloudata 9 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  16. Results Stopping Power Comparison with PSTAR database –––––––PSTAR database ––––––– GOS from Dingfelderdata –––––––GOS from Emfietzogloudata 10 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  17. Results Stopping Power Comparison with PSTAR database –––––––PSTAR database ––––––– GOS from Dingfelderdata –––––––GOS from Emfietzogloudata 10 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  18. Conclusions and future work RPWBA theory offers a start point to calculate differential cross sections. GOS characterizes the response of the material. Results obtained with an asymptotic GOS model shows a good correspondence with PSTAR stopping power in the range of interest. There are no cross section and DCS experimental data for incident energies of the order of 100 MeV. Differences with current G4-DNA data are due to GOS models. Next, with more detailed models for GOS we will produce the cross section databases to be included for Geant4-DNA 11 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

  19. Acknowledgements • Spanish Ministry of Science, Innovation and Universities Project No. FPA2016-77689-C2-1-R • This research was supported by an FPU doctoral grant from the Spanish Ministry of Education and Vocational Training • We also thank Prof. Salvat (U. Barcelona) for his insightful comments 12 ENSAR2 workshop: GEANT4 in nuclear physics Madrid, April 24th-26th 2019

More Related