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Paola Sala INFN Milano For the FLUKA collaboration Roma, 1-03-2007

FLUKA: status and plans. Paola Sala INFN Milano For the FLUKA collaboration Roma, 1-03-2007. Outline. Status, validation and perspectives of ion interaction models Beta-emitter activation: comparison with data Coupling to CT : work in progress and examples

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Paola Sala INFN Milano For the FLUKA collaboration Roma, 1-03-2007

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  1. FLUKA: status and plans Paola Sala INFN Milano For the FLUKA collaboration Roma, 1-03-2007

  2. Outline • Status, validation and perspectives of ion interaction models • Beta-emitter activation: comparison with data • Coupling to CT : work in progress and examples • Low energy neutrons: ongoing developments • Coupling of radiobiological models : tools already exist Paola Sala, Roma 01-03-2007 Info: http://www.fluka.org

  3. Heavy ion interaction models in Fluka • DPMJET-III for energies ≥ 5 GeV/n • DPMJET (R. Engel, J. Ranft and S. Roesler) Nucleus-Nucleus interaction model • Energy range: from 5-10 GeV/n up to the highest Cosmic Ray energies (1018-1020 eV) • Used in many Cosmic Ray shower codes • Based on the Dual Parton Model and the Glauber model, like the high-energy FLUKA hadron-nucleus event generator • Modified and improved version of rQMD-2.4 for 0.1 < E < 5 GeV/n • rQMD-2.4 (H. Sorge et al.) Cascade-Relativistic QMD model • Energy range: from 0.1 GeV/n up to several hundred GeV/n • Successfully applied to relativistic A-A particle production • New QMD model for 0.03 < E < 0.5 GeV/n • BME (BoltzmannMasterEquation) for E< 0.1 GeV/n • FLUKA implementation of BME from E.Gadioli et al (Milan) • Now under test for A≤ 16 • Standard FLUKA evaporation/fission/fragmentation used in both Target/Projectile final deexcitation  Projectile-like evaporation is responsible for the most energetic fragments • Electromagnetic dissociation Paola Sala, Roma 01-03-2007

  4. FLUKA with modified RQMD-2.4 Fragment charge cross section for 1.05 GeV/n Fe ions on Al (left) and Cu (right). : FLUKA, :PRC 56, 388 (1997),  : PRC42, 5208 (1990), : PRC 19, 1309 (1979) Paola Sala, Roma 01-03-2007 Fragment

  5. FLUKA fragmentation results Fragment charge cross section for 750 MeV/nUions on Pb. Data (stars) from J. Benlliure, P. Ambruster et al., Eur. Phys. J. A2, 193-198 (1988). Fission products have been excluded like in the experimental analysis Paola Sala, Roma 01-03-2007

  6. The new QMD model New model developed for FLUKA, based on Quantum Molecular Dynamics : • 2 and 3-body forces + Coulomb -> nuclear potential dynamically evolving during collision -> nuclear compression, fragment formation • semi-classical (molecular) motion of nucleons with nucleon-nucleon interaction terms • Quantum effects: nucleons as wave packets, Pauli blocking, stochastic scattering, particle production (not implemented) Status: • Model developed and coupled to FLUKA equilibrium stage • Comparison with thin target experimental data in progress • Initialization database ready up to Z<83, • First implementation in the full FLUKA scheme working • Tests on thick target experimental data started Energy range: from few tens of MeV/A up to 500-600 MeV/A Paola Sala, Roma 01-03-2007

  7. RQMD + FLUKA QMD + FLUKA EXP data The new QMD model: (data PRC64 (2001) 034607) Paola Sala, Roma 01-03-2007

  8. The new QMD model: examples (proc.Cospar2006 ) 12C 290MeV/A On C, Cu, Pb 5, 10, 20, 30, 40, 60 and 80 deg, (multiplied by powers of 10) Dots: data Iwata et al. PRC64, (2001), 054609 Histo: fluka Ne 400MeV/A On C, Cu, Pb Paola Sala, Roma 01-03-2007

  9. The new QMD model: examples Charge distribution from simulations ( histograms) compared to experimental data (grey points) by the AMPHORA detector at SARA. The results of simulations are extremely sensitive to the implementation of experimental cuts, as can be seen comparing the yellow line, obtained imposing a multiplicity cut of Mz > 5 at the end of the fast stage of the reaction, described by QMD, to the red line, obtained adding at the end of the FLUKA stage of the simulation a multiplicity cut of Mz > 10 and taking into account the acceptance of the detector. Paola Sala, Roma 01-03-2007

  10. The new QMD model:future • Completion of the initialization database • Better description of nucleon-nucleon elastic scattering, with non-isotropic angular distribution • Pion production • …tests, tests, tests……. Paola Sala, Roma 01-03-2007

  11. The BME (Boltzmann Master Equation) theory It describes the thermalization of the composite system formed in A–A collisions at E < 100MeV/n, via nucleon–nucleon scattering and emission into the continuum of single nucleons and nucleons bound in clusters (M. Cavinato et al., Nucl. Phys. A 643, 15 (1998); 679, 753 (2001)) exp. data from E. Holub et al., Phys. Rev. C 28, 252 (1983) Paola Sala, Roma 01-03-2007

  12. THE BME – FLUKA INTERFACEfor nucleus – nucleus interactions below 100 MeV/n A preliminary version of the BME-FLUKA event generator considering two different reaction mechanisms, is presently under test 2. PERIPHERAL COLLISION P = 1 − PCF three body mechanism or “inelastic scattering” (for high b) The complete fusion cross section decreases with increasing bombarding energy. We integrate the nuclear densities of the projectile and the target over their overlapping region, as a function of the impact parameter, and obtain an excited “middle source” and two fragments (projectile and target-like). The kinematics is suggested by break-up studies. 1. COMPLETE FUSION PCF = CF /R preequilibrium according to the BME theory FLUKA evaporation In order to get the multiplicities of the pre-equilibrium particles and their double differential spectra, the BME theory is applied to a few representative systems at different bombarding energies and the results are parameterized. Paola Sala, Roma 01-03-2007

  13. New results and comparison with i-Themba expt. Data BME – FLUKA interfaceStudied reaction: 12C+12C @ 200 MeV PRELIMINARY presented to FLUKA internal meeting Andrea Mairani In collaboration with Dr. F. Cerutti, Dr. A. Ferrari, Prof. E. Gadioli Milan, December 2006

  14. PRELIMINARY OUTLINE • Experimental investigation: • Experimental data for Intermediate Mass Fragment (IMF) emission, 12C+12C @ 200 MeV, experiment performed at iThemba Labs • Bragg Curve Detector (low E threshold, about 1 MeV/u, - no isotope separation, data however still under evaluation) • Silicon detector telescope(about 5 MeV/u energy threshold – isotope identification) • Theoretical analysis: • Benchmark of new FLUKA-BME interface (complete fusion mechanism): reproduction of Fluorine and heaviest Oxygen isotopes • Measurement of Beta+ emitter cross section (15O,13N,11C)

  15. PRELIMINARY Theoretical Analysis • 12C+12C ion pair is included in BME-FLUKA database • The pre-equilibrium emission is obtained using the “interpolated” parameters • Benchmark only of the COMPLETE FUSION mechanism • Coalescence IMF emission, not yetincluded in FLUKA, is obtained with a “full BME run”

  16. PRELIMINARY 19F and 20F spectra Experimental energy threshold Exp data (iThemba) BME (light particles) + FLUKA -> evaporative residues

  17. PRELIMINARY 15O spectra – β+emitter Total prediction σ(15O) about 16 mb 12.8 + 2.6 mb Exp data IMF emission(“fullBME”)BME(light particles)+FLUKA -> ev residues

  18. PRELIMINARY WORK IN PROGESS AND FUTURE DEVELOPMENTS • Experimental investigation: • Completion of experimental data analysis for 12C+12C @ 200 MeV (2006) and starting analysis at 400 MeV (2006) • New experiment: 16O+12C (2007) • New ion source (2007-2008), possible experiments at about 50-60 MeV/u • Theoretical analysis: • Generalize the BME-FLUKA interface for ion pairs not included in the database • Develop and benchmark the already included peripheralprocess (projectile and target break-up – Li, Be, B expdata @ iThemba labs) • Include the IMF emission in the preequilibrium stage

  19. Full transport + RQMD + BME+ ionization : bragg peaks Paola Sala, Roma 01-03-2007

  20. Bragg peaks vs exp. data: 20Ne @ 670 MeV/n Dose vs depth distribution for 670 MeV/n 20Ne ions on a water phantom. The green line is the FLUKA prediction The symbols are exp data from LBL and GSI Exp. Data Jpn.J.Med.Phys. 18, 1,1998 Fragmentation products mostly α’s and p’s Paola Sala, Roma 01-03-2007

  21. 12C Bragg peaks vs exp. data Zoom: 270 AMeV Blue: no spread Green: 0.15% Energy spread (σ) • Experiment: circles (270 AMeV) and triangles (330 AMeV) • FLUKA: lines Sommerer et al: Phys. Med. Biol. 51 2006 Paola Sala, Roma 01-03-2007

  22. In-beam PET: ion beam fragmentation • Final goal: simulation of β+ emitters generated during the irradiation • In-beam treatment plan verification with PET Work in progress: FLUKA validation (F.Sommerer) • Comparison with experimental data on fragment production (Schall et al.) • 12C, 14N, 16O beams, 675 MeV/A • Adjustable water column 0-25.5 cm • Z spectra of escaping fragments for Z4 • Cumulative yield of light fragments • Simulation: corrections applied for angular acceptance and for material in the beam upstream the water target • Comparison with experimental data on +-emitter production (Fiedler et. al.) Paola Sala, Roma 01-03-2007

  23. Fragmentation of therapeutic beams Production of light fragments (mostly α’s) as a function of depth in water Dashed: FLUKA-total Dotted: FLUKA with angular correction acceptance Solid : FLUKA with all corrections Stars : experimental data Paola Sala, Roma 01-03-2007

  24. 12C induced +-Activity Experiment*:12C beams with 337.5 AMeV on different targets, activity measured during irradiation 556s (red) and 10 minutes after irradiation, for 10 minutes (blue) *) Measuring only in pauses between spills. Courtesy of F. Fiedler + -active fragments:11C (20.4min), 15O (122s), 10C (19s), 13N (10min), 8B (0.8s), 9C (0.1s), 14O (71s), 13O (9ms), 12N (11ms) * Fiedler F. et al., The Feasibility of In-Beam PET for Therapeutic Beams of 3He, 2005 IEEE Nuclear Science Symposium Conference Record After 10 minutes dominated by 11C Paola Sala, Roma 01-03-2007

  25. +-Activity after Irradiation graphite PMMA Measured 10 – 20 min after irradiation, therefore dominated by 11C • Further work: • processing with same software than • experiment • profiles during irradiation water Paola Sala, Roma 01-03-2007

  26. New data • New data recently ( one week ago) taken with 16O • Bragg peak • + emission •  comparison of different beams •  test of MC Paola Sala, Roma 01-03-2007

  27. CT-based Calculations of Dose and Positron Emitter Distributions in Proton Therapyusing the FLUKA Monte Carlo code Katia Parodi, Ph.D.1,‡,* 1 Massachusetts General Hospital, Boston, USA ‡ Previously at Forschungszentrum Rossendorf, Dresden, Germany *Now at Heidelberg Ion Therapy Centre, Heidelberg, Germany Workshop on Monte Carlo in Treatment PlanningCatania, Italy, 31.10.2006 (NOTE: part of the presented slides are not included due to unpublished material) Massachusetts General Hospital and Harvard Medical School

  28. The GOLEM phantom Petoussi-Hensset al, 2002 CT-based MC calculation of dose and b+emitters The FLUKA MC code(http://www.fluka.org) - Reliable nuclear models - Already applied to proton therapy: Dosimetric/radiobiological studies (Biaggi et al NIM B 159, 1999) In-beam PET phantom experiments(Parodi et al PMB 47, 2002, Parodi et al IEEE, 52 2005) - Import of raw CT scans with optimized algorithms for efficient transport in voxel geometries(Andersen et al Radiat. Prot. Dosimetry 116, 2005)

  29. 24 from Schneider et al PMB 45, 2000 Air, Lung,Adipose tissue Soft tissue Skeletal tissue • (II) CT information • Segmentation into 27 materials The FLUKA implementation …Extended for HU > 1600 to include Ti (HU ~ 3000)(Parodi et al, MP, in press)

  30. Schneider et al PMB 45, 2000 • (II) CT information • Nominalmean density for each HU interval (Jiang and Paganetti MP 31, 2004) • But real density varies continuously with HU value The FLUKA implementation

  31. p beam PET/CT Measurement MC Results I: phantom experiments 1 SOBP @ 8 Gy in PMMA with 2 Ti rods, tmeas= 60 min, DT ~ 14 min Parodi et al MP (in press)

  32. p beam 50 % fall-offsagree within 1 mm Results I: phantom experiments Range reduction due to metallic rods Parodi et al MP (in press)

  33. Meas 60 minSimuDose MCDose TP Meas 60 minSimuDose MCDose TP Meas 60 minSimu Dose MCDose TP (Focus) Results I: phantom experiments Shadowing effect PET/CT Meas Parodi et al MP (in press) Better description than TP

  34. MC PET Meas. PET TP Dose MC Dose 2 Field 1 Field Agreement within 1-2 mm For position of distal max. And 50 % fall-off Results II: Clinical study Clival Chordoma, 0.96 GyE / field, DT1 ~ 26 min, DT2 ~ 16 min K. Parodi et al IJROBP (submitted)

  35. Thermal neutron pointwise treatment • At present FLUKA uses one thermal group for neutrons, extending from 10-5 eV to 0.414 eV: it is fine for most applications, not for all • The new cross section library will contain some 30 thermal groups, however… • … for some applications a truly pointwise treatment of thermal neutrons could be a must • .. For some applications a fully correlated pointwise treatment could be a must : done for H, Ar, and partially for 10B, 6Li, Xe, Cd WARNING : Pointwisedoes NOT mean correlated: Both multigroup and pointwise codes use the international evaluated databases (e.g. ENDF) which contain onlyinclusive distributions of reaction products To obtain exclusive, correlated final states ad-hoc models and algorithms have to be developed Paola Sala, Roma 01-03-2007

  36. Thermal neutron pointwise treatment • A new fully pointwise free gas thermal treatment has been implemented in FLUKA: in principle can be applied to whichever material (if preprocessed, presently applied to 1H, 6Li and 40Ar) at whichever temperature • This treatment make use of the best physics approach with no approximation and full account of thermal motion (no isotropic assumption for lab scattering) • A special bound hydrogen treatment for water at 293 K has been also developed (based on the ENDF S(α,β) treatment) and it is under test • The correlated treatment of neutron reactions will be extended to all “biological” targets Paola Sala, Roma 01-03-2007

  37. Coupling to radiobiological models • Energy deposition and dose can be calculated on geometry-independent meshes through standard FLUKA scoring utilities • Tools have been developed by the FLUKA collaboration to weight the energy deposition events by • Particle type • Particle energy (or LET) • Weighting is applied run-time, can be linear or quadratic • Needs a data-base for biological effects Paola Sala, Roma 01-03-2007

  38. END Paola Sala, Roma 01-03-2007

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