12 C fragmentation measurements for hadrontherapy applications Introduction Status French program Japanese-French collaboration

20 juillet C fragmentation in hadrontherapy High probability Less accurate dose Biological effectiveness depends on the particle atomic number Way of monitoring the energy deposited by PET imaging or gamma camera I. Pshenichnov, Geant4, Bordeaux 05 Fragment contribution ~20% at the Bragg peak G4 precision ~10% beyond Bragg peak Geant4 simulations Accuracy required : Bragg peak position ~2 mm / Dose deposited ~5%

20 juillet Current status of fragmentation studies for hadrontherapy Japan & Germany «Clinical» approach : validation of the analytical codes (TPS) 12 C depth dose measurements and fragment production in water (or PMMA) from 200 to 400 MeV/u only few published data & no data for E< 100 MeV/u For the future French hadrontherapy center  necessity of fragmentation studies At which energies ? E< 100 MeV/u : GANIL

20 juillet Fragmentation for hadrontherapy in France 2005 : Creation of the join research group: GDR MI2B (IN2P3/CEA) « medical imagery & dosimetry » Objectives : fragment production measurements & Geant4 physics validation for hadrontherapy «Clinical» approach (water, PMMA) Angular distributions, energy spectra of fragments Comparisons Geant4-experimental data → necessity of «physical» measurements ? fragmentation cross sections on the most important elements (C, O, Ca…) Program accepted by the scientific comity of the GDR (April 2006)

20 juillet Experimental set-up 12 C at ~ MeV/u (at 90 MeV/u, the Bragg peak is at 2.1 cm of depth) on water or PMMA targets with various thicknesses Detection of charged particles, neutrons and gamma rays  H 2 0 PMMA 12 C  E/E (2-3) neutron (4-5) Beam Monitor ToF  Gamma rays (study of dose monitoring) Profiles as a function of target depth of : Prompt gamma rays Positron emitter production

20 juillet Schedule Simulations (charged part. γ) New experiments ? (“Physical” approach) Detector design Data-simulation comparison Middle of experiment

20 juillet The french collaboration LPC Caen : 4 researchers G. Ban, J. Colin, D. Cussol, J.M. Fontbonne, M. Labalme IPN Lyon : 4 researchers, 1 student M. Chevallier, D. Dauvergne, A. Demeyer, P. Lautesse, C. Ray, M.C. Ricol, E. Testa IPHC Strasbourg : 3 researchers, 1 student F. Hass, V. Rauch, M. Rousseau, M. D. Salsac

20 juillet Japanese-French collaboration

20 juillet Carbon fragmentation in nuclear emulsion 4  tracking detector (spatial resolution of ~1 µm) Detection and identification of charged particles density of grains along the path Saturation for multiple charge (3  Z) → R&D for charge identification (3  Z  6) Refreshing method Use of CR-39

20 juillet R&D of emulsion technology to study fragmentation TECHNOLOGY R&D in progress in the university of Nagoya (Prof. Niwa) High speed systems developed both in Japan and France (IPN Lyon) for a future neutrino oscillation experiment FIRST RESULTS since 2003 Fragmentation cross sections at HIMAC (Japan) C  Water & C  Lucite interaction for E>150 MeV/u

20 juillet Japanese-French collaboration Fragmentation measurements with emulsion technology at HIMAC and GANIL (~10 MeV/u MeV/u) At GANIL Complementary French and Japanese detection systems Emulsion scanning system available in Lyon