1. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 1

2. 2 What is common in RT and Space exploration Mixed fields of charged particles are present in astronauts environment and patients treated with carbon ions Dose calculation and radiological risk assessment Nuclear measurements are needed Nuclear measurements are needed Radiobiological measurements are needed Radiobiological measurements are needed

3. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 3 Heavy ion fragmentation The HZE particles of CGR produce secondary particles both in human body, and in needed shielding materials Change in the beam quality Carbon ions in radiation therapy undergo fragmentations inside the patient body

4. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 4 Radiation field in Space Trapped radiation: Van Allen belts (electrons, protons up to 600 MeV) Trapped radiation: Van Allen belts (electrons, protons up to 600 MeV) Solar radiation: about 90% protons, E<1 GeV, seldom but potentially dangerous (high dose) events Solar radiation: about 90% protons, E<1 GeV, seldom but potentially dangerous (high dose) events Galactic Cosmic Radiation (GCR): Galactic Cosmic Radiation (GCR):  2% electrons and positrons  98% particles :  87% protons  12%  particles  1% heavier ions ( HZE particles )

5. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 5 GCR charge contribution Earth Dose eq. on Earth: 10  Sv/d Mars Dose eq. on Mars: 100-200 mSv/d Moon Dose eq. on Moon: 300-400 mSv/d GCR Dose eq. from GCR: 1 mSv/d

6. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 6 DNA dsb visualized by immuno-fluorescence of  -H2AX histone in human skin fibroblasts exposed to 2 Gy of ionizing radiation  -rays silicon iron Cucinotta and Durante, Lancet Oncol. 2006

7. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 7 Risk associated to a manned Space exploration Carcinogenesis Carcinogenesis Acute Radiation Sickness Acute Radiation Sickness Degenerative Tissue Damage (heart, lens, digestive, …) Degenerative Tissue Damage (heart, lens, digestive, …) Central Nervous System damage Central Nervous System damage

8. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 8 Uncertainties for risk estimation Overall uncertainty: 400-1500%

9. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 9 Carbon-ion therapy An extensive database on nuclear fragmentation cross sections and fluences are needed at therapeutic energy region Carbon ions fragmentation: Fall of dose in the tumour target region Unwanted dose in normal tissue behind the target volume

10. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 10 Radiation-biophysics needs Biology Assessment of the biological effects of HZE particles Physics Assessment of the radiation environment Shielding optimization

11. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 11 Biological effects in mixed radiation field Biophysical model of radiation action Model for determining the ion track structure and energy deposition at local level Experimental measurements are essential for benchmarking physics models and transport code to give fluence, energy, and dose distribution with the required accuracy

12. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 12 Ground-based experiments

13. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 13 Experimental configuration for mixed radiation field studies and shielding optimization Physics Beam detector Target Radiobiology Target IC

14. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 14 Thick and thin targets Physics Beam detector Target Thick target = fluence measurements Thin target = cross section measurements

15. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 15 CR39 SSNTD in ground-based experiments  LET spectrum measurement through appropriate calibration  Geometrical track parameters measurement Fe 114 MeV/n LET 414 keV/  m D = 62  m Fe 1000 MeV/n LET 147 keV/  m Si 600 MeV/n LET 50 keV  m D = 46  m D = 35  m Etching condition: 6 N NaOH water solution t=24h T=70°C

16. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 16 CR39 SSNTD in ground-based experiments Very good charge resolution Easy to use LET threshold (~keV/  m) Low fluence irradiation (10 3 p/cm 2 ) Track analysis cannot be done manually ADVANTAGESLIMITATIONS

17. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 17 Automatic track analysis systems  Microscope development for image digitization Yasuda et al., Radiat. Meas., 2005 Tawara et al., NIM A., 2008

18. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 18 Cross section measurements (“thin” target) Fe, 1 GeV/n Fe, 1 GeV/n+1 cm PMMA Cecchini S. et al., Nucl. Phys., 2008 INTERCAST CR39 Etching condition: 6 N NaOH water solution t=30 h T=70°C target

19. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 19 Cross section measurements Cecchini S. et al., Nucl. Phys., 2008 Database: IonEnergy rangeTarget 4 He; 6 C; 14 N, 16 C; 20 Ne; 28 Si; 40 Ar; 48 Ti0.2 – 10 A GeVCH 2 ; PMMA; C; Al; Cu; Pb

20. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 20 Measurements with “thick” target Same condition as biological experiments Fe, E=1 A GeV Measurements of primary beam contribution to the total dose after different shielding materials

21. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 21 Shielding properties of different materials Scampoli P. et al., Radiat. Res., 2005 Surviving fraction of incoming particles after different shielding materials is measured with CR39 Intercast detectors 1 A GeV5 A GeV

22. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 22 Biological effectiveness of shielding Durante et al., Radiat. Res, 2005 500 A MeV 1 A GeV Fe beam

23. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 23 Measurements with carbon ions for RT Energies up to 500 A MeV  Track etched detector are used with suitable etching condition  Emulsion detector  Low fluence  Z ≤ 6e Target: tissue equivalent material  Analysis

24. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 24 Emulsion Cloud Chamber Toshito. et al., Phys. Rev. C., 2008 High spatial resolution (~  m) Multiparticle separation Density grain is proportional to energy loss Refreshing method for extending the dynamic range of response High angular resolution (~  mrad)

25. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 25 Cross section measurements Toshito. et al., Phys. Rev. C., 2008 Shall et al., Nim B, 1996 Golovchenko et al., Nim B, 1996 and Phys. Rev. C 2002 Good agreement with previous experimental data Discrepancy of about 10% and 20% with model

26. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 26 Conclusions Ground based experiments are still necessary for code bench marking, both in Space radiation-protection and radio-therapy with carbon ions Shielding properties of new material (e.g. Kevlar and Nextel) have to be investigated Development of technology make more suitable track- etch detectors for these purposes

27. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 27

28. P. Scampoli - 24th ICNTS Bologna, September 4, 2008 28 HZETRN Calculations Wilson J. et al., Health Physics, 1995