New materials for radiation protection buildings Monte Carlo-simulations and measurement for

1. New materials for radiation protection buildings Monte Carlo-simulations and measurement for X-rays, Protons, and Carbon ions a cooperation between university and industry Reinhold G. Müller, Nils Achterberg, Jürgen Karg Inst. Med. Physik, Strahlenklinik Universität Erlangen Otto Pravida, Pravida Bau GmbH Pressath Jan Forster, Renate Forster Ingenieurgesellschaft Ingolstadt

2. wall structure of Sandwich 30 - 40 60 - >900 30 - 40 cm double wall shell filled with concrete variable filling materials and mixtures

3. state of the art concrete of appropriate thickness is widely used for shielding walls: advantage: concrete is availableeverywhere and not too expensive; dis- - concrete needs shuttering and reinforcement; advantage: - long dry out time; - cracking in spite of reinforcement; - for enhancing density aggregates like Baryt are necessary, which increase the costs, up to a factor of 10; - shielding structures of more than 6 m thickness (high energy physics) make cooling necessary because of the process heat during hardening; - dismantling of these structures is very expensive.

4. the technical innovation: Sandwich Construction There is no need for such heavy constructions because of statics. Radiation protection can be reached more efficient and for significant reduced prices using adequate filling. That‘s why the Sandwich construction has been developed. advantage:- precast technology, nearly dry; - shielding by natural minerals like gypsum or limestone (low costs); - ceiling construction in same manner; - erection time less than 1/3 in relation to concrete; - for density enhancement natural minerals like iron-ore, Magnetit, Baryt, iron-slag, etc. can be aggregated (low costs); - optimal combinations are possible for nearly all problems; - the high content of crystal water qualifies gypsum for the attenuation of primary and secondary neutrons; - dismantling of the construction and reinstatement can easily be done with simple techniques; disadvantage: - none -

5. measurement and results suitable for DIN 6847-2 (German regulations, Sept. 2008) and NCRP 144, 153 (American regulations)

6. tenth value layers tvl DIN 6847-2, NCRP

7. materials under investigation • 3 kinds of normal concrete < 2.3 t/m³ (limestone concrete, mixed, silicate concrete) • magnetite concrete 3.5-3,8 t/m³ • magnetite concrete with iron gravel 5.0 t/m³ • natural gypsum 1.8 t/m³ • limestone 1.9 t/m³ • screen glass - - - • iron processing waste (Electric Arc Funrace Slag)2.4 t/m³ • magnetite pure (iron ore) 2.5 t/m³

8. German Regulations: DIN 6847-2 Datum: 2008 September

9. erection of a double wall shells for 8 vaults at once closing of the bunkers & filling the walls

10. planning a huge vault

11. erection of a huge vault

12. filling optimised material mixtures

13. closing the ceiling

14. vaults for particle therapy Datum: 2008 Januar

15. MC-simulations for protons 220 MeV neutron “volume dose” DE/DV [ J/cm³ ] walls made withconcrete GEANT4 7.1 S. Agostinelli et al. 2003, Nucl.Instrum.Methods A 506 250-303

16. protons 220 MeV neutron “volume dose” DE/DV [ J/cm³ ] walls inSandwich Technology

17. carbon ions 430 MeV/u walls withconcrete 550 cm 600 cm 550 cm

18. carbon ions 430 MeV/u walls in Sandwich Technology 550 cm 600 cm 550 cm

19. deuterons 45 MeV graphite target walls inSandwich Technology

20. Fn(E) of carbon ions 430 MeV/u neutron spectra concrete neutron spectra direction 0°

21. Fn(E) of carbon ions 430 MeV/u neutron spectra Sandwich Technology neutron spectra direction 0°

22. convolution with RBE for calculation of H*(10) for neutrons

23. protons 220 MeV effective Dose H*(10) TVL: 109 cm resp. 251 g/cm² direction 0°; same for mixture or concrete effective dose H*(10) behind the wall ofSandwich Technology

24. attenuation measurement at GSI igloo targets beam line 0° p+ carbon ions windows 45° filling material 3 different at once 6 different in total 3 wendi2 detectors neutron dose H*(10) 90°

25. igloo installed at GSI 45° 0°

26. protons 220 MeV Sandwich Technology measurement MC-simulation angle ° effective dose H*(10) per 109 protons behind (inside) the wall depending on energy and angle

27. effective neutron dose H*(10) for protons behind (inside) the wall MC-simulation angle ° normalized to the entrance value, depending on energy and angle

28. effective neutron dose H*(10) for protons behind (inside) the wall E = 220 MeV; angle = 0° MC-simulation normalized to the entrance value,

29. effective neutron dose H*(10) for carbon ions behind the wall; measurement 5 cm Borax

30. tenth value layers TVL for neutron dose H*(10) for carbon ions behind the wall

31. conclusion • theSandwich Construction • is suitable for all radiation sources, • and satisfies all requirements with a variety of advantages • as for example: • cost reduction; • reduced erection time; • flexible adjustment to the aspired wall thickness • because of the free option of filling material; • 4. feasibility of building alterations; • 5. simple and cheap dismantling and reinstatement;

32. the end thank you for your attention