1. X-ray and Neutron Radiography and Tomography at NECSA Presented by Gawie Nothnagel Necsa-Wits Workshop; 10-11 September 2105 Frikkie de Beer, Mabuti Radebe, Robert Nshimirimana Kobus Hoffman, Lunga Bam Senior Manager Radiation Science Department

2. 4. Selective applications 2. Principle of radiography and tomography 5. Discussions Outline 1. Introduction 4. Importance of users and collaboration 3. Facilities/instrumentation

3. The start of non-destructive imaging “Horrified at the result, Bertha Roentgen saw in the image a premonition of death.”

4. Principle of Radiography 4 Mass attenuation coefficient

5. 5 X-ray and neutron attenuation properties Source Collimator Detector Object Beer-Lamberd Law of radiation attenuation: I : the transmission radiation beam I 0 : the incoming radiation beam Σ : macroscopic cross-section (cm -1 ) x : thickness of the sample (cm) This why Necsa have both X-ray and neutron radiography

6. Water distribution in H-fuel cells PSI

7. 1. Principles of tomography

8. Cylindrical symmetry Yes, measure many f(y) values, then determine g(r) Can we construct the density distribution g(r) from the line integrals f(y)? Abel inverse

9. General geometry f(p,  )   Q p

10. Radon’s method (1917) 10 f(p,  ) Q If repeated for many p values the integral can be computed Repeat for many Q values Not a practical method, very noise sensitive

11. Nobel Prize: CAT Fourier expansion Filtered back projection Iterative reconstruction

12. Reconstruction Reconstruction 12 2D 3D

13. 1. Selected Applications

14. Water distribution in concrete Notice Aggregate Distribution Water NUCLEAR WASTE RESEARCH BUILDING MATERIALS OIL & MINERALS EXPLORATION ARCHEOLOGY & PALEOANTHROPOLOGY (HERITAGE STUDIES)

15. Virtual extraction of a fossil from its host rock No preparation No damage or deconsolidation

16. Probing the remote past Cynodont Thermoregulation ? Secondary Palate ? 200 million years

17. Travelling on a neutron beam Osiris statuette Egypt

18. Hypothesis: Symbolic markings Archeology with neutrons Archaeology: Iron Stones from Wonderwerk Cave Jacobson, L., et al., Archeometry 55, 1 (2013) 1- 13. Neutrons tell a different story

19. Geology: Plaglioclase Red (ortho) and green (clino) pyroxenes

20. Drill Core of oil bearing rock Green pores: empty Red pores: oil filled Can quantify pore interconnectedness

21. Water uptake in cement Can extract quantitative data of comparable quality to weighing But get spatial information

22. 1. Our Facilities

23. MIXRAD @ Necsa MICRO-FOCUS X-RAY TOMOGRAPHY FACILITY -NRF Sponsored -1 July 2011

24. Beam line 2 : Neutron Radiography SAFARI-1 reactor wall Shielding Beam stop / door

25. SAFARI-1 NEUTRON BEAMS LINES NDIFF NRAD SANS

26. Hosted by: Necsa ; Wits; SU Workshop: imaging with radiation

27. RESEARCH NEEDS Radiography / tomography in a real time application mode: – Conveyer belt : Evaluation of fruit (infestation) NEED: Fast computing

28. Thank You