1. 3/2003 Rev 1 I.2.9 – slide 1 of 35 Session I.2.9 Part I Review of Fundamentals Module 2Basic Physics and Mathematics Used in Radiation Protection Session 9Nuclear Reactions IAEA Post Graduate Educational Course Radiation Protection and Safety of Radiation Sources

2. 3/2003 Rev 1 I.2.9 – slide 2 of 35  Various examples of nuclear reactions will be discussed  Students will learn about properties of neutrons, nuclear decay processes, cross section, neutron interactions, and various kinds of nuclear reactions including charged particle reactions, spallation, fission and fusion reactions Introduction

3. 3/2003 Rev 1 I.2.9 – slide 3 of 35 Content  Properties of neutrons  Nuclear decay processes  Cross section  Neutron interactions  Charged particle reactions  Spallation  Fission  Fusion

4. 3/2003 Rev 1 I.2.9 – slide 4 of 35 Overview  Various kinds of nuclear reactions will be discussed and examples shown  Health physics significance and energy considerations of nuclear reactions will be discussed

5. 3/2003 Rev 1 I.2.9 – slide 5 of 35 Chadwick, 1932, alpha bombardment He + Be  C + n + Q  Neutron Discovery Thermal (0.0025 eV) Slow (1 - 100 eV) Epithermal (100 eV – 100 keV) Fast (100 keV – 1 MeV) Ultrafast (>1 MeV)  Neutron Classification Properties of Neutrons

6. 3/2003 Rev 1 I.2.9 – slide 6 of 35  Neutron Characteristics  symbol - n  no charge  rest energy 939.507 MeV  has a magnetic moment  it is a fermion  Neutron Interaction with matter  Scattering (2 mechanisms)  Absorption (>4 mechanisms) Properties of Neutrons

7. 3/2003 Rev 1 I.2.9 – slide 7 of 35 Nuclear Reactions Nuclear Decay

8. 3/2003 Rev 1 I.2.9 – slide 8 of 35 Nuclear Reactions Alpha Decay

9. 3/2003 Rev 1 I.2.9 – slide 9 of 35 Nuclear Reactions Beta Decay

10. 3/2003 Rev 1 I.2.9 – slide 10 of 35 Nuclear Reactions Positron Decay or Electron Capture Electron Capture Electron Capture Positron Emission

11. 3/2003 Rev 1 I.2.9 – slide 11 of 35 Nuclear Reactions Summary of Major Decay Mechanisms

12. 3/2003 Rev 1 I.2.9 – slide 12 of 35 Cross Section where  = cross section R = number of reactions per unit time per nucleus I = number of incident particles per unit time per unit area  = RI

13. 3/2003 Rev 1 I.2.9 – slide 13 of 35 Nuclear Reactions Fast Neutron Interactions  Elastic scattering - neutrons interact with particles of approximately the same mass such as protons (billiard ball analogy)  Occurs in materials rich in hydrogen such as water, wax, concrete  Accounts for about 80% of fast neutron dose to tissue

14. 3/2003 Rev 1 I.2.9 – slide 14 of 35  Inelastic scattering – neutrons interact with particles of much greater mass, for example, iron (table tennis ball vs bowling ball analogy) Nuclear Reactions Fast Neutron Interactions

15. 3/2003 Rev 1 I.2.9 – slide 15 of 35 Nuclear Reactions Elastic Scattering of Neutrons

16. 3/2003 Rev 1 I.2.9 – slide 16 of 35 Nuclear Reactions Inelastic Scattering of Neutrons

17. 3/2003 Rev 1 I.2.9 – slide 17 of 35 Neutron Reactions (n, CP) (n, gamma) (n, fission)

18. 3/2003 Rev 1 I.2.9 – slide 18 of 35 Nuclear Reactions Neutron Absorption, Charged Particle n + 10 B  7 Li(*) +  7 Li(*)  7 Li + soft gamma (480 KeV)

19. 3/2003 Rev 1 I.2.9 – slide 19 of 35 Fission

20. 3/2003 Rev 1 I.2.9 – slide 20 of 35 Breeding 239 Pu from 238 U Neutron Capture

21. 3/2003 Rev 1 I.2.9 – slide 21 of 35 Details of 239 U Decay to 239 Pu 239 U (23.5 min)  239 Np (2.3 d)  239 Pu 

22. 3/2003 Rev 1 I.2.9 – slide 22 of 35 Nuclear Reactions Charged Particle Bombardment p + 68 Zn  67 Ga + 2n  + 16 O  18 F + p + n

23. 3/2003 Rev 1 I.2.9 – slide 23 of 35 Nuclear Reactions Spallation

24. 3/2003 Rev 1 I.2.9 – slide 24 of 35 Spallation Products

25. 3/2003 Rev 1 I.2.9 – slide 25 of 35 Spallation Produced by Neutrons or Protons

26. 3/2003 Rev 1 I.2.9 – slide 26 of 35 Nuclear Fusion Reactions Utilize Isotopes of Hydrogen

27. 3/2003 Rev 1 I.2.9 – slide 27 of 35 Nuclear Reactions Fusion

28. 3/2003 Rev 1 I.2.9 – slide 28 of 35 Deuteron – Deuteron Fusion

29. 3/2003 Rev 1 I.2.9 – slide 29 of 35 Tritium – Proton Production from Fusion

30. 3/2003 Rev 1 I.2.9 – slide 30 of 35 3 He with Neutron Production from Fusion

31. 3/2003 Rev 1 I.2.9 – slide 31 of 35 Fusion - Tokamak

32. 3/2003 Rev 1 I.2.9 – slide 32 of 35 Energy Production Reactions in Stars

33. 3/2003 Rev 1 I.2.9 – slide 33 of 35 CNO Energy Production Reactions in Stars

34. 3/2003 Rev 1 I.2.9 – slide 34 of 35 Summary  Various examples of nuclear reactions were discussed  Students learned about properties of neutrons, nuclear decay processes, cross section, neutron interactions, and various kinds of nuclear reactions including charged particle reactions, spallation, fission and fusion

35. 3/2003 Rev 1 I.2.9 – slide 35 of 35 Where to Get More Information  Cember, H., Johnson, T. E., Introduction to Health Physics, 4 th Edition, McGraw-Hill, New York (2008)  Martin, A., Harbison, S. A., Beach, K., Cole, P., An Introduction to Radiation Protection, 6 th Edition, Hodder Arnold, London (2012)  Jelley, N. A., Fundamentals of Nuclear Physics, Cambridge University Press, Cambridge (1990)  Firestone, R.B., Baglin, C.M., Frank-Chu, S.Y., Eds., Table of Isotopes (8 th Edition, 1999 update), Wiley, New York (1999)