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

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

3/2003 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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)

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

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

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 

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

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

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

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

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

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

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

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

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

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

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

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

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

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)