1. PRACTICAL RADIATION PHYSICS FOR EMERGENCY MEDICAL PERSONNEL Module III

2. - 2 What is radiation?

3. Module III - 3 Ionizing radiation

4. Module III - 4 Electromagnetic radiation GAMMA VISIBLE X-RAYSCOSMIC INFRAREDULTRAVIOLET MICROVAVES TV, RADIO Decreasing wave length Increasing frequency Increasing photon energy IONIZING RADIATON

5. Module III - 5 Forms of ionizing radiation Particulate radiation Electromagnetic radiation consisting of atomic or subatomic particles (electrons, protons, etc.) which carry energy in the form of kinetic energy of mass in motion in which energy is carried by oscillating electrical and magnetic fields travelling through space at speed of light Directly ionizing Indirectly ionizing

6. Module III - 6 Origin of radiation What is the relationship between atom structure and radiation production?

7. Module III - 7 Atom anatomy Electron ProtonNeutron Nucleons

8. Module III - 8 Isotopes

9. Module III - 9 Why are some nuclides radioactive ? Why are some nuclides radioactive ? Neutron to proton ratio

10. Module III - 10Half-life

11. Module III - 11 The number of decaying nuclei per unit of time The Systéme International (SI) unit of radioactivity is the Becquerel (Bq) One Bq = 1 disintegration per second Non-SI unit of radioactivity is the Curie (Ci) One Ci = 3,7 x 10 10 transformations per second One milicurie (mCi) = 3,7 x 10 7 s -1 One microcurie (μCi) = 3.7 x 10 4 s -1 1 Bq = 2.7 x 10 -11 Ci Activity

12. Module III - 12 Atomic symbols A XNXN Z SYMBOL OF ELEMENT MASS NUMBER (the number of protons and neutrons) ATOMIC NUMBER (the number of protons) 53 I 78 131 Example: 131 I or I-131 The number of neutrons

13. Module III - 13 E= mc 2 Measured Mass Calculated Mass Mass-energy relationship

14. Module III - 14 Fission

15. Module III - 15 Nuclear reaction and energy production

16. Module III - 16 Mechanisms of radioactive decay

17. Module III - 17 A Z X A-4 Z-2 Y + 4 2 He e.g. 238 92 U 234 90 Th + 4 2 He Alpha (α ++ ) decay

18. Module III - 18 n p + e - + υ A Z X  A Z+1 Y +e - +  e.g. 131 53 I  131 54 Xe+e - +  Beta (  - ) decay

19. Module III - 19 p n + e + + υ A Z X  A Z-1 Y+e + +  e.g. 18 9 F  18 8 O+e + +  Positron (  + ) decay

20. Module III - 20 Electron capture p + + e -  n +  A Z X  A Z-1 Y +  125 53 I  125 52 Te+ 

21. Module III - 21 Gamma (  ) emission

22. Module III - 22 SIMPLIFIED NUCLEAR MODEL Gamma ray Nuclear energy levels: gamma radiation

23. Module III - 23 How does radiation interact with matter?

24. Module III - 24 Excitation

25. Module III - 25 Ionization Electron removal by ionization

26. Module III - 26 Alpha particle interaction

27. Module III - 27 Interaction of alpha radiation with living matter: external deposition l Alpha radiation is not external hazard. l The maximum range in tissue is <0.1 mm l All alpha radiation is absorbed in stratum corneum

28. Module III - 28 Interaction of alpha radiation with living matter: internal deposition Prime danger is inhalation and ingestion of alpha emitter

29. Module III - 29 Beta interaction with matter

30. Module III - 30 Interaction of beta radiation with living matter I I I I I ı 0.001 0.01 0.1 1 10 100 Cell nucleus Cell diameter 100 cell diameter Auger 5.3 MeV alpha 0.15 MeV beta 1.7 MeV beta mm beta alpha

31. Module III - 31 Positron interaction: annihilation reaction

32. Module III - 32 Neutron interaction

33. Module III - 33 Neutron activation

34. Module III - 34 Interaction of gamma radiation with matter l In terms of ionization, gamma radiation interacts with matter in three main ways 1. Photoelectric effect 2. Compton scattering 3. Pair production

35. Module III - 35 Gamma interaction by photoelectric effect

36. Module III - 36 Gamma interaction by Compton scattering

37. Module III - 37 Pair production

38. Module III - 38 Extranuclear energy release l Bremsstrahlung radiation l Characteristic X rays l Auger electrons

39. Module III - 39 Bremsstrahlung radiation

40. Module III - 40 Importance of bremsstrahlung X rays in radiation safety practice

41. Module III - 41 Characteristic X rays

42. Module III - 42 Difference between X rays and gamma rays

43. Module III - 43 Internal conversion: Auger electrons

44. Module III - 44 Specific ionization and linear energy transfer (LET)

45. Module III - 45 Penetrating power of radiation

46. Module III - 46 Review points l Characteristics of representative types of ionizing radiation particulate, charged, and directly ionizing radiation of alpha and beta particles particulate, uncharged, and indirectly ionizing radiation of neutrons electromagnetic, uncharged, and indirectly ionizing radiation of gamma rays and X rays. l Radiation interacts with matter via two main processes: ionization and excitation l Energy, which comes in many forms, can be converted from one form to another l Nuclear potential energy is converted into kinetic energy through nuclear fission l Conversion of mass to energy was predicted by Albert Einstein in his mass-energy equation, E = mc 2 l Penetrating power of ionizing radiation is relative to radiation type and energy