1. Quiz Review…….. 1 st Quiz-Class Average 88% 2 nd Quiz-Class Average 75% What happened? Suggestions from class Suggestions from instructor 1

2. 2

3. 3

4. Review of Science, Math Review of X-Tube Construction Review of X-Ray Production 4

5. Self Quiz Convert 1/7 into a decimal. Convert.11 into a fraction Multiply: Solve for x: 5x 2 =45 Solve for x: 5

6. What is an atom? smallest particle of an element What are the parts of an atom? nucleus-protons, neutrons electrons What is Atomic Number? What is the electrostatic law of attraction? un-like charges attract, like charges repel 6

7. 7

8. BOHR model of the atom Electrons orbit around a nucleus (center) 8

9. 9

10. Remember this for later… 10

11. 11

12. 12

13. Tube Housing Cathode Glass Envelope Anode vacuumvacuum vacuumvacuum 13

14. Review of X-ray Tube Added parts: Stators Rotors Armature Induction motor mA current High voltage current Focal track 14

15. A source of electrons a means to accelerate them A force to stop them quickly 15

16. What is it? Energy radiating thru matter Referred to as a photon, packet of energy, bundle of energy Travels at the speed of light 16

17. A A 17

18. What the heck are those squiggly lines???? 18

19. 1. Spectrum  Continuous range of energy  Although there are precise ranges defined, they often overlap 2. 3 most important to Radiologic technology:  Visible light  X-radiation  Radiofrequency 19

20. Ionizing Radiation Has same properties as all EM radiation, has properties unique to ionizing radiation, has wavelength and frequency unique to ionizing radiation 20

21. Inversely proportional 21

22. Distance 22

23.  Wavelength is the difference between:  Crest to Crest  Valley to Valley 23

24.  Frequency is the number of wavelengths passing a point of observation per second 24

25. 25

26. 26

27. 1. Wavelength & frequency are inversely proportional  As Wavelength increases frequency decreases  As wavelength decreases frequency increases 2. Frequency and wavelength are closely associated with the relative energy of electromagnetic radiation. 3. More energetic radiations have shorter wavelengths and higher frequency. 27

28. 1. Have no mass or physical form 2. Travel in a linear path (until interaction occurs) 3. Dual nature:wave vs. particle 4. Unaffected by  electric or magnetic fields  gravity 28

29. HeatBremsCharacteristic 29

30.  Heat = 99%  X-ray = 1%  Bremsstrahlung (Brems) = 80%  Characteristic = 20% 30

31. 31

32. 32 True or False 1.X-ray production begins as the electrons stream begins toward the anode. 2.The energy production in the x-ray tube is 90% heat, 20%characteristic, 80% Brems 3.Heat results from an excitation instead of an ionization. 4.As wavelength increases, the frequency also increases. 5.The smallest packet of electromagnetic energy is called a photon. 6.Thoughtful challenge question: What is the most frequent ionizing tube interaction?

33. 33

34.  Most kinetic energy of projectile e- is converted into heat – 99%  Projectile e- interact with the outer-shell e- of the target atoms but do not transfer enough energy to the outer-shell e- to ionize 34

35. 35

36. 8 p + + 8e - = neutral atom 1.Projectile electrons from cathode 2.Pass by the electrons in the target 3.Causing the electrons to vibrate (excitation) 4.Excitation produces small amounts of heat e e HEAT 36

37. 37

38.  Diagnostic radiation production happens in the x-ray tube  Two kinds of diagnostic radiation production: characteristic and bremsstrahlung  Incoming electron  Interacts with:  inner shell electron = characteristic radiation  nuclear force field = bremsstrahlung radiation 38

39. 39

40. 40

41. 41 brems animation

42. The closer the Electron passes To the nucleus, The more energetic The resulting x-ray Photon. 42

43. http://youtu.be/q-cTw1x7TzA Brem radiation 2 43 The incoming electron passes near enough to the nucleus to be affected by the law of electrostatic attraction. The electron starts to slow down and veer toward the nucleus but never hits the nucleus or another electron. The slowing down motion changes the direction of the incoming electron and release some of the energy of that electron. The form of energy released is x-ray radiation.

44.  Projectile e- with high enough energy to totally remove an inner-shell electron of the tungsten target  All tube interactions result in a loss of kinetic energy from the projectile e-  Characteristic x-rays are produced when outer- shell e- fills an inner-shell void 44

45. animation of characteristic 45

46. 46

47.  It is called characteristic because it is characteristic of the target element in the energy of the photon produced 47

48. characteristic radiation -1 characteristic radiation-2 48

49. http://www.coursewareobjects.com/objec ts/mrophysics_v1/mod08/0808a.htm 49

50. 1. Electron hits inner shell e in orbit – knocked out & creates a hole 2. Other E’s want to jump in 3. Energy released as PHOTONS 50

51. 51

52. 52 Radiation Interaction in the Tube

53. What do we know so far about x-rays? 53

54. What is This? 54

55. What is This? 55

56. What is This? 56