Fostering Friendships - Enhancing Social Bonds in the Classroom
Xray Beam
1. RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY L 7: X Ray beam IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology
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5. Part 7: X Ray beam Topic 1: Bremsstrahlung production IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology
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8. Electrons strike the nucleus N N n(E) E E 1 E 2 E 3 n 1 n 3 n 2 E 1 E 2 E 3 n 1 E 1 n 2 E 2 n 3 E 3 E E max Bremsstrahlung spectrum
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10. Bremsstrahlung spectra dN/dE dN/dE (spectral density) E From a “thin” target E E 0 E 0 E 0 = energy of electrons From a “thick” target E = energy of emitted photons
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12. Part 7: X Ray beam Topic 2: Characteristic X Rays IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology
17. Part 7: X Ray beam Topic 3: X Ray Beam filtration IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology
18. What is beam filtration? Absorber placed between Source and object Will preferably absorb the lower energy photons Or absorb parts of spectrum (K-edge filters) 10 15 20 25 30 15 10 5 Energy (keV) Number of photons (arbitrary normalisation) X Ray spectrum at 30 kV for an X Ray tube with a Mo target and a 0.03 mm Mo filter
21. Filtration Change in QUANTITY & Change in QUALITY spectrum shifts to higher energy 1- Spectrum out of anode 2- After window tube housing (INHERENT filtration) 3- After ADDITIONAL filtration
22. Part 7: X Ray beam Topic 4: Scattered radiation IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology
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26. Anti scatter grid (II) Source of -rays Lead Scattered X Rays Useful X Rays Film and cassette Patient
27. Part 7: X Ray beam Topic 5: Factors affecting X Ray spectrum IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology
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29. X Ray spectrum: tube current 400 mA 200 mA X Ray Energy (keV) Number of X Rays per unit Energy
30. X Ray spectrum: tube current Change of QUANTITY NO change of quality Effective kV not changed
31. X Ray spectrum: tube potential Change in QUANTITY & Change in QUALITY - spectrum shifts to higher Energy - characteristic lines appear
32. X Ray spectrum: filtration Change in QUANTITY & Change in QUALITY spectrum shifts to higher energy 1- Spectrum out of anode 2- After window tube housing (INHERENT filtration) 3- After ADDITIONAL filtration
33. X Ray spectrum: Target Z Higher Z Lower Z X Ray Energy (keV) Number of X Rays per unit Energy
34. X Ray spectrum: Target Z Three Phase Single Phase X Ray Energy (keV) Number of X Rays per unit Energy
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