1. X-RAY EMISSION SPECTRUM

2. X-RAY PRODUCTION
BREMSTRAHLUNG RADIATION
CHARACTERISTIC RADIATION

3. BREMS

4. BREMS EMISSION-CONTINUOUS

5. Characteristic Radiation

7. CHARACTERISTIC EMISSION- LESS POLYENERGETIC

8. X-RAY EMISSION SPECTRUM
BREMS
INTENSITY
X-RAY ENERGY

9. X-RAY EMISSION SPECTRUM
L-CHARACTERISTIC
K-CHARACTERISTIC
BREMS
INTENSITY
X-RAY ENERGY

10. X-RAY EMISSION SPECTRUM
CHARACTERISTIC
BREMS

11. MAXIMUM ENERGY OF AN X-RAY IN THE BEAM
= kVp OF OPERATION
kVpeak

12. GREATEST # OF PHOTONS IS EMITTED WITH ENERGY:
APPROX. 1/3 OF MAX
PHOTON ENERGY

13. THE TARGET IS RELATIVELY THICK– CAUSING MULTIPLE INTERACTIONS.
FOUR PRINCIPAL FACTORS INFLUENCING THE SHAPE OF AN X-RAY EMISSION SPECTRUM:
ELCTRONS TRAVELING FROM CATHODE TO ANODE HAVE DIFFERENT ENERGIES– NOT JUST PEAK ENERGY
THE TARGET IS RELATIVELY THICK– CAUSING MULTIPLE INTERACTIONS.
LOW ENERGY X-RAYS ARE MORE LIKELY ABSORBED IN THE TARGET
EXTERNAL FILTRATION REMOVES LOW ENERGY PHOTONS

14. MINIMUM VAVELENGTH MAX. X-RAY ENERGY
kVp m
nm DIVIDE BY 10 –9

15. FACTORS AFFECTING THE X-RAY EMISSION SPECTRUM
TUBE CURRENT
TUBE VOLTAGE
ADDED FILTRATION
TARGET MATERIAL
VOLTAGE WAVEFORM

16. TUBE CURRENT CHANGE

17. CURRENT CHANGE INTENSITY ENERGY – NO CHANGE CURRENT
2 * mA = 2 * number of photons
4 * mA = 4 * number of photons

18. Tube voltage

19. Tube voltage (kVp) CHANGE
INTENSITY
ENERGY –
kVp
15% INCREASE OF KVP = 2 * mAs

20. FILTRATION CHANGE
2.5 mm
4 mm

21. FILTRATION CHANGE
INTENSITY
ENERGY –
FILTRATION

22. TARGET MATERIAL CHANGE
TUNGSTEN
MOLYBDENUM 70

23. 74 W
(14)
(50) 75 Re
(43)
(89) 76 Os
(90)
(95) 77 Ir
(96)
(10) 78 Pt
(20)
(21) 79 Au
(22)
(18) 80 Hg
(17)
(18) 81 Tl
(12)
(13) 82 Pb
(24)
(17) 83
Bi-209
(92)
(22)
K-CHARACTERISTIC
ENERGY FOR
DIFFERENT TARGETS

25. TARGET CHANGE INTENSITY ENERGY CHARACTERISTIC TARGET MATERIAL
RADIATION
CHANGE
TARGET MATERIAL
Z #

26. VOLTAGE-WAVEFORM CHANGE
3-PHASE
1-PHASE

27. VOLTAGE WAVEFORM CHANGE
INTENSITY
ENERGY
VOLTAGE WAVEFORM
OPERATION ON 3-PHASE EQUIPMENT = 12% * SINGLE PHASE

28. PATIENT DOSE
SINGLE PHASE
>
THREE PHASE