Chapter 6 - X-ray Production, X-ray Tubes, And X-ray Generators Flashcards
Contains the electron source and target within an evacuated glass or metal envelope
X-Ray tube insert
Provides protective radiation shielding and cools the X-Ray tube insert
Tube housing
Supplies the voltage to accelerate the electrons
X-Ray generator
Shapes the X-Ray energy spectrum
X-Ray beam filters
Define the size and shape of the X-Ray field incident of the patient
Collimators
SI UNIT OF POTENTIAL DIFFERENCE
Volt(V)
Source of electrons
Cathode
Target of electrons
Anode
Probability distribution of X-Ray photons as a function of photon energy (keV)
Bremsstrahlung spectrum
Shows an inverse linear relationship between the number and the energy of the X-rays produced
UNFILTERED bremsstrahlung spectrum
Refers to the removal of X-rays by attenuation in materials that are inherent in the xray tube
Filtration
Discrete X-ray energy peaks
Characteristic radiation
Three major selectable parameters on the X-ray generator control panel that determine the X-ray beam characteristics
kV, mA and exposure time
Product of the tube current and exposure time
mAs (milliamperes second)
Angle of the target surface with respect to the central Ray (central axis) in the X-ray field
Anode angle
- typical range: 7 to 20 degrees
- most commonly used: 12-15 degrees
Area of the anode that is struck by electrons and is primarily determined by the length of the cathode filament and width of the focusing cup slot
Actual focal spot size
Foreshortening of the focal spot length at the central Ray
Line focus principle
Refers to the reduction in the X-ray beam intensity toward the anode side of the X-ray field
Heel effect
Results from electrons that scatter from the anode, and are re-accelerated back to the anode , outside of the focal spot area
Off-focal radiation