FINAL Flashcards
What charge does the cathode/filament have?
Negative
What charge do electrons have?
Negative
What charge does the focusing cup have?
Negative
What surrounds the filament/cathode?
Focusing Cup
What does a dual focus cup contain?
2 Filaments 1 Anode
Which focal spot would have the best spatial resolution small or large?
Small
What charge does an Anode have?
Positive
Anodes can be?
Stationary or Rotating
How fast do Anodes spin?
3,000-10,000 RPM
Which 2 metals can withstand a great amount of heat?
Graphite, Tungsten
Which part of the x-ray tube is the stem and which part is outside of the X-ray tube. Stator and Rotor
Stator- Outside of the X-ray tube. Rotor- Stem
When electrons strike the anode ____ energy is converted into heat and X-rays
Kinetic
When electrons strike the anode, Kinetic energy is converted into __% heat __% X-ray
99% Heat 1% Xray
Xray tube is made out of what type of glass?
Pyrex
Why is the tube made out of pyrex glass?
To withstand heat
Why is the X-ray tube vacuumed?
To provide unobstructed path for electrons
What is the X-ray tube insulated with?
Lead and oil
Leakage radiation cannot exceed?
100mR/hour at a distance of 1 meter
German word for Braking?
Brehmsstrahlung
What forms 85-90% of the beam?
Brems
What occurs when electrons rapidly decelerate and loop around nucleus on surface of anode?
Brems
What forms 10-15% of the beam
Characteristic Radiation
What occurs when elections on face of anode drop to fill hole in inner shell?
Characteristic Radiation
Used for fluoro requires positive pressure?
Deadman switch
Tube current displays only during?
Exposure
Quantity, Number, Amount are controlled by?
mAs
Quality, Energy, Penetrating Ability, driving force are controlled by?
kVp
What kind of transformer has the least ripple(3-5%) is the most efficient?
High Frequency Transformer
What kind of motor is the X-ray tube?
Induction
No practical amount of _____ can ever compensate for inadequate ____
mA, kVp
Recorded detail is controlled by?
Small focal spot, Short/low OID , long/high SID
The smaller the angle the _____ the focal spot
Smaller
Projected or effective focal spot is smaller than actual focal spot
Line focus principle
Too high mas with too small focal spot
Blooming
FAT-CAT intensity of beam is greater on the cathode side of the tube
Anode Heel Effect
Put _____ part of anatomy under cathode end for anode heel effect
Thickest
3 ways to enhance anode heel effect?
Steep/small anode angle, large IR, short SID
Main purpose of filtration
Decrease patients skin dose
If tube operates at 70kv or above you must have at least _____ filtration
2.5mm AL
If tube operates at 60kV you must have _____ filtration
1.5 mm of AL
Amount of metal that cuts intensity to half its initial output
Half value layer