Term
| What part of the x-ray tube does the autotransformer control |
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Definition
| filament circuit and high voltage circuit |
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Term
| what does line compensation do |
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Definition
| makes sure the voltage coming into the tube remains constant |
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Term
| what are the three parts of the x-ray imaging system |
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Definition
| operating console, x-ray tube, and high voltage generator |
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Term
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Definition
| controls the tube current (decrease the voltage t increase the current(mA)) |
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Term
| what does a step up transformer result in |
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Definition
| increase in voltage (high voltage transformer) |
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Term
| what does a step down transformer result in |
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Definition
| increase in current (filament transformer) |
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Term
|
Definition
| the process of converting AC to DC |
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Term
| rectification can only be accomplished with what |
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Definition
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Term
| what is half wave rectification |
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Definition
| when the voltage is not allowed to swing negatively (the inverse voltage is removed from the supply) |
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Term
| what is full wave rectification |
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Definition
| all of the input waveform is rectified into usable output |
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Term
|
Definition
| alternate swing in voltage from zero to max (100% ripple) |
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Term
|
Definition
| 3 simultaneous waves out of step with one another resulting in nearly constant voltage (14% ripple) |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| what are the different types of exposure timers |
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Definition
| mechanical, synchronous, electronic, mAs, AEC |
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Term
| what does the protective housing protect against |
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Definition
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|
Term
| what does isotropically mean |
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Definition
| when x-rays are emitted with equal intensity in all directions |
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Term
| what is the limit of leakage radiation |
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Definition
|
|
Term
| what is the x-ray tube enclosure made of |
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Definition
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|
Term
| what charge does the cathode have |
|
Definition
|
|
Term
| what components are inside the cathode |
|
Definition
| the filament and focusing cup |
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Term
| what is the filment made of and what is it's melting point |
|
Definition
| thoriated tungsten, 3410 degrees C |
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Term
| what is thermionic emission |
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Definition
|
|
Term
|
Definition
| the electron cloud around the filament |
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Term
|
Definition
| two focal spots, one large and one small (2 filaments) |
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Term
| what is the anode made of |
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Definition
| molybdenum, copper, graphite |
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Term
| what are the three functions of the anode |
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Definition
| electrical conductor, mechanical support for target, and thermal dissipator |
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Term
| why is the target made of tungsten |
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Definition
| high atomic number (74), thermal conductivity, high melting point |
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Term
| what type of material does the mammo target use |
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Definition
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|
Term
| why does the anode rotate |
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Definition
| gives a larger area for the electron beam to interact with |
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Term
| what are the two parts of the electromagnetic induction motor |
|
Definition
| stator (coils), and the rotor |
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|
Term
| how does the electromagnetic induction motor work |
|
Definition
| stator windings are energized sequentially so that the induced magnetic field rotates causing the rotor to rotate synchonously with the stator windings |
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Term
| what is the sequence of the electromagnetic induction motor |
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Definition
| push the exposure button, rotor warms up, filament heats up, kVp is applied |
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Term
| what is the line focus principle |
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Definition
| the effective focal size(patient) is smaller than the actual focal size(target) |
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Term
| what is the angle of the target |
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Definition
|
|
Term
| what is the anode heel effect |
|
Definition
| the intensity of the beam is diminished on the anode because it has to travel through the heel |
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|
Term
|
Definition
| electrons that bounce off the focal spot and land somewhere else on the target |
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Term
| what are the different types of tube failure |
|
Definition
| too hot too fast, too hot too long, hot bearings, evaporating filament that breaks, ELECTRON ARCING |
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|
Term
| what is the anode cooling equation |
|
Definition
HU = kVp x mAs
HU = 1.4 x kVp x mAs |
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|
Term
| what are the 2 types of x-rays |
|
Definition
| characteristic and bremsstrahlung |
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|
Term
| what is a characterstic x-ray |
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Definition
| when a projectile electron interacts with/removes an inner shell electron, when an outer shell electron fills the inner spot, charactersitc x-rays are produced |
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Term
| why is it called characteristic x-ray |
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Definition
| because it is characteristic of the target element |
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|
Term
| what does bremsstrahlung mean |
|
Definition
|
|
Term
| how do bremsstrahlung x-rays work |
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Definition
| when a projectile electron is slowed by the electric field of a target atom nucleus |
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Term
| at 100 kVp, how much of the x-rays are characterstic and how much are brems |
|
Definition
| 15% are characteristic and 85% are brems |
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|
Term
| how does current effect x-ray emission spectrum |
|
Definition
| increase quantity, no change in quality |
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Term
| how does voltage effect x-ray emission spectrum |
|
Definition
| increase quantity, increase quality |
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Term
| how does added filtration affect x-ray emission spectrum |
|
Definition
| decrease quantity, increase quality |
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Term
| how does increased target atomic number affect x-ray emission spectrum |
|
Definition
| increase quantity, increase quality |
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Term
| how does increased voltage ripple affect x-ray emission spectrum |
|
Definition
| decrease in quantity, decrease in quality |
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|
Term
| what is the half value layer |
|
Definition
| the thickness of absobing material necessary to reduce the x-ray intesity to half of its original value |
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|
Term
| what is the inverse square law |
|
Definition
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