Exercise (Midterm)

• X-ray Imaging System

  • the operating console operates with alternating current
• Line compensator

  • regulates the input voltage to 220V
• Filament circuit needs ____ amperage

  • large
• Filament transformer

  • filament heating isolation step-down transformer
• Coulomb

  • unit of mAs
• Sievert

  • absorbed dose
• Voltage

  • joule per coulomb
• Amount of ____ determines the amount of space charge electrons the filament will peel off

  • heat
• Rectification

  • converting alternating current to direct current
• Diode

  • make current flow from cathode to anode
• Autotransformer operates at ____

  • self induction (single winding)
• Tube

  • current that crosses from negative electrode of the x-ray tube to the positive electrode
• Filament (Cathode)

  • source of electrons and space charge
• Step down

  • type of transformer that allows induction of large amperage
• Resistors

  • device used to reduce voltage to a value that corresponds to the selected milliamperage
• 3A to 6A

  • operation of filaments
• Line compensators

  • provide the correct voltage for the autotransformer
• Autotransformer

  • single wound transformer designed to supply precise voltage to the filament circuit and to the high-voltage circuit of the imaging system
• Turns ratio

  • where voltage provided by the autotransformer depends
• Filament

  • tube current to be produced comes from this circuit
• Minor kVp selector

  • terminal in the secondary side of the autotransformer that allows the fine tune adjustment of kVp
• Half wave

  • negative cycle of waveform is prevented
• Single Phase

  • waveform will result in pulsating x-ray beam
• Positive

  • voltage across a full-wave-rectified circuit
• 1. Autotransformer
  2. Major kVp selector
  3. Minor kVp selector
  4. kVp meter
  5. X-ray tube
  6. Focal spot selector
  7. High-voltage generator

  
• Which of the following is true?; A. There is a lead lining in the protective house to somehow prevent x-rays from exiting, B. The vacuum permits electrons to flow from cathode to anode without interacting with gas/air atoms, C. The primary only includes x-rays that exit through the window, D. AOTA

  • D. AOTA
• Metal envelope

  • prolongs tube life because it eliminates the problem of tungsten vaporization
• Tube housing

  • for leakage radiation and handling
• Rotor

  • contains silver-plated steel bearings around the shaft
• Anode

  • primary purpose is to decelerate and conduct the high voltage from the cathode
• Tungsten is the metal of choice for the source of x-ray photons because; A. High melting point, B. High mass number, C. High atomic number, D. High conducting ability, E. NOTA

  • B. High mass number
• Diala V oil

  • dielectric oil to dissipate heat and act as an electric insulator
  • found in the protective housing of x-ray tube
• Rotor

  • not a part of external component of an x-ray tube
• Tube window

  • thinnest part of enclosure
• Preferred Detent Position

  • when x-ray tube is centered above the examination table at standard SID
• Enclosure

  • part of x-ray tube specifically designated to support the x-ray tube and maintain its vacuum
• Saturation current

  • rare occurrence where there are no available thermionic electrons to be sent out and decelerated by the target anode
• Stator

  • part of induction motor seen outside the glass or metal enclosure
• Off-focus radiation

  • electrons that bounce off the focal spot
• Focal spot

  • found in the positive side electrode side of x-ray