Unit 6 - Radiology (components and functions) Flashcards
3 components of the Xray tube
Lead- glass housing
Cathode
Anode
Vacuum tube that prevents xrays from escaping in all directions
has “window” that allows xray beam to exit tube and directs it towards the aluminum discs, lead collimator, and PID
Leaded-glass housing
produces negative electrode
Cathode
produces xray photons
Anode
- has tungsten wire/filament in molybdenum cup
- electron (-) generator (when wire heats up)
Cathode
purpose of molybdenum cup
focuses (-) electrons into a beam and directs it across the tube to the tungsten target of anode
- has thin tungsten plate embedded in copper stem
- converts electrons (-) into xray photons (+)
Anode
purpose of copper stem
to dissipate heat away from tungsten plate
PID stands for..
Position Indicating Device
Outer shelled electrons that form a cloud away from the tungsten filament when cathode heats up
Thermionic emission
where does the heat that is produced after the electrons are converted to photons go?
absorbed by insulating oil
Operation of an xray machine
- turn on machine
- current directed to filament circut/step down transformer
- filament heats up (in cathode)
- thermionic cloud builds up
- push exposure button
- electrons projected form cathode to anode
- electrons hit tungsten plate and bounce/convert to xray photons and heat (99%)
- heat is absorbed by insulating oil/ xrays travel down PID