Index Cards PID Flashcards
Filament Circuit
Steps down electricity from house line at the 110 volts to 3-5 volts.
Heats tungsten filament
Thermionic emission effect
Boiling off of electrons at filament to produce the electron cloud
Focal spot aka tungsten target
Found at the ANODE. High speed electrons strike the target to produce 99% heat and 1% of x-radiation
Electron cloud strikes at focal spot
Bremsstrahlung
“Breaking radiation” is the major source of x-ray and creates polychromatic beam
Molybdenum focusing cup
Found on tungsten filament and focuses the freed electrons to the focal spot
Directs electrons across tube
Cathode ray
Stream of electrons crossing the tube from cathode to anode
Kilovoltage
Speed at which determines how fast the electrons move across the tube
Kvp propels the electrons
Kvp set to 65-90/100
Electron cloud
Electrons stay at tungsten filament in the electron cloud
Will remain there until exposure button is pressed
Filament circuit
It uses the step down transformer and takes the house line of 110 volts down to 3-5 volts
Purpose - to heat tungsten filament
High voltage circuit
Step up transformer takes house line of 110 volts and steps it up to 65,000-100,000volt (kvp set at 65-90 or 100)
Polychromatic
Variety at wavelength. X-ray beam has long and short wavelengths, long/weak wavelengths are removed by aluminum filter
Central beam
Central ray - X-ray that is located in center of XR beam as it leaves the tube head
Located the position of the X-ray beam
Primary radiation
X-rays produced at target, exits the PID and strikes the patient
Anode
Is the (+) charge part of the x-ray machine. Made of tungsten metal
Cathode
Is the (-) charge part of the X-ray machine Made of tungsten metal
Tungsten filament
“Source of electrons” on cathode. Electrically heats tungsten filament and produces electrons
Electrons create an electron cloud
Electricity
Step up/step down transformer responsible for creating 99% heat and 1% radiation (110 volts stepped down to 3-5 volts)
Electric current
Flow of electricity through a circuit
AC
Alternate current flows in one direction then flows in opposite direction
(Back and forth)
Always there
DC
Direct current: flows in one direction only (digital radiography)
Voltage
The electrical force that drives an electric current through a circuit
Kilovoltage peak
Known as kvp is penetrating power “speed at electron beam” 65-90/100
High kvp. High penetrating power
Low kvp low penetrating power
Kvp controls QUALITY of X-rays
Ampere
Amount of electric current flowing through a circuit
Milliamperage
Controls DENSITY by controlling temperature of tungsten filament (can be set at 7/10/15 mA)
High mA - high density
Low mA - low density
mA controls QUANTITY of x-rays
Electrons
The source of electrons is the tungsten filament in the cathode
Hotter the filament greater number of electrons
What controls the temperature or tungsten filament?
mA
In order for X-rays to exist 3 things are necessary
Electricity - heating of the cathode at tungsten filament
Electrons
Target - sudden stopping of electrons at anode
