rad tech exam 1

cathode

negative side of x-ray tube, releases electrons

anode

positive side, attracts electrons and is where x-rays are made

thermionic emission

release of electrons from filament when heated

focal spot

area of target that electrons hit

tungsten

material used in x-ray tubes, very strong, hard to melt, high atomic number

mA stands for:

milliampere

what is mA

rate of electron flow

mAs

mA × Seconds, total quantity of x-rays/electrons made

kVp

kilovolt peak, x-ray energy and penetrating ability

bremsstrahlung

electron slowed/deflected by tungsten atom nucleus, some of the energy turns into x-ray photons

characteristic radiation

electron knocks inner layer electron out, and outer layer electron takes its place. releases the energy difference as x-ray photon

line focus principle

an angled anode target allows: larger focal spot for heat, smaller effective focal spot for better detail

actual focal spot

actual area hit by electron

effective focal spot

apparent projected size of x-ray beam

polyenergetic

x-ray containing photons with a range of energies

heterogeneous

not uniform, x-ray has photons with different energies

photon

unit of electromagnetic energy

quanta

plural for photon

primary beam

useful x-ray that exits through tube window

scatter radiation

radiation that changes direction after hitting a patient/object

leakage radiation

radiation that escapes housing outside the tube window

ionization

removal/addition of electron, causes atom to be electrically charged

attenuation

reduction of x-ray beam via absorption/scattering

absorption

x-ray absorbed by matter, energy left in the matter

penetration

ability of x-ray to pass through matter

IR stands for:

image receptor

image receptor

recieves x-rays after passing through patient, records information to create radiograph