making an xray exposure Flashcards
what are the two parts ofmaking an x-ray exposure
preparring the x-ray tube and making the exposure
explain the preperation for an xray exposure on the anode and cathode side
on the cathode side when the xray button is pressed halfway down, the current passes through the filament causing it to heat up and then electrons are released via thermoionic emmision
these electrons form a cloud around the filament with the negatively charged focussing cup holding them together
on the anode side the rotating anode starts rotating rapidly, quickly reaching top speed
explains what happens on the anode and cathode side when the exposure is made
on the cathode side when the button is fully pressed down, the high negative charge of the cathode repels the electrons away from the cloud causing them to move to the anode side due to a potential difference which allows for current to flow
on the anode side the anodes high positive charge attracts the electrons causing them to strike the anode at high speed causing xray and heat production
which factors affect thermoionic emmision
the temperature of the material
how good of a thermoionic emitter the material is
the surface area of the material
what does mAs mean
this relates to the number of electrons flowing from the cathode side to the anode side
what does kVp mean
this relates to the potential difference accross the x-ray tube. the stronger the kVp is, the stronger the force of attraction will be between the cathode and anode meaning the electrins will strike the anode with higher kinetic energy giving the xray photons more penetrating power.
What are collimators
they reduce the radiation exposure to the patient by giving a control and measurable exposure area
