X-ray production

Requirements

• Source of electrons

• Means of accelerating electrons

• Means of decelerating electrons

X-ray tube

(1) electrons produced at the cathode filament by thermionic emission (release of electrons due to heat by a current)

(2) electron cloud formed around the filament

(3) electric voltage (kVp) creates a strong negative charge repelling electrons to the positively charged anode, accelerating the electrons

(4) electrons collide with the anode and release energy as heat and x-ray beams

- increasing the mAs (current) increases number of electrons produced in x-ray tube

- increasing the number of electrons increases number of photons

- increasing the kVp (potential difference/voltage) increases the energy of electrons, increasing the energy of the x-ray beams