x ray beam production

• what happens within the x ray tube when exposure button is prepped for exposure


  on the cathode side :

  • a current is passed through the filament which heats it up
  • this causes electrons to be released via thermionic emission
  • electrons gather in cloud around filament - known as space change
  • negatively charged focusing cup keeps electron cloud together
• what happens within the x ray tube when exposure button is prepped for exposure 


  on the anode side :

  • the rotating anode target starts to turn rapidly
• what happens within the x ray tube when the exposure is made

  on the cathode side :

  • the high negative charge of the cathode strongly repels the electrons within the electron cloud
  • the electrons stream away from the cathode towards the anode due to the potential difference in voltage (kVp) that has been applied across the x ray tube
• what happens within the x ray tube when the exposure is made 


  • anode side:
  • the highly positive charge attracts the electrons
  • the electrons strike the anode at high speed
  • producing heat and x rays at atomic level
• what are the two types of radiation


  • characteristic x rays
  • bremsstrahlung radiation
• explain the process of characteristic radiation

  • occurs when high speed electrons collide with electrons orbiting a target atoms nucleus
  • collision results in removal of electron from its shell
  • atoms positive nucleus immediately attracts electrons from its outer shell to fill vacancy
  • outer electrons are in high energy states and the inward transition causes them to lose energy
  • the energy lost is converted into an x ray photon
• explain the process of bremsstrahlung radiation


  • occurs when high speed electrons pass close enough to target atoms nuclei to enter their electric fields
  • force of attraction suddenly changes their direction of travel
  • this converts some of the electrons kinetic energy into x ray energy
  • producing an x ray photon
• what is the difference between characteristic and bremsstrahlung radiation 


  characteristic :

  • interaction with orbital electrons
  • produces specific energies
  • results in line spectra

  bremsstrahlung :

  • interaction with nucleus
  • produces a continuous spectrum
  • loss of energy emitted as a photon