physics as

• What produces X-rays?

  Charged particles rapidly decelerating
• How are X-rays and gamma rays similar?

  They have overlapping frequency spectra
• What distinguishes gamma rays from X-rays?

  Their history of production
• How are gamma rays produced?

  Via radioactive decay or particle collisions
• What is Bremsstrahlung radiation?

  Radiation from decelerating charged particles
• What are soft X-rays used for?

  Medical imaging with lower energy
• What is the role of the anode in X-ray tubes?

  It is the positive electrode for collisions
• What is thermionic emission?

  Emission of electrons from a heated source
• Why is a vacuum tube used in X-ray tubes?

  To prevent collisions with air molecules
• What potential difference can X-ray tubes produce?

  Up to 200 kV
• What happens to electrons upon collision with the anode?

  They decelerate and emit X-rays
• How is heat managed in the anode?

  By rotating or cooling with water
• How are X-rays emitted from the anode?

  In every direction
• What is the purpose of collimation in X-ray imaging?

  To direct the beam at specific anatomy
• What is the function of the collimator?

  To absorb non-parallel rays
• What does the X-ray spectrum look like?

  Broad range with a hump-shaped profile
• What causes characteristic radiation in X-ray production?

  Incident electrons knocking out bound electrons
• How do X-rays ionize matter?

  By causing electrons to be emitted from atoms
• Why must living tissue be exposed to low intensity X-rays?

  To minimize damage to cells and DNA
• How are X-rays used in cancer treatment?

  To reduce cancer cells while sparing healthy tissue
• What is X-ray attenuation?

  Gradual decrease in X-ray intensity
• What is the formula for intensity in X-ray beams?

  $I =$$\frac{P}{A}$
• How does bone compare to soft tissue in X-ray attenuation?

  Bone attenuates X-rays more than soft tissue
• What happens to photographic film behind a limb in an X-ray?

  It blackens less if behind bone
• What is the advantage of digital detectors over photographic film?

  They are easier to process and store
• How does X-ray intensity change with thickness of bone?

  It decreases exponentially with thickness
• What is the formula for X-ray attenuation?

  $I =$$I_0 e^{-\mu x}$
• What does the attenuation coefficient describe?

  How well a medium absorbs X-rays
• What are the four mechanisms of X-ray absorption?

  • Simple Scattering
  • Photoelectric Effect
  • Compton Effect
  • Pair Production
• What is simple scattering in X-ray absorption?

  X-rays reflect off layers of atoms
• What occurs during the photoelectric effect?

  X-rays are absorbed, releasing a photoelectron
• What happens in the Compton effect?

  X-rays lose energy and scatter in different directions
• What is pair production in X-ray absorption?

  X-rays produce an electron-positron pair
• What are contrast media used for in X-ray imaging?

  To enhance visibility of structures
• Why are heavy atoms used in contrast media?

  They have a large number of electrons
• How does the absorption coefficient relate to proton number?

  It is proportional to the cube of proton number
• What is iodine used for in medical imaging?

  As a contrast medium in liquids
• What is barium sulphate used for?

  As a contrast medium in the digestive system
• What is a CAT scan?

  A method for 3D imaging using X-rays
• How does a CAT scan differ from a conventional X-ray?

  It provides a 3D image instead of 2D