Ionising Radiation

Experiment Instructions

  1. Start with No absorber and measure the count rate for background radiation.
  2. Select a radiation type and record the rate at a fixed distance.
  3. Add an absorber and increase thickness until the radiation is mostly stopped.
  4. Change the distance and observe how the count rate changes.

Results

# Radiation Distance (cm) Absorber Thickness Rate (cps) Actions

Student prompts

  • Which absorber stops alpha most effectively?
  • How many mm of aluminium are needed to reduce beta noticeably?
  • Why does gamma reduce slowly, even with lead?
  • How does doubling the distance affect the count rate?