======Geiger Counter and Radiation Shielding======


<WRAP right box>
**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
\\
**Categories:** {{$demo.categories}}
\\


**Alternative titles:** Measuring Radiation Penetration
</WRAP>

====Summary====                   
{{$demo.summary}}



====Procedure====  
  - Turn on the Geiger counter and ensure the speaker is audible so clicks can be heard for each detection event.
  - Place a radioactive source (e.g., uranium ore, radium dial, smoke detector sample) under the detector and observe the count rate.
  - Place a sheet of paper between the source and the detector; note any reduction in counts.
  - Replace the paper with aluminum foil or a thin aluminum plate; record the effect on the count rate.
  - Place a lead plate between the source and detector; observe the much larger reduction, especially for gamma rays.
  - Compare results across different radioactive sources to highlight the types of radiation emitted.




====Links==== 
Demonstrating the penetrating power of alpha, beta and gamma radiation - Simon Lloyd: 
{{youtube>jZLn5c580_Q?}}\\

Radioactivity demo - alpha, beta, gamma with Geiger counter - MissLowePhysics: 
{{youtube>MWU0BQcnqz0?}}\\

📄 Geiger Counter - Simon Fraser University: [[https://www.sfu.ca/physics/demos/demos-experiments/geiger-counter-burnaby.html]]\\


====Variations====
  * Use multiple Geiger counters to compare different shielding materials simultaneously.
  * Test different thicknesses of aluminum or lead to find how much shielding is required to reduce the count rate significantly.
  * Discuss real-world applications such as protective clothing, nuclear reactor shielding, and medical radiology.



====Safety Precautions====
  * Handle all radioactive sources carefully and for the minimum necessary time.
  * Wash hands thoroughly after handling radioactive samples.
  * Do not allow direct contact of sources with skin or eyes.
  * Keep sources stored in shielded containers when not in use.
  * Handle unsealed items such as lantern mantles with extreme care to avoid spreading radioactive dust.




====Questions to Consider====
  * Why does paper block alpha radiation but not beta or gamma? (Alpha particles are relatively heavy and cannot penetrate even thin barriers.)
  * Why does aluminum stop most beta radiation but not gamma? (Beta particles are lighter and faster, but gamma rays are high-energy photons that require denser materials to absorb.)
  * Why is lead effective at reducing gamma radiation? (Lead’s high density and atomic number increase the probability of gamma absorption.)
  * How does this experiment connect to radiation protection in medicine and industry? (It illustrates why different types of shielding are used depending on the radiation involved.)