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Radiation calculations: decay, distance, shielding

ASP video lesson, 6:29. ASP Domain 1: Mathematical Calculations

Work three ionizing radiation calculations for the ASP exam: radioactive decay with half-life, the inverse square law for distance, and shielding with half-value layers.

Included with every ASP pass, with captions, chapters and the full transcript. Every rule and number is cited on screen to its primary source.

What this lesson covers

In this lesson, you'll learn to: apply the decay equation and half-life, use the inverse square law for distance, calculate shielding with half-value layers, and avoid the common calculation traps. Radioactive activity decays over time. OSHA's health physics handout gives the equation. Activity after time t equals the starting activity, A-zero, times e to the minus lambda t.

  • Intro
  • Learning objectives
  • Radioactive decay
  • Worked example: decay
  • Distance
  • Worked example: distance
  • Shielding
  • Worked example: shielding
  • On the job
  • Common exam traps
  • Recap quiz

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