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5: Activity, Half Life, and Half Value Layers

  • Page ID
    153935
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    Learning Objectives

    ANSI/ASNT CP-105- 2016 Section 2, 3

    Upon completion of this unit, the student will be able to define and understand the following:

    • Review of Units 1, 2, 3 & 4
    • Activity
      • Common Radioisotopes
        • Ir-192
        • Co-60
        • CS-137
    • Half Life
    • Half Value Layer (HVL)

    Learning Activities:

    • Lecture and discussion
    • Midterm Exam

    Learning Resources:

    • Glossary

    Evaluation:

    • Radiation Safety Review Worksheet
    • Midterm Exam

    • 5.1: Radiation Safety Review Worksheet
    • 5.2: Activity, Half Life &amp; Half-Value Layers
      This page explores radioactivity, detailing the measurement units curies (ci) and Becquerels (Bq) for decay rates. It highlights specific activity's importance for the efficiency of radioactive sources in radiography and explains half-lives of isotopes for safety in exposure calculations.
    • 5.3: Glossary of Terms
      This page covers the ALARA principle for managing radiation exposure, highlights gamma rays and radiography techniques involving Cobalt-60 and Iridium-192, and explains key concepts like half-life and biological half-life. It defines the half-value layer (HVL) for radiation shielding and outlines the three pillars of radiation safety: time, distance, and shielding.


    This page titled 5: Activity, Half Life, and Half Value Layers is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Jason S. Ballard via source content that was edited to the style and standards of the LibreTexts platform.