Final answer:
The HVL (half-value layer) in lead for 99m Tech is approximately 6.0 mm, for 18 F is approximately 4.62 mm, and for 137 Cs is approximately 40.76 mm.
Step-by-step explanation:
The HVL (half-value layer) in lead can be calculated using the formula HVL = (0.693 / μ) where μ is the linear attenuation coefficient. The linear attenuation coefficient for a given material and radiation depends on the energy of the radiation. Let's calculate the HVL for the given isotopes:
A. For 99m Tech, the linear attenuation coefficient is μ = 0.115 mm⁻¹ (approx). Therefore, HVL = 0.693 / 0.115 ≈ 6.0 mm (approx).
B. For 18 F, the linear attenuation coefficient is μ = 0.15 mm⁻¹ (approx). Therefore, HVL = 0.693 / 0.15 ≈ 4.62 mm (approx).
C. For 137 Cs, the linear attenuation coefficient is μ = 0.017 mm⁻¹ (approx). Therefore, HVL = 0.693 / 0.017 ≈ 40.76 mm (approx).