Final answer:
Differential absorption of radiation is affected by part thickness, part density, and atomic number. All these factors contribute to the probability of radiation being absorbed by the material, with greater thickness, density, and higher atomic numbers leading to increased absorption.
Step-by-step explanation:
The factors affecting differential absorption include part thickness, part density, and atomic number. Specifically:
- Part thickness: The thicker the material, the more absorption will occur due to a longer path for the radiation to travel through, increasing the probability of interactions that lead to absorption. As the material thickness increases, the probability for absorption also increases.
- Part density: Higher density materials have more atoms per unit volume, providing more opportunities for radiation to interact and be absorbed.
- Atomic number (Z): Materials with higher atomic numbers have more electrons, which means that x-rays and gamma rays are more likely to interact with the material and thus, be absorbed.
Additionally, as x-ray energy increases, phenomena like Compton scattering become more important in X-ray attenuation. However, in the context of this particular question, where we are considering differential absorption of x-rays or gamma rays, the atomic number does contribute significantly to the attenuation process, especially for lower energy radiation where the photoelectric effect is dominant. Higher Z materials are used as contrast agents in medical imaging because they enhance the absorption and visibility of structures.
Therefore, the correct answer to the question is D. 1, 2 & 3.