What is the Half-Value Layer (HVL) and how is it used in shielding calculations?

• A. HVL is the thickness required to reduce beam intensity by 50%.
• B. HVL describes the shield's capacity to stop 50% of incident energy over a given distance.
• C. HVL is the thickness of shielding material required to reduce exposure by 10% for a very high energy beam.
• D. HVL is a measure of the average energy of photons after passing through shielding.

Answer: (A)