What effect does adding more half-value layers (HVL) have on the quality of the x-ray beam?

Adding more half-value layers (HVL) to an x-ray beam enhances its quality. The half-value layer is defined as the thickness of a material that reduces the intensity of the x-ray beam to half its original value. When more HVLs are added, it indicates a greater thickness of absorbing material is required to achieve the same reduction in intensity, suggesting that the beam is more penetrating.

This increased penetration capability means that higher-energy photons dominate the x-ray beam, leading to improved beam quality. Higher-quality x-rays have less variation in energy levels, resulting in a more uniform exposure to the imaging receptor and better image clarity. Consequently, a greater number of HVLs correlates with an increase in the overall quality of the x-ray beam, providing clear and accurate diagnostic images while minimizing patient exposure to lower-energy, less penetrating radiation.