Which statement is true regarding the effect of increasing the anode angle?

Which statement is true regarding the effect of increasing the anode angle?

• A. Increases the focal spot size
• B. Decreases the focal spot size
• C. No change to the focal spot size
• D. Only affects exposure, not focal spot

Answer: (A)

Increasing the anode angle makes the target surface interact with the electron beam over a larger area. When the target is tilted more, the footprint of the electron beam on the anode expands along the surface, so the region where energy is converted to X-rays—the focal spot—becomes larger. This is why the focal spot size increases with a larger anode angle. In practice, a bigger focal spot distributes heat over a wider area on the anode, which helps with heat loading but can reduce image sharpness due to greater geometric unsharpness.