What percentage of the interactions during bremsstrahlung generates X-rays?

Bremsstrahlung, or "braking radiation," occurs when high-speed electrons are decelerated upon interaction with the atomic nuclei of a target material, most commonly tungsten in X-ray tubes. As these electrons lose energy, they emit X-rays as a consequence of this deceleration.

The majority of interactions during bremsstrahlung do not result in the emission of X-rays but instead dissipate energy through other means, such as heat production in the target material. In fact, only a small fraction of these interactions—typically around 1%—actually results in the generation of X-ray photons. This low efficiency can be attributed to the fact that the majority of the kinetic energy from the electrons is converted to thermal energy rather than being emitted as X-rays.

Understanding this statistical aspect of X-ray production is crucial as it emphasizes the need for efficient design in X-ray equipment to maximize X-ray output while minimizing heat generation, which can damage the equipment and impact safety.

Hence, the correct percentage of interactions during bremsstrahlung that generate X-rays is approximately 1%.