What is the primary process by which x-rays are produced?

• A. Bremsstrahlung
• B. Characteristic
• C. Photoelectric
• D. Compton Effect

Answer: (A)

In x-ray production the main process is the deceleration of high-speed electrons as they pass near the nucleus. This slowing (or braking) causes the electrons to emit photons, producing Bremsstrahlung radiation. Because the energy lost during braking can vary continuously from nearly zero up to the incident electron energy, the resulting x-ray beam is a broad, continuous spectrum. This makes Bremsstrahlung the dominant production mechanism in most x-ray tubes.

Characteristic radiation, by contrast, occurs when an incident electron ejects an inner-shell electron from the target atom and an electron from a higher shell fills the vacancy, emitting photons with discrete energies specific to the target material. This adds particular peaks to the spectrum but does not define the primary production. The photoelectric effect and Compton scattering are interactions of x-rays with matter, not how x-rays are generated.