Bremsstrahlung x-rays are produced as a result of what process in XRF?

• A. Nuclear decay
• B. Scattering of neutrons
• C. Emission from bound inner shells only
• D. Slowing down of high-energy electrons in the sample

Answer: (D)

Bremsstrahlung comes from fast electrons being decelerated by the electric fields of nuclei in the material. As these electrons slow down, they emit photons with a continuous range of energies, creating the broad background X-ray spectrum you get in XRF. This is different from nuclear decay (which releases radiation from the nucleus) or neutron scattering (involving neutrons, not producing Bremsstrahlung), and it’s distinct from characteristic X-rays, which are produced by transitions of electrons between inner shells and appear as discrete lines. In the sample, the deceleration of high-energy electrons produces the continuous Bremsstrahlung radiation.