Bremsstrahlung is an X-ray produced when beta particles decelerate.

• A. Alpha particles
• B. Beta particles
• C. Gamma rays
• D. Neutrons

Answer: (B)

The main idea is that Bremsstrahlung arises when a fast charged particle is slowed (decelerated) by the electric field of a nucleus, and this braking radiation manifests as X-rays. In practice, the most common source is fast electrons produced by beta decay, i.e., beta particles. As these high-energy electrons pass through matter, they are deflected and slowed by nuclei, emitting X-ray photons in the process.

Alpha particles, while charged, are much heavier and their energy loss is dominated by ionization rather than radiative braking, so they do not produce Bremsstrahlung X-rays to a meaningful extent. Gamma rays are already photons and are not produced by decelerating charged particles. Neutrons are neutral and do not radiate Bremsstrahlung when they slow down.

So, beta particles (electrons) decelerating in matter is the typical mechanism for Bremsstrahlung X-ray production.