ASNT Radiographic Testing Practice Test 2025 – Comprehensive All-in-One Guide for Exam Success!

The production of x-rays in an accelerator or x-ray tube relies fundamentally on the behavior of electrons. When electrons are accelerated and collide with a target material (often tungsten), they transfer energy, leading to the emission of x-rays. This phenomenon occurs primarily through two mechanisms: characteristic radiation and Bremsstrahlung radiation.

In characteristic radiation, when high-energy electrons knock out inner-shell electrons from atoms in the target, outer-shell electrons drop into the lower energy state, emitting x-rays with energy corresponding to the differences in energy levels. In Bremsstrahlung radiation, as the electrons are decelerated when they pass near the nuclei of the target material, they emit energy in the form of x-rays.

The other components listed—protons, neutrons, and photons—are not directly involved in the x-ray production process in x-ray tubes or accelerators. Protons and neutrons, which are part of atomic nuclei, do not generate x-rays through their interaction in this context. Photons, being the light particles that convey electromagnetic radiation, are actually the resultant output of the x-ray production process rather than a component required for producing x-rays. Hence, electrons are the essential component in x-ray generation.