What is formed when high-speed electrons strike a target?

When high-speed electrons strike a target, the primary outcome is the production of X-rays and heat. This process occurs in an X-ray tube, where electrons are accelerated and directed towards a metal target, typically made of tungsten.

Upon impact, the kinetic energy of the high-speed electrons is converted into X-ray photons through a mechanism called Bremsstrahlung radiation, where the electrons are decelerated by the electric field of the nucleus in the target atom. This deceleration causes a release of energy in the form of X-rays. Additionally, not all energy is converted to X-rays; some is dissipated as heat in the target material due to the interactions between the electrons and the atoms of the target. This heat is managed in X-ray machines through cooling systems to prevent damage to the anode.

Thus, the formation of X-rays and heat is a fundamental principle of radiographic imaging, making this answer the correct one.