röntgenlähde

Röntgenlähde refers to a source of X-rays. X-rays are a form of electromagnetic radiation with wavelengths shorter than ultraviolet light and longer than gamma rays. They are produced when high-energy electrons strike a target material, typically a metal. This process, known as the generation of X-rays, involves two primary mechanisms: bremsstrahlung and characteristic X-ray emission.

Bremsstrahlung, meaning "braking radiation" in German, occurs when electrons are decelerated as they pass through the strong electric field of the atomic nuclei in the target material. This deceleration causes the electrons to lose energy in the form of X-ray photons. The energy of the emitted photons is continuous, ranging from zero up to the initial kinetic energy of the electrons.

Characteristic X-ray emission happens when an incident electron knocks out an electron from an inner shell of an atom in the target material. This leaves a vacancy, and an electron from an outer shell drops down to fill it. The energy difference between the shells is released as an X-ray photon with a specific energy, characteristic of the element. This results in discrete peaks in the X-ray spectrum.

Common röntgenlähteet include X-ray tubes, which are vacuum tubes containing a cathode to emit electrons and an anode that serves as the target. These tubes are widely used in medical imaging, industrial radiography, security screening, and scientific research. Synchrotrons are also powerful sources of X-rays, producing highly intense and tunable beams used in advanced research applications.