katódsugárzás

Katódsugárzás, also known as cathode rays, refers to a stream of electrons emitted from the cathode of a vacuum tube. This phenomenon was first observed in the mid-19th century when experiments were conducted with electrical discharges in evacuated glass tubes. When a high voltage was applied across electrodes in a vacuum tube, the negatively charged electrode, the cathode, emitted invisible rays.

These cathode rays were found to possess several key properties. They traveled in straight lines and could cast shadows of objects placed in their path, indicating they were particles. They could also deflect magnetic fields and electric fields, demonstrating their charged nature. J.J. Thomson's experiments in 1897 were pivotal in identifying cathode rays as streams of negatively charged particles, which he termed "corpuscles." These corpuscles were later identified as electrons, the fundamental building blocks of atoms.

The understanding of cathode rays led to the development of crucial technologies. The most prominent is the cathode ray tube (CRT), which was the basis for early televisions, computer monitors, and oscilloscopes. In a CRT, a beam of electrons is directed towards a fluorescent screen, causing it to glow and form images. While CRTs have largely been replaced by newer display technologies like LCD and LED, the study of cathode rays laid the groundwork for much of modern electronics and our understanding of atomic structure.