ABSTRACT
In 1895, German physicist W.C. Roentgen discovered a new type of radiation in the course of an experiment using the Crookes’ vacuum tube. This radiation penetrated opaque materials such as black paper or wood. He named it x-ray and clari‚ed its properties such as penetrability, ±uorescence action, imaging ability, and ionization. The discovery of x-rays is the starting point of the investigation on ionizing radiation and its application to various ‚elds.
