ABSTRACT
On Friday 8 November 1895 Wilhelm Conrad Röntgen (1845-1923; German physicist) while experimenting with high voltages using a Crooke’s tube (an evacuated tube with electrodes inserted) noticed that invisible radiation was being produced that penetrated the soft tissue of his hand revealing skeletal structure. He called the radiation ‘X-rays’: X denoting their unknown origin. Within a year of their discovery X-rays were being used for medical imaging. In 1901 Röntgen received the first Nobel Prize for physics. In 1913 W.D. Coolidge (1873-1975; USA engineer) produced the electrically heated cathode tube: the forerunner of all modern X-ray tubes.
