Conventional X-Ray Machines

Abstract

At the beginning of the 20th century, there was much interest among experimental physicists in the study of atomic phenomena in rarefied gases subjected to high electric potentials. They used glass discharge tubes (Figure 8.1) which contained an anode and a cathode, and in which gas was maintained at very low pressures, of the order of 0.001 mmHg. Crookes found that, when very high voltages were applied between the electrodes, the gas turned dark and the walls glowed. The glow was attributed to fast-moving, negatively charged particles, later identified as electrons. In 1895, Wilhelm Conrad Roentgen reportedtheemissionofamysterious andpenetratingradiationfrom evacuated tubes that affected the photographic plates stored in light-tight containers. He was, in fact, observing the bremsstrahlung produced by electron interactions. He called the radiation ”X-rays,“ using the letter ”X“ to designate something unknown. Nowadays, these rays are also called Roentgen rays. Roentgen’s radiographing of his own and his wife’s hands marked the beginning of the use of X-rays in the healing arts.