Baby Coolidge Tube

Coolidge type R X-ray tube used in radiotherapy for diagnostics nicknamed the "baby-Coolidge", with its finned radiator. Glass, metal and tungsten tube, designed by the American physicist William David Coolidge (1873-1975). The development of his tube in the research laboratory of the General Electric Company "marks a decisive turning point in radiological technology since current X-ray bulbs still use the same principle" (Pallardy*, p. 352) This tube is characterized by a cathode made of tungsten brought to incandescence by a separate so-called "heating" transformer which emits a flow of electrons and the "perfect" vacuum. Thanks to this tube, the intensity can be modulated and the intensity adapted by the radiologist. The period following this discovery is referred to as the "golden age" of radiology. Manufactured in series by General Electric from 1917 (date of patent filing), the Coolidge tube was part of the radiological equipment of the American army and was built in Europe from 1919 under American license. There are two main models: "Baby" and "Standard" for more powerful semi-penetrating radiotherapy. In France, the consequences of the First World War delayed the discovery. The first French models of this type were manufactured by the manufacturer Pilon**, which holds French exclusivity. This added a water-cooled anti-cathode (patent of July 1914). The Gaiffe-Gallot et Pilon Company was founded in 1919 following the merger between the H. Pilon establishments and the Gallot company founded in 1911. In 1930, it merged with the Ropiquet, Hazart et Roycourt company to form the Compagnie Générale de Radiologie , the CGR based in Issy-les-Moulineaux (Île-de-France), in 1962 entered the Thomson group and was taken over by the General Electric Medical System in 1987. Beautiful model which bears the mention on its glass of "Exclusive License for France" and n°50481. Bibliographic references: *Pallardy, Histoire illustrée de la Radiologie, ed. Roger Dacosta, Paris, 1989. **Pilon H. The Coolidge tube, Masson, Paris, 1919.