William D. Coolidge | |
---|---|
Born | October 23, 1873 Hudson, Massachusetts, U.S. |
Died | February 3, 1975 Schenectady, New York, U.S. |
(aged 101)
Residence | United States |
Nationality | American |
Fields | Electrical engineering |
Alma mater |
University of Leipzig Massachusetts Institute of Technology |
Known for | his contributions to the incandescent electric lighting and the X-rays art |
Notable awards |
IEEE Edison Medal (1927) Hughes Medal (1927) Faraday Medal (1939) Duddell Medal and Prize (1941) |
William David Coolidge (October 23, 1873 – February 3, 1975) was an American physicist and engineer, who made major contributions to X-ray machines. He was the director of the General Electric Research Laboratory and a vice-president of the corporation. He was also famous for the development of "ductile tungsten", which is important for the incandescent light bulb.
Coolidge was born on a farm near Hudson, Massachusetts. He studied electrical engineering from 1891 until 1896 at the Massachusetts Institute of Technology (MIT). After a year as a laboratory assistant, he went to Germany for further study and received his doctorate from the University of Leipzig. From 1899 to 1905 he was a research assistant to Arthur A. Noyes of the Chemistry Department at MIT.
Coolidge went to work as a researcher at General Electric's new research laboratory in 1905, where he conducted experiments that led to the use of tungsten as filaments in light bulbs. He developed 'ductile tungsten', which could be more easily drawn into filaments, by purifying tungsten oxide. Starting in 1911, General Electric marketed lamps using the new metal and they soon became an important source of income for GE. He applied for and received a patent (US#1,082,933) for this 'invention' in 1913. However, in 1928 a US court ruled that his 1913 patent was not valid as an invention.
In 1913 he invented the Coolidge tube, an X-ray tube with an improved cathode for use in X-ray machines that allowed for more intense visualization of deep-seated anatomy and tumors. The Coolidge tube, which also utilized a tungsten filament, was a major development in the then-nascent medical specialty of radiology (US patent filed in 1913 and granted as US Patent 1,203,495 in 1916). Its basic design is still in use. He also invented the first rotating anode X-ray tube.