William David Coolidge was an American physicist, 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.
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, and its basic design is still in use. He invented the first rotating anode X-ray tube. He filed for patent in 1913 and finally it was granted as US Patent 1,203,495 in 1916.
The American Academy of Arts and Sciences awarded Coolidge the Rumford Prize in 1914. Coolidge was awarded the American Institute of Electrical Engineers Edison Medal in 1927 For his contributions to the incandescent electric lighting and the X-rays art. He rejected this prestigious award in 1926 on the basis that his ductile tungsten patent (1913) was ruled by court as invalid. He was awarded the Howard N. Potts Medal in 1926 and the Louis E. Levy Medal in 1927. Coolidge was awarded the Faraday Medal in 1939. He was awarded the Franklin Medal in 1944.In 1975 he was elected to the National Inventors Hall of Fame, shortly before his death at age 101 in Schenectady, New York.