William Coolidge was an American physicist who developed (1908) a method for drawing tungsten into filaments for making light bulbs and radio tubes. In 1916 he patented an X-ray tube (Coolidge tube) capable of producing accurate amounts of radiation. Coolidge also devised portable X-ray units and worked on construction techniques for industrial quality control. During World War 2 he devised a submarine-detection system with Irving Langmuir. Coolidge also worked on atom bomb research. See also electron tube.