William david coolidge biography of martin

It was years ago today that William D. Coolidge first noted in his lab notebook the use of a hot filament as the source of electrons in a high-vacuum x-ray tube. This was a significant improvement and allowed full development of the technology and expanded use in medicine and industrial applications. William David Coolidge — was a research scientist and inventor of the modern x-ray tube.

Besides Roentgen, with his discovery and subsequent studies of x rays, perhaps no other individual contributed more to the advancement of x-ray technology than did Coolidge. That same year, he went to Europe to study under renowned physicists of the time. While studying at Leipzig, he met Roentgen.

William D. Coolidge was an American engineer and physical chemist whose improvement of tungsten filaments was essential in the development.

He promptly began fundamental work on the production of ductile tungsten filaments as a replacement for fragile carbon filaments used in incandescent light bulbs. This improved light bulb was brought to market in It was application of this work that led Coolidge to his studies in x-ray production. The state-of-the-art x-ray tube at the time was the "gas tube" or "cold cathode" type tube.

These x-ray tubes relied on residual gas molecules as a source of electrons for bombardment of low to medium atomic number metal targets. In Coolidge described the use of tungsten as an improved anode target material for x-ray tubes. Great improvements in x-ray tube stability and performance were obtained with the "hot cathode" or "Coolidge tube.

In he was a member of a small committee, appointed by President Franklin D. Roosevelt, to evaluate the military importance of research on uranium.