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William D. Coolidge
THEY WERE GIANTS
OTHA LINTON, MSJ
William D. Coolidge “This is the single most important innovation for radiology,” said a New York City radiologist when, in December 1913, he saw the first version of a hot cathode ray x-ray tube, devised by William D. Coolidge, PhD, a physicist at the General Electric (GE) laboratory in Schenectady, New York. For weeks, the prototype tube was installed in the Manhattan office of Louis Gregory Cole, the Cornell University professor of radiology who tested the new x-ray device and found it was far better than the gas tubes used by Wilhelm Roentgen to discover x-rays in 1895. Dr Cole invited dozens of radiologists for a demonstration of the new tube. Unlike glass vacuum tubes, with no protection from xray beams exposing patients and radiologists, the Coolidge tube was in a metal container with an adjustable aperture to limit exposure dimensions to selected segments of patients. Dr Coolidge returned to the GE laboratory with a batch of orders for the new tube. Within a decade, the Coolidge tube and other versions had replaced most other medical x-ray devices. Dr Coolidge spent his entire career in the GE laboratory, where he made basic contributions to advances in radiologic devices and served as a member of national and international commissions. Besides his creation of basic hot cathode medical x-ray devices, he also produced special dental x-ray units and devised radiation cancer treatment devices with ⬎200 kV energy and later 1,000,000 kV. William Coolidge was born in October of 1873 in Hudson, Massachusetts. He obtained a bachelor’s degree from the Massachusetts Institute of Technology in 1896. He then
went to Leipzig, Germany, where he completed a doctorate in physics in 1899. He returned to a physics faculty appointment at the Massachusetts Institute of Technology, where he spent 6 years before moving to the GE laboratory in 1905. His first GE assignment was to improve the filaments of light bulbs, using tungsten rather than platinum and other metals. GE was competitive with American inventor Thomas Edison, who had devised the first electric devices and had developed an x-ray fluoroscope. Edison then abandoned xray testing because of the death of an assistant from radiation from unshielded x-ray tubes. Because GE wanted to improve the service of electricity, as well as x-ray energy, researchers in the GE laboratories continued to explore ways of stimulating and controlling the energy of electric lights, electric generators, and tungsten as the cathode in x-ray generators. Dr Coolidge and his team began the development of improved x-ray generators in 1910. When the system was ready for testing, he persuaded Dr Cole to allow the unit to be installed in his office. For several months, Dr Cole tested the device with patients and grew enthusiastic. Both Dr Cole and Dr Coolidge published articles about the new device. Dr Coolidge’s “A Powerful Roentgen X-Ray Tube With a Pure Electronic Discharge” appeared in the December 1913 Physical Review, with a second version appearing in the January 1914 American Journal of Roentgenology. Dr Cole’s first article about his experience was published in the December 1913 issue of the American Journal of Roentgenology. Once the hot cathode tubes were
marketed by GE, Dr Coolidge and others in the laboratories continued to develop improved medical devices. The sheltered x-ray tubes could be used by physicians and technicians with much less exposure to themselves than they had endured from the earlier unshielded devices. By 1921, Dr Coolidge had adjusted GE x-ray tubes to eliminate electricity risks, as well as refine x-ray exposures. In the 1920s, the ARRS cooperated with radiologists and scientists in other countries to organize efforts for defining radiation exposures and improving devices for measuring those exposures. Dr Coolidge attended international radiology congresses in England in 1925 and Sweden in 1928 and agreed to serve on international committees to define radiologic measurement standards and to make recommendations for radiation protection. When the US Bureau of Standards created the National Council on Radiation Protection and Measurements, Dr Coolidge was appointed as a member. Dr Coolidge remained active in the GE laboratory, becoming its director in 1932. In 1940, he was a GE corporate vice president, and during World War II, he served on the National Academy of Sciences atomic bomb project. He retired from GE in 1945, remaining an emeritus scientist. Dr Coolidge received numerous awards, in 1921 from the American Radium Society, in 1931 a gold medal from the ACR, and in 1972, he received the William D. Coolidge Award from the American Association of Physicists in Medicine. He survived to the age of 102, dying in 1975.
Otha Linton, MSJ, 11128 Hurdle Hill Dr, Potomac, MD 20854. 672
© 2012 American College of Radiology 0091-2182/12/$36.00 ● DOI 10.1016/j.jacr.2012.01.009
OTHA LINTON, MSJ
William D. Coolidge “This is the single most important innovation for radiology,” said a New York City radiologist when, in December 1913, he saw the first version of a hot cathode ray x-ray tube, devised by William D. Coolidge, PhD, a physicist at the General Electric (GE) laboratory in Schenectady, New York. For weeks, the prototype tube was installed in the Manhattan office of Louis Gregory Cole, the Cornell University professor of radiology who tested the new x-ray device and found it was far better than the gas tubes used by Wilhelm Roentgen to discover x-rays in 1895. Dr Cole invited dozens of radiologists for a demonstration of the new tube. Unlike glass vacuum tubes, with no protection from xray beams exposing patients and radiologists, the Coolidge tube was in a metal container with an adjustable aperture to limit exposure dimensions to selected segments of patients. Dr Coolidge returned to the GE laboratory with a batch of orders for the new tube. Within a decade, the Coolidge tube and other versions had replaced most other medical x-ray devices. Dr Coolidge spent his entire career in the GE laboratory, where he made basic contributions to advances in radiologic devices and served as a member of national and international commissions. Besides his creation of basic hot cathode medical x-ray devices, he also produced special dental x-ray units and devised radiation cancer treatment devices with ⬎200 kV energy and later 1,000,000 kV. William Coolidge was born in October of 1873 in Hudson, Massachusetts. He obtained a bachelor’s degree from the Massachusetts Institute of Technology in 1896. He then
went to Leipzig, Germany, where he completed a doctorate in physics in 1899. He returned to a physics faculty appointment at the Massachusetts Institute of Technology, where he spent 6 years before moving to the GE laboratory in 1905. His first GE assignment was to improve the filaments of light bulbs, using tungsten rather than platinum and other metals. GE was competitive with American inventor Thomas Edison, who had devised the first electric devices and had developed an x-ray fluoroscope. Edison then abandoned xray testing because of the death of an assistant from radiation from unshielded x-ray tubes. Because GE wanted to improve the service of electricity, as well as x-ray energy, researchers in the GE laboratories continued to explore ways of stimulating and controlling the energy of electric lights, electric generators, and tungsten as the cathode in x-ray generators. Dr Coolidge and his team began the development of improved x-ray generators in 1910. When the system was ready for testing, he persuaded Dr Cole to allow the unit to be installed in his office. For several months, Dr Cole tested the device with patients and grew enthusiastic. Both Dr Cole and Dr Coolidge published articles about the new device. Dr Coolidge’s “A Powerful Roentgen X-Ray Tube With a Pure Electronic Discharge” appeared in the December 1913 Physical Review, with a second version appearing in the January 1914 American Journal of Roentgenology. Dr Cole’s first article about his experience was published in the December 1913 issue of the American Journal of Roentgenology. Once the hot cathode tubes were
marketed by GE, Dr Coolidge and others in the laboratories continued to develop improved medical devices. The sheltered x-ray tubes could be used by physicians and technicians with much less exposure to themselves than they had endured from the earlier unshielded devices. By 1921, Dr Coolidge had adjusted GE x-ray tubes to eliminate electricity risks, as well as refine x-ray exposures. In the 1920s, the ARRS cooperated with radiologists and scientists in other countries to organize efforts for defining radiation exposures and improving devices for measuring those exposures. Dr Coolidge attended international radiology congresses in England in 1925 and Sweden in 1928 and agreed to serve on international committees to define radiologic measurement standards and to make recommendations for radiation protection. When the US Bureau of Standards created the National Council on Radiation Protection and Measurements, Dr Coolidge was appointed as a member. Dr Coolidge remained active in the GE laboratory, becoming its director in 1932. In 1940, he was a GE corporate vice president, and during World War II, he served on the National Academy of Sciences atomic bomb project. He retired from GE in 1945, remaining an emeritus scientist. Dr Coolidge received numerous awards, in 1921 from the American Radium Society, in 1931 a gold medal from the ACR, and in 1972, he received the William D. Coolidge Award from the American Association of Physicists in Medicine. He survived to the age of 102, dying in 1975.
Otha Linton, MSJ, 11128 Hurdle Hill Dr, Potomac, MD 20854. 672
© 2012 American College of Radiology 0091-2182/12/$36.00 ● DOI 10.1016/j.jacr.2012.01.009