Louis Harold Gray

Louis Harold Gray ( born November 10, 1905 in London, † July 9, 1965 in Northwood ) was a British physicist and radiologist and founder of radiobiology. His work dealt with the effects of radiation and radioactivity to biological systems. Among other things, he defined the later named after him as Gray ( Gy) SI unit of absorbed radiation dose.

The only son of Mr and Mrs Gray studied after high school - he was temporarily Boarder - with a scholarship at Trinity College, Cambridge physics, mathematics and chemistry. He also a PhD on the absorption of hard gamma radiation.

In 1933 he began his work at Mount Vernon Hospital in London, where in 1936 he, together with William Lawrence Bragg Bragg -Gray equation developed with which the gamma-ray absorption can be determined by materials. From 1938, he conducted research on the biological effects of neutron radiation. In 1940 he developed the concept of the relative biological effectiveness of neutron radiation. In 1950 he began studies for the treatment of tumor cells with an oxygen overpressure therapy and studies of the influence of the radiation sensitivity of cells in dependence on the oxygen concentration in the tissue. In 1953, the Gray Laboratory of the Cancer Research Campaign was established at Mount Vernon Hospital, where he studied with Jack W. Boag at the Impulsradiolyse.

At the age of 57 years, Gray suffered a massive stroke; Three years later he died. The ash was transferred to his holiday island of Alderney. From the marriage with a blind theologian since her youth, a son had emerged.


Gray received the X- Prize and the Faraday Medal for his work. Launched in the 30s by him wheel unit ( abbreviation of radiation absorbed dose ) of the absorbed dose was replaced in 1978 by the eponymous unit Gray.

  • Physicist ( 20th century)
  • Radiologist
  • Physician ( 20th century )
  • Briton
  • Born 1905
  • Died in 1965
  • Man