Harold E. Johns
Harold Elford Johns ( born July 4, 1915 in Chengdu, Republic of China, † August 23 1998 in Kingston, Ontario) was a Canadian medical physicist and pioneer of radiotherapy.
Life
Johns was born in China, where his parents - Alfred and Myrtle Johns - were members of the Presbyterian or Methodist missionaries and teachers. His father was a professor of mathematics at West China Union University (Sichuan University). As the situation in China was too dangerous, the family in 1926 or 1927 went to North America, first to Tacoma, Washington, then to Brandon, Manitoba, and finally to Hamilton, Ontario.
Johns acquired in 1936 at McMaster University in Hamilton a BA in Physics and the University of Toronto in 1937 and a master's degree in 1939 with a PhD in low temperature physics. The work earned him a fellowship to Cambridge, he could not take advantage of due to the outbreak of the Second World War. Instead, John went to the University of Alberta and also worked as a teacher of physics and mathematics as well as practical application of radar and radio navigation in the training of pilots of the Royal Canadian Air Force. He also led a discarded X-ray tube or radium needles by material tests ( radiographic testing ) on aircraft.
1945 or 1946 John received the University of Saskatchewan in Saskatoon a position as Assistant Professor at Ertle Harrington and as a physicist for the Saskatchewan Cancer Commission, where he first established the field of medical physics in Canada. In 1948 he attended here for the safe operation of the first betatron in Canada and in 1951 was a leading participant in the development of cobalt cannon. In 1956 Johns head of the Department of Physics at the Ontario Cancer Institute. In 1958 he became Professor and Head of the Department of Biophysics at the University of Toronto. In 1980, he went into retirement.
Harold Johns was with Sybil Johns, nee Hawkins, married. The couple had three daughters.
Work
John pioneered the development of cobalt cannon and other forms of high-energy radiation with which malignant tumors in the depth of the body could be successfully treated for the first time. He has made numerous contributions to research and teaching in the field of clinical physics and biophysics. His textbook The Physics of Radiology published 1961-1983 in four editions and was translated into several languages, including Chinese.
Johns had influence on the development of the first CT scanner which sonography, magnetic resonance imaging and mammography. He published important work on DNA damage by ultraviolet radiation. He conducted research to determine the necessary radiation dose to treat various types of cancer and to measure the radiation dose during therapy.
John has published more than 200 peer -reviewed work and supervised more than 100 graduate students and postdoctoral fellows.
Awards (selection)
The University of Western Ontario in London ( Ontario) will award a Harold E. Johns Award for biomedical research. The Princess Margaret Hospital Foundation ( as part of the Ontario Institute for Cancer Research ) in Toronto assigns a Harold E. Johns Research Prize.
Writings (selection )
- The Physics of Radiation Therapy. 1953
- The Physics of Radiology. 1961