He worked in the newly developing field of radiation effects in matter and is widely considered a pioneer of ion implantation in solids. Together with colleagues at Aarhus University in Denmark and other institutions world-wide, he developed the concept of ion channelling, which leads to anomalously deep penetration of ions in crystalline materials. John’s standing in the research community and the importance of his work led to McMaster hosting the International Conference on Atomic Collisions in Solids in 1979 and the International Conference on Radiation Effects in Insulators in 1989. John’s many contributions to science have been acknowledged by his being inducted as Fellow of the Royal Society of Canada, the Danish Royal Society of Arts and Sciences and the Böhmische Physikalische Gesellschaft. He received the Noranda Award from the Chemical Institute of Canada in 1956, the T.D. Callinan Award of the Electrochemical Society in 1967, an honorary Doctor of Science degree from Royal Roads Military College in 1984, and the W.B. Lewis Medal of the Canadian Nuclear Society in 1998. John was always generous with his time, was considered a great mentor by students and colleagues alike, and in addition to science enjoyed the great outdoors. He is survived by his wife Florence (Flo), six children, 15 grandchildren and “6.6” great-grandchildren.