In 1940, Farmer began working as assistant physicist in the radiography department at Middlesex Hospital,[1] one of a group of physicists employed by London hospitals during the war to work on issues related to the emerging technology of X-rays, and the use of radium to treat cancer.[3] These issues would become the central focus of Farmer's subsequent career.[2] One of the instruments he invented while at Middlesex, the Farmer dosimeter, became a standard tool used in hospitals around the world to calibrate X-ray machines,[3][1] and is still produced commercially today.[2]
In 1945 he moved to become head physicist at the Royal Victoria Infirmary (RVI) in Newcastle-Upon-Tyne.[3][2] The hospital at that time had Marconi deep therapy X-Ray machines installed, with which Farmer was closely familiar from his time working at Marconi, and as a result the hospital was able to keep these machines in clinical use for many years.[1] Farmer's team brought together experts in health physics, radio-isotopes, ultrasonics, instrumentation and physiological measurement. Specific innovations included the world's first gantry-mounted linear particle accelerator for cancer treatment, installed in 1963,[2] and numerous clinical uses of the radioisotope tracer technique, developed using radio-isotopes from the nuclear reactors at Amersham and Harwell, which became available to researchers after World War II.[2] When the new department opened, Farmer was appointed first Professor of Medical Physics at Newcastle University in 1966.[2][1] While at the RVI, Farmer and his team turned the facility into a renowned centre for research into medical applications of radio-isotope technology, providing services in these areas to the entire region of Northern England, which had previously had none.[2] At the time of Frank Farmer's retirement in 1978, the department had branches in Teesside and Cumbria, as well as the three hospitals in Newcastle, and employed 70 scientific and technical staff.[1]
Farmer was President of the Hospital Physicists Association (1959–60; now the Institute of Physics and Engineering in Medicine) and the British Institute of Radiology (1973–74).[2] During his career he served on the International Commission on Radiation Units and Measurements and many other professional radiography and research bodies,[2] and authored a large number of scientific papers.[1] He was awarded an OBE in 1973 for services to physics applied to medicine.[2][1]