Peter Howard Fowler, Physicist, 1923-1996

Peter Howard Fowler was born in Cambridge on 27 February 1923, the son of the leading theoretical physicist Ralph Howard Fowler the son-in-law of Lord Rutherford, the discoverer of the atomic nucleus. Fowler attended Winchester College between 1936 and 1940 and entered the University of Bristol to study for a B.Sc. in Physics. The Second World War put a temporary halt to his studies but gave him the opportunity to develop knowledge of radar techniques as a signals officer in the RAF between 1942 and 1946. His most remarkable achievement was the detection of German signals jamming the navigation systems of RAF bombers and identifying the signal station responsible which was then destroyed. However, he had been able while at Bristol to assist C.F. Powell as a project assistant before his entering the RAF, and this work led to a Nature paper published in 1947 after the conclusions had been confirmed by other researchers at Liverpool.

In 1946 he was able to resume his undergraduate studies. He graduated in June 1948 and quickly established himself as a leading member of C.F. Powell's cosmic rays research group at Bristol. Fowler was appointed Assistant Lecturer in Physics in 1948, Lecturer in 1951 and Reader in 1961. He spent a year at the University of Minnesota in Minneapolis as a Visiting Professor in 1956-1957 and in 1958 he accepted the post of Professor of Physics at the same university. However the American Embassy refused to grant him an immigrant's visa on medical grounds and consequently he remained at the University of Bristol for the rest of his career. Fowler was elected a Fellow of the Royal Society in 1964 (Rutherford Lecturer 1971, Hughes Medal 1974) and later that year appointed a Royal Society Research Professor in Physics, holding this post until his retirement in 1988.

In collaboration with Powell, Fowler's research concentrated on the study of elementary particles created naturally by interactions of cosmic rays in the upper atmosphere of the earth. High altitude balloons, and later VC10 aircraft, were used to carry nuclear emulsion films that recorded cosmic ray activity, launching from sites worldwide. After Powell's death in 1969, Fowler continued this research and by the early 1980s had extended it through the use of solid-state detectors and gas scintillator detectors flown on the UK satellite Ariel 6. His measurements of super heavy nuclei proved an important step in the understanding of the supernova mechanism. One of Fowler's notable early achievements with Powell's group was the identification in 1949 of the first of a new type of elementary particle called the tau-meson (now called the K-meson). Among Fowler's co-workers was Rosemary Brown, whom he later married.

Fowler's research on cosmic rays in the earth's atmosphere and beyond had a number of practical applications. In 1961 he was asked by the Air Registration Board to investigate whether radiation levels due to solar flares in high altitude flights in Concorde were hazardous for flight crew members. His report concluded they were no more dangerous than in subsonic aircraft. Also in the early 1960s he suggested the use of pi-mesons in cancer treatment. His ideas still contribute to modern targeted radiotherapy practice and his lecture in 1964 on 'Pi mesons vs Cancer' gives an account of this work and formed the basis of his Royal Society Rutherford Memorial Lecture delivered in New Zealand in 1971. As a consultant for Rolls Royce between 1987 and 1993 Fowler devised a method to measure the temperature of the turbine blades of running engines using epithermal neutrons non-invasively. Following the Lockerbie aircraft bombing in 1988 he helped develop a method of screening for explosives in passengers' luggage in airports using thermal neutrons. Fowler continued research after retirement until his death. He served as a director of a private company called Track Analysis Systems Ltd that developed and supplied neutron dosimeters, TASTRAK plastic and radon detectors to local authorities, laboratories and householders.

Meteorology was one of Fowler's life long interests and he served as a member of the Meteorological Committee of the Meteorological Office (1983-1993). He was also chairman of the MRC/NRPB Committee on Radiological Protection from 1983 to 1992, Vice-President of the Royal Astronomical Society 1984, a member of the SERC Neutron Facilities Review Panel and Trustee of the Nehru Memorial Trust 1985-1996. Other commitments included service as a governor of King's School in Bruton, Somerset from 1982 and Chairman of the Herschel House Trust in Bath from 1988, both until his death.

Fowler had three daughters with his wife Rosemary. He died in Bristol on 8 November 1996.

From the guide to the Papers and correspondence of Peter Howard Fowler, physicist (1923-1996), 1940-2002, (University of Bristol Special Collections, Arts & Social Sciences Library)