Bill McGowan 1969 to 1972J. William McGowan [1969-84]] (St.-Francis Xavier, BSc, 1953; Carnegie-Mellon, MSc, 1958; Laval, PhD, 1961) came to Western from General Atomic in San Diego, where he had been for most of the time since his graduation from Laval. Bill introduced the Department to a new style of research with the construction of the MEIBE (Merged Electron and Ion Beam Experiment) laboratory, which permitted the measurement of scattering cross sections at very low rest-frame energies. With its van de Graaff accelerator and large amounts of ultra-high-vacuum equipment, it was laboratory physics on a new scale for the Department. Dr. McGowan also attempted to change the Department in other ways, and the few years of his chairmanship were quite turbulent. He resigned as Chair in 1972, but remained with the Department until 1984 when he accepted the position of Director of the National Museum of Science and Technology in Ottawa.
During this period the Department hired a number of new faculty, laying the foundation for the present atomic and molecular physics group; this included T. Dean Gaily [1970-present] (Washington, PhD, 1968), S. David Rosner [1971-present] (Princeton, PhD, 1968), and, a bit later, Richard A. Holt [1976-present] (Princeton, PhD, 1973). It was an unusual period, as the Department was continuing to grow at the same time as funding and graduate student numbers were starting to decrease. It was the beginning of a period of relative stagnation. Following Bill McGowan's resignation, Gordon Lyon [1962-87] (Saskatchewan, BSc, 1956, PhD, 1961) served as Acting Chairman for 1972-73. In 1973, at the end of a period of almost 30 years of continuous growth, the Department had 27 faculty members, the largest at any time in its history. The faculty included, in addition to those already mentioned elsewhere in this history, the following long-term members of the Department: Yen Fu Bow [1966-1986] (Michigan, PhD, 1964), William R. Jarmain [1960-1977] (Western, BA, 1941, MSc, 1946), Robert P. Lowe [1968-present] (Western, BSc, 1957, PhD, 1967), John Nuttall [1972-1992] (Cambridge, PhD, 1961), and James (Jake) K.E. Tunaley [1971-1996] (Sheffield, PhD, 1967).