Jackson held academic appointments successively at
McGill University, thanks to
Philip Russell Wallace, a prominent Canadian theoretical physicist, (January 1950 – 1957); then the
University of Illinois at Urbana–Champaign (1957–1967); and finally the
University of California, Berkeley (1967–1995). At McGill, he was Assistant and Associate Professor of Mathematics; at Illinois and Berkeley, he was in the Physics Departments. At the latter, he held appointments on campus and at the
Lawrence Berkeley National Laboratory. After retiring from teaching in 1993, he continued to be active at LBNL. He also published an early paper on the theoretical foundation for the then recently discovered
muon-catalyzed fusion of hydrogen isotopes.
Illinois (1957–1967) and CERN (1963–64) While at the University of Illinois (1957–1967) Jackson initially continued work on weak interactions as well as
strange particle interactions at low energy with Wyld and others. On sabbatical leave at
CERN in 1963–64, he collaborated with
Kurt Gottfried on production and decay of unstable resonances in high-energy hadronic collisions. They introduced the use of the
density matrix to connect production mechanisms to the decay patterns and described the influence of competing processes ("absorption") on the reactions. During this period Jackson lectured at three summer schools—on dispersion relations at the first Scottish Universities Summer School in Physics, 1960; on weak interactions at the Brandeis Summer Institute, 1962; and on particle and polarization decay distributions at the Summer School of
Theoretical Physics,
Les Houches, 1965. the second, a small book on mathematics for quantum mechanics (1962) and the third, also in 1962, the first edition of his text on classical electrodynamics. The book is notorious for the difficulty of its problems, and its tendency to treat non-obvious conclusions as self-evident. Jackson's high standards and admonitory vocabulary are the subject of an amusing memorial volume by his son Ian Jackson.
Berkeley Moving to Berkeley in 1967, Jackson taught on campus, both introductory courses for physicists and engineers and graduate courses in particle physics and quantum mechanics. His lecture notes from the latter have been made into book. He did his research at LBNL and served in administrative positions at both the campus (Chair, University of California, Berkeley (UCB) Physics Department, 1978–1981) and the lab (Head, LBNL Physics Division, January 1982 – June 1984). In the formative years of the ill-fated
Superconducting Super Collider (SSC) project, he served as deputy director of operations of the SSC Central Design Group. In 1973–74 he ran the nascent theory group at
Fermilab and co-edited the proceedings of the 1973 "Rochester" Conference. ==Retirement years==