Nuclear shell theory

Interview with Timothy James Symons, Senior Scientist at Lawrence Berkeley National Laboratory and recently retired as Associate Laboratory Director for Physical Sciences, for which he ran the Lab’s programs in high energy and nuclear physics. Symons explains how the Lab has responded to the pandemic and the wide range of physics research he is following at Berkeley and beyond. He recounts his childhood in England and his early interests in science and the opportunities that led to his undergraduate education at Oxford where a tutor focused his interests in nuclear physics. Symons explains his reasons for remaining at Oxford for graduate school and the relevance of the SU(3) shell model for his thesis. He describes his postdoctoral work at the UK Science Research Council, and the opportunities that initially led him to Berkeley to work with David Scott on low energy nuclear structure. Symons provides a history of the Bevatron and the many reasons that compelled him to take a staff position. He describes the challenges in replacing the Bevelac, and the import of the ISABELLE cancellation at Brookhaven on Berkeley’s decisions. He provides detail on the interplay between laboratory experiments and DOE policy decisions and he explains the significant administrative pull of his work for NSAC. Symons reviews broadly the state of U.S. nuclear physics in the 1990s and the value of the APS as a sounding board in shaping policies for the decade. He does the same for rare isotopes in the early 2000s and how the Lab became involved in DUSEL. Symons describes his world as Associate Lab Director and he discusses his interactions with the Lab Director which gave him a high-altitude appreciate for the broad range of research across the Lab. He explains the Lab’s contributions in energy research which stems from Steve Chu’s directorship. At the end of the interview, Symons reflects on the significant changes in the Lab’s scope and mission over his career, the overall trend that once-disparate research areas are now increasingly on a path of convergence, and he conveys optimism on the fundamental discoveries that are within reach for the near future of nuclear physics.

Arrival in the U.S. in 1930; comparison of social, scientific, general intellectual climates in U.S and Europe; early interest in nuclear physics, relationship with graduate students; beta decay, compound nucleus model, Breit-Wigner formula, early shell model; review articles by Bethe; relation of early meson theory to nuclear physics; nuclear forces; charge independence; journal literature of physics ca. 1937; effectiveness of group-theoretic models in nuclear physics; effectiveness of quantum mechanics for nuclear physics; significant early experimental discoveries in nuclear physics: neutron, deutron, artificial radioactivity; fission, shell model of Mayer and Jensen; rotational levels in nuclei; the specialization of physics; effect of World War II on nuclear physics research; work at Chicago; conferences after the war; branching off of high-energy physics from nuclear physics; work personally regarded as interesting.

Natural radioactivity; ideas of nuclear constitution, size in 1920s; Gamow-Condon-Gurney theory of alpha decay 1928; discovery of neutron 1932; Cambridge as a center of research 1933; early theories of nuclear forces; analysis of short-range nuclear forces 1935-40; reasons for writing Rev. Mod. Phys. review articles 1935-37 and detailed review of articles' contents; beta decay and the neutrino hypothesis; application of group-theoretic methods to nuclear physics 1936-37; compound nucleus model 1936; nuclear models in general (compound nucleus, evaporation, liquid drop, direct interaction, statistical); contemporary knowledge of nuclear physics 1938-39; stellar energy production; energy limit on cyclotron; accelerators and theoreticians; nuclear physics at Los Alamos; post-war conferences; origins and development of the shell model of the nucleus; many-body theory in nuclear physics; current algebras in particle physics; origins and development of the optical model; of the collective model; autobiographical comments on political, social, scientific conditions in Germany and England in early 1930s ; nuclear studies at Cornell after the war; building the H-bomb; the Oppenheimer hearings; work as a consultant 1950-1970; involvement with PSAC 1956; views on disarmament; receipt of 1967 Nobel Prize.

Natural radioactivity; ideas of nuclear constitution, size in 1920s; Gamow-Condon-Gurney theory of alpha decay 1928; discovery of neutron 1932; Cambridge as a center of research 1933; early theories of nuclear forces; analysis of short-range nuclear forces 1935-40; reasons for writing Rev. Mod. Phys. review articles 1935-37 and detailed review of articles' contents; beta decay and the neutrino hypothesis; application of group-theoretic methods to nuclear physics 1936-37; compound nucleus model 1936; nuclear models in general (compound nucleus, evaporation, liquid drop, direct interaction, statistical); contemporary knowledge of nuclear physics 1938-39; stellar energy production; energy limit on cyclotron; accelerators and theoreticians; nuclear physics at Los Alamos; post-war conferences; origins and development of the shell model of the nucleus; many-body theory in nuclear physics; current algebras in particle physics; origins and development of the optical model; of the collective model; autobiographical comments on political, social, scientific conditions in Germany and England in early 1930s ; nuclear studies at Cornell after the war; building the H-bomb; the Oppenheimer hearings; work as a consultant 1950-1970; involvement with PSAC 1956; views on disarmament; receipt of 1967 Nobel Prize.

Natural radioactivity; ideas of nuclear constitution, size in 1920s; Gamow-Condon-Gurney theory of alpha decay 1928; discovery of neutron 1932; Cambridge as a center of research 1933; early theories of nuclear forces; analysis of short-range nuclear forces 1935-40; reasons for writing Rev. Mod. Phys. review articles 1935-37 and detailed review of articles' contents; beta decay and the neutrino hypothesis; application of group-theoretic methods to nuclear physics 1936-37; compound nucleus model 1936; nuclear models in general (compound nucleus, evaporation, liquid drop, direct interaction, statistical); contemporary knowledge of nuclear physics 1938-39; stellar energy production; energy limit on cyclotron; accelerators and theoreticians; nuclear physics at Los Alamos; post-war conferences; origins and development of the shell model of the nucleus; many-body theory in nuclear physics; current algebras in particle physics; origins and development of the optical model; of the collective model; autobiographical comments on political, social, scientific conditions in Germany and England in early 1930s ; nuclear studies at Cornell after the war; building the H-bomb; the Oppenheimer hearings; work as a consultant 1950-1970; involvement with PSAC 1956; views on disarmament; receipt of 1967 Nobel Prize.