Solar neutrinos

Interview with Peter Donald MacDougall Parker, Professor Emeritus of Physics at Yale. Parker recounts his childhood growing up in New York City and Massachusetts, attending Amherst College, the excitement of being a graduate student at Caltech in the 1960s working on nuclear physics and nuclear astrophysics, his postgraduate position at Brookhaven National Laboratory, and his move to Wright Nuclear Structure Laboratory at Yale University in 1966. Parker recalls over five decades of research, teaching, and service work that includes: experimental nuclear physics and astrophysics work using tandem accelerators, solar neutrino flux, and dark matter search; teaching every single physics course offered at Yale and developing a new course; committee work; the gradual changes in gender demographics in the physics department at Yale. Also prominently mentioned are Willy Fowler, Richard Kavanaugh, Thomas Tombrello, John Bahcall, Ray Davis Jr., Allan Bromley, and his twin brother Robert Parker.

In this interview, Art McDonald discusses: careerlong work around tests of the Standard Model; Sudbury Neutrino Observatory (SNO) measurement of neutrino properties that fall outside the original Standard Model; childhood and family history in Canada; master’s work on positron annihilation; time at the Kellogg Laboratory at Caltech with William Fowler; early origins of and motivations behind the SNO project; postdoc at Chalk River Nuclear Laboratory using a particle accelerator to continue experimental work on fundamental symmetries; history of Chalk River; collaborations with George Ewan; collaborations with Hamish Robertson studying the measurement and production of lithium-6; work at Princeton with Will Happer using lasers to polarize nuclei; building a continuous laser beam at Chalk River; work on parity violation in nuclei; work on the Princeton cyclotron; overseeing Kevin Coulter’s thesis project, the first use of laser-induced-spin-polarization of helium; polarized Helium-3’s current uses; technical challenges of building SNO and the transition from construction to operations; SNO and the solar neutrino problem; Herb Chen’s involvement with the design of SNO; SNOLAB; decision take position at Queen’s University; early published findings from SNO; comparison of Super-Kamiokande and SNO experiments; impact of SNO results on the understanding of the Standard Model; winning the Nobel Prize for solving the solar neutrino problem, observing that solar electron neutrinos were oscillating into muon and tau neutrinos; current work with the DarkSide-20k collaboration and how that work led to an open-source ventilator project in the midst of the COVID-19 pandemic; current SNOLAB DEAP experiment using liquid argon to attempt to detect dark matter particles. Toward the end of the interview, McDonald reflects on interrelatedness across disciplines within physics, and his ongoing curiosity in searches for dark matter and neutrino-less double beta decay. 

Interview with Wick Haxton, professor of physics at UC Berkeley. Haxton recounts his childhood in Santa Cruz and his early interests in math and science. He describes his undergraduate education at the newly created UC Santa Cruz where his initial interest was in mathematics before he was given the advice that he did “mathematics like a physicist.” Haxton discusses his graduate work at Stanford where his original intent was to study general relativity before he connected with Dirk Walecka and Bill Donnelly to focus on nuclear theory and dense nuclear matter. He discusses his postdoctoral research at the University of Mainz where he concentrated on photo-pion physics during the early days of chiral perturbation theory, and he explains the opportunities that led to his next appointment at the LAMPF facility at Los Alamos. Haxton emphasizes the excellence of both his colleagues and the computational capacity at the Lab, and he describes his faculty appointment at Purdue and the solar neutrino experiment he contributed to in Colorado. He explains the opportunities that led to him joining the faculty at the University of Washington where the DOE was about to fund the Institute for Nuclear Theory. Haxton explains the “breakup” between nuclear theory and particle theory and how the INT addressed that. Haxton discusses the opportunities afforded at the INT to engage in nuclear astrophysics and he explains the rise and fall of the Homestake DUSEL project. He explains his decision to go emeritus at UW and to join the faculty at UC Berkeley and to be dual hatted at the Berkeley Lab, and he describes his tenure as department chair. At the end of the interview, Haxton describes his current work organizing the new Physics Frontier Center and the challenges presented by the pandemic, and he credits his formative time as Los Alamos for the diverse research agenda he has pursued throughout his career.

In this interview, David Zierler, Oral Historian for AIP, interviews Arthur Poskanzer, distinguished senior scientist emeritus at Lawrence Berkeley National Laboratory. Poskanzer recounts his childhood in Manhattan and his experience at Stuyvesant High School where he focused on chemistry. He discusses his undergraduate studies at Harvard and his decision to study at MIT under Charles Coryell in radio chemistry. Poskanzer describes his postgraduate research at Brookhaven where he studied high-energy protons on uranium, and he explains his decision to transfer to Berkeley Lab to work with Earl Hyde on the Bevatron. He explains how he discovered the collective flow of nuclear matter and he describes the origins of the Plastic Ball experimental group. Poskanzer discusses the contributions of the STAR collaboration and the discovery of elliptic flow and the existence of quark gluon plasma. He compares the experiences that led to his discovery of 28 isotopes and why he enjoyed discovering Helium-8 the most. Poskanzer explains the connection between his study of isotope decay and the value this had for solar neutrino experiments, and he explains why 28 was the “magic number” for neutron excess sodium isotopes. At the end of the interview, he describes how Berkeley Lab has changed over the years, and in reflecting on all the discovery he was a part of, Poskanzer emphasizes that successful scientists have an intuition that allows them to pick projects primed for success.

In this interview, David Zierler, Oral Historian for AIP, interviews David Spergel, Director of the Center for Computational Astrophysics at the Flatiron Institute, and Charles Young Professor of Astronomy on the Class of 1897 Foundation, Emeritus, at Princeton. Spergel describes his transition to the Flatiron Institute and he shares that he will become the president of the Simons Foundation in summer of 2021. He explains his initial connection to Jim Simons and how the Institute differs from a traditional academic environment. Spergel describes New York City as a burgeoning center for machine learning both in academic and industrial research and he conveys his long term interest in determining the future value of machine learning to multiscale physics. He recounts his childhood on Long Island and what it was like to have a physicist for a father, and he explains his undergraduate experience in the physics program at Princeton, where Jim Peebles was a formative influence. Spergel describes his graduate work at Harvard where he worked with Bill Press on the solar neutrino problem and James Binney on orbital dynamics, and where he learned about superconducting cosmic strings. He discusses his postdoctoral appointment at the Institute for Advanced Study, where he became interested in galactic orbits and where he realized the value of the data coming out of COBE. Spergel describes his subsequent appointment to the faculty at Princeton and the promise of string theory at this time. He describes the notion of a multiverse as a non-scientific tautology and he explains why his favorite paper is Wigner’s take on the “unreasonable effectiveness of mathematics.” Spergel describes the origins of WMAP, the turning point this collaboration offered his career trajectory, and how the project allowed for pathbreaking avenues to measure the properties of the universe. He surveys the various ways that inflation, expansion, and acceleration of the universe fit with WMAP, and he explains how this collaboration is driving the next generation of experiments, and in particular, the impact in advances in detector technology. Spergel describes his involvement in the Roman Space Telescope Project and the budgeting challenges it has experienced during the Trump administration. He discusses his advocacy work in Congress on behalf of NASA. Spergel surveys his career as a teacher and a graduate mentor, and he describes how the culture of inclusivity at Princeton has improved over the years. At the end of the interview, Spergel shares his plans for the future of the Simons Foundation, he explains how he will attempt to remain close to the science, how he will use his new position to continue to promote diversity in STEM and to support cutting-edge research across a broad array of scientific endeavors.