Piet Cornells Gugelot

Piet Cornelis Gugelot, professor emeritus at the University of Virginia, died in Charlottesville on 2 February 2005 of heart failure. Kees, as he was known to his family, friends, and colleagues, led a distinguished career that began at ETH Zürich and took him to Princeton, New Jersey; Amsterdam; Newport News, Virginia; and ultimately Charlottesville.

Born in Bussum, Holland, on 24 February 1918, Kees grew up in the Netherlands and in Indonesia, where his father was posted as a government physician for two years. In the 1930s he moved with his family to Davos, Switzerland, where his father was the director of the Dutch Tuberculosis Sanatorium and Dutch consul to Switzerland. Kees obtained his secondary education in Davos.

In 1940 Kees received his physics diploma from ETH under Paul Scherrer, a leading and influential professor at the institution, and became a nuclear physicist and the professor’s assistant. Inspired by his mentor’s leadership, Kees learned an immense amount of physics and many techniques from Scherrer and the talented young researchers in his group.

Scherrer encouraged him to be on the lookout for new fields of endeavor. Kees followed that approach, and frequently carried out exploratory experiments during his career.

While at ETH, Kees, along with four other physicists, was responsible for the construction of the institution’s cyclotron, which produced its first internal beam in 1943; the beam was extracted two years later. In 1945 Kees received his PhD for his work, done under Scherrer’s supervision, on the nuclear activation and spectroscopy of short-lived isotopes.

After two years as a research associate at ETH, Kees left in 1947 for Princeton University, where he worked until 1956, first as a research associate and then as an assistant professor. He spent a productive period in the fast-developing field of nuclear reactions induced by proton, neutron, and alpha-particle beams. He was among a team of physicists who reconstructed the prewar Princeton cyclotron and turned it into a powerful research tool. He also built the 60-inch scattering chamber, which allowed researchers to use the cyclotron’s enhanced capabilities to conduct new experiments in nuclear physics. Kees became a leader in research on the evaporation of particles from the compound nucleus, and his pioneering papers from that era are citation classics.

During 1955–56, Kees was a visiting professor at the University of Washington, Seattle. He then returned to the Netherlands to accept an appointment as director of the Instituut voor Kernfysisch Onderzoek (Institute for Nuclear Physics Research, or IKO, now known as the National Institute for Nuclear Physics and High Energy Physics) in Amsterdam. His tenure there was marked by his persistent promotion of research in nuclear reactions. With Haruhiko Morinaga, he began a program of (α, xn) reactions on medium-weight nuclei, thus introducing high-angular-momentum states to study rotational bands. This area of nuclear structure research was later perfected by Richard Diamond and Frank Stephens of Lawrence Berkeley National Laboratory. Kees also stressed the need for an electron accelerator at IKO because the existing synchrocyclotron’s capabilities were limited. He and a few of his students spent time at Stanford University with Robert Hofstadter measuring nuclear form factors. Kees’s advocacy of the accelerator was realized in the construction at IKO, in 1979, of the 700-MeV linear accelerator, nicknamed MEA for medium-energy accelerator.

Kees left the Netherlands in 1966 to take on the scientific directorship of the Space Radiation Effects Laboratory in Newport News. Concurrently, he joined the University of Virginia as a professor of physics. Following the end of his appointment at SREL in 1969, Kees moved to Charlottesville to resume teaching and research in nuclear physics. After he retired in 1990, he maintained a keen interest in contemporary nuclear and particle physics.

Kees was a lively and approachable physicist. His congeniality, experimental ingenuity, and breadth of knowledge in nuclear and particle physics made him a welcome visitor at many laboratories, including Oak Ridge National Laboratory, Los Alamos National Laboratory, CERN, the University of Tokyo, and the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. His association with Heidelberg was sponsored by the Alexander von Humboldt Foundation through a Senior Scientist Award, which was granted to Kees in 1982 and renewed in 1987.

An exceptionally engaging person, Kees had numerous friends, including renowned physicists Hendrik Casimir, Hofstadter, Leon van Hove, Bernd Matthias, and Valentine Telegdi. With friends and colleagues, he shared his hobbies—mountain climbing, skiing, orchid growing, and photography. He filmed citizens of Papua New Guinea in war dress shooting poisoned arrows and made a movie showing orchids blooming.

Kees was an endearing friend, and his presence in any surrounding was stimulating. He is missed by his many friends scattered throughout the world.