Shen made seminal contributions to our understanding of spallation processes involving cosmic rays and the science of spacecraft shielding.
Benjamin Shih-Ping Shen, a pioneer in the use of particle accelerators for astrophysical research, passed away at his home in Philadelphia, Pennsylvania, on April 10, 2022 at the age of 90.
Shen was born in 1931 in Hangzhou, China. He graduated from a French lycée in Shanghai and studied engineering briefly at the National Taiwan University. In 1954 he graduated with a degree in mathematics from Assumption College (now University) in Worcester, Massachusetts, where most of his courses were taught in French. In 1956 he received a master’s degree in physics from Clark University based on experimental research on the absorption of cosmic rays. While an Assistant Professor at St. Johns University in Jamaica, New York he pursued his Ph.D. research at Brookhaven National Laboratory under the direction of Pierre Auger; this was the first large scale use of a high-energy accelerator for astrophysics research. In 1956 he received the doctorat d’Etat from the University of Paris (thesis title “Contribution a l'étude expérimentale du passage des protons de 1 et 3 GeV dans des milieux condenses”).
After a short period at New York University, in 1966 Shen became the first astrophysicist to be hired by the Department of Astronomy (which later merged with the Department of Physics) at the University of Pennsylvania. He was promoted to Full Professor in 1968 and became the Reese W. Flower Professor of Astronomy and Astrophysics in 1972. Shen served as the Chair of the Department of Astronomy and Astrophysics and Director of the Flower and Cook Observatory from 1973 to 1979. Perhaps his most consequential act as Chair was to hire future Nobel Laureate Raymond Davis, whom he had known from the period of his thesis work at Brookhaven, as an Adjunct Professor at Penn. Davis later joined Penn as a full time faculty member.
In 1980–1981 Shen served as Acting Provost at Penn. In this capacity he oversaw a restructuring of Penn’s graduate education and convened the Task Force on the Quality of Teaching, which led to the creation of new teaching awards across Penn’s schools. Shen retired from Penn in 1996, and served as the second president of the Penn Association of Senior and Emeritus Faculty.
Shen’s scientific work centered around the cascade of nuclear interactions triggered by cosmic rays. He was the first to show, in 1961, that the breakup, or “spallation,” of interstellar nuclei by cosmic rays could be the long-sought origin of certain rare chemical elements in the universe. His experiments on nuclear shielding significantly influenced the science of shielding against cosmic radiation in the early days of the space age, and his 1963 monograph on the subject became a key resource for spacecraft shielding design in the 1960’s. He edited and contributed to two books on nuclear astrophysics: “High-Energy Nuclear Reactions in Astrophysics” (1967; ) and “Spallation Nuclear Reactions and Their Applications” (1976; ).
In addition to his work at Penn, Shen engaged actively with the broader scientific community. In 1972, he was appointed the head of a New York Academy of Sciences committee to improve scientific communication to the general public, and in the same year, he was named a fellow of the American Physical Society. As part of this effort, in a 1975 essay he introduced the concept of “civic science literacy,” the basic scientific knowledge needed by the general public and policymakers in an increasingly technological society.
In 1990, Shen was appointed to the National Science Board, where he was a strong advocate for basic science funding and where he chaired a task force on scientific literacy. He was an advisor to the Children’s Television Workshop (now Sesame Workshop) on its science programs, including the award-winning series “3-2-1 Contact.” He became an advisor on science and technology to the Senate Budget Committee (1976–1977) and to the Congressional Office of Technological Assessment (1977–1978). In 1978, he was awarded the Vermeil Medal of the Société d’Encouragement au Progrès. In the late 1970s, he chaired a nationwide panel of the American Association for the Advancement of Science, and in 1996, he was named a fellow of the AAAS. In 1993, he was named a Chevalier of the Ordre des Palmes Académiques in France.
Benjamin Shih-Ping Shen was well-liked and appreciated for his gentle and gracious manner. His scientific legacy continues to influence the astrophysics community in profound ways. He is survived by his wife, Lucia Shen, son William Shen, daughter Juliet Shen (Shane Watters) and granddaughter Josephine Watters.