physicist university professor nuclear scientist
Born Heinrich Hermann Barschall in Berlin, Germany, he was raised in a scholarly family; his father was a patent attorney who earned a Doctor of Philosophy in chemistry studying under Nobel Laureates Emil Fischer and Fritz Haber. Barschall’s early life in Germany was marked by rigorous academic influence and the growing turmoil preceding World War II.
Barschall pursued his education initially at several German universities before emigrating to the United States in 1937 amid the early Holocaust period. He completed his Doctor of Philosophy at Princeton University in 1940 under the supervision of Rudolf Ladenburg. During his graduate studies, he collaborated closely with John A. Wheeler. His doctoral thesis focused on the interaction of fast neutrons with helium.
Shortly after arriving in the United States, and encouraged by physicist Niels Bohr, Barschall, together with fellow graduate student Morton H. Kanner, conducted the first rapid demonstration of fission induced by fast neutrons in thorium and uranium, a groundbreaking achievement in nuclear physics.
Barschall and John A. Wheeler discovered spin-orbit coupling in neutron scattering, a fundamental insight into neutron interactions. He held a position at the University of Kansas before joining the Manhattan Project in Los Alamos, where he continued research on fast neutrons.
In 1946, he joined the University of Wisconsin–Madison, where he led research programs on fast neutron cross-sections and supervised the doctoral dissertations of over forty students. Frustrated with the political and scientific environment in nuclear physics, he left for two years to work at Lawrence Livermore Laboratories, focusing on developing intense high-energy neutron sources for material testing and medical purposes.
Returning to Wisconsin with joint appointments in Nuclear Engineering, Physics, and later Medical Physics, Barschall dedicated much of his later career to the medical applications of neutrons, particularly in cancer therapy. He retired in 1986, leaving a legacy of significant scientific and academic contributions.
Co-discovered spin-orbit coupling in neutron scattering.
Conducted the first demonstration of fission by fast neutrons on thorium and uranium.
Led influential research programs on neutron interactions and applications.
Elected Fellow of the American Academy of Arts and Sciences in 1987.
Doctoral advisor to notable physicists including Charles K. Bockelman.
National Academy of Sciences
American Academy of Arts and Sciences
Barschall was known for his dedication to scientific rigor and mentorship, guiding a generation of nuclear physicists. His commitment extended beyond pure research to applied medical physics, demonstrating a broad vision for science benefiting society.
