Hermann A. Grunder obituary: died at age 94,Development of the Bevalac; founding directorship of Jefferson Lab; adoption of superconducting radio-frequency technology at CEBAF

Hermann A.

Grunder, a Swiss–American accelerator and nuclear physicist and scientific administrator known for his work on the Bevalac and CEBAF, died October 23, 2026, aged 94. Born in Basel, Switzerland, on December 4, 1931, he studied at the University of Basel before moving to California in 1959 with his first wife and their three children.

Grunder became the founding director of the Thomas Jefferson National Accelerator Facility, known as Jefferson Lab, in Newport News, Virginia, serving from 1985 to 2000. He later directed Argonne National Laboratory from 2000 to 2005. At Jefferson Lab, he was closely associated with the choice to build the Continuous Electron Beam Accelerator Facility, or CEBAF, as a recirculating electron accelerator using superconducting radio-frequency technology. The alternative under consideration was a room-temperature accelerator paired with a pulse-stretching ring. The selected design enabled high-duty-factor electron beams for nuclear-physics research and became a defining feature of the facility. His work also included development of the Bevalac, an accelerator associated with his career in nuclear physics. Grunder was a Fellow of the American Physical Society. His professional interests included accelerator science and administration, and he authored works on accelerator physics and the status and scientific prospects of CEBAF in 1989.