From 1971 to 1972, he worked at CERN in the Split Field Magnet Group at
ISR. In 1972, he returned to SLAC, joining the SLAC-LBL Magnetic Detector effort at SPEAR that in 1974 discovered the J/ψ and ψ'. At SLAC he also became involved in
Burton Richter's experiments on the SPEAR storage ring, and new
charmonium states. Starting in 1980 Breidenbach was involved in the construction of the
Stanford Linear Collider (SLC) control system and design of the
SLD detector. In 1989 he became a professor at SLAC. He was also involved in the
Next Linear Collider project of SLAC, an effort replaced by participation in the
International Linear Collider . == Awards, honors ==