21. The treatment head of a linear accelerator consists of both a primary and secondary collimator. 22. The first medical linear accelerator was used at the Hammersmith Hospital in London in 1953. 23. Stanford Linear Accelerator Center : http : / / www . slac . stanford . edu 24. In 1964, Johnston moved to the Stanford Linear Accelerator Center as head of the Electronics Department. 25. The down quark was first observed by experiments at the Stanford Linear Accelerator Center in 1968. 26. Modern plutonium bombs use a minuture linear accelerator and target material for the initial neutron burst. 27. The accelerator has been in use since 1975 and its acronym stands for universal linear accelerator . 28. He is a former director of the Stanford Linear Accelerator Center ( 1999 2007; SLAC ). 29. One is a $ 4 . 5 billion linear accelerator , which makes tritium with high-energy beams. 30. The up quark was first observed by experiments at the Stanford Linear Accelerator Center in 1968.
