The excellent obituary for Burton Richter by Roy Schwitters (Physics Today, August 2019, page 64) does not cover the support, starting in the late 1960s, that Burt gave the Stanford Synchrotron Radiation Project (SSRP) to use synchrotron radiation from the colliding beam storage ring of SPEAR, SLAC’s first electron–positron collider. Nor does it mention his support, starting in the early 1990s, for the Linac Coherent Light Source to use the SLAC linac to drive an x-ray free-electron laser. His advocacy for those projects has enabled SLAC to transform from a high-energy physics lab into a photon science lab. Without his contributions, it is doubtful that SLAC would be in existence today.
Perhaps the first and most critical decision Burt made was to install, as part of the original construction of SPEAR in 1972, a special vacuum chamber with a tangential spout that allowed a small swath of synchrotron radiation, from less than one degree of curved path in a modified bending magnet, to exit the ring.
The chamber made it possible to start synchrotron radiation experiments without having to modify a SPEAR magnet and vacuum chamber. It is hard to imagine that those modifications would have been made after the exciting colliding-beam results that were obtained at the start of SPEAR’s operation, because they would have required that the ring be shut down and vented. The decision to design, construct, and install the chamber could not have been easy for Burt; SPEAR was significantly underfunded, and financing to cover the additional cost of the modifications to the vacuum system would have been hard to find.
