The historical development of cryogenically cooled monochromators for third-generation synchrotron radiation sources

In the period of the late-1980s, before the construction of multi-GeV third -generation storage rings with their intense insertion-device sources, the perceived number one problem for X-ray instrumentation was proper cooling o f the first optical element in the beamline. This article, first given as a n acceptance speech for the Compton Award ceremony at the Advanced Photon S ource, presents a somewhat historical and anecdotal overview of how cryogen ically cooled monochromator optics have been developed to provide a monochr omator cooling solution adequate for today's power levels. A series of work shops and international collaborations were the key components for the prog ress and final success of this development.