1 The National Synchrotron Light Source, Part I: Bright Idea Robert P. Crease* The National Synchrotron Light Source (NSLS) was the first facility designed and built specifi- cally for producing and exploiting synchrotron radiation. It was also the first facility to incorpo- rate the Chasman-Green lattice for maximizing brightness. The NSLS was a $24-million project conceived about 1970. It was officially proposed in 1976, and its groundbreaking took place in 1978. Its construction was a key episode in Brookhaven’s history, in the transition of synchrotron radi- ation from a novelty to a commodity, and in the transition of synchrotron-radiation scientists from parasitic to autonomous researchers. The way the machine was conceived, designed, promoted, and constructed illustrates much both about the tensions and tradeoffs faced by large scientific projects in the age of big science. In this article, the first of two parts, I cover the conception, design, and planning of the NSLS up to its groundbreaking. Part II, covering its construction, will appear in the next issue. Key words: Kenneth Green; Renata Chasman; Martin Blume; Sam Krinsky; Arie van Steenbergen; Richard Watson; Brookhaven National Laboratory; National Synchro- tron Light Source; synchrotron radiation; Chasman-Green lattice; accelerators. Introduction In 1972, an interdisciplinary coalition of scientists at Brookhaven National Laboratory (BNL) on Long Island, New York, began planning a synchrotron-radiation facility, eventually to be called the National Synchrotron Light Source (NSLS). The NSLS was the first facility designed and built specifically for producing and exploiting synchro- tron radiation, and its principal design feature, invented at Brookhaven, would be incorporated into successive generations of synchrotron-radiation facilities. Although in many respects the NSLS, as a materials-science facility, complemented research at Brookhaven’s High Flux Beam Reactor (HFBR), it would significantly transform the lab’s research culture in unanticipated ways. These ways included strengthening the lab’s solid-state physics and materials-science programs, fostering interdisciplinary research, and creating new kinds of interactions among laboratory, university, and industrial researchers. 1 A $24-million project conceived about 1970, officially proposed in 1976, and breaking ground in 1978, the NSLS was a major episode in Brookhaven’s history. It was a key element, too, in the story of the transition of synchrotron radiation Phys. perspect. 9 (2007) 1–30 1422-6944/07/040xxx–30 DOI 10.1007/s00016-007-0357-? * Robert P. Crease is a Professor in the Department of Philosophy of Stony Brook University in Stony Brook, New York, and historian at Brookhaven National Laboratory. 357_crease_I 22.7.2007 13:58 Uhr Seite 1