Chapter 7 The 2000s: A New Millennium

After the turn of the century, dramatic changes occurred in experimental and theoretical shock wave research at Sandia. In the 1950s and 1960s, computational capabilities to design and interpret shock wave experiments were extremely limited. Use of slide rules and small desktop calculators was common. In the 1950s instruments to measure the fine details of shock compression and dynamic material response were limited. In those early decades, the innovation and intuition of experimentalists and modelers were critical in advancing shock wave research in spite of these constraints. By the late 1960s, dynamic phenomenological models to describe the shock compression of complex materials such as composites and porous materials were beginning to be established. The pioneering loading and diagnostic technology developed in the 1960s was instrumental in advancing knowledge in the later decades. This was especially true for high-pressure applications until the mid-1970s, when time-resolved gauges became available for routine use at Sandia. Bob Graham and his team concentrated on developing the piezoelectric gauge, which is also known as the quartz gauge (Graham 1961a, b; Graham 1975; Neilson and Benedick 1960; Neilson et al. 1962; Graham and Ingram 1968; Graham and Reed 1978). Meanwhile, Lynn Barker and his team concentrated on developing optical interferometric gauges and, in particular, the velocity interferometer system for any reflector (or VISAR), which grew out of a wide-angle version of the Michelson interferometer (Barker and Hollenbach 1965, 1972; Barker 1968, 2000a). This allowed considerable progress in understanding dynamic compression processes. Among early researchers, there was an excitement in developing pioneering new capabilities and solving complex dynamic material problems using the new gauges.