Scorpius: The development of a new multi-pulse radiographic system

One of the original drivers behind the development of pulsed power was the need for short-pulse (flash) x-ray sources for hydrodynamic tests. These systems continue to be an important diagnostic for the evaluation of hydrodynamic phenomena. In the United States, three primary facilities provide this function: Flash X-Ray (FXR) at Lawrence Livermore National Laboratory (LLNL); the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility at Los Alamos National Laboratory (LANL); and Cygnus at the Nevada National Security Site (NNSS). FXR and DARHT provide highly penetrating radiographic capabilities but are limited in the types of hydrodynamic experiments that can be performed, while Cygnus can support a larger range of experiments, but does not provide the same penetrating capability. To fill this gap in hydrodynamic experimental capability, the National Nuclear Security Agency (NNSA) has recently issued a set of high-level requirements describing a radiographic capability similar to that of DARHT, but located in a facility similar to Cygnus. In response to these requirements, a project called Scorpius has been developed as a joint partnership between LANL, LLNL, Sandia National Laboratory (SnL), and the NNSS. A key requirement is the delivery of multiple (2 or more) radiographic images along a single axis in a short time scale. This requirement effectively limits the possible system choices to a linear induction accelerator (LIA). However, there are several families of multi-pulse LIA architectures from which to choose. This paper describes the high-level system requirements for Scorpius as well as the evaluation of technologies and systems that might meet those requirements. In addition, the current preferred option and the initial conceptual designs are discussed.

I. Capability Gap and Requirements

Radiographic systems for hydrodynamic experiments require short pulses of high intensity radiation emanating from a small point [1]. In the US, there are two primary facilities with this capability: the FXR facility [2] at LLNL and the DARHT facility [3] at LANL. Both of these facilities are currently used as a primary diagnostic for large scale, explosively driven hydrodynamic experiments, but are limited in the range of materials that can be utilized in those experiments. Conversely, the Cygnus system [4] at the NNSS is authorized to use a broad range of materials in the hydrodynamic test, but lacks the penetrating imaging capability for the desired large scale experiments.