Circuit modeling for ZR

In the Z Refurbishment (ZR) project, the capabilities of the Z accelerator is expanded [D. H. McDaniel et al., June 2002]. Most of the pulsed power hardware is being redesigned for operation with higher reliability, a greater shot rate, and increased pulse energy. The topology of the ZR pulsed power circuit is similar to that of Z with a few significant changes. The initial baseline circuit design for ZR was developed using Screamer [M. L. Kiefer and M. M. Widner, 1985] which has been the primary pulsed power circuit design tool employed at SNL for years. Screamer is, however, limited in the topologies it can simulate. For ZR there are several circuit features which cannot be modeled adequately in Screamer. The most significant of these is the need to allow for a high degree of independence in module firing times so that a prescribed temporally shaped pulse can be generated for isentropic compression experiments (ICE) [3]. For this reason, the baseline circuit design for ZR is now being developed using Bertha [W. N. Weseloh, 1989]. Bertha is a NRL developed T-line circuit simulation code that is not topology limited and runs fast. In this paper, a discussion of the circuit modeling strategy for the ZR project along with a discussion of the current status of the ZR baseline circuit model is presented.