SCREAMER V4.0 — A powerful circuit analysis code

Screamer is a fast, highly optimized circuit-analysis code that was originally developed at Sandia National Laboratories in 1985. Screamer is written in Fortran 77 (with some extensions) and is highly optimized for speed. Screamer V3 solved electrical circuits having a limited, in-line circuit topology with restricted branches. This restricted circuit topology allowed for a very efficient matrix solver. We will describe the mathematical basis of Screamer and show how the topology leads to a very sparse matrix. We will describe the evolution of Screamer V4.0 and show how the development of powerful (> 0.1 TFlops) PCs with large amounts of memory (> 8 GB) enables major extensions to Screamer´s circuit topology without a significant loss in speed. Screamer incorporates many physics-based models such as dynamic loads, gas switching, water switching, oil switching, magnetic switching, and vacuum transmission lines, which are important to the high-voltage, pulsed-power community. Additional circuit models or modifications to existing models can be readily implemented in Screamer. Screamer runs on the Macintosh OS (9 & 10), LINUX, and Windows 7 & 8.