Screamer: A Powerful Circuit Analysis Code

Dr. Rick B. Spielman
Idaho Accelerator Center
Idaho State University

Dr. Yury Gryazin
Mathematics Department
Idaho State University

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 solves electrical circuits having a limited, in-line circuit topology with restricted branches. This restricted circuit topology allows for a very efficient matrix solver. We will describe the mathematical basis for Screamer and show how our chosen topology leads to a sparse matrix. We will describe the evolution of Screamer and show how the development of powerful (> 0.1 TFlops) PCs with large amounts of memory (> 8 GB) enabled major extensions to Screamer’s circuit topology. 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. We will show a sample problem run on Screamer. Screamer runs on the Macintosh OS (9 & 10) and Windows 7 & 8 and is available to users at no cost. We are always looking for new Screamer users who might be interested in using and in supporting improvements to the code. Screamer source code is available to users.