Publications

Why Perform Code-to-Code Comparisons: A Vacuum Arc Discharge Simulation Case Study

Timko, H.; Crozier, Paul C.; Hopkins, Matthew M.; Matyash, K.; Schneider, R.

Numerical modeling is increasingly becoming an indispensable tool for investigations in many fields of physics. Such modeling is especially useful in today's big science projects as a tool that can provide predictions and design parameters. The reliability of simulation results is thus essential. Code-to-code comparisons can help increase our confidence in simulation results, especially when other verification methods - such as comparison to theoretical models or experimental results - are limited or unavailable. In this paper, we describe a code-to-code comparison exercise wherein we compare one-dimensional vacuum arc discharge simulation results from two independent particle-in-cell (PIC) codes. As part of our case study, we define a vacuum arc discharge test problem that can be used by other research groups for further comparison. Early disagreement between the two sets of our results motivated us to re-examine the underlying methods in our codes. After remedying discrepancies, we observe good agreement in vacuum arc discharge time-to-breakdown, as well as in the time evolution of particle and current densities. This exercise demonstrates the usefulness of code-to-code comparisons and provides an example case study for the benefit of other research groups who may wish to carry out similar code-to-code comparisons. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.