  Spherically imploding plasma liners, formed by merging hypersonic plasma
jets, are a proposed standoff driver to compress magnetized target plasmas to
fusion conditions [S. C. Hsu et al., IEEE Trans. Plasma Sci. 40, 1287 (2012)].
In this paper, the parameter space and physics criteria are identified for a
subscale, plasma-liner-formation experiment to provide data, e.g., on liner
ram-pressure scaling and uniformity, that are relevant for addressing
scientific issues of full-scale plasma liners required to achieve fusion
conditions. Based on these criteria, we quantitatively estimate the minimum
liner kinetic energy and mass needed, which informed the design of a subscale
plasma liner experiment now under development.
