http://aip.scitation.org/doi/10.1063/1.4928572
This is perhaps the most interesting and controversial of Holmlid's papers. He documents a measured gain above breakeven in a copper cylinder, despite systemic losses, and suggests that 20:1 gain would be possible in a more sophisticated version.
Contrast that with NIF - the National Ignition Facility at Livermore - where after at least $25 billion down the tubes, they have not achieved real breakeven and probably never will unless they add a step to make UDD for the target.
It is a bit of a surprise that the Holmlid paper even appears on AIP since one can imagine that the editors have received pressure to have it removed.
Jones