Ha!
It looks like tightening anode-cathode distance to increase energy concentration is not as “innovative” as I thought it was, others came at those conclusions too, like: http://www.google.com/patents/US8487536. I’s pity I haven’t traced any science papers on the influence of cathode-anode final distance on the overall device performance like neutron yields. But may be s I’ll have more luck later.
But along those lines; both inventors listed in that patent are located/residents of las Vegas. I’m not familiar with US science facilities, so: are there any recognized research facilities around las vegas? Or should one think that DPF is becoming so hot issue, that patent trolls already smell fresh meat?