That’s “Periodically Oscillating Plasma Sphere”, a variant on the Bussard IEC scheme. In a nutshell, pumping the ion cloud at the core of a chamber with RF timed to its natural resonance permits much higher compression and energy recovery.
http://www.lanl.gov/p/rh_pp_park.shtml
I can’t find a specific date for the above post, but the fine print at the bottom says C. 2009-2010, so I assume it’s pretty current.
The envisaged final ‘rig’ looks pretty complex: “Such a device would contain thousands of tiny spherical IEC reactors within a single reactor vessel to produce a large amount of fusion power (i.e., ~ 100–1000 MW).” See image below. I assume power generation would be standard Carnot steam cycle stuff, using the heat extracted via the pipe vents near the top. (?)
Could be that the “tiny” part is the key; confinement and containment like FF’s, without walls made of unobtainium. But it’s not clear to me from the text whether the fuel is DD or DT, and whether the reactor vessel is filled with water (heavy water?) moderator surrounding the reactors, etc.
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