I’m sure people at LPP do a great job of building up knowledge around physics involved – including tedious plasmoid properties measurements. Obviously that’s valuable, and time consuming.

I only tried to say, that:
1. I’d expect that a sort of perturbence (shake-up of a design) of the DPF device structure/geometry is also exorcised … in the spirit of Edison trying every possible filament for his incandescent light bulb.
2. but mainly I wanted to ask if there is any sort of tutorial/beginners guide on the DPF device parameters: like basic dependencies of output-jet total energy, and its ion energy spectrum v.s basic device design like: anode diameter, anode lip curvature, number/diameter of cathodes; length of pyrex insulator; its thickness, etc.

before we fully understand the physics of the process (and thus can “design for” a successfull cross-over to Q> 1), it’s usually worth (blindly) testing various “engineering options”.

I for one would like to know how the density-time varies with the number of cathode rods – may be one does not need that many (like: what if just three would do?) … or if it pays to have a lot of them (in consequence to have as many as possible plasma spokes crossing the sheath) and thus one needs to change the cathode array geometry towards a circular comb of copper blades. Anyone knows what’s better?

And one “engineering option” I’d personally would surely check very early (but haven’t seen done) is to check the D2-B10 filament. This does not require any changes in hardware, while this close to target density-time constraint should highlight any influence spin has on the reaction.