AntaresMC

You can make around the problem by having too much He3 (something like EnrichedFusionPellets), at least twice than normal. N radiation falls below 1% as you go about 3-4x (dont remember exact numbers) the needed, but other problems start being unburnt, not-really-cheap-Id-say He3 and wasteful (economic and energy wise, hharder to ignite, less energy output) He3-He3 fusion, but being expensive is a small price for a torch and the engine still uses far below the theoretical max so... Edit: Sorry, I monopolized quite a bit of the thread

It works, thats evidence that we have to work with, the best thing I can think of to explain it is that the tanks being so obscenely heavy is because the kerbals are quite OCD with boiloffs and its all thermal insulation and some PV paint to power pelters. Any better thoughts that dont rule out canon, gameplay proof?

Ive got a question: Why where there those intakes in the first place? Dont tell me because the reaction is inside, and if that, explain me how THE HELL manages that heat. I assumed they were for cooling and the actual athmo burning mode was (as the non athmo) few meters back (Zpinch occurs in the big ring at the end) and exhaust driven in a simillar way to VISTA/Kerbstein (I have to talk about its thermodynamics in other post...), Opdalus and probably Unobtusstard as well. Even twith that trick (that renders redundant the thermal nozzle, the aerospike looked like the pellet gun, so is good for me), I evision a Z-pinch engine as a compact quasi-torch (I usually call it candle/lantern, depending on its Isp (former)/TWR(latter) orientation but they are both KSPIE engines Xd), with a high thermal power output (enough to power itself + the equivalent of a fission reactor) but an AWFULL waste heat footprint, that will render it unusable for power unless serious radiators used.

Yea, LF should remain as kinda unobtanium. But, take into account that all bodies but Jool and Gilly (mabe Pol and Minmus, havent done the math) are made of degenerate matter and Kerbol is a brown dwarf several times older than the universe and as dense as a gas giant. And all parts are from 1/2 to 1/3 of their real counterparts, thing that would (moreless and assuming mass ratios keep againt the ^2/^3 law). We dont know if its toxic or not. With that awfull mass ratio it may even be a void layer with gold coating or something like that to trap the heat so well, and given the densities is obviously pressurized and overcooled. Dont know where the 80% H2s EV, actually, the Isps are quite pitty for H2, even for H2O, and we dont know chanber pressures nor temperatures, dont have better clue than the Nerv's Isp (rules out everithing but H2/He, and He aint the best fuel ever...). And the apparent hypergolicity may be beause of suspended aerosols of an easily igniteable (just a metal spark) monoprop. The pumping will be let to the same witchery that powers the orbital scanner (its actually canon xD). I actually need a way to convert LF-O into some interstellar fuel (preferrably cheap) as do with N2H4-monoprop because of simplicity. I also use a list of USI mods (I believe everyone but Karbonite an the ones depend on it) an MKS uses a lot of LFO that I need different drills, converters, tanks and engines in the bases that suck up my load times and FPS, and last thing I need is to have another 10-20 parts EACH base I have And as LFO is an awfull fuel compared to everything else of KSPIE, I have to use both... Or some patch to make MKS generators/transport credits/production chains use Interstellar fuels.

LF has to be LH2 to have the nerva work with that Isp, and pressurized, gaseous O2 as oxidizer (yes, I know is a stupid idea, but, better thoughts?) would make for the low densities and absurdly heavy tanks. The low Isp for HydroOx is explained with bad engineering abilities from the kerbals (that also explain the awful oxidizer choice), and because of that, they hired you to design/fly, but give you the parts done beacuse of low budget XD Monoprop is robably HTP, because its cheap, relatively dense and makes for the Isp, but can be everything, not like the LF, that has to be H2, or the NERVA wont work... We need more info, but Id say HTP. And ore may be just things that contain H and regular rocks, and the ISRU module is just a brute force hyper electrolizer+H2/O2 separator...

The model has a problem: its regular nozzle would be instantly vaporized, and frankly, is redundant, at this temperatures would be all ionized plasma. I originally thought that the external coils werent a magnetic nozzle, but the Z-pinch coils put in such a way that the reaction is outside (a few meters only) and directed by a VISTA-style lorenz forze magnetic nozzle. Even with that trick, and assuming reflectivity to the X-rays (a bit unobtanium...), a lot of radiators or ablator woul be needed. But, if the reaction is inside and the extra ropellant isnt shooted back as an afterburner, dont know how on Kerbin this engine will survive... I think to widen and shorten the coils (like the areospike Zpinch, (wose intakes are redundant in this design), remove the thermal nozzle, have it generate thermal power so it can sustain itself with an external generator, and give it an awful waste heat footprint, that is reduced by a bit (but not much) when using criogenic propellants by open cycle cooling.