On the radiation of heat in space

[Darth Wong]

Ghetto edit, should be:
"At a kilometer (this is a star ship in a very literal sense of the word after all), counting a red dwarf as 'stellar', lower-energy neutrinos, or a high-grade of efficiency, this is quite tolerable."

The waste heat produced by the heat exchange unit for the neutrino converter would be a much more serious threat than the neutrinos anyway. Efficiency is obviously not near-perfect if you need such powerful heat dissipation devices in the first place, yet it needs to be near-perfect for the conversion and collection of this waste heat. It's still hand-wavium to a certain extent, although at least you can say the math works out, if not the feasibility.

[Ariphaos]

Of course, but there is a slight caveat to those systems that naturally produce neutrinos - they are inefficiencies that modern designs do not need to be realistically concerned about. This is important for fusion power in space - it means less insanely high efficiencies are tolerable. A fusion reactor producing 3% of its energy as neutrino's is, at best, 97% efficient, as far as we're concerned, but that 3% does not need to be dissipated.

For say, a petawatt reactor, that's 30 terawatts that doesn't need to be dissipated, or three square kilometers of my magic carbon heatsink. And you need reactors at that level to have interesting accelerations in the first place.

The idea, say, would be to find a form of fusion configuration (handwaving, probably) that sloughed off more of its inefficiency into neutrinos, by whatever means.

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Now, if you can generate neutrinos at will, at that sort of scale, a PeV or more likely EeV-scale neutrino 'laser' (higher energy as needed for smaller vessels) seems like a hella fun weapon. Normal lasers and projectile ammunition have to get through all this pesky armor / shields that work so well in soft-sci-fi, but a sufficiently high-energy neutrino gun will start scattering hundreds of meters to kilometers inside your target's ship, causing all sorts of nastiness with sensitive electronics and life forms. In sufficiently dense engagements, you might even hit multiple ships with a single beam.

[Wyrm]

As to the "lethal neutrino pulse" issue, I do have some calcs to show how deadly a sufficiently intense neutrino pulse can be. Here, I showed that there is such thing as a lethal neutrino dose, and at ~20 MeV per neutrino, 3.56e30 neutrinos/cm^2 would equal an exposure of at least 7566 rads, enough to turn your CNS into jello. True, I was talking about a neutrino pulse from a supernova, but then the supernova's neutrino pulse is still deadly at 1 AU, whereas Ender puts 20 km as a safe distance.

[Ariphaos]

As to the "lethal neutrino pulse" issue, I do have some calcs to show how deadly a sufficiently intense neutrino pulse can be. Here, I showed that there is such thing as a lethal neutrino dose, and at ~20 MeV per neutrino, 3.56e30 neutrinos/cm^2 would equal an exposure of at least 7566 rads, enough to turn your CNS into jello. True, I was talking about a neutrino pulse from a supernova, but then the supernova's neutrino pulse is still deadly at 1 AU, whereas Ender puts 20 km as a safe distance.

It would very likely be worse than that. Solar neutrinos don't often exceed an MeV, and we can't detect those below 5 MeV at -all-. Meaning, what we're seeing is basically the Sun's most energetic Neutrino reactions, the most common of which react a whopping 14 MeV.

Your -average- is already above that, meaning, on average, every single neutrino is a candidate for getting absorbed, minus the PeV-or-better-grade neutrinos which are likely the ones driving the supernova.

If I were to make a guess based on the numbers giving the Solar spectrum on this site, your calculations are at least six orders of magnitude too low. That's being generous to the poor sod sitting at an AU, or a thousand.