Question about UT power generators

[David L Pulver]

Originally Posted by Anthony

Any nuclear or neutron-producing fusion reactor should probably have around ten tenth-thicknesses of shielding, or about 2kg/cm^2 (1,000 lb/sf). Antimatter produces somewhat more penetrating radiation, so you'd want several times as much (the difference isn't that huge).

Is there a good rule of thumb for the radiation amount that is produced in the core in case you want less weight? I imagine some systems - e.g., a military robot designed for a nuclear battlefield - might get by with less shielding (being worried mostly about frying its own electronics). Is it constant regardless of the power output, or would a small 20 kW (say) antimatter reactor make less than a 2 megawatt system? Or is this factored in since the smaller reactor would have a lower surface area and so need less shielding?

Or more precisely, is shielding requirement based only on reactor size, or would a reactor that has a low power output (kilowatts rather than megawatts) need less shielding?