is it possible to make a nuclear "battery" which works off nuclear not electrochemical reactions using berylium/graphite shielding?
You can make one even smaller than that. For Pu-239 with a reflector it can be as small as a sphere with radius ~5 cm.i know that but what im asking is:theoreticly can you make a nuclear reactor 50cm by 50cm asuming the u-235 was dense enough to reach critical mass?
Well you don't need a moderator for a reflected plutonium sphere. And it can be designed to be self-regulating. But you're right that it would still need a coolant system, heat exchanger, and thermoelectric converter to actually produce electricity. I imagine the SNAP-10 reactor, at about the size of a microwave oven, is about as small as one could be practically made.Well, a sphere of plutonium is not a reactor. You need moderation, control mechanisms, cooling cycles, power generation and so on.
Enormous. The ability of a magnetic confinement fusion reactor to produce power is proportional to its volume. ITER will hopefully be the first reactor to achieve better than break-even, I think it has a diameter of something like 20 meters.assuming break even fusion was achieved how big do you think the smallest fusion reactor could be?
There are no laser confinement fusion methods close to achieving breakeven, and even if they were they are even more massive machines than the tokamak. There is no compact way to producing fusion power, as all of the various methods require enormous power inputs in either magnetic fields or lasers to produce the conditions required for fusion to occur. These simply cannot me miniaturized.out of the hypothetical methods of fusion (inertial, z-pinch, laser ect..) what would be the smallest?