http://web.mit.edu/newsoffice/2005/matter.html I presume? Even if isotope separation based on boson/fermion-ness possible, wouldn't be economical. Cooling to 50 nanokelvin gas as in the lithium experiment is extremely expensive per kilogram. In fact, a single gram would probably bankrupt the world. --- Here's something little-related to think on. Allegedly, neutron star matter is not merely a liquid, but a superfluid. Critical temperature allegedly about 10^10 kelvin. Also electrical superconductivity allegedly going on. You may ask how they can possibly know enough theoretically or experimentally to claim that. Well, I admit to a lot of such skepticism myself, but what you could naively do is just say "well, we know helium-3 goes superfluid at 0.002491 kelvin... so now attempt to scale appropriately for neutrons given their much greater density and interaction-energies and what order of magnitude estimate would you get for neutron superfluidity temperature?" I get 10^8 kelvin, disagreeing with the allege, but making the phenomenon at least plausible. But then we note that helium stops being superfluid, in fact solidifies, when 25 atm pressure applied. So might neutron-star-stuff solidify at the (enormous) pressures it is under? I suspect not. In fact, the more pressure you apply, the more "fermi confinement energy" the neutrons should gain, presumably becoming more delocalized, i.e. more pressure should make it more liquid. That re-liquification might also happen with helium, but if it does, only at pressures higher than experimenters have yet reached.